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984 lines
22 KiB
ArmAsm
984 lines
22 KiB
ArmAsm
/* Optimized memcmp implementation for POWER7/PowerPC64.
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Copyright (C) 2010, 2011 Free Software Foundation, Inc.
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This file is part of the GNU C Library.
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The GNU C Library is free software; you can redistribute it and/or
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modify it under the terms of the GNU Lesser General Public
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License as published by the Free Software Foundation; either
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version 2.1 of the License, or (at your option) any later version.
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The GNU C Library is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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Lesser General Public License for more details.
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You should have received a copy of the GNU Lesser General Public
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License along with the GNU C Library; if not, see
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<http://www.gnu.org/licenses/>. */
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#include <sysdep.h>
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#include <bp-sym.h>
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#include <bp-asm.h>
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/* int [r3] memcmp (const char *s1 [r3],
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const char *s2 [r4],
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size_t size [r5]) */
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.machine power7
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EALIGN (BP_SYM(memcmp),4,0)
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CALL_MCOUNT 3
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#define rTMP r0
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#define rRTN r3
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#define rSTR1 r3 /* first string arg */
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#define rSTR2 r4 /* second string arg */
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#define rN r5 /* max string length */
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/* Note: The Bounded pointer support in this code is broken. This code
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was inherited from PPC32 and that support was never completed.
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Current PPC gcc does not support -fbounds-check or -fbounded-pointers. */
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#define rWORD1 r6 /* current word in s1 */
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#define rWORD2 r7 /* current word in s2 */
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#define rWORD3 r8 /* next word in s1 */
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#define rWORD4 r9 /* next word in s2 */
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#define rWORD5 r10 /* next word in s1 */
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#define rWORD6 r11 /* next word in s2 */
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#define rBITDIF r12 /* bits that differ in s1 & s2 words */
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#define rWORD7 r30 /* next word in s1 */
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#define rWORD8 r31 /* next word in s2 */
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xor rTMP,rSTR2,rSTR1
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cmpldi cr6,rN,0
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cmpldi cr1,rN,12
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clrldi. rTMP,rTMP,61
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clrldi rBITDIF,rSTR1,61
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cmpldi cr5,rBITDIF,0
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beq- cr6,L(zeroLength)
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dcbt 0,rSTR1
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dcbt 0,rSTR2
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/* If less than 8 bytes or not aligned, use the unalligned
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byte loop. */
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blt cr1,L(bytealigned)
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std rWORD8,-8(r1)
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cfi_offset(rWORD8,-8)
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std rWORD7,-16(r1)
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cfi_offset(rWORD7,-16)
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bne L(unaligned)
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/* At this point we know both strings have the same alignment and the
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compare length is at least 8 bytes. rBITDIF containes the low order
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3 bits of rSTR1 and cr5 contains the result of the logical compare
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of rBITDIF to 0. If rBITDIF == 0 then we are already double word
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aligned and can perform the DWaligned loop.
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Otherwise we know the two strings have the same alignment (but not
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yet DW). So we can force the string addresses to the next lower DW
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boundary and special case this first DW word using shift left to
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ellimiate bits preceeding the first byte. Since we want to join the
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normal (DWaligned) compare loop, starting at the second double word,
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we need to adjust the length (rN) and special case the loop
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versioning for the first DW. This insures that the loop count is
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correct and the first DW (shifted) is in the expected resister pair. */
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.align 4
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L(samealignment):
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clrrdi rSTR1,rSTR1,3
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clrrdi rSTR2,rSTR2,3
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beq cr5,L(DWaligned)
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add rN,rN,rBITDIF
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sldi r11,rBITDIF,3
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srdi rTMP,rN,5 /* Divide by 32 */
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andi. rBITDIF,rN,24 /* Get the DW remainder */
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ld rWORD1,0(rSTR1)
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ld rWORD2,0(rSTR2)
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cmpldi cr1,rBITDIF,16
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cmpldi cr7,rN,32
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clrldi rN,rN,61
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beq L(dPs4)
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mtctr rTMP
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bgt cr1,L(dPs3)
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beq cr1,L(dPs2)
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/* Remainder is 8 */
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.align 3
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L(dsP1):
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sld rWORD5,rWORD1,r11
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sld rWORD6,rWORD2,r11
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cmpld cr5,rWORD5,rWORD6
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blt cr7,L(dP1x)
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/* Do something useful in this cycle since we have to branch anyway. */
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ld rWORD1,8(rSTR1)
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ld rWORD2,8(rSTR2)
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cmpld cr0,rWORD1,rWORD2
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b L(dP1e)
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/* Remainder is 16 */
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.align 4
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L(dPs2):
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sld rWORD5,rWORD1,r11
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sld rWORD6,rWORD2,r11
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cmpld cr6,rWORD5,rWORD6
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blt cr7,L(dP2x)
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/* Do something useful in this cycle since we have to branch anyway. */
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ld rWORD7,8(rSTR1)
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ld rWORD8,8(rSTR2)
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cmpld cr5,rWORD7,rWORD8
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b L(dP2e)
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/* Remainder is 24 */
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.align 4
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L(dPs3):
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sld rWORD3,rWORD1,r11
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sld rWORD4,rWORD2,r11
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cmpld cr1,rWORD3,rWORD4
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b L(dP3e)
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/* Count is a multiple of 32, remainder is 0 */
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.align 4
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L(dPs4):
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mtctr rTMP
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sld rWORD1,rWORD1,r11
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sld rWORD2,rWORD2,r11
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cmpld cr0,rWORD1,rWORD2
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b L(dP4e)
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/* At this point we know both strings are double word aligned and the
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compare length is at least 8 bytes. */
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.align 4
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L(DWaligned):
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andi. rBITDIF,rN,24 /* Get the DW remainder */
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srdi rTMP,rN,5 /* Divide by 32 */
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cmpldi cr1,rBITDIF,16
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cmpldi cr7,rN,32
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clrldi rN,rN,61
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beq L(dP4)
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bgt cr1,L(dP3)
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beq cr1,L(dP2)
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/* Remainder is 8 */
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.align 4
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L(dP1):
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mtctr rTMP
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/* Normally we'd use rWORD7/rWORD8 here, but since we might exit early
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(8-15 byte compare), we want to use only volitile registers. This
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means we can avoid restoring non-volitile registers since we did not
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change any on the early exit path. The key here is the non-early
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exit path only cares about the condition code (cr5), not about which
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register pair was used. */
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ld rWORD5,0(rSTR1)
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ld rWORD6,0(rSTR2)
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cmpld cr5,rWORD5,rWORD6
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blt cr7,L(dP1x)
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ld rWORD1,8(rSTR1)
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ld rWORD2,8(rSTR2)
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cmpld cr0,rWORD1,rWORD2
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L(dP1e):
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ld rWORD3,16(rSTR1)
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ld rWORD4,16(rSTR2)
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cmpld cr1,rWORD3,rWORD4
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ld rWORD5,24(rSTR1)
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ld rWORD6,24(rSTR2)
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cmpld cr6,rWORD5,rWORD6
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bne cr5,L(dLcr5)
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bne cr0,L(dLcr0)
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ldu rWORD7,32(rSTR1)
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ldu rWORD8,32(rSTR2)
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bne cr1,L(dLcr1)
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cmpld cr5,rWORD7,rWORD8
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bdnz L(dLoop)
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bne cr6,L(dLcr6)
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ld rWORD8,-8(r1)
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ld rWORD7,-16(r1)
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.align 3
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L(dP1x):
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sldi. r12,rN,3
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bne cr5,L(dLcr5)
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subfic rN,r12,64 /* Shift count is 64 - (rN * 8). */
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bne L(d00)
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li rRTN,0
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blr
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/* Remainder is 16 */
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.align 4
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L(dP2):
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mtctr rTMP
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ld rWORD5,0(rSTR1)
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ld rWORD6,0(rSTR2)
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cmpld cr6,rWORD5,rWORD6
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blt cr7,L(dP2x)
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ld rWORD7,8(rSTR1)
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ld rWORD8,8(rSTR2)
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cmpld cr5,rWORD7,rWORD8
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L(dP2e):
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ld rWORD1,16(rSTR1)
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ld rWORD2,16(rSTR2)
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cmpld cr0,rWORD1,rWORD2
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ld rWORD3,24(rSTR1)
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ld rWORD4,24(rSTR2)
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cmpld cr1,rWORD3,rWORD4
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addi rSTR1,rSTR1,8
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addi rSTR2,rSTR2,8
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bne cr6,L(dLcr6)
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bne cr5,L(dLcr5)
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b L(dLoop2)
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/* Again we are on a early exit path (16-23 byte compare), we want to
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only use volitile registers and avoid restoring non-volitile
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registers. */
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.align 4
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L(dP2x):
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ld rWORD3,8(rSTR1)
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ld rWORD4,8(rSTR2)
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cmpld cr5,rWORD3,rWORD4
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sldi. r12,rN,3
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bne cr6,L(dLcr6)
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addi rSTR1,rSTR1,8
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addi rSTR2,rSTR2,8
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bne cr5,L(dLcr5)
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subfic rN,r12,64 /* Shift count is 64 - (rN * 8). */
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bne L(d00)
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li rRTN,0
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blr
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/* Remainder is 24 */
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.align 4
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L(dP3):
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mtctr rTMP
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ld rWORD3,0(rSTR1)
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ld rWORD4,0(rSTR2)
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cmpld cr1,rWORD3,rWORD4
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L(dP3e):
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ld rWORD5,8(rSTR1)
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ld rWORD6,8(rSTR2)
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cmpld cr6,rWORD5,rWORD6
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blt cr7,L(dP3x)
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ld rWORD7,16(rSTR1)
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ld rWORD8,16(rSTR2)
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cmpld cr5,rWORD7,rWORD8
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ld rWORD1,24(rSTR1)
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ld rWORD2,24(rSTR2)
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cmpld cr0,rWORD1,rWORD2
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addi rSTR1,rSTR1,16
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addi rSTR2,rSTR2,16
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bne cr1,L(dLcr1)
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bne cr6,L(dLcr6)
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b L(dLoop1)
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/* Again we are on a early exit path (24-31 byte compare), we want to
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only use volitile registers and avoid restoring non-volitile
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registers. */
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.align 4
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L(dP3x):
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ld rWORD1,16(rSTR1)
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ld rWORD2,16(rSTR2)
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cmpld cr5,rWORD1,rWORD2
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sldi. r12,rN,3
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bne cr1,L(dLcr1)
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addi rSTR1,rSTR1,16
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addi rSTR2,rSTR2,16
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bne cr6,L(dLcr6)
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subfic rN,r12,64 /* Shift count is 64 - (rN * 8). */
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bne cr5,L(dLcr5)
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bne L(d00)
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li rRTN,0
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blr
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/* Count is a multiple of 32, remainder is 0 */
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.align 4
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L(dP4):
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mtctr rTMP
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ld rWORD1,0(rSTR1)
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ld rWORD2,0(rSTR2)
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cmpld cr0,rWORD1,rWORD2
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L(dP4e):
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ld rWORD3,8(rSTR1)
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ld rWORD4,8(rSTR2)
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cmpld cr1,rWORD3,rWORD4
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ld rWORD5,16(rSTR1)
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ld rWORD6,16(rSTR2)
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cmpld cr6,rWORD5,rWORD6
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ldu rWORD7,24(rSTR1)
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ldu rWORD8,24(rSTR2)
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cmpld cr5,rWORD7,rWORD8
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bne cr0,L(dLcr0)
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bne cr1,L(dLcr1)
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bdz- L(d24) /* Adjust CTR as we start with +4 */
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/* This is the primary loop */
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.align 4
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L(dLoop):
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ld rWORD1,8(rSTR1)
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ld rWORD2,8(rSTR2)
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cmpld cr1,rWORD3,rWORD4
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bne cr6,L(dLcr6)
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L(dLoop1):
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ld rWORD3,16(rSTR1)
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ld rWORD4,16(rSTR2)
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cmpld cr6,rWORD5,rWORD6
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bne cr5,L(dLcr5)
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L(dLoop2):
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ld rWORD5,24(rSTR1)
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ld rWORD6,24(rSTR2)
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cmpld cr5,rWORD7,rWORD8
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bne cr0,L(dLcr0)
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L(dLoop3):
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ldu rWORD7,32(rSTR1)
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ldu rWORD8,32(rSTR2)
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bne cr1,L(dLcr1)
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cmpld cr0,rWORD1,rWORD2
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bdnz L(dLoop)
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L(dL4):
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cmpld cr1,rWORD3,rWORD4
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bne cr6,L(dLcr6)
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cmpld cr6,rWORD5,rWORD6
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bne cr5,L(dLcr5)
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cmpld cr5,rWORD7,rWORD8
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L(d44):
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bne cr0,L(dLcr0)
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L(d34):
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bne cr1,L(dLcr1)
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L(d24):
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bne cr6,L(dLcr6)
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L(d14):
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sldi. r12,rN,3
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bne cr5,L(dLcr5)
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L(d04):
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ld rWORD8,-8(r1)
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ld rWORD7,-16(r1)
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subfic rN,r12,64 /* Shift count is 64 - (rN * 8). */
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beq L(zeroLength)
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/* At this point we have a remainder of 1 to 7 bytes to compare. Since
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we are aligned it is safe to load the whole double word, and use
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shift right double to elliminate bits beyond the compare length. */
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L(d00):
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ld rWORD1,8(rSTR1)
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ld rWORD2,8(rSTR2)
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srd rWORD1,rWORD1,rN
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srd rWORD2,rWORD2,rN
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cmpld cr5,rWORD1,rWORD2
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bne cr5,L(dLcr5x)
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li rRTN,0
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blr
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.align 4
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L(dLcr0):
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ld rWORD8,-8(r1)
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ld rWORD7,-16(r1)
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li rRTN,1
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bgtlr cr0
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li rRTN,-1
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blr
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.align 4
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L(dLcr1):
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ld rWORD8,-8(r1)
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ld rWORD7,-16(r1)
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li rRTN,1
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bgtlr cr1
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li rRTN,-1
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blr
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.align 4
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L(dLcr6):
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ld rWORD8,-8(r1)
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ld rWORD7,-16(r1)
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li rRTN,1
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bgtlr cr6
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li rRTN,-1
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blr
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.align 4
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L(dLcr5):
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ld rWORD8,-8(r1)
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ld rWORD7,-16(r1)
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L(dLcr5x):
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li rRTN,1
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bgtlr cr5
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li rRTN,-1
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blr
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.align 4
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L(bytealigned):
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mtctr rN
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beq cr6,L(zeroLength)
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/* We need to prime this loop. This loop is swing modulo scheduled
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to avoid pipe delays. The dependent instruction latencies (load to
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compare to conditional branch) is 2 to 3 cycles. In this loop each
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dispatch group ends in a branch and takes 1 cycle. Effectively
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the first iteration of the loop only serves to load operands and
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branches based on compares are delayed until the next loop.
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So we must precondition some registers and condition codes so that
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we don't exit the loop early on the first iteration. */
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lbz rWORD1,0(rSTR1)
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lbz rWORD2,0(rSTR2)
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bdz L(b11)
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cmpld cr0,rWORD1,rWORD2
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lbz rWORD3,1(rSTR1)
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lbz rWORD4,1(rSTR2)
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bdz L(b12)
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cmpld cr1,rWORD3,rWORD4
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lbzu rWORD5,2(rSTR1)
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lbzu rWORD6,2(rSTR2)
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bdz L(b13)
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.align 4
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L(bLoop):
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lbzu rWORD1,1(rSTR1)
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lbzu rWORD2,1(rSTR2)
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bne cr0,L(bLcr0)
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cmpld cr6,rWORD5,rWORD6
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bdz L(b3i)
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lbzu rWORD3,1(rSTR1)
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lbzu rWORD4,1(rSTR2)
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bne cr1,L(bLcr1)
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cmpld cr0,rWORD1,rWORD2
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bdz L(b2i)
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lbzu rWORD5,1(rSTR1)
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lbzu rWORD6,1(rSTR2)
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bne cr6,L(bLcr6)
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cmpld cr1,rWORD3,rWORD4
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bdnz L(bLoop)
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/* We speculatively loading bytes before we have tested the previous
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bytes. But we must avoid overrunning the length (in the ctr) to
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prevent these speculative loads from causing a segfault. In this
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case the loop will exit early (before the all pending bytes are
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tested. In this case we must complete the pending operations
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before returning. */
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L(b1i):
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bne cr0,L(bLcr0)
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bne cr1,L(bLcr1)
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b L(bx56)
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.align 4
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L(b2i):
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bne cr6,L(bLcr6)
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bne cr0,L(bLcr0)
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b L(bx34)
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.align 4
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L(b3i):
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bne cr1,L(bLcr1)
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bne cr6,L(bLcr6)
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b L(bx12)
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.align 4
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L(bLcr0):
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li rRTN,1
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bgtlr cr0
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li rRTN,-1
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blr
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L(bLcr1):
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li rRTN,1
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bgtlr cr1
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li rRTN,-1
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blr
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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):
|
|
ld rWORD8,-8(r1)
|
|
ld rWORD7,-16(r1)
|
|
L(zeroLength):
|
|
li rRTN,0
|
|
blr
|
|
|
|
.align 4
|
|
/* At this point we know the strings have different alignment and the
|
|
compare length is at least 8 bytes. rBITDIF containes the low order
|
|
3 bits of rSTR1 and cr5 contains the result of the logical compare
|
|
of rBITDIF to 0. If rBITDIF == 0 then rStr1 is double word
|
|
aligned and can perform the DWunaligned loop.
|
|
|
|
Otherwise we know that rSTR1 is not aready DW aligned yet.
|
|
So we can force the string addresses to the next lower DW
|
|
boundary and special case this first DW word using shift left to
|
|
ellimiate bits preceeding the first byte. Since we want to join the
|
|
normal (DWaligned) compare loop, starting at the second double word,
|
|
we need to adjust the length (rN) and special case the loop
|
|
versioning for the first DW. This insures that the loop count is
|
|
correct and the first DW (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):
|
|
std r29,-24(r1)
|
|
cfi_offset(r29,-24)
|
|
clrldi rSHL,rSTR2,61
|
|
beq cr6,L(duzeroLength)
|
|
std r28,-32(r1)
|
|
cfi_offset(r28,-32)
|
|
beq cr5,L(DWunaligned)
|
|
std r27,-40(r1)
|
|
cfi_offset(r27,-40)
|
|
/* Adjust the logical start of rSTR2 ro compensate for the extra bits
|
|
in the 1st rSTR1 DW. */
|
|
sub r27,rSTR2,rBITDIF
|
|
/* But do not attempt to address the DW before that DW that contains
|
|
the actual start of rSTR2. */
|
|
clrrdi rSTR2,rSTR2,3
|
|
std r26,-48(r1)
|
|
cfi_offset(r26,-48)
|
|
/* Compute the leaft/right shift counts for the unalign rSTR2,
|
|
compensating for the logical (DW aligned) start of rSTR1. */
|
|
clrldi rSHL,r27,61
|
|
clrrdi rSTR1,rSTR1,3
|
|
std r25,-56(r1)
|
|
cfi_offset(r25,-56)
|
|
sldi rSHL,rSHL,3
|
|
cmpld cr5,r27,rSTR2
|
|
add rN,rN,rBITDIF
|
|
sldi r11,rBITDIF,3
|
|
std r24,-64(r1)
|
|
cfi_offset(r24,-64)
|
|
subfic rSHR,rSHL,64
|
|
srdi rTMP,rN,5 /* Divide by 32 */
|
|
andi. rBITDIF,rN,24 /* Get the DW remainder */
|
|
/* We normally need to load 2 DWs to start the unaligned rSTR2, but in
|
|
this special case those bits may be discarded anyway. Also we
|
|
must avoid loading a DW 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)
|
|
ld rWORD8,0(rSTR2)
|
|
la rSTR2,8(rSTR2)
|
|
sld rWORD8,rWORD8,rSHL
|
|
|
|
L(dus0):
|
|
ld rWORD1,0(rSTR1)
|
|
ld rWORD2,0(rSTR2)
|
|
cmpldi cr1,rBITDIF,16
|
|
cmpldi cr7,rN,32
|
|
srd rG,rWORD2,rSHR
|
|
clrldi rN,rN,61
|
|
beq L(duPs4)
|
|
mtctr rTMP
|
|
or rWORD8,rG,rWORD8
|
|
bgt cr1,L(duPs3)
|
|
beq cr1,L(duPs2)
|
|
|
|
/* Remainder is 8 */
|
|
.align 4
|
|
L(dusP1):
|
|
sld rB,rWORD2,rSHL
|
|
sld rWORD7,rWORD1,r11
|
|
sld rWORD8,rWORD8,r11
|
|
bge cr7,L(duP1e)
|
|
/* At this point we exit early with the first double word compare
|
|
complete and remainder of 0 to 7 bytes. See L(du14) for details on
|
|
how we handle the remaining bytes. */
|
|
cmpld cr5,rWORD7,rWORD8
|
|
sldi. rN,rN,3
|
|
bne cr5,L(duLcr5)
|
|
cmpld cr7,rN,rSHR
|
|
beq L(duZeroReturn)
|
|
li rA,0
|
|
ble cr7,L(dutrim)
|
|
ld rWORD2,8(rSTR2)
|
|
srd rA,rWORD2,rSHR
|
|
b L(dutrim)
|
|
/* Remainder is 16 */
|
|
.align 4
|
|
L(duPs2):
|
|
sld rH,rWORD2,rSHL
|
|
sld rWORD5,rWORD1,r11
|
|
sld rWORD6,rWORD8,r11
|
|
b L(duP2e)
|
|
/* Remainder is 24 */
|
|
.align 4
|
|
L(duPs3):
|
|
sld rF,rWORD2,rSHL
|
|
sld rWORD3,rWORD1,r11
|
|
sld rWORD4,rWORD8,r11
|
|
b L(duP3e)
|
|
/* Count is a multiple of 32, remainder is 0 */
|
|
.align 4
|
|
L(duPs4):
|
|
mtctr rTMP
|
|
or rWORD8,rG,rWORD8
|
|
sld rD,rWORD2,rSHL
|
|
sld rWORD1,rWORD1,r11
|
|
sld rWORD2,rWORD8,r11
|
|
b L(duP4e)
|
|
|
|
/* At this point we know rSTR1 is double word aligned and the
|
|
compare length is at least 8 bytes. */
|
|
.align 4
|
|
L(DWunaligned):
|
|
std r27,-40(r1)
|
|
cfi_offset(r27,-40)
|
|
clrrdi rSTR2,rSTR2,3
|
|
std r26,-48(r1)
|
|
cfi_offset(r26,-48)
|
|
srdi rTMP,rN,5 /* Divide by 32 */
|
|
std r25,-56(r1)
|
|
cfi_offset(r25,-56)
|
|
andi. rBITDIF,rN,24 /* Get the DW remainder */
|
|
std r24,-64(r1)
|
|
cfi_offset(r24,-64)
|
|
sldi rSHL,rSHL,3
|
|
ld rWORD6,0(rSTR2)
|
|
ldu rWORD8,8(rSTR2)
|
|
cmpldi cr1,rBITDIF,16
|
|
cmpldi cr7,rN,32
|
|
clrldi rN,rN,61
|
|
subfic rSHR,rSHL,64
|
|
sld rH,rWORD6,rSHL
|
|
beq L(duP4)
|
|
mtctr rTMP
|
|
bgt cr1,L(duP3)
|
|
beq cr1,L(duP2)
|
|
|
|
/* Remainder is 8 */
|
|
.align 4
|
|
L(duP1):
|
|
srd rG,rWORD8,rSHR
|
|
ld rWORD7,0(rSTR1)
|
|
sld rB,rWORD8,rSHL
|
|
or rWORD8,rG,rH
|
|
blt cr7,L(duP1x)
|
|
L(duP1e):
|
|
ld rWORD1,8(rSTR1)
|
|
ld rWORD2,8(rSTR2)
|
|
cmpld cr5,rWORD7,rWORD8
|
|
srd rA,rWORD2,rSHR
|
|
sld rD,rWORD2,rSHL
|
|
or rWORD2,rA,rB
|
|
ld rWORD3,16(rSTR1)
|
|
ld rWORD4,16(rSTR2)
|
|
cmpld cr0,rWORD1,rWORD2
|
|
srd rC,rWORD4,rSHR
|
|
sld rF,rWORD4,rSHL
|
|
bne cr5,L(duLcr5)
|
|
or rWORD4,rC,rD
|
|
ld rWORD5,24(rSTR1)
|
|
ld rWORD6,24(rSTR2)
|
|
cmpld cr1,rWORD3,rWORD4
|
|
srd rE,rWORD6,rSHR
|
|
sld rH,rWORD6,rSHL
|
|
bne cr0,L(duLcr0)
|
|
or rWORD6,rE,rF
|
|
cmpld cr6,rWORD5,rWORD6
|
|
b L(duLoop3)
|
|
.align 4
|
|
/* At this point we exit early with the first double word compare
|
|
complete and remainder of 0 to 7 bytes. See L(du14) for details on
|
|
how we handle the remaining bytes. */
|
|
L(duP1x):
|
|
cmpld cr5,rWORD7,rWORD8
|
|
sldi. rN,rN,3
|
|
bne cr5,L(duLcr5)
|
|
cmpld cr7,rN,rSHR
|
|
beq L(duZeroReturn)
|
|
li rA,0
|
|
ble cr7,L(dutrim)
|
|
ld rWORD2,8(rSTR2)
|
|
srd rA,rWORD2,rSHR
|
|
b L(dutrim)
|
|
/* Remainder is 16 */
|
|
.align 4
|
|
L(duP2):
|
|
srd rE,rWORD8,rSHR
|
|
ld rWORD5,0(rSTR1)
|
|
or rWORD6,rE,rH
|
|
sld rH,rWORD8,rSHL
|
|
L(duP2e):
|
|
ld rWORD7,8(rSTR1)
|
|
ld rWORD8,8(rSTR2)
|
|
cmpld cr6,rWORD5,rWORD6
|
|
srd rG,rWORD8,rSHR
|
|
sld rB,rWORD8,rSHL
|
|
or rWORD8,rG,rH
|
|
blt cr7,L(duP2x)
|
|
ld rWORD1,16(rSTR1)
|
|
ld rWORD2,16(rSTR2)
|
|
cmpld cr5,rWORD7,rWORD8
|
|
bne cr6,L(duLcr6)
|
|
srd rA,rWORD2,rSHR
|
|
sld rD,rWORD2,rSHL
|
|
or rWORD2,rA,rB
|
|
ld rWORD3,24(rSTR1)
|
|
ld rWORD4,24(rSTR2)
|
|
cmpld cr0,rWORD1,rWORD2
|
|
bne cr5,L(duLcr5)
|
|
srd rC,rWORD4,rSHR
|
|
sld rF,rWORD4,rSHL
|
|
or rWORD4,rC,rD
|
|
addi rSTR1,rSTR1,8
|
|
addi rSTR2,rSTR2,8
|
|
cmpld cr1,rWORD3,rWORD4
|
|
b L(duLoop2)
|
|
.align 4
|
|
L(duP2x):
|
|
cmpld cr5,rWORD7,rWORD8
|
|
addi rSTR1,rSTR1,8
|
|
addi rSTR2,rSTR2,8
|
|
bne cr6,L(duLcr6)
|
|
sldi. rN,rN,3
|
|
bne cr5,L(duLcr5)
|
|
cmpld cr7,rN,rSHR
|
|
beq L(duZeroReturn)
|
|
li rA,0
|
|
ble cr7,L(dutrim)
|
|
ld rWORD2,8(rSTR2)
|
|
srd rA,rWORD2,rSHR
|
|
b L(dutrim)
|
|
|
|
/* Remainder is 24 */
|
|
.align 4
|
|
L(duP3):
|
|
srd rC,rWORD8,rSHR
|
|
ld rWORD3,0(rSTR1)
|
|
sld rF,rWORD8,rSHL
|
|
or rWORD4,rC,rH
|
|
L(duP3e):
|
|
ld rWORD5,8(rSTR1)
|
|
ld rWORD6,8(rSTR2)
|
|
cmpld cr1,rWORD3,rWORD4
|
|
srd rE,rWORD6,rSHR
|
|
sld rH,rWORD6,rSHL
|
|
or rWORD6,rE,rF
|
|
ld rWORD7,16(rSTR1)
|
|
ld rWORD8,16(rSTR2)
|
|
cmpld cr6,rWORD5,rWORD6
|
|
bne cr1,L(duLcr1)
|
|
srd rG,rWORD8,rSHR
|
|
sld rB,rWORD8,rSHL
|
|
or rWORD8,rG,rH
|
|
blt cr7,L(duP3x)
|
|
ld rWORD1,24(rSTR1)
|
|
ld rWORD2,24(rSTR2)
|
|
cmpld cr5,rWORD7,rWORD8
|
|
bne cr6,L(duLcr6)
|
|
srd rA,rWORD2,rSHR
|
|
sld rD,rWORD2,rSHL
|
|
or rWORD2,rA,rB
|
|
addi rSTR1,rSTR1,16
|
|
addi rSTR2,rSTR2,16
|
|
cmpld cr0,rWORD1,rWORD2
|
|
b L(duLoop1)
|
|
.align 4
|
|
L(duP3x):
|
|
addi rSTR1,rSTR1,16
|
|
addi rSTR2,rSTR2,16
|
|
bne cr1,L(duLcr1)
|
|
cmpld cr5,rWORD7,rWORD8
|
|
bne cr6,L(duLcr6)
|
|
sldi. rN,rN,3
|
|
bne cr5,L(duLcr5)
|
|
cmpld cr7,rN,rSHR
|
|
beq L(duZeroReturn)
|
|
li rA,0
|
|
ble cr7,L(dutrim)
|
|
ld rWORD2,8(rSTR2)
|
|
srd rA,rWORD2,rSHR
|
|
b L(dutrim)
|
|
|
|
/* Count is a multiple of 32, remainder is 0 */
|
|
.align 4
|
|
L(duP4):
|
|
mtctr rTMP
|
|
srd rA,rWORD8,rSHR
|
|
ld rWORD1,0(rSTR1)
|
|
sld rD,rWORD8,rSHL
|
|
or rWORD2,rA,rH
|
|
L(duP4e):
|
|
ld rWORD3,8(rSTR1)
|
|
ld rWORD4,8(rSTR2)
|
|
cmpld cr0,rWORD1,rWORD2
|
|
srd rC,rWORD4,rSHR
|
|
sld rF,rWORD4,rSHL
|
|
or rWORD4,rC,rD
|
|
ld rWORD5,16(rSTR1)
|
|
ld rWORD6,16(rSTR2)
|
|
cmpld cr1,rWORD3,rWORD4
|
|
bne cr0,L(duLcr0)
|
|
srd rE,rWORD6,rSHR
|
|
sld rH,rWORD6,rSHL
|
|
or rWORD6,rE,rF
|
|
ldu rWORD7,24(rSTR1)
|
|
ldu rWORD8,24(rSTR2)
|
|
cmpld cr6,rWORD5,rWORD6
|
|
bne cr1,L(duLcr1)
|
|
srd rG,rWORD8,rSHR
|
|
sld rB,rWORD8,rSHL
|
|
or rWORD8,rG,rH
|
|
cmpld cr5,rWORD7,rWORD8
|
|
bdz L(du24) /* Adjust CTR as we start with +4 */
|
|
/* This is the primary loop */
|
|
.align 4
|
|
L(duLoop):
|
|
ld rWORD1,8(rSTR1)
|
|
ld rWORD2,8(rSTR2)
|
|
cmpld cr1,rWORD3,rWORD4
|
|
bne cr6,L(duLcr6)
|
|
srd rA,rWORD2,rSHR
|
|
sld rD,rWORD2,rSHL
|
|
or rWORD2,rA,rB
|
|
L(duLoop1):
|
|
ld rWORD3,16(rSTR1)
|
|
ld rWORD4,16(rSTR2)
|
|
cmpld cr6,rWORD5,rWORD6
|
|
bne cr5,L(duLcr5)
|
|
srd rC,rWORD4,rSHR
|
|
sld rF,rWORD4,rSHL
|
|
or rWORD4,rC,rD
|
|
L(duLoop2):
|
|
ld rWORD5,24(rSTR1)
|
|
ld rWORD6,24(rSTR2)
|
|
cmpld cr5,rWORD7,rWORD8
|
|
bne cr0,L(duLcr0)
|
|
srd rE,rWORD6,rSHR
|
|
sld rH,rWORD6,rSHL
|
|
or rWORD6,rE,rF
|
|
L(duLoop3):
|
|
ldu rWORD7,32(rSTR1)
|
|
ldu rWORD8,32(rSTR2)
|
|
cmpld cr0,rWORD1,rWORD2
|
|
bne- cr1,L(duLcr1)
|
|
srd rG,rWORD8,rSHR
|
|
sld rB,rWORD8,rSHL
|
|
or rWORD8,rG,rH
|
|
bdnz L(duLoop)
|
|
|
|
L(duL4):
|
|
bne cr1,L(duLcr1)
|
|
cmpld cr1,rWORD3,rWORD4
|
|
bne cr6,L(duLcr6)
|
|
cmpld cr6,rWORD5,rWORD6
|
|
bne cr5,L(duLcr5)
|
|
cmpld cr5,rWORD7,rWORD8
|
|
L(du44):
|
|
bne cr0,L(duLcr0)
|
|
L(du34):
|
|
bne cr1,L(duLcr1)
|
|
L(du24):
|
|
bne cr6,L(duLcr6)
|
|
L(du14):
|
|
sldi. rN,rN,3
|
|
bne cr5,L(duLcr5)
|
|
/* At this point we have a remainder of 1 to 7 bytes to compare. We use
|
|
shift right double to elliminate bits beyond the compare length.
|
|
This allows the use of double word subtract to compute the final
|
|
result.
|
|
|
|
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). */
|
|
cmpld cr7,rN,rSHR
|
|
beq L(duZeroReturn)
|
|
li rA,0
|
|
ble cr7,L(dutrim)
|
|
ld rWORD2,8(rSTR2)
|
|
srd rA,rWORD2,rSHR
|
|
.align 4
|
|
L(dutrim):
|
|
ld rWORD1,8(rSTR1)
|
|
ld rWORD8,-8(r1)
|
|
subfic rN,rN,64 /* Shift count is 64 - (rN * 8). */
|
|
or rWORD2,rA,rB
|
|
ld rWORD7,-16(r1)
|
|
ld r29,-24(r1)
|
|
srd rWORD1,rWORD1,rN
|
|
srd rWORD2,rWORD2,rN
|
|
ld r28,-32(r1)
|
|
ld r27,-40(r1)
|
|
li rRTN,0
|
|
cmpld cr0,rWORD1,rWORD2
|
|
ld r26,-48(r1)
|
|
ld r25,-56(r1)
|
|
beq cr0,L(dureturn24)
|
|
li rRTN,1
|
|
ld r24,-64(r1)
|
|
bgtlr cr0
|
|
li rRTN,-1
|
|
blr
|
|
.align 4
|
|
L(duLcr0):
|
|
ld rWORD8,-8(r1)
|
|
ld rWORD7,-16(r1)
|
|
li rRTN,1
|
|
bgt cr0,L(dureturn29)
|
|
ld r29,-24(r1)
|
|
ld r28,-32(r1)
|
|
li rRTN,-1
|
|
b L(dureturn27)
|
|
.align 4
|
|
L(duLcr1):
|
|
ld rWORD8,-8(r1)
|
|
ld rWORD7,-16(r1)
|
|
li rRTN,1
|
|
bgt cr1,L(dureturn29)
|
|
ld r29,-24(r1)
|
|
ld r28,-32(r1)
|
|
li rRTN,-1
|
|
b L(dureturn27)
|
|
.align 4
|
|
L(duLcr6):
|
|
ld rWORD8,-8(r1)
|
|
ld rWORD7,-16(r1)
|
|
li rRTN,1
|
|
bgt cr6,L(dureturn29)
|
|
ld r29,-24(r1)
|
|
ld r28,-32(r1)
|
|
li rRTN,-1
|
|
b L(dureturn27)
|
|
.align 4
|
|
L(duLcr5):
|
|
ld rWORD8,-8(r1)
|
|
ld rWORD7,-16(r1)
|
|
li rRTN,1
|
|
bgt cr5,L(dureturn29)
|
|
ld r29,-24(r1)
|
|
ld r28,-32(r1)
|
|
li rRTN,-1
|
|
b L(dureturn27)
|
|
.align 3
|
|
L(duZeroReturn):
|
|
li rRTN,0
|
|
.align 4
|
|
L(dureturn):
|
|
ld rWORD8,-8(r1)
|
|
ld rWORD7,-16(r1)
|
|
L(dureturn29):
|
|
ld r29,-24(r1)
|
|
ld r28,-32(r1)
|
|
L(dureturn27):
|
|
ld r27,-40(r1)
|
|
L(dureturn26):
|
|
ld r26,-48(r1)
|
|
L(dureturn25):
|
|
ld r25,-56(r1)
|
|
L(dureturn24):
|
|
ld r24,-64(r1)
|
|
blr
|
|
L(duzeroLength):
|
|
li rRTN,0
|
|
blr
|
|
|
|
END (BP_SYM (memcmp))
|
|
libc_hidden_builtin_def (memcmp)
|
|
weak_alias (memcmp,bcmp)
|