Linux-2.6.12-rc2v2.6.12-rc2

Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.

Let it rip!

1 files changed, 355 insertions, 0 deletions

diff --git a/arch/sparc/lib/udiv.S b/arch/sparc/lib/udiv.S
new file mode 100644
index 0000000..2abfc6b
--- /dev/null
+++ b/arch/sparc/lib/udiv.S
@@ -0,0 +1,355 @@
+/* $Id: udiv.S,v 1.4 1996/09/30 02:22:38 davem Exp $
+ * udiv.S:      This routine was taken from glibc-1.09 and is covered
+ *              by the GNU Library General Public License Version 2.
+ */
+
+
+/* This file is generated from divrem.m4; DO NOT EDIT! */
+/*
+ * Division and remainder, from Appendix E of the Sparc Version 8
+ * Architecture Manual, with fixes from Gordon Irlam.
+ */
+
+/*
+ * Input: dividend and divisor in %o0 and %o1 respectively.
+ *
+ * m4 parameters:
+ *  .udiv	name of function to generate
+ *  div		div=div => %o0 / %o1; div=rem => %o0 % %o1
+ *  false		false=true => signed; false=false => unsigned
+ *
+ * Algorithm parameters:
+ *  N		how many bits per iteration we try to get (4)
+ *  WORDSIZE	total number of bits (32)
+ *
+ * Derived constants:
+ *  TOPBITS	number of bits in the top decade of a number
+ *
+ * Important variables:
+ *  Q		the partial quotient under development (initially 0)
+ *  R		the remainder so far, initially the dividend
+ *  ITER	number of main division loop iterations required;
+ *		equal to ceil(log2(quotient) / N).  Note that this
+ *		is the log base (2^N) of the quotient.
+ *  V		the current comparand, initially divisor*2^(ITER*N-1)
+ *
+ * Cost:
+ *  Current estimate for non-large dividend is
+ *	ceil(log2(quotient) / N) * (10 + 7N/2) + C
+ *  A large dividend is one greater than 2^(31-TOPBITS) and takes a
+ *  different path, as the upper bits of the quotient must be developed
+ *  one bit at a time.
+ */
+
+
+	.globl .udiv
+.udiv:
+
+	! Ready to divide.  Compute size of quotient; scale comparand.
+	orcc	%o1, %g0, %o5
+	bne	1f
+	 mov	%o0, %o3
+
+		! Divide by zero trap.  If it returns, return 0 (about as
+		! wrong as possible, but that is what SunOS does...).
+		ta	ST_DIV0
+		retl
+		 clr	%o0
+
+1:
+	cmp	%o3, %o5			! if %o1 exceeds %o0, done
+	blu	Lgot_result		! (and algorithm fails otherwise)
+	 clr	%o2
+
+	sethi	%hi(1 << (32 - 4 - 1)), %g1
+
+	cmp	%o3, %g1
+	blu	Lnot_really_big
+	 clr	%o4
+
+	! Here the dividend is >= 2**(31-N) or so.  We must be careful here,
+	! as our usual N-at-a-shot divide step will cause overflow and havoc.
+	! The number of bits in the result here is N*ITER+SC, where SC <= N.
+	! Compute ITER in an unorthodox manner: know we need to shift V into
+	! the top decade: so do not even bother to compare to R.
+	1:
+		cmp	%o5, %g1
+		bgeu	3f
+		 mov	1, %g7
+
+		sll	%o5, 4, %o5
+
+		b	1b
+		 add	%o4, 1, %o4
+
+	! Now compute %g7.
+	2:
+		addcc	%o5, %o5, %o5
+		bcc	Lnot_too_big
+		 add	%g7, 1, %g7
+
+		! We get here if the %o1 overflowed while shifting.
+		! This means that %o3 has the high-order bit set.
+		! Restore %o5 and subtract from %o3.
+		sll	%g1, 4, %g1	! high order bit
+		srl	%o5, 1, %o5		! rest of %o5
+		add	%o5, %g1, %o5
+
+		b	Ldo_single_div
+		 sub	%g7, 1, %g7
+
+	Lnot_too_big:
+	3:
+		cmp	%o5, %o3
+		blu	2b
+		 nop
+
+		be	Ldo_single_div
+		 nop
+	/* NB: these are commented out in the V8-Sparc manual as well */
+	/* (I do not understand this) */
+	! %o5 > %o3: went too far: back up 1 step
+	!	srl	%o5, 1, %o5
+	!	dec	%g7
+	! do single-bit divide steps
+	!
+	! We have to be careful here.  We know that %o3 >= %o5, so we can do the
+	! first divide step without thinking.  BUT, the others are conditional,
+	! and are only done if %o3 >= 0.  Because both %o3 and %o5 may have the high-
+	! order bit set in the first step, just falling into the regular
+	! division loop will mess up the first time around.
+	! So we unroll slightly...
+	Ldo_single_div:
+		subcc	%g7, 1, %g7
+		bl	Lend_regular_divide
+		 nop
+
+		sub	%o3, %o5, %o3
+		mov	1, %o2
+
+		b	Lend_single_divloop
+		 nop
+	Lsingle_divloop:
+		sll	%o2, 1, %o2
+		bl	1f
+		 srl	%o5, 1, %o5
+		! %o3 >= 0
+		sub	%o3, %o5, %o3
+		b	2f
+		 add	%o2, 1, %o2
+	1:	! %o3 < 0
+		add	%o3, %o5, %o3
+		sub	%o2, 1, %o2
+	2:
+	Lend_single_divloop:
+		subcc	%g7, 1, %g7
+		bge	Lsingle_divloop
+		 tst	%o3
+
+		b,a	Lend_regular_divide
+
+Lnot_really_big:
+1:
+	sll	%o5, 4, %o5
+
+	cmp	%o5, %o3
+	bleu	1b
+	 addcc	%o4, 1, %o4
+
+	be	Lgot_result
+	 sub	%o4, 1, %o4
+
+	tst	%o3	! set up for initial iteration
+Ldivloop:
+	sll	%o2, 4, %o2
+		! depth 1, accumulated bits 0
+	bl	L.1.16
+	 srl	%o5,1,%o5
+	! remainder is positive
+	subcc	%o3,%o5,%o3
+			! depth 2, accumulated bits 1
+	bl	L.2.17
+	 srl	%o5,1,%o5
+	! remainder is positive
+	subcc	%o3,%o5,%o3
+			! depth 3, accumulated bits 3
+	bl	L.3.19
+	 srl	%o5,1,%o5
+	! remainder is positive
+	subcc	%o3,%o5,%o3
+			! depth 4, accumulated bits 7
+	bl	L.4.23
+	 srl	%o5,1,%o5
+	! remainder is positive
+	subcc	%o3,%o5,%o3
+	b	9f
+	 add	%o2, (7*2+1), %o2
+
+L.4.23:
+	! remainder is negative
+	addcc	%o3,%o5,%o3
+	b	9f
+	 add	%o2, (7*2-1), %o2
+
+L.3.19:
+	! remainder is negative
+	addcc	%o3,%o5,%o3
+			! depth 4, accumulated bits 5
+	bl	L.4.21
+	 srl	%o5,1,%o5
+	! remainder is positive
+	subcc	%o3,%o5,%o3
+	b	9f
+	 add	%o2, (5*2+1), %o2
+
+L.4.21:
+	! remainder is negative
+	addcc	%o3,%o5,%o3
+	b	9f
+	 add	%o2, (5*2-1), %o2
+
+L.2.17:
+	! remainder is negative
+	addcc	%o3,%o5,%o3
+			! depth 3, accumulated bits 1
+	bl	L.3.17
+	 srl	%o5,1,%o5
+	! remainder is positive
+	subcc	%o3,%o5,%o3
+			! depth 4, accumulated bits 3
+	bl	L.4.19
+	 srl	%o5,1,%o5
+	! remainder is positive
+	subcc	%o3,%o5,%o3
+	b	9f
+	 add	%o2, (3*2+1), %o2
+
+L.4.19:
+	! remainder is negative
+	addcc	%o3,%o5,%o3
+	b	9f
+	 add	%o2, (3*2-1), %o2
+
+L.3.17:
+	! remainder is negative
+	addcc	%o3,%o5,%o3
+			! depth 4, accumulated bits 1
+	bl	L.4.17
+	 srl	%o5,1,%o5
+	! remainder is positive
+	subcc	%o3,%o5,%o3
+	b	9f
+	 add	%o2, (1*2+1), %o2
+
+L.4.17:
+	! remainder is negative
+	addcc	%o3,%o5,%o3
+	b	9f
+	 add	%o2, (1*2-1), %o2
+
+L.1.16:
+	! remainder is negative
+	addcc	%o3,%o5,%o3
+			! depth 2, accumulated bits -1
+	bl	L.2.15
+	 srl	%o5,1,%o5
+	! remainder is positive
+	subcc	%o3,%o5,%o3
+			! depth 3, accumulated bits -1
+	bl	L.3.15
+	 srl	%o5,1,%o5
+	! remainder is positive
+	subcc	%o3,%o5,%o3
+			! depth 4, accumulated bits -1
+	bl	L.4.15
+	 srl	%o5,1,%o5
+	! remainder is positive
+	subcc	%o3,%o5,%o3
+	b	9f
+	 add	%o2, (-1*2+1), %o2
+
+L.4.15:
+	! remainder is negative
+	addcc	%o3,%o5,%o3
+	b	9f
+	 add	%o2, (-1*2-1), %o2
+
+L.3.15:
+	! remainder is negative
+	addcc	%o3,%o5,%o3
+			! depth 4, accumulated bits -3
+	bl	L.4.13
+	 srl	%o5,1,%o5
+	! remainder is positive
+	subcc	%o3,%o5,%o3
+	b	9f
+	 add	%o2, (-3*2+1), %o2
+
+L.4.13:
+	! remainder is negative
+	addcc	%o3,%o5,%o3
+	b	9f
+	 add	%o2, (-3*2-1), %o2
+
+L.2.15:
+	! remainder is negative
+	addcc	%o3,%o5,%o3
+			! depth 3, accumulated bits -3
+	bl	L.3.13
+	 srl	%o5,1,%o5
+	! remainder is positive
+	subcc	%o3,%o5,%o3
+			! depth 4, accumulated bits -5
+	bl	L.4.11
+	 srl	%o5,1,%o5
+	! remainder is positive
+	subcc	%o3,%o5,%o3
+	b	9f
+	 add	%o2, (-5*2+1), %o2
+
+L.4.11:
+	! remainder is negative
+	addcc	%o3,%o5,%o3
+	b	9f
+	 add	%o2, (-5*2-1), %o2
+
+L.3.13:
+	! remainder is negative
+	addcc	%o3,%o5,%o3
+			! depth 4, accumulated bits -7
+	bl	L.4.9
+	 srl	%o5,1,%o5
+	! remainder is positive
+	subcc	%o3,%o5,%o3
+	b	9f
+	 add	%o2, (-7*2+1), %o2
+
+L.4.9:
+	! remainder is negative
+	addcc	%o3,%o5,%o3
+	b	9f
+	 add	%o2, (-7*2-1), %o2
+
+	9:
+Lend_regular_divide:
+	subcc	%o4, 1, %o4
+	bge	Ldivloop
+	 tst	%o3
+
+	bl,a	Lgot_result
+	! non-restoring fixup here (one instruction only!)
+	sub	%o2, 1, %o2
+
+Lgot_result:
+
+	retl
+	 mov %o2, %o0
+
+	.globl	.udiv_patch
+.udiv_patch:
+	wr	%g0, 0x0, %y
+	nop
+	nop
+	retl
+	 udiv	%o0, %o1, %o0
+	nop