patch-2.1.9 linux/arch/sparc/lib/sdiv.S

• Lines: 431
• Date: Sat Nov 9 10:12:08 1996
• Orig file: v2.1.8/linux/arch/sparc/lib/sdiv.S
• Orig date: Sat Nov 25 02:59:06 1995

diff -u --recursive --new-file v2.1.8/linux/arch/sparc/lib/sdiv.S linux/arch/sparc/lib/sdiv.S
@@ -1,4 +1,4 @@
-/* $Id: sdiv.S,v 1.2 1995/11/25 00:59:04 davem Exp $
+/* $Id: sdiv.S,v 1.6 1996/10/02 17:37:00 davem Exp $
  * sdiv.S:      This routine was taken from glibc-1.09 and is covered
  *              by the GNU Library General Public License Version 2.
  */
@@ -47,13 +47,14 @@
 	! 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, %g6	! compute sign in any case
+	 xor	%o1, %o0, %g2	! compute sign in any case
+
 	tst	%o1
 	bge	1f
-	tst	%o0
+	 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
+	 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:
@@ -61,22 +62,24 @@
 	! Ready to divide.  Compute size of quotient; scale comparand.
 	orcc	%o1, %g0, %o5
 	bne	1f
-	mov	%o0, %o3
+	 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
+		 clr	%o0
 
 1:
 	cmp	%o3, %o5			! if %o1 exceeds %o0, done
 	blu	Lgot_result		! (and algorithm fails otherwise)
-	clr	%o2
+	 clr	%o2
+
 	sethi	%hi(1 << (32 - 4 - 1)), %g1
+
 	cmp	%o3, %g1
 	blu	Lnot_really_big
-	clr	%o4
+	 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.
@@ -86,15 +89,18 @@
 	1:
 		cmp	%o5, %g1
 		bgeu	3f
-		mov	1, %g7
+		 mov	1, %g7
+
 		sll	%o5, 4, %o5
+
 		b	1b
-		add	%o4, 1, %o4
+		 add	%o4, 1, %o4
 
 	! Now compute %g7.
-	2:	addcc	%o5, %o5, %o5
+	2:
+		addcc	%o5, %o5, %o5
 		bcc	Lnot_too_big
-		add	%g7, 1, %g7
+		 add	%g7, 1, %g7
 
 		! We get here if the %o1 overflowed while shifting.
 		! This means that %o3 has the high-order bit set.
@@ -102,15 +108,18 @@
 		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
+		 sub	%g7, 1, %g7
 
 	Lnot_too_big:
-	3:	cmp	%o5, %o3
+	3:
+		cmp	%o5, %o3
 		blu	2b
-		nop
+		 nop
+
 		be	Ldo_single_div
-		nop
+		 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
@@ -127,19 +136,23 @@
 	Ldo_single_div:
 		subcc	%g7, 1, %g7
 		bl	Lend_regular_divide
-		nop
+		 nop
+
 		sub	%o3, %o5, %o3
 		mov	1, %o2
+
 		b	Lend_single_divloop
-		nop
+		 nop
 	Lsingle_divloop:
 		sll	%o2, 1, %o2
+
 		bl	1f
-		srl	%o5, 1, %o5
+		 srl	%o5, 1, %o5
 		! %o3 >= 0
 		sub	%o3, %o5, %o3
+
 		b	2f
-		add	%o2, 1, %o2
+		 add	%o2, 1, %o2
 	1:	! %o3 < 0
 		add	%o3, %o5, %o3
 		sub	%o2, 1, %o2
@@ -147,7 +160,8 @@
 	Lend_single_divloop:
 		subcc	%g7, 1, %g7
 		bge	Lsingle_divloop
-		tst	%o3
+		 tst	%o3
+
 		b,a	Lend_regular_divide
 
 Lnot_really_big:
@@ -155,83 +169,81 @@
 	sll	%o5, 4, %o5
 	cmp	%o5, %o3
 	bleu	1b
-	addcc	%o4, 1, %o4
+	 addcc	%o4, 1, %o4
+
 	be	Lgot_result
-	sub	%o4, 1, %o4
+	 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
+	 srl	%o5,1,%o5
 	! remainder is positive
 	subcc	%o3,%o5,%o3
 			! depth 2, accumulated bits 1
 	bl	L.2.17
-	srl	%o5,1,%o5
+	 srl	%o5,1,%o5
 	! remainder is positive
 	subcc	%o3,%o5,%o3
 			! depth 3, accumulated bits 3
 	bl	L.3.19
-	srl	%o5,1,%o5
+	 srl	%o5,1,%o5
 	! remainder is positive
 	subcc	%o3,%o5,%o3
 			! depth 4, accumulated bits 7
 	bl	L.4.23
-	srl	%o5,1,%o5
+	 srl	%o5,1,%o5
 	! remainder is positive
 	subcc	%o3,%o5,%o3
-		b	9f
-		add	%o2, (7*2+1), %o2
-	
+	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
-	
-	
+	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
+	 srl	%o5,1,%o5
 	! remainder is positive
 	subcc	%o3,%o5,%o3
-		b	9f
-		add	%o2, (5*2+1), %o2
-	
+	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
-	
-	
-	
+	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
+	 srl	%o5,1,%o5
 	! remainder is positive
 	subcc	%o3,%o5,%o3
 			! depth 4, accumulated bits 3
 	bl	L.4.19
-	srl	%o5,1,%o5
+	 srl	%o5,1,%o5
 	! remainder is positive
 	subcc	%o3,%o5,%o3
-		b	9f
-		add	%o2, (3*2+1), %o2
-	
+	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
+	b	9f
+	 add	%o2, (3*2-1), %o2
 	
 	
 L.3.17:
@@ -239,126 +251,129 @@
 	addcc	%o3,%o5,%o3
 			! depth 4, accumulated bits 1
 	bl	L.4.17
-	srl	%o5,1,%o5
+	 srl	%o5,1,%o5
 	! remainder is positive
 	subcc	%o3,%o5,%o3
-		b	9f
-		add	%o2, (1*2+1), %o2
-	
+	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
-	
-	
-	
-	
+	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
+	 srl	%o5,1,%o5
 	! remainder is positive
 	subcc	%o3,%o5,%o3
 			! depth 3, accumulated bits -1
 	bl	L.3.15
-	srl	%o5,1,%o5
+	 srl	%o5,1,%o5
 	! remainder is positive
 	subcc	%o3,%o5,%o3
 			! depth 4, accumulated bits -1
 	bl	L.4.15
-	srl	%o5,1,%o5
+	 srl	%o5,1,%o5
 	! remainder is positive
 	subcc	%o3,%o5,%o3
-		b	9f
-		add	%o2, (-1*2+1), %o2
-	
+	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
-	
-	
+	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
+	 srl	%o5,1,%o5
 	! remainder is positive
 	subcc	%o3,%o5,%o3
-		b	9f
-		add	%o2, (-3*2+1), %o2
-	
+	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
-	
-	
-	
+	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
+	 srl	%o5,1,%o5
 	! remainder is positive
 	subcc	%o3,%o5,%o3
 			! depth 4, accumulated bits -5
 	bl	L.4.11
-	srl	%o5,1,%o5
+	 srl	%o5,1,%o5
 	! remainder is positive
 	subcc	%o3,%o5,%o3
-		b	9f
-		add	%o2, (-5*2+1), %o2
-	
+	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
-	
-	
+	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
+	 srl	%o5,1,%o5
 	! remainder is positive
 	subcc	%o3,%o5,%o3
-		b	9f
-		add	%o2, (-7*2+1), %o2
-	
+	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
-	
-	
-	
-	
+	b	9f
+	 add	%o2, (-7*2-1), %o2
+
 	9:
 Lend_regular_divide:
 	subcc	%o4, 1, %o4
 	bge	Ldivloop
-	tst	%o3
+	 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	%g6
+	tst	%g2
 	bl,a	1f
-	sub %g0, %o2, %o2
+	 sub %g0, %o2, %o2
 1:
 	retl
-	mov %o2, %o0
+	 mov %o2, %o0
+
+	.globl	.div_patch
+.div_patch:
+	sra	%o0, 0x1f, %o2
+	wr	%o2, 0x0, %y
+	nop
+	nop
+	nop
+	sdivcc	%o0, %o1, %o0
+	bvs,a	1f
+	 xnor	%o0, %g0, %o0
+1:	retl
+	 nop