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| author | "Steven J. Hill" <sjhill@realitydiluted.com> | 2005-08-26 00:53:46 +0000 | 
|---|---|---|
| committer | "Steven J. Hill" <sjhill@realitydiluted.com> | 2005-08-26 00:53:46 +0000 | 
| commit | bb35aec076a113b3fc8e92ea307f482e02571aae (patch) | |
| tree | d2e3faf6948d436e3444b84381dc0fd56ef38568 /libc/sysdeps/linux/sparc/udiv.S | |
| parent | 62452e396bf7f941bc61386f13b2bf73f04ff3fa (diff) | |
| download | uClibc-alpine-bb35aec076a113b3fc8e92ea307f482e02571aae.tar.bz2 uClibc-alpine-bb35aec076a113b3fc8e92ea307f482e02571aae.tar.xz  | |
Sync with trunk.
Diffstat (limited to 'libc/sysdeps/linux/sparc/udiv.S')
| -rw-r--r-- | libc/sysdeps/linux/sparc/udiv.S | 357 | 
1 files changed, 9 insertions, 348 deletions
diff --git a/libc/sysdeps/linux/sparc/udiv.S b/libc/sysdeps/linux/sparc/udiv.S index 85eeb40fc..a1355a761 100644 --- a/libc/sysdeps/linux/sparc/udiv.S +++ b/libc/sysdeps/linux/sparc/udiv.S @@ -1,348 +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: - *  .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. - */ - - - -#include <sys/syscall.h> - -.global   .udiv; -.align 4; -.type  .udiv ,@function;  - -.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	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: - -	retl -	mov %o2, %o0 - -.size .udiv,.-.udiv; +#include "_math_inc.h" + +#if defined(__CONFIG_SPARC_V9__) || defined(__CONFIG_SPARC_V9B__) +# include "sparcv9/udiv.S" +#elif defined(__CONFIG_SPARC_V8__) +# include "sparcv8/udiv.S" +#else +# include "sparcv7/udiv.S" +#endif  | 
