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diff --git a/contrib/binutils/gas/doc/c-arc.texi b/contrib/binutils/gas/doc/c-arc.texi new file mode 100644 index 0000000..04544d1 --- /dev/null +++ b/contrib/binutils/gas/doc/c-arc.texi @@ -0,0 +1,333 @@ +@c Copyright 2000, 2001, 2005 Free Software Foundation, Inc. +@c This is part of the GAS manual. +@c For copying conditions, see the file as.texinfo. + +@ifset GENERIC +@page +@node ARC-Dependent +@chapter ARC Dependent Features +@end ifset + +@ifclear GENERIC +@node Machine Dependencies +@chapter ARC Dependent Features +@end ifclear + +@set ARC_CORE_DEFAULT 6 + +@cindex ARC support +@menu +* ARC Options:: Options +* ARC Syntax:: Syntax +* ARC Floating Point:: Floating Point +* ARC Directives:: ARC Machine Directives +* ARC Opcodes:: Opcodes +@end menu + + +@node ARC Options +@section Options +@cindex ARC options (none) +@cindex options for ARC (none) + +@table @code + +@cindex @code{-marc[5|6|7|8]} command line option, ARC +@item -marc[5|6|7|8] +This option selects the core processor variant. Using +@code{-marc} is the same as @code{-marc@value{ARC_CORE_DEFAULT}}, which +is also the default. + +@table @code + +@cindex @code{arc5} arc5, ARC +@item arc5 +Base instruction set. + +@cindex @code{arc6} arc6, ARC +@item arc6 +Jump-and-link (jl) instruction. No requirement of an instruction between +setting flags and conditional jump. For example: + +@smallexample + mov.f r0,r1 + beq foo +@end smallexample + +@cindex @code{arc7} arc7, ARC +@item arc7 +Break (brk) and sleep (sleep) instructions. + +@cindex @code{arc8} arc8, ARC +@item arc8 +Software interrupt (swi) instruction. + +@end table + +Note: the @code{.option} directive can to be used to select a core +variant from within assembly code. + +@cindex @code{-EB} command line option, ARC +@item -EB +This option specifies that the output generated by the assembler should +be marked as being encoded for a big-endian processor. + +@cindex @code{-EL} command line option, ARC +@item -EL +This option specifies that the output generated by the assembler should +be marked as being encoded for a little-endian processor - this is the +default. + +@end table + + +@node ARC Syntax +@section Syntax +@menu +* ARC-Chars:: Special Characters +* ARC-Regs:: Register Names +@end menu + +@node ARC-Chars +@subsection Special Characters + +@cindex ARC special characters +@cindex special characters, ARC +*TODO* + +@node ARC-Regs +@subsection Register Names + +@cindex ARC register names +@cindex register names, ARC +*TODO* + + +@node ARC Floating Point +@section Floating Point + +@cindex floating point, ARC (@sc{ieee}) +@cindex ARC floating point (@sc{ieee}) +The ARC core does not currently have hardware floating point +support. Software floating point support is provided by @code{GCC} +and uses @sc{ieee} floating-point numbers. + + +@node ARC Directives +@section ARC Machine Directives + +@cindex machine directives, ARC +@cindex ARC machine directives +The ARC version of @code{@value{AS}} supports the following additional +machine directives: + +@table @code + +@cindex @code{2byte} directive, ARC +@item .2byte @var{expressions} +*TODO* + +@cindex @code{3byte} directive, ARC +@item .3byte @var{expressions} +*TODO* + +@cindex @code{4byte} directive, ARC +@item .4byte @var{expressions} +*TODO* + +@cindex @code{extAuxRegister} directive, ARC +@item .extAuxRegister @var{name},@var{address},@var{mode} +The ARCtangent A4 has extensible auxiliary register space. The +auxiliary registers can be defined in the assembler source code by +using this directive. The first parameter is the @var{name} of the +new auxiallry register. The second parameter is the @var{address} of +the register in the auxiliary register memory map for the variant of +the ARC. The third parameter specifies the @var{mode} in which the +register can be operated is and it can be one of: + +@table @code +@item r (readonly) +@item w (write only) +@item r|w (read or write) +@end table + +For example: + +@smallexample + .extAuxRegister mulhi,0x12,w +@end smallexample + +This specifies an extension auxiliary register called @emph{mulhi} +which is at address 0x12 in the memory space and which is only +writable. + +@cindex @code{extCondCode} directive, ARC +@item .extCondCode @var{suffix},@var{value} +The condition codes on the ARCtangent A4 are extensible and can be +specified by means of this assembler directive. They are specified +by the suffix and the value for the condition code. They can be used to +specify extra condition codes with any values. For example: + +@smallexample + .extCondCode is_busy,0x14 + + add.is_busy r1,r2,r3 + bis_busy _main +@end smallexample + +@cindex @code{extCoreRegister} directive, ARC +@item .extCoreRegister @var{name},@var{regnum},@var{mode},@var{shortcut} +Specifies an extension core register @var{name} for the application. +This allows a register @var{name} with a valid @var{regnum} between 0 +and 60, with the following as valid values for @var{mode} + +@table @samp +@item @emph{r} (readonly) +@item @emph{w} (write only) +@item @emph{r|w} (read or write) +@end table + + +The other parameter gives a description of the register having a +@var{shortcut} in the pipeline. The valid values are: + +@table @code +@item can_shortcut +@item cannot_shortcut +@end table + +For example: + +@smallexample + .extCoreRegister mlo,57,r,can_shortcut +@end smallexample + +This defines an extension core register mlo with the value 57 which +can shortcut the pipeline. + +@cindex @code{extInstruction} directive, ARC +@item .extInstruction @var{name},@var{opcode},@var{subopcode},@var{suffixclass},@var{syntaxclass} +The ARCtangent A4 allows the user to specify extension instructions. +The extension instructions are not macros. The assembler creates +encodings for use of these instructions according to the specification +by the user. The parameters are: + +@table @bullet +@item @var{name} +Name of the extension instruction + +@item @var{opcode} +Opcode to be used. (Bits 27:31 in the encoding). Valid values +0x10-0x1f or 0x03 + +@item @var{subopcode} +Subopcode to be used. Valid values are from 0x09-0x3f. However the +correct value also depends on @var{syntaxclass} + +@item @var{suffixclass} +Determines the kinds of suffixes to be allowed. Valid values are +@code{SUFFIX_NONE}, @code{SUFFIX_COND}, +@code{SUFFIX_FLAG} which indicates the absence or presence of +conditional suffixes and flag setting by the extension instruction. +It is also possible to specify that an instruction sets the flags and +is conditional by using @code{SUFFIX_CODE} | @code{SUFFIX_FLAG}. + +@item @var{syntaxclass} +Determines the syntax class for the instruction. It can have the +following values: + +@table @code +@item @code{SYNTAX_2OP}: +2 Operand Instruction +@item @code{SYNTAX_3OP}: +3 Operand Instruction +@end table + +In addition there could be modifiers for the syntax class as described +below: + +@itemize @minus +Syntax Class Modifiers are: + +@item @code{OP1_MUST_BE_IMM}: +Modifies syntax class SYNTAX_3OP, specifying that the first operand +of a three-operand instruction must be an immediate (i.e. the result +is discarded). OP1_MUST_BE_IMM is used by bitwise ORing it with +SYNTAX_3OP as given in the example below. This could usually be used +to set the flags using specific instructions and not retain results. + +@item @code{OP1_IMM_IMPLIED}: +Modifies syntax class SYNTAX_20P, it specifies that there is an +implied immediate destination operand which does not appear in the +syntax. For example, if the source code contains an instruction like: + +@smallexample +inst r1,r2 +@end smallexample + +it really means that the first argument is an implied immediate (that +is, the result is discarded). This is the same as though the source +code were: inst 0,r1,r2. You use OP1_IMM_IMPLIED by bitwise ORing it +with SYNTAX_20P. + +@end itemize +@end table + +For example, defining 64-bit multiplier with immediate operands: + +@smallexample +.extInstruction mp64,0x14,0x0,SUFFIX_COND | SUFFIX_FLAG , + SYNTAX_3OP|OP1_MUST_BE_IMM +@end smallexample + +The above specifies an extension instruction called mp64 which has 3 operands, +sets the flags, can be used with a condition code, for which the +first operand is an immediate. (Equivalent to discarding the result +of the operation). + +@smallexample + .extInstruction mul64,0x14,0x00,SUFFIX_COND, SYNTAX_2OP|OP1_IMM_IMPLIED +@end smallexample + +This describes a 2 operand instruction with an implicit first +immediate operand. The result of this operation would be discarded. + +@cindex @code{half} directive, ARC +@item .half @var{expressions} +*TODO* + +@cindex @code{long} directive, ARC +@item .long @var{expressions} +*TODO* + +@cindex @code{option} directive, ARC +@item .option @var{arc|arc5|arc6|arc7|arc8} +The @code{.option} directive must be followed by the desired core +version. Again @code{arc} is an alias for +@code{arc@value{ARC_CORE_DEFAULT}}. + +Note: the @code{.option} directive overrides the command line option +@code{-marc}; a warning is emitted when the version is not consistent +between the two - even for the implicit default core version +(arc@value{ARC_CORE_DEFAULT}). + +@cindex @code{short} directive, ARC +@item .short @var{expressions} +*TODO* + +@cindex @code{word} directive, ARC +@item .word @var{expressions} +*TODO* + +@end table + + +@node ARC Opcodes +@section Opcodes + +@cindex ARC opcodes +@cindex opcodes for ARC + +For information on the ARC instruction set, see @cite{ARC Programmers +Reference Manual}, ARC International (www.arc.com) + |
