IFH@204581

10 files changed, 4288 insertions, 0 deletions

diff --git a/usr.bin/dc/Makefile b/usr.bin/dc/Makefile
new file mode 100644
index 0000000..ee91c95
--- /dev/null
+++ b/usr.bin/dc/Makefile
@@ -0,0 +1,10 @@
+#	$FreeBSD$
+#	$OpenBSD: Makefile,v 1.2 2006/11/26 11:31:09 deraadt Exp $
+
+PROG=	dc
+SRCS=	dc.c bcode.c inout.c mem.c stack.c
+CFLAGS+=--param max-inline-insns-single=64
+DPADD=	${LIBCRYPTO}
+LDADD=	-lcrypto
+
+.include <bsd.prog.mk>
diff --git a/usr.bin/dc/USD.doc/dc b/usr.bin/dc/USD.doc/dc
new file mode 100644
index 0000000..4caa0f4
--- /dev/null
+++ b/usr.bin/dc/USD.doc/dc
@@ -0,0 +1,753 @@
+.\"	$FreeBSD$
+.\"	$OpenBSD: dc,v 1.2 2003/09/22 19:08:27 otto Exp $
+.\"
+.\" Copyright (C) Caldera International Inc.  2001-2002.
+.\" All rights reserved.
+.\"
+.\" Redistribution and use in source and binary forms, with or without
+.\" modification, are permitted provided that the following conditions
+.\" are met:
+.\" 1. Redistributions of source code and documentation must retain the above
+.\"    copyright notice, this list of conditions and the following disclaimer.
+.\" 2. Redistributions in binary form must reproduce the above copyright
+.\"    notice, this list of conditions and the following disclaimer in the
+.\"    documentation and/or other materials provided with the distribution.
+.\" 3. All advertising materials mentioning features or use of this software
+.\"    must display the following acknowledgement:
+.\"	This product includes software developed or owned by Caldera
+.\"	International, Inc.
+.\" 4. Neither the name of Caldera International, Inc. nor the names of other
+.\"    contributors may be used to endorse or promote products derived from
+.\"    this software without specific prior written permission.
+.\"
+.\" USE OF THE SOFTWARE PROVIDED FOR UNDER THIS LICENSE BY CALDERA
+.\" INTERNATIONAL, INC. AND CONTRIBUTORS ``AS IS'' AND ANY EXPRESS OR
+.\" IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+.\" OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
+.\" IN NO EVENT SHALL CALDERA INTERNATIONAL, INC. BE LIABLE FOR ANY DIRECT,
+.\" INDIRECT INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+.\" (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+.\" SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+.\" STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
+.\" IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+.\" POSSIBILITY OF SUCH DAMAGE.
+.\"
+.\"	@(#)dc	8.1 (Berkeley) 6/8/93
+.\"
+.EH 'USD:5-%''DC \- An Interactive Desk Calculator'
+.OH 'DC \- An Interactive Desk Calculator''USD:5-%'
+.\".RP
+.\" ....TM 75-1271-8 39199 39199-11
+.ND
+.TL
+DC \- An Interactive Desk Calculator
+.AU "MH 2C-524" 3878
+Robert Morris
+.AU
+Lorinda Cherry
+.AI
+.\" .MH
+.AB
+DC is an interactive desk calculator program implemented
+on the
+.UX
+time-sharing system to do arbitrary-precision
+integer arithmetic.
+It has provision for manipulating scaled fixed-point numbers and
+for input and output in bases other than decimal.
+.PP
+The size of numbers that can be manipulated is limited
+only by available core storage.
+On typical implementations of
+.UX ,
+the size of numbers that
+can be handled varies from several hundred digits on the smallest
+systems to several thousand on the largest.
+.AE
+.PP
+.SH
+.PP
+.ft I
+Editor's note: the description of the implementation details of DC in this
+paper is only valid for the original version of DC.
+The current version of DC uses a different approach.
+.ft
+.PP
+DC is an arbitrary precision arithmetic package implemented
+on the
+.UX
+time-sharing system
+in the form of an interactive desk calculator.
+It works like a stacking calculator using reverse Polish notation.
+Ordinarily DC operates on decimal integers, but one may
+specify an input base, output base, and a number of fractional
+digits to be maintained.
+.PP
+A language called BC [1] has been developed which accepts
+programs written in the familiar style of higher-level
+programming languages and compiles output which is
+interpreted by DC.
+Some of the commands described below were designed
+for the compiler interface and are not easy for a human user
+to manipulate.
+.PP
+Numbers that are typed into DC are put on a push-down
+stack.
+DC commands work by taking the top number or two
+off the stack, performing the desired operation, and pushing the result
+on the stack.
+If an argument is given,
+input is taken from that file until its end,
+then from the standard input.
+.SH
+SYNOPTIC DESCRIPTION
+.PP
+Here we describe the DC commands that are intended
+for use by people.  The additional commands that are
+intended to be invoked by compiled output are
+described in the detailed description.
+.PP
+Any number of commands are permitted on a line.
+Blanks and new-line characters are ignored except within numbers
+and in places where a register name is expected.
+.PP
+The following constructions are recognized:
+.SH
+number
+.IP
+The value of the number is pushed onto the main stack.
+A number is an unbroken string of the digits 0-9
+and the capital letters A\-F which are treated as digits
+with values 10\-15 respectively.
+The number may be preceded by an underscore _ to input a
+negative number.
+Numbers may contain decimal points.
+.SH
++  \-  *  %  ^
+.IP
+The
+top two values on the stack are added
+(\fB+\fP),
+subtracted
+(\fB\-\fP),
+multiplied (\fB*\fP),
+divided (\fB/\fP),
+remaindered (\fB%\fP),
+or exponentiated (^).
+The two entries are popped off the stack;
+the result is pushed on the stack in their place.
+The result of a division is an integer truncated toward zero.
+See the detailed description below for the treatment of
+numbers with decimal points.
+An exponent must not have any digits after the decimal point.
+.SH
+s\fIx\fP
+.IP
+The
+top of the main stack is popped and stored into
+a register named \fIx\fP, where \fIx\fP may be any character.
+If
+the
+.ft B
+s
+.ft
+is capitalized,
+.ft I
+x
+.ft
+is treated as a stack and the value is pushed onto it.
+Any character, even blank or new-line, is a valid register name.
+.SH
+l\fIx\fP
+.IP
+The
+value in register
+.ft I
+x
+.ft
+is pushed onto the stack.
+The register
+.ft I
+x
+.ft
+is not altered.
+If the
+.ft B
+l
+.ft
+is capitalized,
+register
+.ft I
+x
+.ft
+is treated as a stack and its top value is popped onto the main stack.
+.LP
+All registers start with empty value which is treated as a zero
+by the command \fBl\fP and is treated as an error by the command \fBL\fP.
+.SH
+d
+.IP
+The
+top value on the stack is duplicated.
+.SH
+p
+.IP
+The top value on the stack is printed.
+The top value remains unchanged.
+.SH
+f
+.IP
+All values on the stack and in registers are printed.
+.SH
+x
+.IP
+treats the top element of the stack as a character string,
+removes it from the stack, and
+executes it as a string of DC commands.
+.SH
+[ ... ]
+.IP
+puts the bracketed character string onto the top of the stack.
+.SH
+q
+.IP
+exits the program.
+If executing a string, the recursion level is
+popped by two.
+If
+.ft B
+q
+.ft
+is capitalized,
+the top value on the stack is popped and the string execution level is popped
+by that value.
+.SH
+<\fIx\fP  >\fIx\fP  =\fIx\fP  !<\fIx\fP  !>\fIx\fP  !=\fIx\fP
+.IP
+The
+top two elements of the stack are popped and compared.
+Register
+.ft I
+x
+.ft
+is executed if they obey the stated
+relation.
+Exclamation point is negation.
+.SH
+v
+.IP
+replaces the top element on the stack by its square root.
+The square root of an integer is truncated to an integer.
+For the treatment of numbers with decimal points, see
+the detailed description below.
+.SH
+!
+.IP
+interprets the rest of the line as a
+.UX
+command.
+Control returns to DC when the
+.UX
+command terminates.
+.SH
+c
+.IP
+All values on the stack are popped; the stack becomes empty.
+.SH
+i
+.IP
+The top value on the stack is popped and used as the
+number radix for further input.
+If \fBi\fP is capitalized, the value of
+the input base is pushed onto the stack.
+No mechanism has been provided for the input of arbitrary
+numbers in bases less than 1 or greater than 16.
+.SH
+o
+.IP
+The top value on the stack is popped and used as the
+number radix for further output.
+If \fBo\fP is capitalized, the value of the output
+base is pushed onto the stack.
+.SH
+k
+.IP
+The top of the stack is popped, and that value is used as
+a scale factor
+that influences the number of decimal places
+that are maintained during multiplication, division, and exponentiation.
+The scale factor must be greater than or equal to zero and
+less than 100.
+If \fBk\fP is capitalized, the value of the scale factor
+is pushed onto the stack.
+.SH
+z
+.IP
+The value of the stack level is pushed onto the stack.
+.SH
+?
+.IP
+A line of input is taken from the input source (usually the console)
+and executed.
+.SH
+DETAILED DESCRIPTION
+.SH
+Internal Representation of Numbers
+.PP
+Numbers are stored internally using a dynamic storage allocator.
+Numbers are kept in the form of a string
+of digits to the base 100 stored one digit per byte
+(centennial digits).
+The string is stored with the low-order digit at the
+beginning of the string.
+For example, the representation of 157
+is 57,1.
+After any arithmetic operation on a number, care is taken
+that all digits are in the range 0\-99 and that
+the number has no leading zeros.
+The number zero is represented by the empty string.
+.PP
+Negative numbers are represented in the 100's complement
+notation, which is analogous to two's complement notation for binary
+numbers.
+The high order digit of a negative number is always \-1
+and all other digits are in the range 0\-99.
+The digit preceding the high order \-1 digit is never a 99.
+The representation of \-157 is 43,98,\-1.
+We shall call this the canonical form of a number.
+The advantage of this kind of representation of negative
+numbers is ease of addition.  When addition is performed digit
+by digit, the result is formally correct.  The result need only
+be modified, if necessary, to put it into canonical form.
+.PP
+Because the largest valid digit is 99 and the byte can
+hold numbers twice that large, addition can be carried out
+and the handling of carries done later when
+that is convenient, as it sometimes is.
+.PP
+An additional byte is stored with each number beyond
+the high order digit to indicate the number of
+assumed decimal digits after the decimal point.  The representation
+of .001 is 1,\fI3\fP
+where the scale has been italicized to emphasize the fact that it
+is not the high order digit.
+The value of this extra byte is called the
+.ft B
+scale factor
+.ft
+of the number.
+.SH
+The Allocator
+.PP
+DC uses a dynamic string storage allocator
+for all of its internal storage.
+All reading and writing of numbers internally is done through
+the allocator.
+Associated with each string in the allocator is a four-word header containing pointers
+to the beginning of the string, the end of the string,
+the next place to write, and the next place to read.
+Communication between the allocator and DC
+is done via pointers to these headers.
+.PP
+The allocator initially has one large string on a list
+of free strings.  All headers except the one pointing
+to this string are on a list of free headers.
+Requests for strings are made by size.
+The size of the string actually supplied is the next higher
+power of 2.
+When a request for a string is made, the allocator
+first checks the free list to see if there is
+a string of the desired size.
+If none is found, the allocator finds the next larger free string and splits it repeatedly until
+it has a string of the right size.
+Left-over strings are put on the free list.
+If there are no larger strings,
+the allocator tries to coalesce smaller free strings into
+larger ones.
+Since all strings are the result
+of splitting large strings,
+each string has a neighbor that is next to it in core
+and, if free, can be combined with it to make a string twice as long.
+This is an implementation of the `buddy system' of allocation
+described in [2].
+.PP
+Failing to find a string of the proper length after coalescing,
+the allocator asks the system for more space.
+The amount of space on the system is the only limitation
+on the size and number of strings in DC.
+If at any time in the process of trying to allocate a string, the allocator runs out of
+headers, it also asks the system for more space.
+.PP
+There are routines in the allocator for reading, writing, copying, rewinding,
+forward-spacing, and backspacing strings.
+All string manipulation is done using these routines.
+.PP
+The reading and writing routines
+increment the read pointer or write pointer so that
+the characters of a string are read or written in
+succession by a series of read or write calls.
+The write pointer is interpreted as the end of the
+information-containing portion of a string and a call
+to read beyond that point returns an end-of-string indication.
+An attempt to write beyond the end of a string
+causes the allocator to
+allocate a larger space and then copy
+the old string into the larger block.
+.SH
+Internal Arithmetic
+.PP
+All arithmetic operations are done on integers.
+The operands (or operand) needed for the operation are popped
+from the main stack and their scale factors stripped off.
+Zeros are added or digits removed as necessary to get
+a properly scaled result from the internal arithmetic routine.
+For example, if the scale of the operands is different and decimal
+alignment is required, as it is for
+addition, zeros are appended to the operand with the smaller
+scale.
+After performing the required arithmetic operation,
+the proper scale factor is appended to the end of the number before
+it is pushed on the stack.
+.PP
+A register called \fBscale\fP plays a part
+in the results of most arithmetic operations.
+\fBscale\fP is the bound on the number of decimal places retained in
+arithmetic computations.
+\fBscale\fP may be set to the number on the top of the stack
+truncated to an integer with the \fBk\fP command.
+\fBK\fP may be used to push the value of \fBscale\fP on the stack.
+\fBscale\fP must be greater than or equal to 0 and less than 100.
+The descriptions of the individual arithmetic operations will
+include the exact effect of \fBscale\fP on the computations.
+.SH
+Addition and Subtraction
+.PP
+The scales of the two numbers are compared and trailing
+zeros are supplied to the number with the lower scale to give both
+numbers the same scale.  The number with the smaller scale is
+multiplied by 10 if the difference of the scales is odd.
+The scale of the result is then set to the larger of the scales
+of the two operands.
+.PP
+Subtraction is performed by negating the number
+to be subtracted and proceeding as in addition.
+.PP
+Finally, the addition is performed digit by digit from the
+low order end of the number.  The carries are propagated
+in the usual way.
+The resulting number is brought into canonical form, which may
+require stripping of leading zeros, or for negative numbers
+replacing the high-order configuration 99,\-1 by the digit \-1.
+In any case, digits which are not in the range 0\-99 must
+be brought into that range, propagating any carries or borrows
+that result.
+.SH
+Multiplication
+.PP
+The scales are removed from the two operands and saved.
+The operands are both made positive.
+Then multiplication is performed in
+a digit by digit manner that exactly mimics the hand method
+of multiplying.
+The first number is multiplied by each digit of the second
+number, beginning with its low order digit.  The intermediate
+products are accumulated into a partial sum which becomes the
+final product.
+The product is put into the canonical form and its sign is
+computed from the signs of the original operands.
+.PP
+The scale of the result is set equal to the sum
+of the scales of the two operands.
+If that scale is larger than the internal register
+.ft B
+scale
+.ft
+and also larger than both of the scales of the two operands,
+then the scale of the result is set equal to the largest
+of these three last quantities.
+.SH
+Division
+.PP
+The scales are removed from the two operands.
+Zeros are appended or digits removed from the dividend to make
+the scale of the result of the integer division equal to
+the internal quantity
+\fBscale\fP.
+The signs are removed and saved.
+.PP
+Division is performed much as it would be done by hand.
+The difference of the lengths of the two numbers
+is computed.
+If the divisor is longer than the dividend,
+zero is returned.
+Otherwise the top digit of the divisor is divided into the top
+two digits of the dividend.
+The result is used as the first (high-order) digit of the
+quotient.
+It may turn out be one unit too low, but if it is, the next
+trial quotient will be larger than 99 and this will be
+adjusted at the end of the process.
+The trial digit is multiplied by the divisor and the result subtracted
+from the dividend and the process is repeated to get
+additional quotient digits until the remaining
+dividend is smaller than the divisor.
+At the end, the digits of the quotient are put into
+the canonical form, with propagation of carry as needed.
+The sign is set from the sign of the operands.
+.SH
+Remainder
+.PP
+The division routine is called and division is performed
+exactly as described.  The quantity returned is the remains of the
+dividend at the end of the divide process.
+Since division truncates toward zero, remainders have the same
+sign as the dividend.
+The scale of the remainder is set to 
+the maximum of the scale of the dividend and
+the scale of the quotient plus the scale of the divisor.
+.SH
+Square Root
+.PP
+The scale is stripped from the operand.
+Zeros are added if necessary to make the
+integer result have a scale that is the larger of
+the internal quantity
+\fBscale\fP
+and the scale of the operand.
+.PP
+The method used to compute sqrt(y) is Newton's method
+with successive approximations by the rule
+.EQ
+x sub {n+1} ~=~ half ( x sub n + y over x sub n )
+.EN
+The initial guess is found by taking the integer square root
+of the top two digits.
+.SH
+Exponentiation
+.PP
+Only exponents with zero scale factor are handled.  If the exponent is
+zero, then the result is 1.  If the exponent is negative, then
+it is made positive and the base is divided into one.  The scale
+of the base is removed.
+.PP
+The integer exponent is viewed as a binary number.
+The base is repeatedly squared and the result is
+obtained as a product of those powers of the base that
+correspond to the positions of the one-bits in the binary
+representation of the exponent.
+Enough digits of the result
+are removed to make the scale of the result the same as if the
+indicated multiplication had been performed.
+.SH
+Input Conversion and Base
+.PP
+Numbers are converted to the internal representation as they are read
+in.
+The scale stored with a number is simply the number of fractional digits input.
+Negative numbers are indicated by preceding the number with a \fB\_\fP (an 
+underscore).
+The hexadecimal digits A\-F correspond to the numbers 10\-15 regardless of input base.
+The \fBi\fP command can be used to change the base of the input numbers.
+This command pops the stack, truncates the resulting number to an integer,
+and uses it as the input base for all further input.
+The input base is initialized to 10 but may, for example be changed to
+8 or 16 to do octal or hexadecimal to decimal conversions.
+The command \fBI\fP will push the value of the input base on the stack.
+.SH
+Output Commands
+.PP
+The command \fBp\fP causes the top of the stack to be printed.
+It does not remove the top of the stack.
+All of the stack and internal registers can be output
+by typing the command \fBf\fP.
+The \fBo\fP command can be used to change the output base.
+This command uses the top of the stack, truncated to an integer as
+the base for all further output.
+The output base in initialized to 10.
+It will work correctly for any base.
+The command \fBO\fP pushes the value of the output base on the stack.
+.SH
+Output Format and Base
+.PP
+The input and output bases only affect
+the interpretation of numbers on input and output; they have no
+effect on arithmetic computations.
+Large numbers are output with 70 characters per line;
+a \\ indicates a continued line.
+All choices of input and output bases work correctly, although not all are
+useful.
+A particularly useful output base is 100000, which has the effect of
+grouping digits in fives.
+Bases of 8 and 16 can be used for decimal-octal or decimal-hexadecimal
+conversions.
+.SH
+Internal Registers
+.PP
+Numbers or strings may be stored in internal registers or loaded on the stack
+from registers with the commands \fBs\fP and \fBl\fP.
+The command \fBs\fIx\fR pops the top of the stack and
+stores the result in register \fBx\fP.
+\fIx\fP can be any character.
+\fBl\fIx\fR puts the contents of register \fBx\fP on the top of the stack.
+The \fBl\fP command has no effect on the contents of register \fIx\fP.
+The \fBs\fP command, however, is destructive.
+.SH
+Stack Commands
+.PP
+The command \fBc\fP clears the stack.
+The command \fBd\fP pushes a duplicate of the number on the top of the stack
+on the stack.
+The command \fBz\fP pushes the stack size on the stack.
+The command \fBX\fP replaces the number on the top of the stack
+with its scale factor.
+The command \fBZ\fP replaces the top of the stack
+with its length.
+.SH
+Subroutine Definitions and Calls
+.PP
+Enclosing a string in \fB[ ]\fP pushes the ascii string on the stack.
+The \fBq\fP command quits or in executing a string, pops the recursion levels by two.
+.SH
+Internal Registers \- Programming DC
+.PP
+The load and store
+commands together with \fB[ ]\fP to store strings, \fBx\fP to execute
+and the testing commands `<', `>', `=', `!<', `!>', `!=' can be used to program
+DC.
+The \fBx\fP command assumes the top of the stack is an string of DC commands
+and executes it.
+The testing commands compare the top two elements on the stack and if the relation holds, execute the register
+that follows the relation.
+For example, to print the numbers 0-9,
+.DS
+[lip1+  si  li10>a]sa
+0si  lax
+.DE
+.SH
+Push-Down Registers and Arrays
+.PP
+These commands were designed for used by a compiler, not by
+people.
+They involve push-down registers and arrays.
+In addition to the stack that commands work on, DC can be thought
+of as having individual stacks for each register.
+These registers are operated on by the commands \fBS\fP and \fBL\fP.
+\fBS\fIx\fR pushes the top value of the main stack onto the stack for
+the register \fIx\fP.
+\fBL\fIx\fR pops the stack for register \fIx\fP and puts the result on the main
+stack.
+The commands \fBs\fP and \fBl\fP also work on registers but not as push-down
+stacks.
+\fBl\fP doesn't effect the top of the
+register stack, and \fBs\fP destroys what was there before.
+.PP
+The commands to work on arrays are \fB:\fP and \fB;\fP.
+\fB:\fIx\fR pops the stack and uses this value as an index into
+the array \fIx\fP.
+The next element on the stack is stored at this index in \fIx\fP.
+An index must be greater than or equal to 0 and
+less than 2048.
+\fB;\fIx\fR is the command to load the main stack from the array \fIx\fP.
+The value on the top of the stack is the index
+into the array \fIx\fP of the value to be loaded.
+.SH
+Miscellaneous Commands
+.PP
+The command \fB!\fP interprets the rest of the line as a 
+.UX 
+command and passes it to 
+.UX
+to execute.
+One other compiler command is \fBQ\fP.
+This command uses the top of the stack as the number of levels of recursion to skip.
+.SH
+DESIGN CHOICES
+.PP
+The real reason for the use of a dynamic storage allocator was
+that a general purpose program could be (and in fact has been)
+used for a variety of other tasks.
+The allocator has some value for input and for compiling (i.e.
+the bracket [...] commands) where it cannot be known in advance
+how long a string will be.
+The result was that at a modest
+cost in execution time, all considerations of string allocation
+and sizes of strings were removed from the remainder of the program
+and debugging was made easier.  The allocation method
+used wastes approximately 25% of available space.
+.PP
+The choice of 100 as a base for internal arithmetic
+seemingly has no compelling advantage.  Yet the base cannot
+exceed 127 because of hardware limitations and at the cost
+of 5% in space, debugging was made a great deal easier and
+decimal output was made much faster.
+.PP
+The reason for a stack-type arithmetic design was
+to permit all DC commands from addition to subroutine execution
+to be implemented in essentially the same way.  The result
+was a considerable degree of logical separation of the final
+program into modules with very little communication between
+modules.
+.PP
+The rationale for the lack of interaction between the scale and the bases
+was to provide an understandable means of proceeding after
+a change of base or scale when numbers had already been entered.
+An earlier implementation which had global notions of
+scale and base did not work out well.
+If the value of
+.ft B
+scale
+.ft
+were to be interpreted in the current
+input or output base,
+then a change of base or scale in the midst of a
+computation would cause great confusion in the interpretation
+of the results.
+The current scheme has the advantage that the value of
+the input and output bases
+are only used for input and output, respectively, and they
+are ignored in all other operations.
+The value of
+scale
+is not used for any essential purpose by any part of the program
+and it is used only to prevent the number of
+decimal places resulting from the arithmetic operations from
+growing beyond all bounds.
+.PP
+The design rationale for the choices for the scales of
+the results of arithmetic were that in no case should
+any significant digits be thrown away if, on appearances, the
+user actually wanted them.  Thus, if the user wants
+to add the numbers 1.5 and 3.517, it seemed reasonable to give
+him the result 5.017 without requiring him to unnecessarily
+specify his rather obvious requirements for precision.
+.PP
+On the other hand, multiplication and exponentiation produce
+results with many more digits than their operands and it
+seemed reasonable to give as a minimum the number of decimal
+places in the operands but not to give more than that
+number of digits
+unless the user asked for them by specifying a value for \fBscale\fP.
+Square root can be handled in just the same way as multiplication.
+The operation of division gives arbitrarily many decimal places
+and there is simply no way to guess how many places the user
+wants.
+In this case only, the user must
+specify a \fBscale\fP to get any decimal places at all.
+.PP
+The scale of remainder was chosen to make it possible
+to recreate the dividend from the quotient and remainder.
+This is easy to implement; no digits are thrown away.
+.SH
+References
+.IP [1]
+L. L. Cherry, R. Morris,
+.ft I
+BC \- An Arbitrary Precision Desk-Calculator Language.
+.ft
+.IP [2]
+K. C. Knowlton,
+.ft I
+A Fast Storage Allocator,
+.ft
+Comm. ACM \fB8\fP, pp. 623-625 (Oct. 1965).
diff --git a/usr.bin/dc/bcode.c b/usr.bin/dc/bcode.c
new file mode 100644
index 0000000..e80c635
--- /dev/null
+++ b/usr.bin/dc/bcode.c
@@ -0,0 +1,1775 @@
+/*	$OpenBSD: bcode.c,v 1.40 2009/10/27 23:59:37 deraadt Exp $	*/
+
+/*
+ * Copyright (c) 2003, Otto Moerbeek <otto@drijf.net>
+ *
+ * Permission to use, copy, modify, and distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+
+#include <sys/cdefs.h>
+__FBSDID("$FreeBSD$");
+
+#include <err.h>
+#include <limits.h>
+#include <openssl/ssl.h>
+#include <signal.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include "extern.h"
+
+BIGNUM		zero;
+
+#define __inline	
+
+#define MAX_ARRAY_INDEX		2048
+#define READSTACK_SIZE		8
+
+#define NO_ELSE			-2	/* -1 is EOF */
+#define REG_ARRAY_SIZE_SMALL	(UCHAR_MAX + 1)
+#define REG_ARRAY_SIZE_BIG	(UCHAR_MAX + 1 + USHRT_MAX + 1)
+
+struct bmachine {
+	struct source		*readstack;
+	struct stack		*reg;
+	struct stack		 stack;
+	volatile sig_atomic_t	 interrupted;
+	u_int			 scale;
+	u_int			 obase;
+	u_int			 ibase;
+	size_t			 readsp;
+	size_t			 reg_array_size;
+	size_t			 readstack_sz;
+	bool			 extended_regs;
+};
+
+static struct bmachine	 bmachine;
+static void		 sighandler(int);
+
+static __inline int	 readch(void);
+static __inline void	 unreadch(void);
+static __inline char	*readline(void);
+static __inline void	 src_free(void);
+
+static __inline u_int	 max(u_int, u_int);
+static u_long		 get_ulong(struct number *);
+
+static __inline void	 push_number(struct number *);
+static __inline void	 push_string(char *);
+static __inline void	 push(struct value *);
+static __inline struct value *tos(void);
+static __inline struct number	*pop_number(void);
+static __inline char	*pop_string(void);
+static __inline void	 clear_stack(void);
+static __inline void	 print_tos(void);
+static void		 pop_print(void);
+static void		 pop_printn(void);
+static __inline void	 print_stack(void);
+static __inline void	 dup(void);
+static void		 swap(void);
+static void		 drop(void);
+
+static void		 get_scale(void);
+static void		 set_scale(void);
+static void		 get_obase(void);
+static void		 set_obase(void);
+static void		 get_ibase(void);
+static void		 set_ibase(void);
+static void		 stackdepth(void);
+static void		 push_scale(void);
+static u_int		 count_digits(const struct number *);
+static void		 num_digits(void);
+static void		 to_ascii(void);
+static void		 push_line(void);
+static void		 comment(void);
+static void		 bexec(char *);
+static void		 badd(void);
+static void		 bsub(void);
+static void		 bmul(void);
+static void		 bdiv(void);
+static void		 bmod(void);
+static void		 bdivmod(void);
+static void		 bexp(void);
+static bool		 bsqrt_stop(const BIGNUM *, const BIGNUM *, u_int *);
+static void		 bsqrt(void);
+static void		 not(void);
+static void		 equal_numbers(void);
+static void		 less_numbers(void);
+static void		 lesseq_numbers(void);
+static void		 equal(void);
+static void		 not_equal(void);
+static void		 less(void);
+static void		 not_less(void);
+static void		 greater(void);
+static void		 not_greater(void);
+static void		 not_compare(void);
+static bool		 compare_numbers(enum bcode_compare, struct number *,
+			     struct number *);
+static void		 compare(enum bcode_compare);
+static int		 readreg(void);
+static void		 load(void);
+static void		 store(void);
+static void		 load_stack(void);
+static void		 store_stack(void);
+static void		 load_array(void);
+static void		 store_array(void);
+static void		 nop(void);
+static void		 quit(void);
+static void		 quitN(void);
+static void		 skipN(void);
+static void		 skip_until_mark(void);
+static void		 parse_number(void);
+static void		 unknown(void);
+static void		 eval_string(char *);
+static void		 eval_line(void);
+static void		 eval_tos(void);
+
+
+typedef void		(*opcode_function)(void);
+
+struct jump_entry {
+	u_char		 ch;
+	opcode_function	 f;
+};
+
+static opcode_function jump_table[UCHAR_MAX];
+
+static const struct jump_entry jump_table_data[] = {
+	{ ' ',	nop		},
+	{ '!',	not_compare	},
+	{ '#',	comment		},
+	{ '%',	bmod		},
+	{ '(',	less_numbers	},
+	{ '*',	bmul		},
+	{ '+',	badd		},
+	{ '-',	bsub		},
+	{ '.',	parse_number	},
+	{ '/',	bdiv		},
+	{ '0',	parse_number	},
+	{ '1',	parse_number	},
+	{ '2',	parse_number	},
+	{ '3',	parse_number	},
+	{ '4',	parse_number	},
+	{ '5',	parse_number	},
+	{ '6',	parse_number	},
+	{ '7',	parse_number	},
+	{ '8',	parse_number	},
+	{ '9',	parse_number	},
+	{ ':',	store_array	},
+	{ ';',	load_array	},
+	{ '<',	less		},
+	{ '=',	equal		},
+	{ '>',	greater		},
+	{ '?',	eval_line	},
+	{ 'A',	parse_number	},
+	{ 'B',	parse_number	},
+	{ 'C',	parse_number	},
+	{ 'D',	parse_number	},
+	{ 'E',	parse_number	},
+	{ 'F',	parse_number	},
+	{ 'G',	equal_numbers	},
+	{ 'I',	get_ibase	},
+	{ 'J',	skipN		},
+	{ 'K',	get_scale	},
+	{ 'L',	load_stack	},
+	{ 'M',	nop		},
+	{ 'N',	not		},
+	{ 'O',	get_obase	},
+	{ 'P',	pop_print	},
+	{ 'Q',	quitN		},
+	{ 'R',	drop		},
+	{ 'S',	store_stack	},
+	{ 'X',	push_scale	},
+	{ 'Z',	num_digits	},
+	{ '[',	push_line	},
+	{ '\f',	nop		},
+	{ '\n',	nop		},
+	{ '\r',	nop		},
+	{ '\t',	nop		},
+	{ '^',	bexp		},
+	{ '_',	parse_number	},
+	{ 'a',	to_ascii	},
+	{ 'c',	clear_stack	},
+	{ 'd',	dup		},
+	{ 'f',	print_stack	},
+	{ 'i',	set_ibase	},
+	{ 'k',	set_scale	},
+	{ 'l',	load		},
+	{ 'n',	pop_printn	},
+	{ 'o',	set_obase	},
+	{ 'p',	print_tos	},
+	{ 'q',	quit		},
+	{ 'r',	swap		},
+	{ 's',	store		},
+	{ 'v',	bsqrt		},
+	{ 'x',	eval_tos	},
+	{ 'z',	stackdepth	},
+	{ '{',	lesseq_numbers	},
+	{ '~',	bdivmod		}
+};
+
+#define JUMP_TABLE_DATA_SIZE \
+	(sizeof(jump_table_data)/sizeof(jump_table_data[0]))
+
+static void
+sighandler(int ignored)
+{
+
+	switch (ignored)
+	{
+	default:
+		bmachine.interrupted = true;
+	}
+}
+
+void
+init_bmachine(bool extended_registers)
+{
+	unsigned int i;
+
+	bmachine.extended_regs = extended_registers;
+	bmachine.reg_array_size = bmachine.extended_regs ?
+	    REG_ARRAY_SIZE_BIG : REG_ARRAY_SIZE_SMALL;
+
+	bmachine.reg = calloc(bmachine.reg_array_size,
+	    sizeof(bmachine.reg[0]));
+	if (bmachine.reg == NULL)
+		err(1, NULL);
+
+	for (i = 0; i < UCHAR_MAX; i++)
+		jump_table[i] = unknown;
+	for (i = 0; i < JUMP_TABLE_DATA_SIZE; i++)
+		jump_table[jump_table_data[i].ch] = jump_table_data[i].f;
+
+	stack_init(&bmachine.stack);
+
+	for (i = 0; i < bmachine.reg_array_size; i++)
+		stack_init(&bmachine.reg[i]);
+
+	bmachine.readstack_sz = READSTACK_SIZE;
+	bmachine.readstack = calloc(sizeof(struct source),
+	    bmachine.readstack_sz);
+	if (bmachine.readstack == NULL)
+		err(1, NULL);
+	bmachine.obase = bmachine.ibase = 10;
+	BN_init(&zero);
+	bn_check(BN_zero(&zero));
+	signal(SIGINT, sighandler);
+}
+
+/* Reset the things needed before processing a (new) file */
+void
+reset_bmachine(struct source *src)
+{
+
+	bmachine.readsp = 0;
+	bmachine.readstack[0] = *src;
+}
+
+static __inline int
+readch(void)
+{
+	struct source *src = &bmachine.readstack[bmachine.readsp];
+
+	return (src->vtable->readchar(src));
+}
+
+static __inline void
+unreadch(void)
+{
+	struct source *src = &bmachine.readstack[bmachine.readsp];
+
+	src->vtable->unreadchar(src);
+}
+
+static __inline char *
+readline(void)
+{
+	struct source *src = &bmachine.readstack[bmachine.readsp];
+
+	return (src->vtable->readline(src));
+}
+
+static __inline void
+src_free(void)
+{
+	struct source *src = &bmachine.readstack[bmachine.readsp];
+
+	src->vtable->free(src);
+}
+
+#ifdef DEBUGGING
+void
+pn(const char *str, const struct number *n)
+{
+	char *p = BN_bn2dec(n->number);
+
+	if (p == NULL)
+		err(1, "BN_bn2dec failed");
+	fputs(str, stderr);
+	fprintf(stderr, " %s (%u)\n" , p, n->scale);
+	OPENSSL_free(p);
+}
+
+void
+pbn(const char *str, const BIGNUM *n)
+{
+	char *p = BN_bn2dec(n);
+
+	if (p == NULL)
+		err(1, "BN_bn2dec failed");
+	fputs(str, stderr);
+	fprintf(stderr, " %s\n", p);
+	OPENSSL_free(p);
+}
+
+#endif
+
+static __inline u_int
+max(u_int a, u_int b)
+{
+
+	return (a > b ? a : b);
+}
+
+static unsigned long factors[] = {
+	0, 10, 100, 1000, 10000, 100000, 1000000, 10000000,
+	100000000, 1000000000
+};
+
+void
+scale_number(BIGNUM *n, int s)
+{
+	unsigned int abs_scale;
+
+	if (s == 0)
+		return;
+
+	abs_scale = s > 0 ? s : -s;
+
+	if (abs_scale < sizeof(factors)/sizeof(factors[0])) {
+		if (s > 0)
+			bn_check(BN_mul_word(n, factors[abs_scale]));
+		else
+			BN_div_word(n, factors[abs_scale]);
+	} else {
+		BIGNUM *a, *p;
+		BN_CTX *ctx;
+
+		a = BN_new();
+		bn_checkp(a);
+		p = BN_new();
+		bn_checkp(p);
+		ctx = BN_CTX_new();
+		bn_checkp(ctx);
+
+		bn_check(BN_set_word(a, 10));
+		bn_check(BN_set_word(p, abs_scale));
+		bn_check(BN_exp(a, a, p, ctx));
+		if (s > 0)
+			bn_check(BN_mul(n, n, a, ctx));
+		else
+			bn_check(BN_div(n, NULL, n, a, ctx));
+		BN_CTX_free(ctx);
+		BN_free(a);
+		BN_free(p);
+	}
+}
+
+void
+split_number(const struct number *n, BIGNUM *i, BIGNUM *f)
+{
+	u_long rem;
+
+	bn_checkp(BN_copy(i, n->number));
+
+	if (n->scale == 0 && f != NULL)
+		bn_check(BN_zero(f));
+	else if (n->scale < sizeof(factors)/sizeof(factors[0])) {
+		rem = BN_div_word(i, factors[n->scale]);
+		if (f != NULL)
+			bn_check(BN_set_word(f, rem));
+	} else {
+		BIGNUM	*a, *p;
+		BN_CTX	*ctx;
+
+		a = BN_new();
+		bn_checkp(a);
+		p = BN_new();
+		bn_checkp(p);
+		ctx = BN_CTX_new();
+		bn_checkp(ctx);
+
+		bn_check(BN_set_word(a, 10));
+		bn_check(BN_set_word(p, n->scale));
+		bn_check(BN_exp(a, a, p, ctx));
+		bn_check(BN_div(i, f, n->number, a, ctx));
+		BN_CTX_free(ctx);
+		BN_free(a);
+		BN_free(p);
+	}
+}
+
+__inline void
+normalize(struct number *n, u_int s)
+{
+
+	scale_number(n->number, s - n->scale);
+	n->scale = s;
+}
+
+static u_long
+get_ulong(struct number *n)
+{
+
+	normalize(n, 0);
+	return (BN_get_word(n->number));
+}
+
+void
+negate(struct number *n)
+{
+
+	bn_check(BN_sub(n->number, &zero, n->number));
+}
+
+static __inline void
+push_number(struct number *n)
+{
+
+	stack_pushnumber(&bmachine.stack, n);
+}
+
+static __inline void
+push_string(char *string)
+{
+
+	stack_pushstring(&bmachine.stack, string);
+}
+
+static __inline void
+push(struct value *v)
+{
+
+	stack_push(&bmachine.stack, v);
+}
+
+static __inline struct value *
+tos(void)
+{
+
+	return (stack_tos(&bmachine.stack));
+}
+
+static __inline struct value *
+pop(void)
+{
+
+	return (stack_pop(&bmachine.stack));
+}
+
+static __inline struct number *
+pop_number(void)
+{
+
+	return (stack_popnumber(&bmachine.stack));
+}
+
+static __inline char *
+pop_string(void)
+{
+
+	return (stack_popstring(&bmachine.stack));
+}
+
+static __inline void
+clear_stack(void)
+{
+
+	stack_clear(&bmachine.stack);
+}
+
+static __inline void
+print_stack(void)
+{
+
+	stack_print(stdout, &bmachine.stack, "", bmachine.obase);
+}
+
+static __inline void
+print_tos(void)
+{
+	struct value *value = tos();
+
+	if (value != NULL) {
+		print_value(stdout, value, "", bmachine.obase);
+		putchar('\n');
+	}
+	else
+		warnx("stack empty");
+}
+
+static void
+pop_print(void)
+{
+	struct value *value = pop();
+
+	if (value != NULL) {
+		switch (value->type) {
+		case BCODE_NONE:
+			break;
+		case BCODE_NUMBER:
+			normalize(value->u.num, 0);
+			print_ascii(stdout, value->u.num);
+			fflush(stdout);
+			break;
+		case BCODE_STRING:
+			fputs(value->u.string, stdout);
+			fflush(stdout);
+			break;
+		}
+		stack_free_value(value);
+	}
+}
+
+static void
+pop_printn(void)
+{
+	struct value *value = pop();
+
+	if (value != NULL) {
+		print_value(stdout, value, "", bmachine.obase);
+		fflush(stdout);
+		stack_free_value(value);
+	}
+}
+
+static __inline void
+dup(void)
+{
+
+	stack_dup(&bmachine.stack);
+}
+
+static void
+swap(void)
+{
+
+	stack_swap(&bmachine.stack);
+}
+
+static void
+drop(void)
+{
+	struct value *v = pop();
+	if (v != NULL)
+		stack_free_value(v);
+}
+
+static void
+get_scale(void)
+{
+	struct number *n;
+
+	n = new_number();
+	bn_check(BN_set_word(n->number, bmachine.scale));
+	push_number(n);
+}
+
+static void
+set_scale(void)
+{
+	struct number *n;
+	u_long scale;
+
+	n = pop_number();
+	if (n != NULL) {
+		if (BN_cmp(n->number, &zero) < 0)
+			warnx("scale must be a nonnegative number");
+		else {
+			scale = get_ulong(n);
+			if (scale != BN_MASK2 && scale <= UINT_MAX)
+				bmachine.scale = (u_int)scale;
+			else
+				warnx("scale too large");
+			}
+		free_number(n);
+	}
+}
+
+static void
+get_obase(void)
+{
+	struct number *n;
+
+	n = new_number();
+	bn_check(BN_set_word(n->number, bmachine.obase));
+	push_number(n);
+}
+
+static void
+set_obase(void)
+{
+	struct number *n;
+	u_long base;
+
+	n = pop_number();
+	if (n != NULL) {
+		base = get_ulong(n);
+		if (base != BN_MASK2 && base > 1 && base <= UINT_MAX)
+			bmachine.obase = (u_int)base;
+		else
+			warnx("output base must be a number greater than 1");
+		free_number(n);
+	}
+}
+
+static void
+get_ibase(void)
+{
+	struct number *n;
+
+	n = new_number();
+	bn_check(BN_set_word(n->number, bmachine.ibase));
+	push_number(n);
+}
+
+static void
+set_ibase(void)
+{
+	struct number *n;
+	u_long base;
+
+	n = pop_number();
+	if (n != NULL) {
+		base = get_ulong(n);
+		if (base != BN_MASK2 && 2 <= base && base <= 16)
+			bmachine.ibase = (u_int)base;
+		else
+			warnx("input base must be a number between 2 and 16 "
+			    "(inclusive)");
+		free_number(n);
+	}
+}
+
+static void
+stackdepth(void)
+{
+	struct number *n;
+	size_t i;
+
+	i = stack_size(&bmachine.stack);
+	n = new_number();
+	bn_check(BN_set_word(n->number, i));
+	push_number(n);
+}
+
+static void
+push_scale(void)
+{
+	struct number *n;
+	struct value *value;
+	u_int scale = 0;
+
+	value = pop();
+	if (value != NULL) {
+		switch (value->type) {
+		case BCODE_NONE:
+			return;
+		case BCODE_NUMBER:
+			scale = value->u.num->scale;
+			break;
+		case BCODE_STRING:
+			break;
+		}
+		stack_free_value(value);
+		n = new_number();
+		bn_check(BN_set_word(n->number, scale));
+		push_number(n);
+	}
+}
+
+static u_int
+count_digits(const struct number *n)
+{
+	struct number *int_part, *fract_part;
+	u_int i;
+
+	if (BN_is_zero(n->number))
+		return (1);
+
+	int_part = new_number();
+	fract_part = new_number();
+	fract_part->scale = n->scale;
+	split_number(n, int_part->number, fract_part->number);
+
+	i = 0;
+	while (!BN_is_zero(int_part->number)) {
+		BN_div_word(int_part->number, 10);
+		i++;
+	}
+	free_number(int_part);
+	free_number(fract_part);
+	return (i + n->scale);
+}
+
+static void
+num_digits(void)
+{
+	struct number *n = NULL;
+	struct value *value;
+	size_t digits;
+
+	value = pop();
+	if (value != NULL) {
+		switch (value->type) {
+		case BCODE_NONE:
+			return;
+		case BCODE_NUMBER:
+			digits = count_digits(value->u.num);
+			n = new_number();
+			bn_check(BN_set_word(n->number, digits));
+			break;
+		case BCODE_STRING:
+			digits = strlen(value->u.string);
+			n = new_number();
+			bn_check(BN_set_word(n->number, digits));
+			break;
+		}
+		stack_free_value(value);
+		push_number(n);
+	}
+}
+
+static void
+to_ascii(void)
+{
+	struct number *n;
+	struct value *value;
+	char str[2];
+
+	value = pop();
+	if (value != NULL) {
+		str[1] = '\0';
+		switch (value->type) {
+		case BCODE_NONE:
+			return;
+		case BCODE_NUMBER:
+			n = value->u.num;
+			normalize(n, 0);
+			if (BN_num_bits(n->number) > 8)
+				bn_check(BN_mask_bits(n->number, 8));
+			str[0] = (char)BN_get_word(n->number);
+			break;
+		case BCODE_STRING:
+			str[0] = value->u.string[0];
+			break;
+		}
+		stack_free_value(value);
+		push_string(bstrdup(str));
+	}
+}
+
+static int
+readreg(void)
+{
+	int ch1, ch2, idx;
+
+	idx = readch();
+	if (idx == 0xff && bmachine.extended_regs) {
+		ch1 = readch();
+		ch2 = readch();
+		if (ch1 == EOF || ch2 == EOF) {
+			warnx("unexpected eof");
+			idx = -1;
+		} else
+			idx = (ch1 << 8) + ch2 + UCHAR_MAX + 1;
+	}
+	if (idx < 0 || (unsigned)idx >= bmachine.reg_array_size) {
+		warnx("internal error: reg num = %d", idx);
+		idx = -1;
+	}
+	return (idx);
+}
+
+static void
+load(void)
+{
+	struct number *n;
+	struct value *v;
+	struct value copy;
+	int idx;
+
+	idx = readreg();
+	if (idx >= 0) {
+		v = stack_tos(&bmachine.reg[idx]);
+		if (v == NULL) {
+			n = new_number();
+			bn_check(BN_zero(n->number));
+			push_number(n);
+		} else
+			push(stack_dup_value(v, &copy));
+	}
+}
+
+static void
+store(void)
+{
+	struct value *val;
+	int idx;
+
+	idx = readreg();
+	if (idx >= 0) {
+		val = pop();
+		if (val == NULL) {
+			return;
+		}
+		stack_set_tos(&bmachine.reg[idx], val);
+	}
+}
+
+static void
+load_stack(void)
+{
+	struct stack *stack;
+	struct value *value;
+	int idx;
+
+	idx = readreg();
+	if (idx >= 0) {
+		stack = &bmachine.reg[idx];
+		value = NULL;
+		if (stack_size(stack) > 0) {
+			value = stack_pop(stack);
+		}
+		if (value != NULL)
+			push(value);
+		else
+			warnx("stack register '%c' (0%o) is empty",
+			    idx, idx);
+	}
+}
+
+static void
+store_stack(void)
+{
+	struct value *value;
+	int idx;
+
+	idx = readreg();
+	if (idx >= 0) {
+		value = pop();
+		if (value == NULL)
+			return;
+		stack_push(&bmachine.reg[idx], value);
+	}
+}
+
+static void
+load_array(void)
+{
+	struct number *inumber, *n;
+	struct stack *stack;
+	struct value *v;
+	struct value copy;
+	u_long idx;
+	int reg;
+
+	reg = readreg();
+	if (reg >= 0) {
+		inumber = pop_number();
+		if (inumber == NULL)
+			return;
+		idx = get_ulong(inumber);
+		if (BN_cmp(inumber->number, &zero) < 0)
+			warnx("negative idx");
+		else if (idx == BN_MASK2 || idx > MAX_ARRAY_INDEX)
+			warnx("idx too big");
+		else {
+			stack = &bmachine.reg[reg];
+			v = frame_retrieve(stack, idx);
+			if (v == NULL || v->type == BCODE_NONE) {
+				n = new_number();
+				bn_check(BN_zero(n->number));
+				push_number(n);
+			}
+			else
+				push(stack_dup_value(v, &copy));
+		}
+		free_number(inumber);
+	}
+}
+
+static void
+store_array(void)
+{
+	struct number *inumber;
+	struct value *value;
+	struct stack *stack;
+	u_long idx;
+	int reg;
+
+	reg = readreg();
+	if (reg >= 0) {
+		inumber = pop_number();
+		if (inumber == NULL)
+			return;
+		value = pop();
+		if (value == NULL) {
+			free_number(inumber);
+			return;
+		}
+		idx = get_ulong(inumber);
+		if (BN_cmp(inumber->number, &zero) < 0) {
+			warnx("negative idx");
+			stack_free_value(value);
+		} else if (idx == BN_MASK2 || idx > MAX_ARRAY_INDEX) {
+			warnx("idx too big");
+			stack_free_value(value);
+		} else {
+			stack = &bmachine.reg[reg];
+			frame_assign(stack, idx, value);
+		}
+		free_number(inumber);
+	}
+}
+
+static void
+push_line(void)
+{
+
+	push_string(read_string(&bmachine.readstack[bmachine.readsp]));
+}
+
+static void
+comment(void)
+{
+
+	free(readline());
+}
+
+static void
+bexec(char *line)
+{
+
+	system(line);
+	free(line);
+}
+
+static void
+badd(void)
+{
+	struct number	*a, *b, *r;
+
+	a = pop_number();
+	if (a == NULL) {
+		return;
+	}
+	b = pop_number();
+	if (b == NULL) {
+		push_number(a);
+		return;
+	}
+
+	r = new_number();
+	r->scale = max(a->scale, b->scale);
+	if (r->scale > a->scale)
+		normalize(a, r->scale);
+	else if (r->scale > b->scale)
+		normalize(b, r->scale);
+	bn_check(BN_add(r->number, a->number, b->number));
+	push_number(r);
+	free_number(a);
+	free_number(b);
+}
+
+static void
+bsub(void)
+{
+	struct number	*a, *b, *r;
+
+	a = pop_number();
+	if (a == NULL) {
+		return;
+	}
+	b = pop_number();
+	if (b == NULL) {
+		push_number(a);
+		return;
+	}
+
+	r = new_number();
+
+	r->scale = max(a->scale, b->scale);
+	if (r->scale > a->scale)
+		normalize(a, r->scale);
+	else if (r->scale > b->scale)
+		normalize(b, r->scale);
+	bn_check(BN_sub(r->number, b->number, a->number));
+	push_number(r);
+	free_number(a);
+	free_number(b);
+}
+
+void
+bmul_number(struct number *r, struct number *a, struct number *b)
+{
+	BN_CTX *ctx;
+
+	/* Create copies of the scales, since r might be equal to a or b */
+	u_int ascale = a->scale;
+	u_int bscale = b->scale;
+	u_int rscale = ascale + bscale;
+
+	ctx = BN_CTX_new();
+	bn_checkp(ctx);
+	bn_check(BN_mul(r->number, a->number, b->number, ctx));
+	BN_CTX_free(ctx);
+
+	if (rscale > bmachine.scale && rscale > ascale && rscale > bscale) {
+		r->scale = rscale;
+		normalize(r, max(bmachine.scale, max(ascale, bscale)));
+	} else
+		r->scale = rscale;
+}
+
+static void
+bmul(void)
+{
+	struct number *a, *b, *r;
+
+	a = pop_number();
+	if (a == NULL) {
+		return;
+	}
+	b = pop_number();
+	if (b == NULL) {
+		push_number(a);
+		return;
+	}
+
+	r = new_number();
+	bmul_number(r, a, b);
+
+	push_number(r);
+	free_number(a);
+	free_number(b);
+}
+
+static void
+bdiv(void)
+{
+	struct number *a, *b, *r;
+	BN_CTX *ctx;
+	u_int scale;
+
+	a = pop_number();
+	if (a == NULL) {
+		return;
+	}
+	b = pop_number();
+	if (b == NULL) {
+		push_number(a);
+		return;
+	}
+
+	r = new_number();
+	r->scale = bmachine.scale;
+	scale = max(a->scale, b->scale);
+
+	if (BN_is_zero(a->number))
+		warnx("divide by zero");
+	else {
+		normalize(a, scale);
+		normalize(b, scale + r->scale);
+
+		ctx = BN_CTX_new();
+		bn_checkp(ctx);
+		bn_check(BN_div(r->number, NULL, b->number, a->number, ctx));
+		BN_CTX_free(ctx);
+	}
+	push_number(r);
+	free_number(a);
+	free_number(b);
+}
+
+static void
+bmod(void)
+{
+	struct number *a, *b, *r;
+	BN_CTX *ctx;
+	u_int scale;
+
+	a = pop_number();
+	if (a == NULL) {
+		return;
+	}
+	b = pop_number();
+	if (b == NULL) {
+		push_number(a);
+		return;
+	}
+
+	r = new_number();
+	scale = max(a->scale, b->scale);
+	r->scale = max(b->scale, a->scale + bmachine.scale);
+
+	if (BN_is_zero(a->number))
+		warnx("remainder by zero");
+	else {
+		normalize(a, scale);
+		normalize(b, scale + bmachine.scale);
+
+		ctx = BN_CTX_new();
+		bn_checkp(ctx);
+		bn_check(BN_mod(r->number, b->number, a->number, ctx));
+		BN_CTX_free(ctx);
+	}
+	push_number(r);
+	free_number(a);
+	free_number(b);
+}
+
+static void
+bdivmod(void)
+{
+	struct number *a, *b, *rdiv, *rmod;
+	BN_CTX *ctx;
+	u_int scale;
+
+	a = pop_number();
+	if (a == NULL) {
+		return;
+	}
+	b = pop_number();
+	if (b == NULL) {
+		push_number(a);
+		return;
+	}
+
+	rdiv = new_number();
+	rmod = new_number();
+	rdiv->scale = bmachine.scale;
+	rmod->scale = max(b->scale, a->scale + bmachine.scale);
+	scale = max(a->scale, b->scale);
+
+	if (BN_is_zero(a->number))
+		warnx("divide by zero");
+	else {
+		normalize(a, scale);
+		normalize(b, scale + bmachine.scale);
+
+		ctx = BN_CTX_new();
+		bn_checkp(ctx);
+		bn_check(BN_div(rdiv->number, rmod->number,
+		    b->number, a->number, ctx));
+		BN_CTX_free(ctx);
+	}
+	push_number(rdiv);
+	push_number(rmod);
+	free_number(a);
+	free_number(b);
+}
+
+static void
+bexp(void)
+{
+	struct number *a, *p, *r;
+	u_int scale;
+	bool neg;
+
+	p = pop_number();
+	if (p == NULL) {
+		return;
+	}
+	a = pop_number();
+	if (a == NULL) {
+		push_number(p);
+		return;
+	}
+
+	if (p->scale != 0)
+		warnx("Runtime warning: non-zero scale in exponent");
+	normalize(p, 0);
+
+	neg = false;
+	if (BN_cmp(p->number, &zero) < 0) {
+		neg = true;
+		negate(p);
+		scale = bmachine.scale;
+	} else {
+		/* Posix bc says min(a.scale * b, max(a.scale, scale) */
+		u_long b;
+		u_int m;
+
+		b = BN_get_word(p->number);
+		m = max(a->scale, bmachine.scale);
+		scale = a->scale * (u_int)b;
+		if (scale > m || (a->scale > 0 && (b == BN_MASK2 ||
+		    b > UINT_MAX)))
+			scale = m;
+	}
+
+	if (BN_is_zero(p->number)) {
+		r = new_number();
+		bn_check(BN_one(r->number));
+		normalize(r, scale);
+	} else {
+		while (!BN_is_bit_set(p->number, 0)) {
+			bmul_number(a, a, a);
+			bn_check(BN_rshift1(p->number, p->number));
+		}
+
+		r = dup_number(a);
+		normalize(r, scale);
+		bn_check(BN_rshift1(p->number, p->number));
+
+		while (!BN_is_zero(p->number)) {
+			bmul_number(a, a, a);
+			if (BN_is_bit_set(p->number, 0))
+				bmul_number(r, r, a);
+			bn_check(BN_rshift1(p->number, p->number));
+		}
+
+		if (neg) {
+			BN_CTX *ctx;
+			BIGNUM *one;
+
+			one = BN_new();
+			bn_checkp(one);
+			bn_check(BN_one(one));
+			ctx = BN_CTX_new();
+			bn_checkp(ctx);
+			scale_number(one, r->scale + scale);
+			normalize(r, scale);
+			bn_check(BN_div(r->number, NULL, one, r->number, ctx));
+			BN_free(one);
+			BN_CTX_free(ctx);
+		} else
+			normalize(r, scale);
+	}
+	push_number(r);
+	free_number(a);
+	free_number(p);
+}
+
+static bool
+bsqrt_stop(const BIGNUM *x, const BIGNUM *y, u_int *onecount)
+{
+	BIGNUM *r;
+	bool ret;
+
+	r = BN_new();
+	bn_checkp(r);
+	bn_check(BN_sub(r, x, y));
+	if (BN_is_one(r))
+		(*onecount)++;
+	ret = BN_is_zero(r);
+	BN_free(r);
+	return (ret || *onecount > 1);
+}
+
+static void
+bsqrt(void)
+{
+	struct number *n, *r;
+	BIGNUM *x, *y;
+	BN_CTX *ctx;
+	u_int onecount, scale;
+
+	onecount = 0;
+	n = pop_number();
+	if (n == NULL) {
+		return;
+	}
+	if (BN_is_zero(n->number)) {
+		r = new_number();
+		push_number(r);
+	} else if (BN_cmp(n->number, &zero) < 0)
+		warnx("square root of negative number");
+	else {
+		scale = max(bmachine.scale, n->scale);
+		normalize(n, 2*scale);
+		x = BN_dup(n->number);
+		bn_checkp(x);
+		bn_check(BN_rshift(x, x, BN_num_bits(x)/2));
+		y = BN_new();
+		bn_checkp(y);
+		ctx = BN_CTX_new();
+		bn_checkp(ctx);
+		for (;;) {
+			bn_checkp(BN_copy(y, x));
+			bn_check(BN_div(x, NULL, n->number, x, ctx));
+			bn_check(BN_add(x, x, y));
+			bn_check(BN_rshift1(x, x));
+			if (bsqrt_stop(x, y, &onecount))
+				break;
+		}
+		r = bmalloc(sizeof(*r));
+		r->scale = scale;
+		r->number = y;
+		BN_free(x);
+		BN_CTX_free(ctx);
+		push_number(r);
+	}
+
+	free_number(n);
+}
+
+static void
+not(void)
+{
+	struct number *a;
+
+	a = pop_number();
+	if (a == NULL) {
+		return;
+	}
+	a->scale = 0;
+	bn_check(BN_set_word(a->number, BN_get_word(a->number) ? 0 : 1));
+	push_number(a);
+}
+
+static void
+equal(void)
+{
+
+	compare(BCODE_EQUAL);
+}
+
+static void
+equal_numbers(void)
+{
+	struct number *a, *b, *r;
+
+	a = pop_number();
+	if (a == NULL) {
+		return;
+	}
+	b = pop_number();
+	if (b == NULL) {
+		push_number(a);
+		return;
+	}
+	r = new_number();
+	bn_check(BN_set_word(r->number,
+	    compare_numbers(BCODE_EQUAL, a, b) ? 1 : 0));
+	push_number(r);
+}
+
+static void
+less_numbers(void)
+{
+	struct number *a, *b, *r;
+
+	a = pop_number();
+	if (a == NULL) {
+		return;
+	}
+	b = pop_number();
+	if (b == NULL) {
+		push_number(a);
+		return;
+	}
+	r = new_number();
+	bn_check(BN_set_word(r->number,
+	    compare_numbers(BCODE_LESS, a, b) ? 1 : 0));
+	push_number(r);
+}
+
+static void
+lesseq_numbers(void)
+{
+	struct number *a, *b, *r;
+
+	a = pop_number();
+	if (a == NULL) {
+		return;
+	}
+	b = pop_number();
+	if (b == NULL) {
+		push_number(a);
+		return;
+	}
+	r = new_number();
+	bn_check(BN_set_word(r->number,
+	    compare_numbers(BCODE_NOT_GREATER, a, b) ? 1 : 0));
+	push_number(r);
+}
+
+static void
+not_equal(void)
+{
+
+	compare(BCODE_NOT_EQUAL);
+}
+
+static void
+less(void)
+{
+
+	compare(BCODE_LESS);
+}
+
+static void
+not_compare(void)
+{
+
+	switch (readch()) {
+	case '<':
+		not_less();
+		break;
+	case '>':
+		not_greater();
+		break;
+	case '=':
+		not_equal();
+		break;
+	default:
+		unreadch();
+		bexec(readline());
+		break;
+	}
+}
+
+static void
+not_less(void)
+{
+
+	compare(BCODE_NOT_LESS);
+}
+
+static void
+greater(void)
+{
+
+	compare(BCODE_GREATER);
+}
+
+static void
+not_greater(void)
+{
+
+	compare(BCODE_NOT_GREATER);
+}
+
+static bool
+compare_numbers(enum bcode_compare type, struct number *a, struct number *b)
+{
+	u_int scale;
+	int cmp;
+
+	scale = max(a->scale, b->scale);
+
+	if (scale > a->scale)
+		normalize(a, scale);
+	else if (scale > b->scale)
+		normalize(b, scale);
+
+	cmp = BN_cmp(a->number, b->number);
+
+	free_number(a);
+	free_number(b);
+
+	switch (type) {
+	case BCODE_EQUAL:
+		return (cmp == 0);
+	case BCODE_NOT_EQUAL:
+		return (cmp != 0);
+	case BCODE_LESS:
+		return (cmp < 0);
+	case BCODE_NOT_LESS:
+		return (cmp >= 0);
+	case BCODE_GREATER:
+		return (cmp > 0);
+	case BCODE_NOT_GREATER:
+		return (cmp <= 0);
+	}
+	return (false);
+}
+
+static void
+compare(enum bcode_compare type)
+{
+	struct number *a, *b;
+	struct value *v;
+	int idx, elseidx;
+	bool ok;
+
+	elseidx = NO_ELSE;
+	idx = readreg();
+	if (readch() == 'e')
+		elseidx = readreg();
+	else
+		unreadch();
+
+	a = pop_number();
+	if (a == NULL)
+		return;
+	b = pop_number();
+	if (b == NULL) {
+		push_number(a);
+		return;
+	}
+
+	ok = compare_numbers(type, a, b);
+
+	if (!ok && elseidx != NO_ELSE)
+		idx = elseidx;
+
+	if (idx >= 0 && (ok || (!ok && elseidx != NO_ELSE))) {
+		v = stack_tos(&bmachine.reg[idx]);
+		if (v == NULL)
+			warnx("register '%c' (0%o) is empty", idx, idx);
+		else {
+			switch(v->type) {
+			case BCODE_NONE:
+				warnx("register '%c' (0%o) is empty", idx, idx);
+				break;
+			case BCODE_NUMBER:
+				warn("eval called with non-string argument");
+				break;
+			case BCODE_STRING:
+				eval_string(bstrdup(v->u.string));
+				break;
+			}
+		}
+	}
+}
+
+
+static void
+nop(void)
+{
+
+}
+
+static void
+quit(void)
+{
+
+	if (bmachine.readsp < 2)
+		exit(0);
+	src_free();
+	bmachine.readsp--;
+	src_free();
+	bmachine.readsp--;
+}
+
+static void
+quitN(void)
+{
+	struct number *n;
+	u_long i;
+
+	n = pop_number();
+	if (n == NULL)
+		return;
+	i = get_ulong(n);
+	free_number(n);
+	if (i == BN_MASK2 || i == 0)
+		warnx("Q command requires a number >= 1");
+	else if (bmachine.readsp < i)
+		warnx("Q command argument exceeded string execution depth");
+	else {
+		while (i-- > 0) {
+			src_free();
+			bmachine.readsp--;
+		}
+	}
+}
+
+static void
+skipN(void)
+{
+	struct number *n;
+	u_long i;
+
+	n = pop_number();
+	if (n == NULL)
+		return;
+	i = get_ulong(n);
+	if (i == BN_MASK2)
+		warnx("J command requires a number >= 0");
+	else if (i > 0 && bmachine.readsp < i)
+		warnx("J command argument exceeded string execution depth");
+	else {
+		while (i-- > 0) {
+			src_free();
+			bmachine.readsp--;
+		}
+		skip_until_mark();
+	}
+}
+
+static void
+skip_until_mark(void)
+{
+
+	for (;;) {
+		switch (readch()) {
+		case 'M':
+			return;
+		case EOF:
+			errx(1, "mark not found");
+			return;
+		case 'l':
+		case 'L':
+		case 's':
+		case 'S':
+		case ':':
+		case ';':
+		case '<':
+		case '>':
+		case '=':
+			readreg();
+			if (readch() == 'e')
+				readreg();
+			else
+				unreadch();
+			break;
+		case '[':
+			free(read_string(&bmachine.readstack[bmachine.readsp]));
+			break;
+		case '!':
+			switch (readch()) {
+				case '<':
+				case '>':
+				case '=':
+					readreg();
+					if (readch() == 'e')
+						readreg();
+					else
+						unreadch();
+					break;
+				default:
+					free(readline());
+					break;
+			}
+			break;
+		default:
+			break;
+		}
+	}
+}
+
+static void
+parse_number(void)
+{
+
+	unreadch();
+	push_number(readnumber(&bmachine.readstack[bmachine.readsp],
+	    bmachine.ibase));
+}
+
+static void
+unknown(void)
+{
+	int ch = bmachine.readstack[bmachine.readsp].lastchar;
+	warnx("%c (0%o) is unimplemented", ch, ch);
+}
+
+static void
+eval_string(char *p)
+{
+	int ch;
+
+	if (bmachine.readsp > 0) {
+		/* Check for tail call. Do not recurse in that case. */
+		ch = readch();
+		if (ch == EOF) {
+			src_free();
+			src_setstring(&bmachine.readstack[bmachine.readsp], p);
+			return;
+		} else
+			unreadch();
+	}
+	if (bmachine.readsp == bmachine.readstack_sz - 1) {
+		size_t newsz = bmachine.readstack_sz * 2;
+		struct source *stack;
+		stack = realloc(bmachine.readstack, newsz *
+		    sizeof(struct source));
+		if (stack == NULL)
+			err(1, "recursion too deep");
+		bmachine.readstack_sz = newsz;
+		bmachine.readstack = stack;
+	}
+	src_setstring(&bmachine.readstack[++bmachine.readsp], p);
+}
+
+static void
+eval_line(void)
+{
+	/* Always read from stdin */
+	struct source in;
+	char *p;
+
+	clearerr(stdin);
+	src_setstream(&in, stdin);
+	p = (*in.vtable->readline)(&in);
+	eval_string(p);
+}
+
+static void
+eval_tos(void)
+{
+	char *p;
+
+	p = pop_string();
+	if (p == NULL)
+		return;
+	eval_string(p);
+}
+
+void
+eval(void)
+{
+	int ch;
+
+	for (;;) {
+		ch = readch();
+		if (ch == EOF) {
+			if (bmachine.readsp == 0)
+				return;
+			src_free();
+			bmachine.readsp--;
+			continue;
+		}
+		if (bmachine.interrupted) {
+			if (bmachine.readsp > 0) {
+				src_free();
+				bmachine.readsp--;
+				continue;
+			} else
+				bmachine.interrupted = false;
+		}
+#ifdef DEBUGGING
+		fprintf(stderr, "# %c\n", ch);
+		stack_print(stderr, &bmachine.stack, "* ",
+		    bmachine.obase);
+		fprintf(stderr, "%zd =>\n", bmachine.readsp);
+#endif
+
+		if (0 <= ch && ch < (signed)UCHAR_MAX)
+			(*jump_table[ch])();
+		else
+			warnx("internal error: opcode %d", ch);
+
+#ifdef DEBUGGING
+		stack_print(stderr, &bmachine.stack, "* ",
+		    bmachine.obase);
+		fprintf(stderr, "%zd ==\n", bmachine.readsp);
+#endif
+	}
+}
diff --git a/usr.bin/dc/bcode.h b/usr.bin/dc/bcode.h
new file mode 100644
index 0000000..9290cf1
--- /dev/null
+++ b/usr.bin/dc/bcode.h
@@ -0,0 +1,98 @@
+/*	$FreeBSD$						*/
+/*	$OpenBSD: bcode.h,v 1.5 2006/01/16 08:09:25 otto Exp $	*/
+
+/*
+ * Copyright (c) 2003, Otto Moerbeek <otto@drijf.net>
+ *
+ * Permission to use, copy, modify, and distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+
+#include <sys/types.h>
+#include <openssl/bn.h>
+
+struct number {
+	BIGNUM	*number;
+	u_int	 scale;
+};
+
+enum stacktype {
+	BCODE_NONE,
+	BCODE_NUMBER,
+	BCODE_STRING
+};
+
+enum bcode_compare {
+	BCODE_EQUAL,
+	BCODE_NOT_EQUAL,
+	BCODE_LESS,
+	BCODE_NOT_LESS,
+	BCODE_GREATER,
+	BCODE_NOT_GREATER
+};
+
+struct array;
+
+struct value {
+	union {
+		struct number	*num;
+		char		*string;
+	} u;
+	struct array	*array;
+	enum stacktype	 type;
+};
+
+struct array {
+	struct value	*data;
+	size_t		 size;
+};
+
+struct stack {
+	struct value	*stack;
+	ssize_t		 size;
+	ssize_t		 sp;
+};
+
+struct source;
+
+struct vtable {
+	int	(*readchar)(struct source *);
+	void	(*unreadchar)(struct source *);
+	char	*(*readline)(struct source *);
+	void	(*free)(struct source *);
+};
+
+struct source {
+	union {
+			struct {
+				u_char	*buf;
+				size_t	 pos;
+			} string;
+			FILE	*stream;
+	} u;
+	struct vtable	*vtable;
+	int		 lastchar;
+};
+
+void			 init_bmachine(bool);
+void			 reset_bmachine(struct source *);
+void			 scale_number(BIGNUM *, int);
+void			 normalize(struct number *, u_int);
+void			 eval(void);
+void			 pn(const char *, const struct number *);
+void			 pbn(const char *, const BIGNUM *);
+void			 negate(struct number *);
+void			 split_number(const struct number *, BIGNUM *, BIGNUM *);
+void			 bmul_number(struct number *, struct number *,
+			    struct number *);
+
+extern BIGNUM		 zero;
diff --git a/usr.bin/dc/dc.1 b/usr.bin/dc/dc.1
new file mode 100644
index 0000000..03fc762
--- /dev/null
+++ b/usr.bin/dc/dc.1
@@ -0,0 +1,548 @@
+.\"	$FreeBSD$
+.\"	$OpenBSD: dc.1,v 1.24 2010/01/02 19:48:56 schwarze Exp $
+.\"
+.\" Copyright (C) Caldera International Inc.  2001-2002.
+.\" All rights reserved.
+.\"
+.\" Redistribution and use in source and binary forms, with or without
+.\" modification, are permitted provided that the following conditions
+.\" are met:
+.\" 1. Redistributions of source code and documentation must retain the above
+.\"    copyright notice, this list of conditions and the following disclaimer.
+.\" 2. Redistributions in binary form must reproduce the above copyright
+.\"    notice, this list of conditions and the following disclaimer in the
+.\"    documentation and/or other materials provided with the distribution.
+.\" 3. All advertising materials mentioning features or use of this software
+.\"    must display the following acknowledgement:
+.\"	This product includes software developed or owned by Caldera
+.\"	International, Inc.
+.\" 4. Neither the name of Caldera International, Inc. nor the names of other
+.\"    contributors may be used to endorse or promote products derived from
+.\"    this software without specific prior written permission.
+.\"
+.\" USE OF THE SOFTWARE PROVIDED FOR UNDER THIS LICENSE BY CALDERA
+.\" INTERNATIONAL, INC. AND CONTRIBUTORS ``AS IS'' AND ANY EXPRESS OR
+.\" IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+.\" OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
+.\" IN NO EVENT SHALL CALDERA INTERNATIONAL, INC. BE LIABLE FOR ANY DIRECT,
+.\" INDIRECT INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+.\" (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+.\" SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+.\" STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
+.\" IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+.\" POSSIBILITY OF SUCH DAMAGE.
+.\"
+.\"	@(#)dc.1	8.1 (Berkeley) 6/6/93
+.\"
+.Dd January 22, 2010
+.Dt DC 1
+.Os
+.Sh NAME
+.Nm dc
+.Nd desk calculator
+.Sh SYNOPSIS
+.Nm
+.Op Fl hxV
+.Op Fl e Ar expression
+.Op Fl f Ar filename
+.Op Ar filename
+.Sh DESCRIPTION
+.Nm
+is an arbitrary precision arithmetic package.
+The overall structure of
+.Nm
+is
+a stacking (reverse Polish) calculator i.e.\&
+numbers are stored on a stack.
+Adding a number pushes it onto the stack.
+Arithmetic operations pop arguments off the stack
+and push the results.
+See also the
+.Xr bc 1
+utility, which is a preprocessor for
+.Nm
+providing infix notation and a C-like syntax
+which implements functions and reasonable control
+structures for programs.
+The options are as follows:
+.Bl -tag -width Ds
+.It Fl e Ar expr , Fl Fl expression Ar expr
+Evaluate
+.Ar expression .
+If multiple
+.Fl e
+options are specified, they will be processed in the order given.
+If no
+.Ar filename
+argument is given, execution will stop after processing the expressions
+given on the command line,
+otherwise processing will continue with the contents of
+.Ar filename .
+.It Fl f Ar filename , Fl Fl file Ar filename
+Process the content of the given file before further calculations are done.
+If multiple
+.Fl f
+options are specified, they will be processed in the order given.
+.It Fl h , Fl Fl help
+Print short usage info.
+.It Fl V , Fl Fl version
+Print version info.
+.It Fl x
+Enable extended register mode.
+This mode is used by
+.Xr bc 1
+to allow more than 256 registers.
+See
+.Sx Registers
+for a more detailed description.
+.El
+.Pp
+Ordinarily,
+.Nm
+operates on decimal integers,
+but one may specify an input base, output base,
+and a number of fractional digits (scale) to be maintained.
+If an argument is given,
+input is taken from that file until its end,
+then from the standard input.
+Whitespace is ignored, except where it signals the end of a number,
+end of a line or when a register name is expected.
+The following constructions are recognized:
+.Bl -tag -width "number"
+.It Va number
+The value of the number is pushed on the stack.
+A number is an unbroken string of the digits 0\-9 and letters A\-F.
+It may be preceded by an underscore
+.Pq Sq _
+to input a negative number.
+A number may contain a single decimal point.
+A number may also contain the characters A\-F, with the values 10\-15.
+.It Cm "+ - / * % ~ ^"
+The
+top two values on the stack are added
+(+),
+subtracted
+(\-),
+multiplied (*),
+divided (/),
+remaindered (%),
+divided and remaindered (~),
+or exponentiated (^).
+The two entries are popped off the stack;
+the result is pushed on the stack in their place.
+Any fractional part of an exponent is ignored.
+.Pp
+For addition and subtraction, the scale of the result is the maximum
+of scales of the operands.
+For division the scale of the result is defined
+by the scale set by the
+.Ic k
+operation.
+For multiplication, the scale is defined by the expression
+.Sy min(a+b,max(a,b,scale)) ,
+where
+.Sy a
+and
+.Sy b
+are the scales of the operands, and
+.Sy scale
+is the scale defined by the
+.Ic k
+operation.
+For exponentiation with a non-negative exponent, the scale of the result is
+.Sy min(a*b,max(scale,a)) ,
+where
+.Sy a
+is the scale of the base, and
+.Sy b
+is the
+.Em value
+of the exponent.
+If the exponent is negative, the scale of the result is the scale
+defined by the
+.Ic k
+operation.
+.Pp
+In the case of the division and modulus operator (~),
+the resultant quotient is pushed first followed by the remainder.
+This is a shorthand for the sequence:
+.Bd -literal -offset indent -compact
+x y / x y %
+.Ed
+The division and modulus operator is a non-portable extension.
+.It Ic a
+Pop the top value from the stack.
+If that value is a number, compute the integer part of the number modulo 256.
+If the result is zero, push an empty string.
+Otherwise push a one character string by interpreting the computed value
+as an
+.Tn ASCII
+character.
+.Pp
+If the top value is a string, push a string containing the first character
+of the original string.
+If the original string is empty, an empty string is pushed back.
+The
+.Ic a
+operator is a non-portable extension.
+.It Ic c
+All values on the stack are popped.
+.It Ic d
+The top value on the stack is duplicated.
+.It Ic f
+All values on the stack are printed, separated by newlines.
+.It Ic G
+The top two numbers are popped from the stack and compared.
+A one is pushed if the top of the stack is equal to the second number
+on the stack.
+A zero is pushed otherwise.
+This is a non-portable extension.
+.It Ic I
+Pushes the input base on the top of the stack.
+.It Ic i
+The top value on the stack is popped and used as the
+base for further input.
+The initial input base is 10.
+.It Ic J
+Pop the top value from the stack.
+The recursion level is popped by that value and, following that,
+the input is skipped until the first occurrence of the
+.Ic M
+operator.
+The
+.Ic J
+operator is a non-portable extension, used by the
+.Xr bc 1
+command.
+.It Ic K
+The current scale factor is pushed onto the stack.
+.It Ic k
+The top of the stack is popped, and that value is used as
+a non-negative scale factor:
+the appropriate number of places
+are printed on output,
+and maintained during multiplication, division, and exponentiation.
+The interaction of scale factor,
+input base, and output base will be reasonable if all are changed
+together.
+.It Ic L Ns Ar x
+Register
+.Ar x
+is treated as a stack and its top value is popped onto the main stack.
+.It Ic l Ns Ar x
+The
+value in register
+.Ar x
+is pushed on the stack.
+The register
+.Ar x
+is not altered.
+Initially, all registers contain the value zero.
+.It Ic M
+Mark used by the
+.Ic J
+operator.
+The
+.Ic M
+operator is a non-portable extensions, used by the
+.Xr bc 1
+command.
+.It Ic N
+The top of the stack is replaced by one if the top of the stack
+is equal to zero.
+If the top of the stack is unequal to zero, it is replaced by zero.
+This is a non-portable extension.
+.It Ic n
+The top value on the stack is popped and printed without a newline.
+This is a non-portable extension.
+.It Ic O
+Pushes the output base on the top of the stack.
+.It Ic o
+The top value on the stack is popped and used as the
+base for further output.
+The initial output base is 10.
+.It Ic P
+The top of the stack is popped.
+If the top of the stack is a string, it is printed without a trailing newline.
+If the top of the stack is a number, it is interpreted as a
+base 256 number, and each digit of this base 256 number is printed as
+an
+.Tn ASCII
+character, without a trailing newline.
+.It Ic p
+The top value on the stack is printed with a trailing newline.
+The top value remains unchanged.
+.It Ic Q
+The top value on the stack is popped and the string execution level is popped
+by that value.
+.It Ic q
+Exits the program.
+If executing a string, the recursion level is
+popped by two.
+.It Ic R
+The top of the stack is removed (popped).
+This is a non-portable extension.
+.It Ic r
+The top two values on the stack are reversed (swapped).
+This is a non-portable extension.
+.It Ic S Ns Ar x
+Register
+.Ar x
+is treated as a stack.
+The top value of the main stack is popped and pushed on it.
+.It Ic s Ns Ar x
+The
+top of the stack is popped and stored into
+a register named
+.Ar x .
+.It Ic v
+Replaces the top element on the stack by its square root.
+The scale of the result is the maximum of the scale of the argument
+and the current value of scale.
+.It Ic X
+Replaces the number on the top of the stack with its scale factor.
+If the top of the stack is a string, replace it with the integer 0.
+.It Ic x
+Treats the top element of the stack as a character string
+and executes it as a string of
+.Nm
+commands.
+.It Ic Z
+Replaces the number on the top of the stack with its length.
+The length of a string is its number of characters.
+The length of a number is its number of digits, not counting the minus sign
+and decimal point.
+.It Ic z
+The stack level is pushed onto the stack.
+.It Cm [ Ns ... Ns Cm ]
+Puts the bracketed
+.Tn ASCII
+string onto the top of the stack.
+If the string includes brackets, these must be properly balanced.
+The backslash character
+.Pq Sq \e
+may be used as an escape character, making it
+possible to include unbalanced brackets in strings.
+To include a backslash in a string, use a double backslash.
+.It Xo
+.Cm < Ns Va x
+.Cm > Ns Va x
+.Cm = Ns Va x
+.Cm !< Ns Va x
+.Cm !> Ns Va x
+.Cm != Ns Va x
+.Xc
+The top two elements of the stack are popped and compared.
+Register
+.Ar x
+is executed if they obey the stated
+relation.
+.It Xo
+.Cm < Ns Va x Ns e Ns Va y
+.Cm > Ns Va x Ns e Ns Va y
+.Cm = Ns Va x Ns e Ns Va y
+.Cm !< Ns Va x Ns e Ns Va y
+.Cm !> Ns Va x Ns e Ns Va y
+.Cm != Ns Va x Ns e Ns Va y
+.Xc
+These operations are variants of the comparison operations above.
+The first register name is followed by the letter
+.Sq e
+and another register name.
+Register
+.Ar x
+will be executed if the relation is true, and register
+.Ar y
+will be executed if the relation is false.
+This is a non-portable extension.
+.It Ic \&(
+The top two numbers are popped from the stack and compared.
+A one is pushed if the top of the stack is less than the second number
+on the stack.
+A zero is pushed otherwise.
+This is a non-portable extension.
+.It Ic {
+The top two numbers are popped from the stack and compared.
+A one is pushed if the top of stack is less than or equal to the
+second number on the stack.
+A zero is pushed otherwise.
+This is a non-portable extension.
+.It Ic \&!
+Interprets the rest of the line as a
+.Ux
+command.
+.It Ic \&?
+A line of input is taken from the input source (usually the terminal)
+and executed.
+.It Ic : Ns Ar r
+Pop two values from the stack.
+The second value on the stack is stored into the array
+.Ar r
+indexed by the top of stack.
+.It Ic ; Ns Ar r
+Pop a value from the stack.
+The value is used as an index into register
+.Ar r .
+The value in this register is pushed onto the stack.
+.Pp
+Array elements initially have the value zero.
+Each level of a stacked register has its own array associated with
+it.
+The command sequence
+.Bd -literal -offset indent
+[first] 0:a [dummy] Sa [second] 0:a 0;a p La 0;a p
+.Ed
+.Pp
+will print
+.Bd -literal -offset indent
+second
+first
+.Ed
+.Pp
+since the string
+.Ql second
+is written in an array that is later popped, to reveal the array that
+stored
+.Ql first .
+.It Ic #
+Skip the rest of the line.
+This is a non-portable extension.
+.El
+.Ss Registers
+Registers have a single character name
+.Ar x ,
+where
+.Ar x
+may be any character, including space, tab or any other special character.
+If extended register mode is enabled using the
+.Fl x
+option and the register identifier
+.Ar x
+has the value 255, the next two characters are interpreted as a
+two-byte register index.
+The set of standard single character registers and the set of extended
+registers do not overlap.
+Extended register mode is a non-portable extension.
+.Sh EXAMPLES
+An example which prints the first ten values of
+.Ic n! :
+.Bd -literal -offset indent
+[la1+dsa*pla10>y]sy
+0sa1
+lyx
+.Ed
+.Pp
+Independent of the current input base, the command
+.Bd -literal -offset indent
+Ai
+.Ed
+.Pp
+will reset the input base to decimal 10.
+.Sh DIAGNOSTICS
+.Bl -diag
+.It %c (0%o) is unimplemented
+an undefined operation was called.
+.It stack empty
+for not enough elements on the stack to do what was asked.
+.It stack register '%c' (0%o) is empty
+for an
+.Ar L
+operation from a stack register that is empty.
+.It Runtime warning: non-zero scale in exponent
+for a fractional part of an exponent that is being ignored.
+.It divide by zero
+for trying to divide by zero.
+.It remainder by zero
+for trying to take a remainder by zero.
+.It square root of negative number
+for trying to take the square root of a negative number.
+.It index too big
+for an array index that is larger than 2048.
+.It negative index
+for a negative array index.
+.It "input base must be a number between 2 and 16"
+for trying to set an illegal input base.
+.It output base must be a number greater than 1
+for trying to set an illegal output base.
+.It scale must be a nonnegative number
+for trying to set a negative or zero scale.
+.It scale too large
+for trying to set a scale that is too large.
+A scale must be representable as a 32-bit unsigned number.
+.It Q command argument exceeded string execution depth
+for trying to pop the recursion level more than the current
+recursion level.
+.It Q command requires a number >= 1
+for trying to pop an illegal number of recursion levels.
+.It recursion too deep
+for too many levels of nested execution.
+.Pp
+The recursion level is increased by one if the
+.Ar x
+or
+.Ar ?\&
+operation or one of the compare operations resulting in the execution
+of register is executed.
+As an exception, the recursion level is not increased if the operation
+is executed as the last command of a string.
+For example, the commands
+.Bd -literal -offset indent
+[lax]sa
+1 lax
+.Ed
+.Pp
+will execute an endless loop, while the commands
+.Bd -literal -offset indent
+[laxp]sa
+1 lax
+.Ed
+.Pp
+will terminate because of a too deep recursion level.
+.It J command argument exceeded string execution depth
+for trying to pop the recursion level more than the current
+recursion level.
+.It mark not found
+for a failed scan for an occurrence of the
+.Ic M
+operator.
+.El
+.Sh SEE ALSO
+.Xr bc 1
+.Pp
+.An -nosplit
+.An L. L. Cherry ,
+.An R. Morris
+"DC \- An Interactive Desk Calculator"
+.Pa /usr/share/doc/usd/05.dc/ .
+.Sh STANDARDS
+The arithmetic operations of the
+.Nm
+utility are expected to conform to the definition listed in the
+.Xr bc 1
+section of the
+.St -p1003.2
+specification.
+.Sh HISTORY
+The
+.Nm
+command first appeared in
+.At v6 .
+A complete rewrite of the
+.Nm
+command using the
+.Xr bn 3
+big number routines first appeared in
+.Ox 3.5 .
+.Sh AUTHORS
+.An -nosplit
+The original version of the
+.Nm
+command was written by
+.An Robert Morris
+and
+.An Lorinda Cherry .
+The current version of the
+.Nm
+utility was written by
+.An Otto Moerbeek .
diff --git a/usr.bin/dc/dc.c b/usr.bin/dc/dc.c
new file mode 100644
index 0000000..1376653
--- /dev/null
+++ b/usr.bin/dc/dc.c
@@ -0,0 +1,135 @@
+/*	$OpenBSD: dc.c,v 1.11 2009/10/27 23:59:37 deraadt Exp $	*/
+
+/*
+ * Copyright (c) 2003, Otto Moerbeek <otto@drijf.net>
+ * Copyright (c) 2009, Gabor Kovesdan <gabor@FreeBSD.org>
+ *
+ * Permission to use, copy, modify, and distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+
+#include <sys/cdefs.h>
+__FBSDID("$FreeBSD$");
+
+#include <sys/stat.h>
+
+#include <ctype.h>
+#include <err.h>
+#include <errno.h>
+#include <getopt.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+
+#include "extern.h"
+
+#define	DC_VER		"1.3-FreeBSD"
+
+static void		 usage(void);
+
+extern char		*__progname;
+
+struct source		 src;
+
+struct option long_options[] =
+{
+	{"expression",		required_argument,	NULL,	'e'},
+	{"file",		required_argument,	NULL,	'f'},
+	{"help",		no_argument,		NULL,	'h'},
+	{"version",		no_argument,		NULL,	'V'}
+};
+
+static void
+usage(void)
+{
+	fprintf(stderr, "usage: %s [-hVx] [-e expression] [file]\n",
+	    __progname);
+	exit(1);
+}
+
+static void
+procfile(char *fname) {
+	struct stat st;
+	FILE *file;
+
+	file = fopen(fname, "r");
+	if (file == NULL)
+		err(1, "cannot open file %s", fname);
+	if (fstat(fileno(file), &st) == -1)
+		err(1, "%s", fname);
+	if (S_ISDIR(st.st_mode)) {
+		errno = EISDIR;
+		err(1, "%s", fname);
+	}                
+	src_setstream(&src, file);
+	reset_bmachine(&src);
+	eval();
+	fclose(file);
+}
+
+int
+main(int argc, char *argv[])
+{
+	int ch;
+	bool extended_regs = false, preproc_done = false;
+
+	/* accept and ignore a single dash to be 4.4BSD dc(1) compatible */
+	while ((ch = getopt_long(argc, argv, "e:f:Vx", long_options, NULL)) != -1) {
+		switch (ch) {
+		case 'e':
+			src_setstring(&src, optarg);
+			reset_bmachine(&src);
+			eval();
+			preproc_done = true;
+			break;
+		case 'f':
+			procfile(optarg);
+			preproc_done = true;
+			break;
+		case 'x':
+			extended_regs = true;
+			break;
+		case 'V':
+			fprintf(stderr, "%s (BSD bc) %s\n", __progname, DC_VER);
+			exit(0);
+			break;
+		case '-':
+			break;
+		case 'h':
+			/* FALLTHROUGH */
+		default:
+			usage();
+		}
+	}
+	argc -= optind;
+	argv += optind;
+
+	init_bmachine(extended_regs);
+	setlinebuf(stdout);
+	setlinebuf(stderr);
+
+	if (argc > 1)
+		usage();
+	if (argc == 1) {
+		procfile(argv[0]);
+		preproc_done = true;
+	}
+	if (preproc_done)
+		return (0);
+
+	src_setstream(&src, stdin);
+	reset_bmachine(&src);
+	eval();
+
+	return (0);
+}
diff --git a/usr.bin/dc/extern.h b/usr.bin/dc/extern.h
new file mode 100644
index 0000000..4abf063
--- /dev/null
+++ b/usr.bin/dc/extern.h
@@ -0,0 +1,63 @@
+/*	$FreeBSD$						*/
+/*	$OpenBSD: extern.h,v 1.3 2006/01/16 08:09:25 otto Exp $	*/
+
+/*
+ * Copyright (c) 2003, Otto Moerbeek <otto@drijf.net>
+ *
+ * Permission to use, copy, modify, and distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+
+#include <stdbool.h>
+#include "bcode.h"
+
+
+/* inout.c */
+void		 src_setstream(struct source *, FILE *);
+void		 src_setstring(struct source *, char *);
+struct number	*readnumber(struct source *, u_int);
+void		 printnumber(FILE *, const struct number *, u_int);
+char		*read_string(struct source *);
+void		 print_value(FILE *, const struct value *, const char *, u_int);
+void		 print_ascii(FILE *, const struct number *);
+
+/* mem.c */
+struct number	*new_number(void);
+void		 free_number(struct number *);
+struct number	*dup_number(const struct number *);
+void		*bmalloc(size_t);
+void		*brealloc(void *, size_t);
+char		*bstrdup(const char *p);
+void		 bn_check(int);
+void		 bn_checkp(const void *);
+
+/* stack.c */
+void		 stack_init(struct stack *);
+void		 stack_free_value(struct value *);
+struct value	*stack_dup_value(const struct value *, struct value *);
+void		 stack_swap(struct stack *);
+size_t		 stack_size(const struct stack *);
+void		 stack_dup(struct stack *);
+void		 stack_pushnumber(struct stack *, struct number *);
+void		 stack_pushstring(struct stack *stack, char *);
+void	 	 stack_push(struct stack *, struct value *);
+void		 stack_set_tos(struct stack *, struct value *);
+struct value	*stack_tos(const struct stack *);
+struct value	*stack_pop(struct stack *);
+struct number	*stack_popnumber(struct stack *);
+char		*stack_popstring(struct stack *);
+void		 stack_clear(struct stack *);
+void		 stack_print(FILE *, const struct stack *, const char *,
+		    u_int base);
+void		 frame_assign(struct stack *, size_t, const struct value *);
+struct value	*frame_retrieve(const struct stack *, size_t);
+/* void		 frame_free(struct stack *); */
diff --git a/usr.bin/dc/inout.c b/usr.bin/dc/inout.c
new file mode 100644
index 0000000..4a2bb70
--- /dev/null
+++ b/usr.bin/dc/inout.c
@@ -0,0 +1,417 @@
+/*	$OpenBSD: inout.c,v 1.15 2009/10/27 23:59:37 deraadt Exp $	*/
+
+/*
+ * Copyright (c) 2003, Otto Moerbeek <otto@drijf.net>
+ *
+ * Permission to use, copy, modify, and distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+
+#include <sys/cdefs.h>
+__FBSDID("$FreeBSD$");
+
+#include <openssl/ssl.h>
+#include <ctype.h>
+#include <err.h>
+#include <string.h>
+
+#include "extern.h"
+
+#define MAX_CHARS_PER_LINE 68
+
+static int	 lastchar;
+static int	 charcount;
+
+static int	 src_getcharstream(struct source *);
+static void	 src_ungetcharstream(struct source *);
+static char	*src_getlinestream(struct source *);
+static int	 src_getcharstring(struct source *);
+static void	 src_ungetcharstring(struct source *);
+static char	*src_getlinestring(struct source *);
+static void	 src_freestring(struct source *);
+static void	 flushwrap(FILE *);
+static void	 putcharwrap(FILE *, int);
+static void	 printwrap(FILE *, const char *);
+static char	*get_digit(u_long, int, u_int);
+
+static struct vtable stream_vtable = {
+	src_getcharstream,
+	src_ungetcharstream,
+	src_getlinestream,
+	NULL
+};
+
+static struct vtable string_vtable = {
+	src_getcharstring,
+	src_ungetcharstring,
+	src_getlinestring,
+	src_freestring
+};
+
+void
+src_setstream(struct source *src, FILE *stream)
+{
+
+	src->u.stream = stream;
+	src->vtable = &stream_vtable;
+}
+
+void
+src_setstring(struct source *src, char *p)
+{
+
+	src->u.string.buf = (u_char *)p;
+	src->u.string.pos = 0;
+	src->vtable = &string_vtable;
+}
+
+static int
+src_getcharstream(struct source *src)
+{
+
+	return (src->lastchar = getc(src->u.stream));
+}
+
+static void
+src_ungetcharstream(struct source *src)
+{
+
+	ungetc(src->lastchar, src->u.stream);
+}
+
+static char *
+src_getlinestream(struct source *src)
+{
+	char buf[BUFSIZ];
+
+	if (fgets(buf, BUFSIZ, src->u.stream) == NULL)
+		return (bstrdup(""));
+	return bstrdup(buf);
+}
+
+static int
+src_getcharstring(struct source *src)
+{
+
+	src->lastchar = src->u.string.buf[src->u.string.pos];
+	if (src->lastchar == '\0')
+		return (EOF);
+	else {
+		src->u.string.pos++;
+		return (src->lastchar);
+	}
+}
+
+static void
+src_ungetcharstring(struct source *src)
+{
+
+	if (src->u.string.pos > 0) {
+		if (src->lastchar != '\0')
+			--src->u.string.pos;
+	}
+}
+
+static char *
+src_getlinestring(struct source *src)
+{
+	char buf[BUFSIZ];
+	int i, ch;
+
+	i = 0;
+	while (i < BUFSIZ-1) {
+		ch = src_getcharstring(src);
+		if (ch == EOF)
+			break;
+		buf[i++] = ch;
+		if (ch == '\n')
+			break;
+	}
+	buf[i] = '\0';
+	return (bstrdup(buf));
+}
+
+static void
+src_freestring(struct source *src)
+{
+
+	free(src->u.string.buf);
+}
+
+static void
+flushwrap(FILE *f)
+{
+
+	if (lastchar != -1)
+		putc(lastchar, f);
+}
+
+static void
+putcharwrap(FILE *f, int ch)
+{
+
+	if (charcount >= MAX_CHARS_PER_LINE) {
+		charcount = 0;
+		fputs("\\\n", f);
+	}
+	if (lastchar != -1) {
+		charcount++;
+		putc(lastchar, f);
+	}
+	lastchar = ch;
+}
+
+static void
+printwrap(FILE *f, const char *p)
+{
+	char *q;
+	char buf[12];
+
+	q = buf;
+	strlcpy(buf, p, sizeof(buf));
+	while (*q)
+		putcharwrap(f, *q++);
+}
+
+struct number *
+readnumber(struct source *src, u_int base)
+{
+	struct number *n;
+	BN_ULONG v;
+	u_int i;
+	int ch;
+	bool dot = false, sign = false;
+
+	n = new_number();
+	bn_check(BN_zero(n->number));
+
+	while ((ch = (*src->vtable->readchar)(src)) != EOF) {
+
+		if ('0' <= ch && ch <= '9')
+			v = ch - '0';
+		else if ('A' <= ch && ch <= 'F')
+			v = ch - 'A' + 10;
+		else if (ch == '_') {
+			sign = true;
+			continue;
+		} else if (ch == '.') {
+			if (dot)
+				break;
+			dot = true;
+			continue;
+		} else {
+			(*src->vtable->unreadchar)(src);
+			break;
+		}
+		if (dot)
+			n->scale++;
+
+		bn_check(BN_mul_word(n->number, base));
+
+#if 0
+		/* work around a bug in BN_add_word: 0 += 0 is buggy.... */
+		if (v > 0)
+#endif
+			bn_check(BN_add_word(n->number, v));
+	}
+	if (base != 10) {
+		scale_number(n->number, n->scale);
+		for (i = 0; i < n->scale; i++)
+			BN_div_word(n->number, base);
+	}
+	if (sign)
+		negate(n);
+	return (n);
+}
+
+char *
+read_string(struct source *src)
+{
+	char *p;
+	int count, ch, i, new_sz, sz;
+	bool escape;
+
+	escape = false;
+	count = 1;
+	i = 0;
+	sz = 15;
+	p = bmalloc(sz + 1);
+
+	while ((ch = (*src->vtable->readchar)(src)) != EOF) {
+		if (!escape) {
+			if (ch == '[')
+				count++;
+			else if (ch == ']')
+				count--;
+			if (count == 0)
+				break;
+		}
+		if (ch == '\\' && !escape)
+			escape = true;
+		else {
+			escape = false;
+			if (i == sz) {
+				new_sz = sz * 2;
+				p = brealloc(p, new_sz + 1);
+				sz = new_sz;
+			}
+			p[i++] = ch;
+		}
+	}
+	p[i] = '\0';
+	return (p);
+}
+
+static char *
+get_digit(u_long num, int digits, u_int base)
+{
+	char *p;
+
+	if (base <= 16) {
+		p = bmalloc(2);
+		p[0] = num >= 10 ? num + 'A' - 10 : num + '0';
+		p[1] = '\0';
+	} else {
+		if (asprintf(&p, "%0*lu", digits, num) == -1)
+			err(1, NULL);
+	}
+	return (p);
+}
+
+void
+printnumber(FILE *f, const struct number *b, u_int base)
+{
+	struct number *fract_part, *int_part;
+	struct stack stack;
+	char *p;
+	char buf[11];
+	size_t sz;
+	unsigned int i;
+	int digits;
+
+	charcount = 0;
+	lastchar = -1;
+	if (BN_is_zero(b->number))
+		putcharwrap(f, '0');
+
+	int_part = new_number();
+	fract_part = new_number();
+	fract_part->scale = b->scale;
+
+	if (base <= 16)
+		digits = 1;
+	else {
+		digits = snprintf(buf, sizeof(buf), "%u", base-1);
+	}
+	split_number(b, int_part->number, fract_part->number);
+
+	i = 0;
+	stack_init(&stack);
+	while (!BN_is_zero(int_part->number)) {
+		BN_ULONG rem = BN_div_word(int_part->number, base);
+		stack_pushstring(&stack, get_digit(rem, digits, base));
+		i++;
+	}
+	sz = i;
+	if (BN_cmp(b->number, &zero) < 0)
+		putcharwrap(f, '-');
+	for (i = 0; i < sz; i++) {
+		p = stack_popstring(&stack);
+		if (base > 16)
+			putcharwrap(f, ' ');
+		printwrap(f, p);
+		free(p);
+	}
+	stack_clear(&stack);
+	if (b->scale > 0) {
+		struct number *num_base;
+		BIGNUM mult, stop;
+
+		putcharwrap(f, '.');
+		num_base = new_number();
+		bn_check(BN_set_word(num_base->number, base));
+		BN_init(&mult);
+		bn_check(BN_one(&mult));
+		BN_init(&stop);
+		bn_check(BN_one(&stop));
+		scale_number(&stop, b->scale);
+
+		i = 0;
+		while (BN_cmp(&mult, &stop) < 0) {
+			u_long rem;
+
+			if (i && base > 16)
+				putcharwrap(f, ' ');
+			i = 1;
+
+			bmul_number(fract_part, fract_part, num_base);
+			split_number(fract_part, int_part->number, NULL);
+			rem = BN_get_word(int_part->number);
+			p = get_digit(rem, digits, base);
+			int_part->scale = 0;
+			normalize(int_part, fract_part->scale);
+			bn_check(BN_sub(fract_part->number, fract_part->number,
+			    int_part->number));
+			printwrap(f, p);
+			free(p);
+			bn_check(BN_mul_word(&mult, base));
+		}
+		free_number(num_base);
+		BN_free(&mult);
+		BN_free(&stop);
+	}
+	flushwrap(f);
+	free_number(int_part);
+	free_number(fract_part);
+}
+
+void
+print_value(FILE *f, const struct value *value, const char *prefix, u_int base)
+{
+
+	fputs(prefix, f);
+	switch (value->type) {
+	case BCODE_NONE:
+		if (value->array != NULL)
+			fputs("<array>", f);
+		break;
+	case BCODE_NUMBER:
+		printnumber(f, value->u.num, base);
+		break;
+	case BCODE_STRING:
+		fputs(value->u.string, f);
+		break;
+	}
+}
+
+void
+print_ascii(FILE *f, const struct number *n)
+{
+	BIGNUM *v;
+	int ch, i, numbits;
+
+	v = BN_dup(n->number);
+	bn_checkp(v);
+
+	if (BN_cmp(v, &zero) < 0)
+		bn_check(BN_sub(v, &zero, v));
+
+	numbits = BN_num_bytes(v) * 8;
+	while (numbits > 0) {
+		ch = 0;
+		for (i = 0; i < 8; i++)
+			ch |= BN_is_bit_set(v, numbits-i-1) << (7 - i);
+		putc(ch, f);
+		numbits -= 8;
+	}
+	BN_free(v);
+}
diff --git a/usr.bin/dc/mem.c b/usr.bin/dc/mem.c
new file mode 100644
index 0000000..78fb429
--- /dev/null
+++ b/usr.bin/dc/mem.c
@@ -0,0 +1,110 @@
+/*	$OpenBSD: mem.c,v 1.5 2009/10/27 23:59:37 deraadt Exp $	*/
+
+/*
+ * Copyright (c) 2003, Otto Moerbeek <otto@drijf.net>
+ *
+ * Permission to use, copy, modify, and distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+
+#include <sys/cdefs.h>
+__FBSDID("$FreeBSD$");
+
+#include <openssl/err.h>
+
+#include <err.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include "extern.h"
+
+struct number *
+new_number(void)
+{
+	struct number *n;
+
+	n = bmalloc(sizeof(*n));
+	n->scale = 0;
+	n->number = BN_new();
+	if (n->number == NULL)
+		err(1, NULL);
+	return (n);
+}
+
+void
+free_number(struct number *n)
+{
+
+	BN_free(n->number);
+	free(n);
+}
+
+struct number *
+dup_number(const struct number *a)
+{
+	struct number *n;
+
+	n = bmalloc(sizeof(*n));
+	n->scale = a->scale;
+	n->number = BN_dup(a->number);
+	bn_checkp(n->number);
+	return (n);
+}
+
+void *
+bmalloc(size_t sz)
+{
+	void *p;
+
+	p = malloc(sz);
+	if (p == NULL)
+		err(1, NULL);
+	return (p);
+}
+
+void *
+brealloc(void *p, size_t sz)
+{
+	void *q;
+
+	q = realloc(p, sz);
+	if (q == NULL)
+		err(1, NULL);
+	return (q);
+}
+
+char *
+bstrdup(const char *p)
+{
+	char *q;
+
+	q = strdup(p);
+	if (q == NULL)
+		err(1, NULL);
+	return (q);
+}
+
+void
+bn_check(int x)						\
+{
+
+	if (x == 0)
+		err(1, "big number failure %lx", ERR_get_error());
+}
+
+void
+bn_checkp(const void *p)						\
+{
+
+	if (p == NULL)
+		err(1, "allocation failure %lx", ERR_get_error());
+}
diff --git a/usr.bin/dc/stack.c b/usr.bin/dc/stack.c
new file mode 100644
index 0000000..950b4e5
--- /dev/null
+++ b/usr.bin/dc/stack.c
@@ -0,0 +1,379 @@
+/*	$OpenBSD: stack.c,v 1.11 2009/10/27 23:59:37 deraadt Exp $	*/
+
+/*
+ * Copyright (c) 2003, Otto Moerbeek <otto@drijf.net>
+ *
+ * Permission to use, copy, modify, and distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+
+#include <sys/cdefs.h>
+__FBSDID("$FreeBSD$");
+
+#include <err.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include "extern.h"
+
+static __inline bool	 stack_empty(const struct stack *);
+static void		 stack_grow(struct stack *);
+static struct array	*array_new(void);
+static __inline void	 array_free(struct array *);
+static struct array	*array_dup(const struct array *);
+static __inline void	 array_grow(struct array *, size_t);
+static __inline void	 array_assign(struct array *, size_t, const struct value *);
+static __inline struct value	*array_retrieve(const struct array *, size_t);
+
+void
+stack_init(struct stack *stack)
+{
+
+	stack->size = 0;
+	stack->sp = -1;
+	stack->stack = NULL;
+}
+
+static __inline bool
+stack_empty(const struct stack *stack)
+{
+	bool empty = stack->sp == -1;
+
+	if (empty)
+		warnx("stack empty");
+	return empty;
+}
+
+/* Clear number or string, but leave value itself */
+void
+stack_free_value(struct value *v)
+{
+
+	switch (v->type) {
+	case BCODE_NONE:
+		break;
+	case BCODE_NUMBER:
+		free_number(v->u.num);
+		break;
+	case BCODE_STRING:
+		free(v->u.string);
+		break;
+	}
+	if (v->array != NULL) {
+		array_free(v->array);
+		v->array = NULL;
+	}
+}
+
+/* Copy number or string content into already allocated target */
+struct value *
+stack_dup_value(const struct value *a, struct value *copy)
+{
+
+	copy->type = a->type;
+
+	switch (a->type) {
+	case BCODE_NONE:
+		break;
+	case BCODE_NUMBER:
+		copy->u.num = dup_number(a->u.num);
+		break;
+	case BCODE_STRING:
+		copy->u.string = strdup(a->u.string);
+		if (copy->u.string == NULL)
+			err(1, NULL);
+		break;
+	}
+
+	copy->array = a->array == NULL ? NULL : array_dup(a->array);
+
+	return (copy);
+}
+
+size_t
+stack_size(const struct stack *stack)
+{
+
+	return (stack->sp + 1);
+}
+
+void
+stack_dup(struct stack *stack)
+{
+	struct value *value;
+	struct value copy;
+
+	value = stack_tos(stack);
+	if (value == NULL) {
+		warnx("stack empty");
+		return;
+	}
+	stack_push(stack, stack_dup_value(value, &copy));
+}
+
+void
+stack_swap(struct stack *stack)
+{
+	struct value copy;
+
+	if (stack->sp < 1) {
+		warnx("stack empty");
+		return;
+	}
+	copy = stack->stack[stack->sp];
+	stack->stack[stack->sp] = stack->stack[stack->sp-1];
+	stack->stack[stack->sp-1] = copy;
+}
+
+static void
+stack_grow(struct stack *stack)
+{
+	size_t i, new_size;
+
+	if (++stack->sp == stack->size) {
+		new_size = stack->size * 2 + 1;
+		stack->stack = brealloc(stack->stack,
+		    new_size * sizeof(*stack->stack));
+		for (i = stack->size; i < new_size; i++)
+			stack->stack[i].array = NULL;
+		stack->size = new_size;
+	}
+}
+
+void
+stack_pushnumber(struct stack *stack, struct number *b)
+{
+
+	stack_grow(stack);
+	stack->stack[stack->sp].type = BCODE_NUMBER;
+	stack->stack[stack->sp].u.num = b;
+}
+
+void
+stack_pushstring(struct stack *stack, char *string)
+{
+
+	stack_grow(stack);
+	stack->stack[stack->sp].type = BCODE_STRING;
+	stack->stack[stack->sp].u.string = string;
+}
+
+void
+stack_push(struct stack *stack, struct value *v)
+{
+
+	switch (v->type) {
+	case BCODE_NONE:
+		stack_grow(stack);
+		stack->stack[stack->sp].type = BCODE_NONE;
+		break;
+	case BCODE_NUMBER:
+		stack_pushnumber(stack, v->u.num);
+		break;
+	case BCODE_STRING:
+		stack_pushstring(stack, v->u.string);
+		break;
+	}
+	stack->stack[stack->sp].array = v->array == NULL ?
+	    NULL : array_dup(v->array);
+}
+
+struct value *
+stack_tos(const struct stack *stack)
+{
+
+	if (stack->sp == -1)
+		return (NULL);
+	return &stack->stack[stack->sp];
+}
+
+void
+stack_set_tos(struct stack *stack, struct value *v)
+{
+
+	if (stack->sp == -1)
+		stack_push(stack, v);
+	else {
+		stack_free_value(&stack->stack[stack->sp]);
+		stack->stack[stack->sp] = *v;
+		stack->stack[stack->sp].array = v->array == NULL ?
+		    NULL : array_dup(v->array);
+	}
+}
+
+struct value *
+stack_pop(struct stack *stack)
+{
+
+	if (stack_empty(stack))
+		return (NULL);
+	return &stack->stack[stack->sp--];
+}
+
+struct number *
+stack_popnumber(struct stack *stack)
+{
+
+	if (stack_empty(stack))
+		return (NULL);
+	if (stack->stack[stack->sp].array != NULL) {
+		array_free(stack->stack[stack->sp].array);
+		stack->stack[stack->sp].array = NULL;
+	}
+	if (stack->stack[stack->sp].type != BCODE_NUMBER) {
+		warnx("not a number"); /* XXX remove */
+		return (NULL);
+	}
+	return stack->stack[stack->sp--].u.num;
+}
+
+char *
+stack_popstring(struct stack *stack)
+{
+
+	if (stack_empty(stack))
+		return (NULL);
+	if (stack->stack[stack->sp].array != NULL) {
+		array_free(stack->stack[stack->sp].array);
+		stack->stack[stack->sp].array = NULL;
+	}
+	if (stack->stack[stack->sp].type != BCODE_STRING) {
+		warnx("not a string"); /* XXX remove */
+		return (NULL);
+	}
+	return stack->stack[stack->sp--].u.string;
+}
+
+void
+stack_clear(struct stack *stack)
+{
+
+	while (stack->sp >= 0) {
+		stack_free_value(&stack->stack[stack->sp--]);
+	}
+	free(stack->stack);
+	stack_init(stack);
+}
+
+void
+stack_print(FILE *f, const struct stack *stack, const char *prefix, u_int base)
+{
+	ssize_t i;
+
+	for (i = stack->sp; i >= 0; i--) {
+		print_value(f, &stack->stack[i], prefix, base);
+		putc('\n', f);
+	}
+}
+
+
+static struct array *
+array_new(void)
+{
+	struct array *a;
+
+	a = bmalloc(sizeof(*a));
+	a->data = NULL;
+	a->size = 0;
+	return a;
+}
+
+static __inline void
+array_free(struct array *a)
+{
+	size_t i;
+
+	if (a == NULL)
+		return;
+	for (i = 0; i < a->size; i++)
+		stack_free_value(&a->data[i]);
+	free(a->data);
+	free(a);
+}
+
+static struct array *
+array_dup(const struct array *a)
+{
+	struct array *n;
+	size_t i;
+
+	if (a == NULL)
+		return (NULL);
+	n = array_new();
+	array_grow(n, a->size);
+	for (i = 0; i < a->size; i++)
+		stack_dup_value(&a->data[i], &n->data[i]);
+	return (n);
+}
+
+static __inline void
+array_grow(struct array *array, size_t newsize)
+{
+	size_t i;
+
+	array->data = brealloc(array->data, newsize * sizeof(*array->data));
+	for (i = array->size; i < newsize; i++) {
+		array->data[i].type = BCODE_NONE;
+		array->data[i].array = NULL;
+	}
+	array->size = newsize;
+}
+
+static __inline void
+array_assign(struct array *array, size_t i, const struct value *v)
+{
+
+	if (i >= array->size)
+		array_grow(array, i + 1);
+	stack_free_value(&array->data[i]);
+	array->data[i] = *v;
+}
+
+static __inline struct value *
+array_retrieve(const struct array *array, size_t i)
+{
+
+	if (i >= array->size)
+		return (NULL);
+	return &array->data[i];
+}
+
+void
+frame_assign(struct stack *stack, size_t i, const struct value *v)
+{
+	struct array *a;
+	struct value n;
+
+	if (stack->sp == -1) {
+		n.type = BCODE_NONE;
+		n.array = NULL;
+		stack_push(stack, &n);
+	}
+
+	a = stack->stack[stack->sp].array;
+	if (a == NULL)
+		a = stack->stack[stack->sp].array = array_new();
+	array_assign(a, i, v);
+}
+
+struct value *
+frame_retrieve(const struct stack *stack, size_t i)
+{
+	struct array *a;
+
+	if (stack->sp == -1)
+		return (NULL);
+	a = stack->stack[stack->sp].array;
+	if (a == NULL)
+		a = stack->stack[stack->sp].array = array_new();
+	return array_retrieve(a, i);
+}