import different optimized versions of div funcs based upon target sparc arch

1 files changed, 9 insertions, 366 deletions

diff --git a/libc/sysdeps/linux/sparc/sdiv.S b/libc/sysdeps/linux/sparc/sdiv.S
index 8fdb7daf8..7e9a9c923 100644
--- a/libc/sysdeps/linux/sparc/sdiv.S
+++ b/libc/sysdeps/linux/sparc/sdiv.S
@@ -1,366 +1,9 @@
-   /* 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:
- *  .div	name of function to generate
- *  div		div=div => %o0 / %o1; div=rem => %o0 % %o1
- *  true		true=true => signed; true=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.
- */
-
-
-
-#include <sys/syscall.h>
-
-.global   .div;
-.align 4;
-.type  .div ,@function; 
-
-.div: 
-	! compute sign of result; if neither is negative, no problem
-	orcc	%o1, %o0, %g0	! either negative?
-	bge	2f			! no, go do the divide
-	xor	%o1, %o0, %g3	! compute sign in any case
-	tst	%o1
-	bge	1f
-	tst	%o0
-	! %o1 is definitely negative; %o0 might also be negative
-	bge	2f			! if %o0 not negative...
-	sub	%g0, %o1, %o1	! in any case, make %o1 nonneg
-1:	! %o0 is negative, %o1 is nonnegative
-	sub	%g0, %o0, %o0	! make %o0 nonnegative
-2:
-
-	! 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	0x02
-		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, %g2
-		sll	%o5, 4, %o5
-		b	1b
-		add	%o4, 1, %o4
-
-	! Now compute %g2.
-	2:	addcc	%o5, %o5, %o5
-		bcc	.Lnot_too_big
-		add	%g2, 1, %g2
-
-		! 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	%g2, 1, %g2
-
-	.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	%g2
-	! 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	%g2, 1, %g2
-		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	%g2, 1, %g2
-		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	.L1.16
-	srl	%o5,1,%o5
-	! remainder is positive
-	subcc	%o3,%o5,%o3
-			! depth 2, accumulated bits 1
-	bl	.L2.17
-	srl	%o5,1,%o5
-	! remainder is positive
-	subcc	%o3,%o5,%o3
-			! depth 3, accumulated bits 3
-	bl	.L3.19
-	srl	%o5,1,%o5
-	! remainder is positive
-	subcc	%o3,%o5,%o3
-			! depth 4, accumulated bits 7
-	bl	.L4.23
-	srl	%o5,1,%o5
-	! remainder is positive
-	subcc	%o3,%o5,%o3
-		b	9f
-		add	%o2, (7*2+1), %o2
-	
-.L4.23:
-	! remainder is negative
-	addcc	%o3,%o5,%o3
-		b	9f
-		add	%o2, (7*2-1), %o2
-	
-	
-.L3.19:
-	! remainder is negative
-	addcc	%o3,%o5,%o3
-			! depth 4, accumulated bits 5
-	bl	.L4.21
-	srl	%o5,1,%o5
-	! remainder is positive
-	subcc	%o3,%o5,%o3
-		b	9f
-		add	%o2, (5*2+1), %o2
-	
-.L4.21:
-	! remainder is negative
-	addcc	%o3,%o5,%o3
-		b	9f
-		add	%o2, (5*2-1), %o2
-	
-	
-	
-.L2.17:
-	! remainder is negative
-	addcc	%o3,%o5,%o3
-			! depth 3, accumulated bits 1
-	bl	.L3.17
-	srl	%o5,1,%o5
-	! remainder is positive
-	subcc	%o3,%o5,%o3
-			! depth 4, accumulated bits 3
-	bl	.L4.19
-	srl	%o5,1,%o5
-	! remainder is positive
-	subcc	%o3,%o5,%o3
-		b	9f
-		add	%o2, (3*2+1), %o2
-	
-.L4.19:
-	! remainder is negative
-	addcc	%o3,%o5,%o3
-		b	9f
-		add	%o2, (3*2-1), %o2
-	
-	
-.L3.17:
-	! remainder is negative
-	addcc	%o3,%o5,%o3
-			! depth 4, accumulated bits 1
-	bl	.L4.17
-	srl	%o5,1,%o5
-	! remainder is positive
-	subcc	%o3,%o5,%o3
-		b	9f
-		add	%o2, (1*2+1), %o2
-	
-.L4.17:
-	! remainder is negative
-	addcc	%o3,%o5,%o3
-		b	9f
-		add	%o2, (1*2-1), %o2
-	
-	
-	
-	
-.L1.16:
-	! remainder is negative
-	addcc	%o3,%o5,%o3
-			! depth 2, accumulated bits -1
-	bl	.L2.15
-	srl	%o5,1,%o5
-	! remainder is positive
-	subcc	%o3,%o5,%o3
-			! depth 3, accumulated bits -1
-	bl	.L3.15
-	srl	%o5,1,%o5
-	! remainder is positive
-	subcc	%o3,%o5,%o3
-			! depth 4, accumulated bits -1
-	bl	.L4.15
-	srl	%o5,1,%o5
-	! remainder is positive
-	subcc	%o3,%o5,%o3
-		b	9f
-		add	%o2, (-1*2+1), %o2
-	
-.L4.15:
-	! remainder is negative
-	addcc	%o3,%o5,%o3
-		b	9f
-		add	%o2, (-1*2-1), %o2
-	
-	
-.L3.15:
-	! remainder is negative
-	addcc	%o3,%o5,%o3
-			! depth 4, accumulated bits -3
-	bl	.L4.13
-	srl	%o5,1,%o5
-	! remainder is positive
-	subcc	%o3,%o5,%o3
-		b	9f
-		add	%o2, (-3*2+1), %o2
-	
-.L4.13:
-	! remainder is negative
-	addcc	%o3,%o5,%o3
-		b	9f
-		add	%o2, (-3*2-1), %o2
-	
-	
-	
-.L2.15:
-	! remainder is negative
-	addcc	%o3,%o5,%o3
-			! depth 3, accumulated bits -3
-	bl	.L3.13
-	srl	%o5,1,%o5
-	! remainder is positive
-	subcc	%o3,%o5,%o3
-			! depth 4, accumulated bits -5
-	bl	.L4.11
-	srl	%o5,1,%o5
-	! remainder is positive
-	subcc	%o3,%o5,%o3
-		b	9f
-		add	%o2, (-5*2+1), %o2
-	
-.L4.11:
-	! remainder is negative
-	addcc	%o3,%o5,%o3
-		b	9f
-		add	%o2, (-5*2-1), %o2
-	
-	
-.L3.13:
-	! remainder is negative
-	addcc	%o3,%o5,%o3
-			! depth 4, accumulated bits -7
-	bl	.L4.9
-	srl	%o5,1,%o5
-	! remainder is positive
-	subcc	%o3,%o5,%o3
-		b	9f
-		add	%o2, (-7*2+1), %o2
-	
-.L4.9:
-	! 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:
-	! check to see if answer should be < 0
-	tst	%g3
-	bl,a	1f
-	sub %g0, %o2, %o2
-1:
-	retl
-	mov %o2, %o0
-
-.size .div,.-.div;
+#include "_math_inc.h"
+
+#if defined(__CONFIG_SPARC_V9__) || defined(__CONFIG_SPARC_V9B__)
+# include "sparcv9/sdiv.S"
+#elif defined(__CONFIG_SPARC_V8__)
+# include "sparcv8/sdiv.S"
+#else
+# include "sparcv7/sdiv.S"
+#endif