about summary refs log tree commit diff
path: root/sysdeps/powerpc/powerpc32/power4/memcmp.S
diff options
context:
space:
mode:
Diffstat (limited to 'sysdeps/powerpc/powerpc32/power4/memcmp.S')
-rw-r--r--sysdeps/powerpc/powerpc32/power4/memcmp.S985
1 files changed, 985 insertions, 0 deletions
diff --git a/sysdeps/powerpc/powerpc32/power4/memcmp.S b/sysdeps/powerpc/powerpc32/power4/memcmp.S
new file mode 100644
index 0000000000..4715302739
--- /dev/null
+++ b/sysdeps/powerpc/powerpc32/power4/memcmp.S
@@ -0,0 +1,985 @@
+/* Optimized strcmp implementation for PowerPC64.
+   Copyright (C) 2003, 2006 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, write to the Free
+   Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston MA
+   02110-1301 USA.  */
+
+#include <sysdep.h>
+#include <bp-sym.h>
+#include <bp-asm.h>
+
+/* int [r3] memcmp (const char *s1 [r3], const char *s2 [r4], size_t size [r5])  */
+
+EALIGN (BP_SYM(memcmp), 4, 0)
+	CALL_MCOUNT
+
+#define rTMP	r0
+#define rRTN	r3
+#define rSTR1	r3	/* first string arg */
+#define rSTR2	r4	/* second string arg */
+#define rN	r5	/* max string length */
+#define rWORD1	r6	/* current word in s1 */
+#define rWORD2	r7	/* current word in s2 */
+#define rWORD3	r8	/* next word in s1 */
+#define rWORD4	r9	/* next word in s2 */
+#define rWORD5	r10	/* next word in s1 */
+#define rWORD6	r11	/* next word in s2 */
+#define rBITDIF	r12	/* bits that differ in s1 & s2 words */
+#define rWORD7	r30	/* next word in s1 */
+#define rWORD8	r31	/* next word in s2 */
+
+	xor	rTMP, rSTR2, rSTR1
+	cmplwi	cr6, rN, 0
+	cmplwi	cr1, rN, 12
+	clrlwi.	rTMP, rTMP, 30
+	clrlwi	rBITDIF, rSTR1, 30
+	cmplwi	cr5, rBITDIF, 0
+	beq-	cr6, L(zeroLength)
+	dcbt	0,rSTR1
+	dcbt	0,rSTR2
+/* If less than 8 bytes or not aligned, use the unaligned
+   byte loop.  */
+	blt	cr1, L(bytealigned)
+        stwu    1,-64(1)
+	cfi_adjust_cfa_offset(64)
+        stw     r31,48(1)	
+	cfi_offset(31,(48-64))
+        stw     r30,44(1)	
+	cfi_offset(30,(44-64))
+	bne	L(unaligned)
+/* At this point we know both strings have the same alignment and the
+   compare length is at least 8 bytes.  rBITDIF contains the low order
+   2 bits of rSTR1 and cr5 contains the result of the logical compare
+   of rBITDIF to 0.  If rBITDIF == 0 then we are already word 
+   aligned and can perform the word aligned loop.
+  
+   Otherwise we know the two strings have the same alignment (but not
+   yet word aligned).  So we force the string addresses to the next lower
+   word boundary and special case this first word using shift left to
+   eliminate bits preceeding the first byte.  Since we want to join the
+   normal (word aligned) compare loop, starting at the second word,
+   we need to adjust the length (rN) and special case the loop
+   versioning for the first word. This insures that the loop count is
+   correct and the first word (shifted) is in the expected register pair. */
+	.align 4
+L(samealignment):
+	clrrwi	rSTR1, rSTR1, 2
+	clrrwi	rSTR2, rSTR2, 2
+	beq	cr5, L(Waligned)
+	add	rN, rN, rBITDIF
+	slwi	r11, rBITDIF, 3
+	srwi	rTMP, rN, 4	 /* Divide by 16 */
+	andi.	rBITDIF, rN, 12  /* Get the word remainder */
+	lwz	rWORD1, 0(rSTR1)
+	lwz	rWORD2, 0(rSTR2)
+	cmplwi	cr1, rBITDIF, 8
+	cmplwi	cr7, rN, 16
+	clrlwi	rN, rN, 30
+	beq	L(dPs4)
+	mtctr   rTMP	/* Power4 wants mtctr 1st in dispatch group */
+	bgt	cr1, L(dPs3)
+	beq	cr1, L(dPs2)
+
+/* Remainder is 4 */
+	.align 3
+L(dsP1):
+	slw	rWORD5, rWORD1, r11
+	slw	rWORD6, rWORD2, r11
+	cmplw	cr5, rWORD5, rWORD6
+	blt	cr7, L(dP1x)
+/* Do something useful in this cycle since we have to branch anyway.  */
+	lwz	rWORD1, 4(rSTR1)
+	lwz	rWORD2, 4(rSTR2)
+	cmplw	cr0, rWORD1, rWORD2
+	b	L(dP1e)
+/* Remainder is 8 */
+	.align 4
+L(dPs2):
+	slw	rWORD5, rWORD1, r11
+	slw	rWORD6, rWORD2, r11
+	cmplw	cr6, rWORD5, rWORD6
+	blt	cr7, L(dP2x)
+/* Do something useful in this cycle since we have to branch anyway.  */
+	lwz	rWORD7, 4(rSTR1)
+	lwz	rWORD8, 4(rSTR2)
+	cmplw	cr5, rWORD7, rWORD8
+	b	L(dP2e)
+/* Remainder is 12 */
+	.align 4
+L(dPs3):
+	slw	rWORD3, rWORD1, r11
+	slw	rWORD4, rWORD2, r11
+	cmplw	cr1, rWORD3, rWORD4
+	b	L(dP3e)
+/* Count is a multiple of 16, remainder is 0 */
+	.align 4
+L(dPs4):
+	mtctr   rTMP	/* Power4 wants mtctr 1st in dispatch group */
+	slw	rWORD1, rWORD1, r11
+	slw	rWORD2, rWORD2, r11
+	cmplw	cr0, rWORD1, rWORD2
+	b	L(dP4e)
+
+/* At this point we know both strings are word aligned and the
+   compare length is at least 8 bytes.  */
+	.align 4
+L(Waligned):
+	andi.	rBITDIF, rN, 12  /* Get the word remainder */
+	srwi	rTMP, rN, 4	 /* Divide by 16 */
+	cmplwi	cr1, rBITDIF, 8
+	cmplwi	cr7, rN, 16
+	clrlwi	rN, rN, 30
+	beq	L(dP4)
+	bgt	cr1, L(dP3)
+	beq	cr1, L(dP2)
+		
+/* Remainder is 4 */
+	.align 4
+L(dP1):
+	mtctr   rTMP	/* Power4 wants mtctr 1st in dispatch group */
+/* Normally we'd use rWORD7/rWORD8 here, but since we might exit early
+   (8-15 byte compare), we want to use only volatile registers.  This
+   means we can avoid restoring non-volatile registers since we did not
+   change any on the early exit path.  The key here is the non-early
+   exit path only cares about the condition code (cr5), not about which 
+   register pair was used.  */
+	lwz	rWORD5, 0(rSTR1)
+	lwz	rWORD6, 0(rSTR2)
+	cmplw	cr5, rWORD5, rWORD6
+	blt	cr7, L(dP1x)
+	lwz	rWORD1, 4(rSTR1)
+	lwz	rWORD2, 4(rSTR2)
+	cmplw	cr0, rWORD1, rWORD2
+L(dP1e):
+	lwz	rWORD3, 8(rSTR1)
+	lwz	rWORD4, 8(rSTR2)
+	cmplw	cr1, rWORD3, rWORD4
+	lwz	rWORD5, 12(rSTR1)
+	lwz	rWORD6, 12(rSTR2)
+	cmplw	cr6, rWORD5, rWORD6
+	bne	cr5, L(dLcr5)
+	bne	cr0, L(dLcr0)
+	
+	lwzu	rWORD7, 16(rSTR1)
+	lwzu	rWORD8, 16(rSTR2)
+	bne	cr1, L(dLcr1)
+	cmplw	cr5, rWORD7, rWORD8
+	bdnz	L(dLoop)
+	bne	cr6, L(dLcr6)
+        lwz     r30,44(1)
+        lwz     r31,48(1)
+	.align 3
+L(dP1x):
+	slwi.	r12, rN, 3
+	bne	cr5, L(dLcr5)
+	subfic	rN, r12, 32	/* Shift count is 32 - (rN * 8).  */
+        lwz     1,0(1)
+	bne	L(d00)
+	li	rRTN, 0
+	blr
+		
+/* Remainder is 8 */
+	.align 4
+L(dP2):
+	mtctr   rTMP	/* Power4 wants mtctr 1st in dispatch group */
+	lwz	rWORD5, 0(rSTR1)
+	lwz	rWORD6, 0(rSTR2)
+	cmplw	cr6, rWORD5, rWORD6
+	blt	cr7, L(dP2x)
+	lwz	rWORD7, 4(rSTR1)
+	lwz	rWORD8, 4(rSTR2)
+	cmplw	cr5, rWORD7, rWORD8
+L(dP2e):
+	lwz	rWORD1, 8(rSTR1)
+	lwz	rWORD2, 8(rSTR2)
+	cmplw	cr0, rWORD1, rWORD2
+	lwz	rWORD3, 12(rSTR1)
+	lwz	rWORD4, 12(rSTR2)
+	cmplw	cr1, rWORD3, rWORD4
+	addi	rSTR1, rSTR1, 4
+	addi	rSTR2, rSTR2, 4
+	bne	cr6, L(dLcr6)
+	bne	cr5, L(dLcr5)
+	b	L(dLoop2)
+/* Again we are on a early exit path (16-23 byte compare), we want to
+   only use volatile registers and avoid restoring non-volatile
+   registers.  */
+	.align 4
+L(dP2x):
+	lwz	rWORD3, 4(rSTR1)
+	lwz	rWORD4, 4(rSTR2)
+	cmplw	cr5, rWORD3, rWORD4
+	slwi.	r12, rN, 3
+	bne	cr6, L(dLcr6)
+	addi	rSTR1, rSTR1, 4
+	addi	rSTR2, rSTR2, 4
+	bne	cr5, L(dLcr5)
+	subfic	rN, r12, 32	/* Shift count is 32 - (rN * 8).  */
+        lwz     1,0(1)
+	bne	L(d00)
+	li	rRTN, 0
+	blr
+		
+/* Remainder is 12 */
+	.align 4
+L(dP3):
+	mtctr   rTMP	/* Power4 wants mtctr 1st in dispatch group */
+	lwz	rWORD3, 0(rSTR1)
+	lwz	rWORD4, 0(rSTR2)
+	cmplw	cr1, rWORD3, rWORD4
+L(dP3e):
+	lwz	rWORD5, 4(rSTR1)
+	lwz	rWORD6, 4(rSTR2)
+	cmplw	cr6, rWORD5, rWORD6
+	blt	cr7, L(dP3x)
+	lwz	rWORD7, 8(rSTR1)
+	lwz	rWORD8, 8(rSTR2)
+	cmplw	cr5, rWORD7, rWORD8
+	lwz	rWORD1, 12(rSTR1)
+	lwz	rWORD2, 12(rSTR2)
+	cmplw	cr0, rWORD1, rWORD2
+	addi	rSTR1, rSTR1, 8
+	addi	rSTR2, rSTR2, 8
+	bne	cr1, L(dLcr1)
+	bne	cr6, L(dLcr6)
+	b	L(dLoop1)
+/* Again we are on a early exit path (24-31 byte compare), we want to
+   only use volatile registers and avoid restoring non-volatile
+   registers.  */
+	.align 4
+L(dP3x):
+	lwz	rWORD1, 8(rSTR1)
+	lwz	rWORD2, 8(rSTR2)
+	cmplw	cr5, rWORD1, rWORD2
+	slwi.	r12, rN, 3
+	bne	cr1, L(dLcr1)
+	addi	rSTR1, rSTR1, 8
+	addi	rSTR2, rSTR2, 8
+	bne	cr6, L(dLcr6)
+	subfic	rN, r12, 32	/* Shift count is 32 - (rN * 8).  */
+	bne	cr5, L(dLcr5)
+        lwz     1,0(1)
+	bne	L(d00)
+	li	rRTN, 0
+	blr
+	
+/* Count is a multiple of 16, remainder is 0 */
+	.align 4
+L(dP4):
+	mtctr   rTMP	/* Power4 wants mtctr 1st in dispatch group */
+	lwz	rWORD1, 0(rSTR1)
+	lwz	rWORD2, 0(rSTR2)
+	cmplw	cr0, rWORD1, rWORD2
+L(dP4e):
+	lwz	rWORD3, 4(rSTR1)
+	lwz	rWORD4, 4(rSTR2)
+	cmplw	cr1, rWORD3, rWORD4
+	lwz	rWORD5, 8(rSTR1)
+	lwz	rWORD6, 8(rSTR2)
+	cmplw	cr6, rWORD5, rWORD6
+	lwzu	rWORD7, 12(rSTR1)
+	lwzu	rWORD8, 12(rSTR2)
+	cmplw	cr5, rWORD7, rWORD8
+	bne	cr0, L(dLcr0)
+	bne	cr1, L(dLcr1)
+	bdz-	L(d24)		/* Adjust CTR as we start with +4 */
+/* This is the primary loop */
+	.align 4
+L(dLoop):
+	lwz	rWORD1, 4(rSTR1)
+	lwz	rWORD2, 4(rSTR2)
+	cmplw	cr1, rWORD3, rWORD4
+	bne	cr6, L(dLcr6)
+L(dLoop1):
+	lwz	rWORD3, 8(rSTR1)
+	lwz	rWORD4, 8(rSTR2)
+	cmplw	cr6, rWORD5, rWORD6
+	bne	cr5, L(dLcr5)
+L(dLoop2):
+	lwz	rWORD5, 12(rSTR1)
+	lwz	rWORD6, 12(rSTR2)
+	cmplw	cr5, rWORD7, rWORD8
+	bne	cr0, L(dLcr0)
+L(dLoop3):
+	lwzu	rWORD7, 16(rSTR1)
+	lwzu	rWORD8, 16(rSTR2)
+	bne-	cr1, L(dLcr1)
+	cmplw	cr0, rWORD1, rWORD2
+	bdnz+	L(dLoop)	
+	
+L(dL4):
+	cmplw	cr1, rWORD3, rWORD4
+	bne	cr6, L(dLcr6)
+	cmplw	cr6, rWORD5, rWORD6
+	bne	cr5, L(dLcr5)
+	cmplw	cr5, rWORD7, rWORD8
+L(d44):
+	bne	cr0, L(dLcr0)
+L(d34):
+	bne	cr1, L(dLcr1)
+L(d24):
+	bne	cr6, L(dLcr6)
+L(d14):
+	slwi.	r12, rN, 3
+	bne	cr5, L(dLcr5) 
+L(d04):
+        lwz     r30,44(1)
+        lwz     r31,48(1)
+        lwz     1,0(1)
+	subfic	rN, r12, 32	/* Shift count is 32 - (rN * 8).  */
+	beq	L(zeroLength)
+/* At this point we have a remainder of 1 to 3 bytes to compare.  Since
+   we are aligned it is safe to load the whole word, and use
+   shift right to eliminate bits beyond the compare length. */ 
+L(d00):
+	lwz	rWORD1, 4(rSTR1)
+	lwz	rWORD2, 4(rSTR2) 
+	srw	rWORD1, rWORD1, rN
+	srw	rWORD2, rWORD2, rN
+        cmplw   rWORD1,rWORD2
+        li      rRTN,0
+        beqlr
+        li      rRTN,1
+        bgtlr
+        li      rRTN,-1
+        blr
+
+	.align 4
+L(dLcr0):
+        lwz     r30,44(1)
+        lwz     r31,48(1)
+	li	rRTN, 1
+        lwz     1,0(1)
+	bgtlr	cr0
+	li	rRTN, -1
+	blr
+	.align 4
+L(dLcr1):
+        lwz     r30,44(1)
+        lwz     r31,48(1)
+	li	rRTN, 1
+        lwz     1,0(1)
+	bgtlr	cr1
+	li	rRTN, -1
+	blr
+	.align 4
+L(dLcr6):
+        lwz     r30,44(1)
+        lwz     r31,48(1)
+	li	rRTN, 1
+        lwz     1,0(1)
+	bgtlr	cr6
+	li	rRTN, -1
+	blr
+	.align 4
+L(dLcr5):
+        lwz     r30,44(1)
+        lwz     r31,48(1)
+L(dLcr5x):
+	li	rRTN, 1
+        lwz     1,0(1)
+	bgtlr	cr5
+	li	rRTN, -1
+	blr
+	
+	.align 4
+L(bytealigned):
+	cfi_adjust_cfa_offset(-64)
+	mtctr   rN	/* Power4 wants mtctr 1st in dispatch group */
+
+/* We need to prime this loop.  This loop is swing modulo scheduled
+   to avoid pipe delays.  The dependent instruction latencies (load to 
+   compare to conditional branch) is 2 to 3 cycles.  In this loop each
+   dispatch group ends in a branch and takes 1 cycle.  Effectively
+   the first iteration of the loop only serves to load operands and 
+   branches based on compares are delayed until the next loop. 
+
+   So we must precondition some registers and condition codes so that
+   we don't exit the loop early on the first iteration.  */
+   
+	lbz	rWORD1, 0(rSTR1)
+	lbz	rWORD2, 0(rSTR2)
+	bdz-	L(b11)
+	cmplw	cr0, rWORD1, rWORD2
+	lbz	rWORD3, 1(rSTR1)
+	lbz	rWORD4, 1(rSTR2)
+	bdz-	L(b12)
+	cmplw	cr1, rWORD3, rWORD4
+	lbzu	rWORD5, 2(rSTR1)
+	lbzu	rWORD6, 2(rSTR2)
+	bdz-	L(b13)
+	.align 4
+L(bLoop):
+	lbzu	rWORD1, 1(rSTR1)
+	lbzu	rWORD2, 1(rSTR2)
+	bne-	cr0, L(bLcr0)
+
+	cmplw	cr6, rWORD5, rWORD6
+	bdz-	L(b3i)
+	
+	lbzu	rWORD3, 1(rSTR1)
+	lbzu	rWORD4, 1(rSTR2)
+	bne-	cr1, L(bLcr1)
+
+	cmplw	cr0, rWORD1, rWORD2
+	bdz-	L(b2i)
+
+	lbzu	rWORD5, 1(rSTR1)
+	lbzu	rWORD6, 1(rSTR2)
+	bne-	cr6, L(bLcr6)
+
+	cmplw	cr1, rWORD3, rWORD4
+	bdnz+	L(bLoop)
+	
+/* We speculatively loading bytes before we have tested the previous
+   bytes.  But we must avoid overrunning the length (in the ctr) to
+   prevent these speculative loads from causing a segfault.  In this 
+   case the loop will exit early (before the all pending bytes are
+   tested.  In this case we must complete the pending operations
+   before returning.  */
+L(b1i):
+	bne-	cr0, L(bLcr0)
+	bne-	cr1, L(bLcr1)
+	b	L(bx56)
+	.align 4
+L(b2i):
+	bne-	cr6, L(bLcr6)
+	bne-	cr0, L(bLcr0)
+	b	L(bx34)
+	.align 4
+L(b3i):
+	bne-	cr1, L(bLcr1)
+	bne-	cr6, L(bLcr6)
+	b	L(bx12)
+	.align 4
+L(bLcr0):
+	li	rRTN, 1
+	bgtlr	cr0
+	li	rRTN, -1
+	blr
+L(bLcr1):
+	li	rRTN, 1
+	bgtlr	cr1
+	li	rRTN, -1
+	blr
+L(bLcr6):
+	li	rRTN, 1
+	bgtlr	cr6
+	li	rRTN, -1
+	blr
+
+L(b13):
+	bne-	cr0, L(bx12)
+	bne-	cr1, L(bx34)
+L(bx56):
+	sub	rRTN, rWORD5, rWORD6
+	blr
+	nop
+L(b12):
+	bne-	cr0, L(bx12)
+L(bx34):	
+	sub	rRTN, rWORD3, rWORD4
+	blr
+
+L(b11):
+L(bx12):
+	sub	rRTN, rWORD1, rWORD2
+	blr
+
+	.align 4 
+L(zeroLengthReturn):
+
+L(zeroLength):
+	li	rRTN, 0
+	blr
+
+	cfi_adjust_cfa_offset(64)
+	.align 4
+/* At this point we know the strings have different alignment and the
+   compare length is at least 8 bytes.  rBITDIF contains the low order
+   2 bits of rSTR1 and cr5 contains the result of the logical compare
+   of rBITDIF to 0.  If rBITDIF == 0 then rStr1 is word aligned and can 
+   perform the Wunaligned loop.
+  
+   Otherwise we know that rSTR1 is not aready word aligned yet.
+   So we can force the string addresses to the next lower word
+   boundary and special case this first word using shift left to
+   eliminate bits preceeding the first byte.  Since we want to join the
+   normal (Wualigned) compare loop, starting at the second word,
+   we need to adjust the length (rN) and special case the loop
+   versioning for the first W. This insures that the loop count is
+   correct and the first W (shifted) is in the expected resister pair.  */
+#define rSHL		r29	/* Unaligned shift left count.  */
+#define rSHR		r28	/* Unaligned shift right count.  */
+#define rB		r27	/* Left rotation temp for rWORD2.  */
+#define rD		r26	/* Left rotation temp for rWORD4.  */
+#define rF		r25	/* Left rotation temp for rWORD6.  */
+#define rH		r24	/* Left rotation temp for rWORD8.  */
+#define rA		r0	/* Right rotation temp for rWORD2.  */
+#define rC		r12	/* Right rotation temp for rWORD4.  */
+#define rE		r0	/* Right rotation temp for rWORD6.  */
+#define rG		r12	/* Right rotation temp for rWORD8.  */
+L(unaligned):
+	stw     r29,40(r1)	
+	cfi_offset(r29,(40-64))	
+	clrlwi	rSHL, rSTR2, 30
+        stw     r28,36(r1)	
+	cfi_offset(r28,(36-64))
+	beq	cr5, L(Wunaligned)
+        stw     r27,32(r1)	
+	cfi_offset(r27,(32-64))
+/* Adjust the logical start of rSTR2 to compensate for the extra bits
+   in the 1st rSTR1 W.  */
+	sub	r27, rSTR2, rBITDIF
+/* But do not attempt to address the W before that W that contains
+   the actual start of rSTR2.  */
+	clrrwi	rSTR2, rSTR2, 2
+        stw     r26,28(r1)	
+	cfi_offset(r26,(28-64))
+/* Compute the left/right shift counts for the unalign rSTR2,
+   compensating for the logical (W aligned) start of rSTR1.  */ 
+	clrlwi	rSHL, r27, 30
+	clrrwi	rSTR1, rSTR1, 2	
+        stw     r25,24(r1)	
+	cfi_offset(r25,(24-64))
+	slwi	rSHL, rSHL, 3
+	cmplw	cr5, r27, rSTR2
+	add	rN, rN, rBITDIF
+	slwi	r11, rBITDIF, 3
+        stw     r24,20(r1)	
+	cfi_offset(r24,(20-64))
+	subfic	rSHR, rSHL, 32
+	srwi	rTMP, rN, 4      /* Divide by 16 */
+	andi.	rBITDIF, rN, 12  /* Get the W remainder */
+/* We normally need to load 2 Ws to start the unaligned rSTR2, but in
+   this special case those bits may be discarded anyway.  Also we
+   must avoid loading a W where none of the bits are part of rSTR2 as
+   this may cross a page boundary and cause a page fault.  */
+	li	rWORD8, 0
+	blt	cr5, L(dus0)
+	lwz	rWORD8, 0(rSTR2)
+	la	rSTR2, 4(rSTR2)
+	slw	rWORD8, rWORD8, rSHL
+
+L(dus0):
+	lwz	rWORD1, 0(rSTR1)
+	lwz	rWORD2, 0(rSTR2)
+	cmplwi	cr1, rBITDIF, 8
+	cmplwi	cr7, rN, 16
+	srw	rG, rWORD2, rSHR
+	clrlwi	rN, rN, 30
+	beq	L(duPs4)
+	mtctr   rTMP	/* Power4 wants mtctr 1st in dispatch group */
+	or	rWORD8, rG, rWORD8
+	bgt	cr1, L(duPs3)
+	beq	cr1, L(duPs2)
+
+/* Remainder is 4 */
+	.align 4
+L(dusP1):
+	slw	rB, rWORD2, rSHL
+	slw	rWORD7, rWORD1, r11
+	slw	rWORD8, rWORD8, r11
+	bge	cr7, L(duP1e)
+/* At this point we exit early with the first word compare
+   complete and remainder of 0 to 3 bytes.  See L(du14) for details on
+   how we handle the remaining bytes.  */
+	cmplw	cr5, rWORD7, rWORD8
+	slwi.	rN, rN, 3
+	bne	cr5, L(duLcr5)
+	cmplw	cr7, rN, rSHR
+	beq	L(duZeroReturn)
+	li	rA, 0
+	ble	cr7, L(dutrim)
+	lwz	rWORD2, 4(rSTR2)
+	srw	rA, rWORD2, rSHR
+	b	L(dutrim)
+/* Remainder is 8 */
+	.align 4
+L(duPs2):
+	slw	rH, rWORD2, rSHL
+	slw	rWORD5, rWORD1, r11
+	slw	rWORD6, rWORD8, r11
+	b	L(duP2e)
+/* Remainder is 12 */
+	.align 4
+L(duPs3):
+	slw	rF, rWORD2, rSHL
+	slw	rWORD3, rWORD1, r11
+	slw	rWORD4, rWORD8, r11
+	b	L(duP3e)
+/* Count is a multiple of 16, remainder is 0 */
+	.align 4
+L(duPs4):
+	mtctr   rTMP	/* Power4 wants mtctr 1st in dispatch group */
+	or	rWORD8, rG, rWORD8
+	slw	rD, rWORD2, rSHL
+	slw	rWORD1, rWORD1, r11
+	slw	rWORD2, rWORD8, r11
+	b	L(duP4e)
+
+/* At this point we know rSTR1 is word aligned and the
+   compare length is at least 8 bytes.  */
+	.align 4
+L(Wunaligned):
+        stw     r27,32(r1)	
+	cfi_offset(r27,(32-64))
+	clrrwi	rSTR2, rSTR2, 2
+        stw     r26,28(r1)	
+	cfi_offset(r26,(28-64))
+	srwi	rTMP, rN, 4	 /* Divide by 16 */
+        stw     r25,24(r1)	
+	cfi_offset(r25,(24-64))
+	andi.	rBITDIF, rN, 12  /* Get the W remainder */
+        stw     r24,20(r1)	
+	cfi_offset(r24,(24-64))
+	slwi	rSHL, rSHL, 3
+	lwz	rWORD6, 0(rSTR2)
+	lwzu	rWORD8, 4(rSTR2)
+	cmplwi	cr1, rBITDIF, 8
+	cmplwi	cr7, rN, 16
+	clrlwi	rN, rN, 30
+	subfic	rSHR, rSHL, 32
+	slw	rH, rWORD6, rSHL
+	beq	L(duP4)
+	mtctr   rTMP	/* Power4 wants mtctr 1st in dispatch group */
+	bgt	cr1, L(duP3)
+	beq	cr1, L(duP2)
+		
+/* Remainder is 4 */
+	.align 4
+L(duP1):
+	srw	rG, rWORD8, rSHR
+	lwz	rWORD7, 0(rSTR1)
+	slw	rB, rWORD8, rSHL
+	or	rWORD8, rG, rH
+	blt	cr7, L(duP1x)
+L(duP1e):
+	lwz	rWORD1, 4(rSTR1)
+	lwz	rWORD2, 4(rSTR2)
+	cmplw	cr5, rWORD7, rWORD8
+	srw	rA, rWORD2, rSHR
+	slw	rD, rWORD2, rSHL
+	or	rWORD2, rA, rB
+	lwz	rWORD3, 8(rSTR1)
+	lwz	rWORD4, 8(rSTR2)
+	cmplw	cr0, rWORD1, rWORD2
+	srw	rC, rWORD4, rSHR
+	slw	rF, rWORD4, rSHL
+	bne	cr5, L(duLcr5)
+	or	rWORD4, rC, rD
+	lwz	rWORD5, 12(rSTR1)
+	lwz	rWORD6, 12(rSTR2)
+	cmplw	cr1, rWORD3, rWORD4
+	srw	rE, rWORD6, rSHR
+	slw	rH, rWORD6, rSHL
+	bne	cr0, L(duLcr0)
+	or	rWORD6, rE, rF
+	cmplw	cr6, rWORD5, rWORD6
+	b	L(duLoop3)	
+	.align 4
+/* At this point we exit early with the first word compare
+   complete and remainder of 0 to 3 bytes.  See L(du14) for details on
+   how we handle the remaining bytes.  */
+L(duP1x):
+	cmplw	cr5, rWORD7, rWORD8
+	slwi.	rN, rN, 3
+	bne	cr5, L(duLcr5)
+	cmplw	cr7, rN, rSHR
+	beq	L(duZeroReturn)
+	li	rA, 0
+	ble	cr7, L(dutrim)
+	ld	rWORD2, 8(rSTR2)
+	srw	rA, rWORD2, rSHR
+	b	L(dutrim)
+/* Remainder is 8 */
+	.align 4
+L(duP2):
+	srw	rE, rWORD8, rSHR
+	lwz	rWORD5, 0(rSTR1)
+	or	rWORD6, rE, rH
+	slw	rH, rWORD8, rSHL
+L(duP2e):
+	lwz	rWORD7, 4(rSTR1)
+	lwz	rWORD8, 4(rSTR2)
+	cmplw	cr6, rWORD5, rWORD6
+	srw	rG, rWORD8, rSHR
+	slw	rB, rWORD8, rSHL
+	or	rWORD8, rG, rH
+	blt	cr7, L(duP2x)
+	lwz	rWORD1, 8(rSTR1)
+	lwz	rWORD2, 8(rSTR2)
+	cmplw	cr5, rWORD7, rWORD8
+	bne	cr6, L(duLcr6)
+	srw	rA, rWORD2, rSHR
+	slw	rD, rWORD2, rSHL
+	or	rWORD2, rA, rB
+	lwz	rWORD3, 12(rSTR1)
+	lwz	rWORD4, 12(rSTR2)
+	cmplw	cr0, rWORD1, rWORD2
+	bne	cr5, L(duLcr5)
+	srw	rC, rWORD4, rSHR
+	slw	rF, rWORD4, rSHL
+	or	rWORD4, rC, rD
+	addi	rSTR1, rSTR1, 4
+	addi	rSTR2, rSTR2, 4
+	cmplw	cr1, rWORD3, rWORD4
+	b	L(duLoop2)
+	.align 4
+L(duP2x):
+	cmplw	cr5, rWORD7, rWORD8
+	addi	rSTR1, rSTR1, 4
+	addi	rSTR2, rSTR2, 4
+	bne	cr6, L(duLcr6)
+	slwi.	rN, rN, 3
+	bne	cr5, L(duLcr5)
+	cmplw	cr7, rN, rSHR
+	beq	L(duZeroReturn)
+	li	rA, 0
+	ble	cr7, L(dutrim)
+	lwz	rWORD2, 4(rSTR2)
+	srw	rA, rWORD2, rSHR
+	b	L(dutrim)
+		
+/* Remainder is 12 */
+	.align 4
+L(duP3):
+	srw	rC, rWORD8, rSHR
+	lwz	rWORD3, 0(rSTR1)
+	slw	rF, rWORD8, rSHL
+	or	rWORD4, rC, rH
+L(duP3e):
+	lwz	rWORD5, 4(rSTR1)
+	lwz	rWORD6, 4(rSTR2)
+	cmplw	cr1, rWORD3, rWORD4
+	srw	rE, rWORD6, rSHR
+	slw	rH, rWORD6, rSHL
+	or	rWORD6, rE, rF
+	lwz	rWORD7, 8(rSTR1)
+	lwz	rWORD8, 8(rSTR2)
+	cmplw	cr6, rWORD5, rWORD6
+	bne	cr1, L(duLcr1)
+	srw	rG, rWORD8, rSHR
+	slw	rB, rWORD8, rSHL
+	or	rWORD8, rG, rH
+	blt	cr7, L(duP3x)
+	lwz	rWORD1, 12(rSTR1)
+	lwz	rWORD2, 12(rSTR2)
+	cmplw	cr5, rWORD7, rWORD8
+	bne	cr6, L(duLcr6)
+	srw	rA, rWORD2, rSHR
+	slw	rD, rWORD2, rSHL
+	or	rWORD2, rA, rB
+	addi	rSTR1, rSTR1, 8
+	addi	rSTR2, rSTR2, 8
+	cmplw	cr0, rWORD1, rWORD2
+	b	L(duLoop1)
+	.align 4
+L(duP3x):
+	addi	rSTR1, rSTR1, 8
+	addi	rSTR2, rSTR2, 8
+	bne	cr1, L(duLcr1)
+	cmplw	cr5, rWORD7, rWORD8
+	bne	cr6, L(duLcr6)
+	slwi.	rN, rN, 3
+	bne	cr5, L(duLcr5)
+	cmplw	cr7, rN, rSHR
+	beq	L(duZeroReturn)
+	li	rA, 0
+	ble	cr7, L(dutrim)
+	lwz	rWORD2, 4(rSTR2)
+	srw	rA, rWORD2, rSHR
+	b	L(dutrim)
+	
+/* Count is a multiple of 16, remainder is 0 */
+	.align 4
+L(duP4):
+	mtctr   rTMP	/* Power4 wants mtctr 1st in dispatch group */
+	srw	rA, rWORD8, rSHR
+	lwz	rWORD1, 0(rSTR1)
+	slw	rD, rWORD8, rSHL
+	or	rWORD2, rA, rH
+L(duP4e):
+	lwz	rWORD3, 4(rSTR1)
+	lwz	rWORD4, 4(rSTR2)
+	cmplw	cr0, rWORD1, rWORD2
+	srw	rC, rWORD4, rSHR
+	slw	rF, rWORD4, rSHL
+	or	rWORD4, rC, rD
+	lwz	rWORD5, 8(rSTR1)
+	lwz	rWORD6, 8(rSTR2)
+	cmplw	cr1, rWORD3, rWORD4
+	bne	cr0, L(duLcr0)
+	srw	rE, rWORD6, rSHR
+	slw	rH, rWORD6, rSHL
+	or	rWORD6, rE, rF
+	lwzu	rWORD7, 12(rSTR1)
+	lwzu	rWORD8, 12(rSTR2)
+	cmplw	cr6, rWORD5, rWORD6
+	bne	cr1, L(duLcr1)
+	srw	rG, rWORD8, rSHR
+	slw	rB, rWORD8, rSHL
+	or	rWORD8, rG, rH
+	cmplw	cr5, rWORD7, rWORD8
+	bdz-	L(du24)		/* Adjust CTR as we start with +4 */
+/* This is the primary loop */
+	.align 4
+L(duLoop):
+	lwz	rWORD1, 4(rSTR1)
+	lwz	rWORD2, 4(rSTR2)
+	cmplw	cr1, rWORD3, rWORD4
+	bne	cr6, L(duLcr6)
+	srw	rA, rWORD2, rSHR
+	slw	rD, rWORD2, rSHL
+	or	rWORD2, rA, rB
+L(duLoop1):
+	lwz	rWORD3, 8(rSTR1)
+	lwz	rWORD4, 8(rSTR2)
+	cmplw	cr6, rWORD5, rWORD6
+	bne	cr5, L(duLcr5)
+	srw	rC, rWORD4, rSHR
+	slw	rF, rWORD4, rSHL
+	or	rWORD4, rC, rD
+L(duLoop2):
+	lwz	rWORD5, 12(rSTR1)
+	lwz	rWORD6, 12(rSTR2)
+	cmplw	cr5, rWORD7, rWORD8
+	bne	cr0, L(duLcr0)
+	srw	rE, rWORD6, rSHR
+	slw	rH, rWORD6, rSHL
+	or	rWORD6, rE, rF
+L(duLoop3):
+	lwzu	rWORD7, 16(rSTR1)
+	lwzu	rWORD8, 16(rSTR2)
+	cmplw	cr0, rWORD1, rWORD2
+	bne-	cr1, L(duLcr1)
+	srw	rG, rWORD8, rSHR
+	slw	rB, rWORD8, rSHL
+	or	rWORD8, rG, rH
+	bdnz+	L(duLoop)	
+	
+L(duL4):
+	bne	cr1, L(duLcr1)
+	cmplw	cr1, rWORD3, rWORD4
+	bne	cr6, L(duLcr6)
+	cmplw	cr6, rWORD5, rWORD6
+	bne	cr5, L(duLcr5)
+	cmplw	cr5, rWORD7, rWORD8
+L(du44):
+	bne	cr0, L(duLcr0)
+L(du34):
+	bne	cr1, L(duLcr1)
+L(du24):
+	bne	cr6, L(duLcr6)
+L(du14):
+	slwi.	rN, rN, 3
+	bne	cr5, L(duLcr5)
+/* At this point we have a remainder of 1 to 3 bytes to compare.  We use
+   shift right to eliminate bits beyond the compare length. 
+
+   However it may not be safe to load rWORD2 which may be beyond the 
+   string length. So we compare the bit length of the remainder to
+   the right shift count (rSHR). If the bit count is less than or equal
+   we do not need to load rWORD2 (all significant bits are already in
+   rB).  */
+	cmplw	cr7, rN, rSHR
+	beq	L(duZeroReturn)
+	li	rA, 0
+	ble	cr7, L(dutrim)
+	lwz	rWORD2, 4(rSTR2)
+	srw	rA, rWORD2, rSHR
+	.align 4
+L(dutrim):
+	lwz	rWORD1, 4(rSTR1)
+        lwz     r31,48(1)
+	subfic	rN, rN, 32	/* Shift count is 32 - (rN * 8).  */ 
+	or	rWORD2, rA, rB
+        lwz     r30,44(1)
+        lwz     r29,40(r1)
+	srw	rWORD1, rWORD1, rN
+	srw	rWORD2, rWORD2, rN
+        lwz     r28,36(r1)	
+        lwz     r27,32(r1)
+        cmplw   rWORD1,rWORD2
+        li      rRTN,0
+        beq     L(dureturn26)
+        li      rRTN,1
+        bgt     L(dureturn26)
+        li      rRTN,-1
+	b    L(dureturn26)
+	.align 4
+L(duLcr0):
+        lwz     r31,48(1)
+        lwz     r30,44(1)
+	li	rRTN, 1
+	bgt	cr0, L(dureturn29)	
+	lwz     r29,40(r1)
+        lwz     r28,36(r1)	
+	li	rRTN, -1
+	b	L(dureturn27)
+	.align 4
+L(duLcr1):
+        lwz     r31,48(1)
+        lwz     r30,44(1)
+	li	rRTN, 1
+	bgt	cr1, L(dureturn29)	
+        lwz     r29,40(r1)
+        lwz     r28,36(r1)	
+	li	rRTN, -1
+	b	L(dureturn27)
+	.align 4
+L(duLcr6):
+        lwz     r31,48(1)
+        lwz     r30,44(1)
+	li	rRTN, 1
+	bgt	cr6, L(dureturn29)	
+        lwz     r29,40(r1)
+        lwz     r28,36(r1)	
+	li	rRTN, -1
+	b	L(dureturn27)
+	.align 4
+L(duLcr5):
+        lwz     r31,48(1)
+        lwz     r30,44(1)
+	li	rRTN, 1
+	bgt	cr5, L(dureturn29)	
+        lwz     r29,40(r1)
+        lwz     r28,36(r1)	
+	li	rRTN, -1
+	b	L(dureturn27)
+	.align	3
+L(duZeroReturn):
+	li	rRTN,0
+	.align	4
+L(dureturn):
+        lwz     r31,48(1)
+        lwz     r30,44(1)
+L(dureturn29):	
+        lwz     r29,40(r1)
+        lwz     r28,36(r1)	
+L(dureturn27):	
+        lwz     r27,32(r1)
+L(dureturn26):	
+        lwz     r26,28(r1)
+L(dureturn25):	
+        lwz     r25,24(r1)
+        lwz     r24,20(r1)
+        lwz     1,0(1)
+	blr
+END (BP_SYM (memcmp))
+
+libc_hidden_builtin_def (memcmp)
+weak_alias (memcmp, bcmp)