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-rw-r--r--sysdeps/sparc/sparc32/sdiv.S365
1 files changed, 11 insertions, 354 deletions
diff --git a/sysdeps/sparc/sparc32/sdiv.S b/sysdeps/sparc/sparc32/sdiv.S
index ab29718827..bfc4acf2fa 100644
--- a/sysdeps/sparc/sparc32/sdiv.S
+++ b/sysdeps/sparc/sparc32/sdiv.S
@@ -1,363 +1,20 @@
-   /* 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.
+ * Sparc v8 has divide.
  */
 
-/*
- * 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 <sysdep.h>
-#include <sys/trap.h>
 
 ENTRY(.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	ST_DIV0
-		retl
-		clr	%o0
-
-1:
-	cmp	%o3, %o5			! if %o1 exceeds %o0, done
-	blu	LOC(got_result)		! (and algorithm fails otherwise)
-	clr	%o2
-	sethi	%hi(1 << (32 - 4 - 1)), %g1
-	cmp	%o3, %g1
-	blu	LOC(not_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	LOC(not_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	LOC(do_single_div)
-		sub	%g2, 1, %g2
-
-	LOC(not_too_big):
-	3:	cmp	%o5, %o3
-		blu	2b
-		nop
-		be	LOC(do_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...
-	LOC(do_single_div):
-		subcc	%g2, 1, %g2
-		bl	LOC(end_regular_divide)
-		nop
-		sub	%o3, %o5, %o3
-		mov	1, %o2
-		b	LOC(end_single_divloop)
-		nop
-	LOC(single_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:
-	LOC(end_single_divloop):
-		subcc	%g2, 1, %g2
-		bge	LOC(single_divloop)
-		tst	%o3
-		b,a	LOC(end_regular_divide)
-
-LOC(not_really_big):
-1:
-	sll	%o5, 4, %o5
-	cmp	%o5, %o3
-	bleu	1b
-	addcc	%o4, 1, %o4
-	be	LOC(got_result)
-	sub	%o4, 1, %o4
-
-	tst	%o3	! set up for initial iteration
-LOC(divloop):
-	sll	%o2, 4, %o2
-		! depth 1, accumulated bits 0
-	bl	LOC(1.16)
-	srl	%o5,1,%o5
-	! remainder is positive
-	subcc	%o3,%o5,%o3
-			! depth 2, accumulated bits 1
-	bl	LOC(2.17)
-	srl	%o5,1,%o5
-	! remainder is positive
-	subcc	%o3,%o5,%o3
-			! depth 3, accumulated bits 3
-	bl	LOC(3.19)
-	srl	%o5,1,%o5
-	! remainder is positive
-	subcc	%o3,%o5,%o3
-			! depth 4, accumulated bits 7
-	bl	LOC(4.23)
-	srl	%o5,1,%o5
-	! remainder is positive
-	subcc	%o3,%o5,%o3
-		b	9f
-		add	%o2, (7*2+1), %o2
-
-LOC(4.23):
-	! remainder is negative
-	addcc	%o3,%o5,%o3
-		b	9f
-		add	%o2, (7*2-1), %o2
-
-
-LOC(3.19):
-	! remainder is negative
-	addcc	%o3,%o5,%o3
-			! depth 4, accumulated bits 5
-	bl	LOC(4.21)
-	srl	%o5,1,%o5
-	! remainder is positive
-	subcc	%o3,%o5,%o3
-		b	9f
-		add	%o2, (5*2+1), %o2
-
-LOC(4.21):
-	! remainder is negative
-	addcc	%o3,%o5,%o3
-		b	9f
-		add	%o2, (5*2-1), %o2
-
-
-
-LOC(2.17):
-	! remainder is negative
-	addcc	%o3,%o5,%o3
-			! depth 3, accumulated bits 1
-	bl	LOC(3.17)
-	srl	%o5,1,%o5
-	! remainder is positive
-	subcc	%o3,%o5,%o3
-			! depth 4, accumulated bits 3
-	bl	LOC(4.19)
-	srl	%o5,1,%o5
-	! remainder is positive
-	subcc	%o3,%o5,%o3
-		b	9f
-		add	%o2, (3*2+1), %o2
-
-LOC(4.19):
-	! remainder is negative
-	addcc	%o3,%o5,%o3
-		b	9f
-		add	%o2, (3*2-1), %o2
-
-
-LOC(3.17):
-	! remainder is negative
-	addcc	%o3,%o5,%o3
-			! depth 4, accumulated bits 1
-	bl	LOC(4.17)
-	srl	%o5,1,%o5
-	! remainder is positive
-	subcc	%o3,%o5,%o3
-		b	9f
-		add	%o2, (1*2+1), %o2
-
-LOC(4.17):
-	! remainder is negative
-	addcc	%o3,%o5,%o3
-		b	9f
-		add	%o2, (1*2-1), %o2
-
-
-
-
-LOC(1.16):
-	! remainder is negative
-	addcc	%o3,%o5,%o3
-			! depth 2, accumulated bits -1
-	bl	LOC(2.15)
-	srl	%o5,1,%o5
-	! remainder is positive
-	subcc	%o3,%o5,%o3
-			! depth 3, accumulated bits -1
-	bl	LOC(3.15)
-	srl	%o5,1,%o5
-	! remainder is positive
-	subcc	%o3,%o5,%o3
-			! depth 4, accumulated bits -1
-	bl	LOC(4.15)
-	srl	%o5,1,%o5
-	! remainder is positive
-	subcc	%o3,%o5,%o3
-		b	9f
-		add	%o2, (-1*2+1), %o2
-
-LOC(4.15):
-	! remainder is negative
-	addcc	%o3,%o5,%o3
-		b	9f
-		add	%o2, (-1*2-1), %o2
-
-
-LOC(3.15):
-	! remainder is negative
-	addcc	%o3,%o5,%o3
-			! depth 4, accumulated bits -3
-	bl	LOC(4.13)
-	srl	%o5,1,%o5
-	! remainder is positive
-	subcc	%o3,%o5,%o3
-		b	9f
-		add	%o2, (-3*2+1), %o2
-
-LOC(4.13):
-	! remainder is negative
-	addcc	%o3,%o5,%o3
-		b	9f
-		add	%o2, (-3*2-1), %o2
-
-
-
-LOC(2.15):
-	! remainder is negative
-	addcc	%o3,%o5,%o3
-			! depth 3, accumulated bits -3
-	bl	LOC(3.13)
-	srl	%o5,1,%o5
-	! remainder is positive
-	subcc	%o3,%o5,%o3
-			! depth 4, accumulated bits -5
-	bl	LOC(4.11)
-	srl	%o5,1,%o5
-	! remainder is positive
-	subcc	%o3,%o5,%o3
-		b	9f
-		add	%o2, (-5*2+1), %o2
-
-LOC(4.11):
-	! remainder is negative
-	addcc	%o3,%o5,%o3
-		b	9f
-		add	%o2, (-5*2-1), %o2
-
-
-LOC(3.13):
-	! remainder is negative
-	addcc	%o3,%o5,%o3
-			! depth 4, accumulated bits -7
-	bl	LOC(4.9)
-	srl	%o5,1,%o5
-	! remainder is positive
-	subcc	%o3,%o5,%o3
-		b	9f
-		add	%o2, (-7*2+1), %o2
-
-LOC(4.9):
-	! remainder is negative
-	addcc	%o3,%o5,%o3
-		b	9f
-		add	%o2, (-7*2-1), %o2
-
-
-
-
-9:
-LOC(end_regular_divide):
-	subcc	%o4, 1, %o4
-	bge	LOC(divloop)
-	tst	%o3
-	bl,a	LOC(got_result)
-	! non-restoring fixup here (one instruction only!)
-	sub	%o2, 1, %o2
-
 
-LOC(got_result):
-	! check to see if answer should be < 0
-	tst	%g3
-	bl,a	1f
-	sub %g0, %o2, %o2
-1:
-	retl
-	mov %o2, %o0
+	sra	%o0, 31, %o2
+	wr	%o2, 0, %y
+	nop
+	nop
+	nop
+	sdivcc	%o0, %o1, %o0
+	bvs,a	1f
+	 xnor	%o0, %g0, %o0
+1:	retl
+	 nop
 
 END(.div)