/* Optimized memcmp implementation for POWER7/PowerPC64. Copyright (C) 2010-2017 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, see . */ #include /* int [r3] memcmp (const char *s1 [r3], const char *s2 [r4], size_t size [r5]) */ /* TODO: change these to the actual instructions when the minimum required binutils allows it. */ #define MFVRD(r,v) .long (0x7c000067 | ((v)<<(32-11)) | ((r)<<(32-16))) #ifndef MEMCMP # define MEMCMP memcmp #endif .machine power7 EALIGN (MEMCMP, 4, 0) CALL_MCOUNT 3 #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 rOFF8 r20 /* 8 bytes offset. */ #define rOFF16 r21 /* 16 bytes offset. */ #define rOFF24 r22 /* 24 bytes offset. */ #define rOFF32 r23 /* 24 bytes offset. */ #define rWORD6_SHIFT r24 /* Left rotation temp for rWORD8. */ #define rWORD4_SHIFT r25 /* Left rotation temp for rWORD6. */ #define rWORD2_SHIFT r26 /* Left rotation temp for rWORD4. */ #define rWORD8_SHIFT r27 /* Left rotation temp for rWORD2. */ #define rSHR r28 /* Unaligned shift right count. */ #define rSHL r29 /* Unaligned shift left count. */ #define rWORD7 r30 /* Next word in s1. */ #define rWORD8 r31 /* Next word in s2. */ #define rWORD8SAVE (-8) #define rWORD7SAVE (-16) #define rOFF8SAVE (-24) #define rOFF16SAVE (-32) #define rOFF24SAVE (-40) #define rOFF32SAVE (-48) #define rSHRSAVE (-56) #define rSHLSAVE (-64) #define rWORD8SHIFTSAVE (-72) #define rWORD2SHIFTSAVE (-80) #define rWORD4SHIFTSAVE (-88) #define rWORD6SHIFTSAVE (-96) #ifdef __LITTLE_ENDIAN__ # define LD ldbrx #else # define LD ldx #endif xor r10, rSTR2, rSTR1 cmpldi cr6, rN, 0 cmpldi cr1, rN, 8 clrldi. r0, r10, 61 clrldi r12, rSTR1, 61 cmpldi cr5, r12, 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) bne L(unalignedqw) /* At this point we know both strings have the same alignment and the compare length is at least 8 bytes. r12 contains the low order 3 bits of rSTR1 and cr5 contains the result of the logical compare of r12 to 0. If r12 == 0 then we are already double word aligned and can perform the DW aligned loop. */ .align 4 L(samealignment): or r11, rSTR2, rSTR1 clrldi. r11, r11, 60 beq L(qw_align) /* Try to align to QW else proceed to DW loop. */ clrldi. r10, r10, 60 bne L(DW) /* For the difference to reach QW alignment, load as DW. */ clrrdi rSTR1, rSTR1, 3 clrrdi rSTR2, rSTR2, 3 subfic r10, r12, 8 LD rWORD1, 0, rSTR1 LD rWORD2, 0, rSTR2 sldi r9, r10, 3 subfic r9, r9, 64 sld rWORD1, rWORD1, r9 sld rWORD2, rWORD2, r9 cmpld cr6, rWORD1, rWORD2 addi rSTR1, rSTR1, 8 addi rSTR2, rSTR2, 8 bne cr6, L(ret_diff) subf rN, r10, rN cmpld cr6, r11, r12 bgt cr6, L(qw_align) LD rWORD1, 0, rSTR1 LD rWORD2, 0, rSTR2 cmpld cr6, rWORD1, rWORD2 addi rSTR1, rSTR1, 8 addi rSTR2, rSTR2, 8 bne cr6, L(different) cmpldi cr6, rN, 8 ble cr6, L(zeroLength) addi rN, rN, -8 /* Now both rSTR1 and rSTR2 are aligned to QW. */ .align 4 L(qw_align): vspltisb v0, 0 srdi. r6, rN, 6 li r8, 16 li r10, 32 li r11, 48 ble cr0, L(lessthan64) mtctr r6 vspltisb v8, 0 vspltisb v6, 0 /* Aligned vector loop. */ .align 4 L(aligned_loop): lvx v4, 0, rSTR1 lvx v5, 0, rSTR2 vcmpequb. v7, v6, v8 bnl cr6, L(different3) lvx v6, rSTR1, r8 lvx v8, rSTR2, r8 vcmpequb. v7, v5, v4 bnl cr6, L(different2) lvx v4, rSTR1, r10 lvx v5, rSTR2, r10 vcmpequb. v7, v6, v8 bnl cr6, L(different3) lvx v6, rSTR1, r11 lvx v8, rSTR2, r11 vcmpequb. v7, v5, v4 bnl cr6, L(different2) addi rSTR1, rSTR1, 64 addi rSTR2, rSTR2, 64 bdnz L(aligned_loop) vcmpequb. v7, v6, v8 bnl cr6, L(different3) clrldi rN, rN, 58 /* Handle remainder for aligned loop. */ .align 4 L(lessthan64): mr r9, rSTR1 cmpdi cr6, rN, 0 li rSTR1, 0 blelr cr6 lvx v4, 0, r9 lvx v5, 0, rSTR2 vcmpequb. v7, v5, v4 bnl cr6, L(different1) addi rN, rN, -16 cmpdi cr6, rN, 0 blelr cr6 lvx v4, r9, r8 lvx v5, rSTR2, r8 vcmpequb. v7, v5, v4 bnl cr6, L(different1) addi rN, rN, -16 cmpdi cr6, rN, 0 blelr cr6 lvx v4, r9, r10 lvx v5, rSTR2, r10 vcmpequb. v7, v5, v4 bnl cr6, L(different1) addi rN, rN, -16 cmpdi cr6, rN, 0 blelr cr6 lvx v4, r9, r11 lvx v5, rSTR2, r11 vcmpequb. v7, v5, v4 bnl cr6, L(different1) blr /* Calculate and return the difference. */ .align 4 L(different1): cmpdi cr6, rN, 16 bge cr6, L(different2) /* Discard unwanted bytes. */ #ifdef __LITTLE_ENDIAN__ lvsr v1, 0, rN vperm v4, v4, v0, v1 vperm v5, v5, v0, v1 #else lvsl v1, 0, rN vperm v4, v0, v4, v1 vperm v5, v0, v5, v1 #endif vcmpequb. v7, v4, v5 li rRTN, 0 bltlr cr6 .align 4 L(different2): #ifdef __LITTLE_ENDIAN__ /* Reverse bytes for direct comparison. */ lvsl v10, r0, r0 vspltisb v8, 15 vsububm v9, v8, v10 vperm v4, v4, v0, v9 vperm v5, v5, v0, v9 #endif MFVRD(r7, v4) MFVRD(r9, v5) cmpld cr6, r7, r9 bne cr6, L(ret_diff) /* Difference in second DW. */ vsldoi v4, v4, v4, 8 vsldoi v5, v5, v5, 8 MFVRD(r7, v4) MFVRD(r9, v5) cmpld cr6, r7, r9 L(ret_diff): li rRTN, 1 bgtlr cr6 li rRTN, -1 blr .align 4 L(different3): #ifdef __LITTLE_ENDIAN__ /* Reverse bytes for direct comparison. */ vspltisb v9, 15 lvsl v10, r0, r0 vsububm v9, v9, v10 vperm v6, v6, v0, v9 vperm v8, v8, v0, v9 #endif MFVRD(r7, v6) MFVRD(r9, v8) cmpld cr6, r7, r9 bne cr6, L(ret_diff) /* Difference in second DW. */ vsldoi v6, v6, v6, 8 vsldoi v8, v8, v8, 8 MFVRD(r7, v6) MFVRD(r9, v8) cmpld cr6, r7, r9 li rRTN, 1 bgtlr cr6 li rRTN, -1 blr .align 4 L(different): cmpldi cr7, rN, 8 bgt cr7, L(end) /* Skip unwanted bytes. */ sldi r8, rN, 3 subfic r8, r8, 64 srd rWORD1, rWORD1, r8 srd rWORD2, rWORD2, r8 cmpld cr6, rWORD1, rWORD2 li rRTN, 0 beqlr cr6 L(end): li rRTN, 1 bgtlr cr6 li rRTN, -1 blr .align 4 L(unalignedqw): /* Proceed to DW unaligned loop,if there is a chance of pagecross. */ rldicl r9, rSTR1, 0, 52 add r9, r9, rN cmpldi cr0, r9, 4096-16 bgt cr0, L(unaligned) rldicl r9, rSTR2, 0, 52 add r9, r9, rN cmpldi cr0, r9, 4096-16 bgt cr0, L(unaligned) li r0, 0 li r8, 16 vspltisb v0, 0 /* Check if rSTR1 is aligned to QW. */ andi. r11, rSTR1, 0xF beq L(s1_align) /* Compare 16B and align S1 to QW. */ #ifdef __LITTLE_ENDIAN__ lvsr v10, 0, rSTR1 /* Compute mask. */ lvsr v6, 0, rSTR2 /* Compute mask. */ #else lvsl v10, 0, rSTR1 /* Compute mask. */ lvsl v6, 0, rSTR2 /* Compute mask. */ #endif lvx v5, 0, rSTR2 lvx v9, rSTR2, r8 #ifdef __LITTLE_ENDIAN__ vperm v5, v9, v5, v6 #else vperm v5, v5, v9, v6 #endif lvx v4, 0, rSTR1 lvx v9, rSTR1, r8 #ifdef __LITTLE_ENDIAN__ vperm v4, v9, v4, v10 #else vperm v4, v4, v9, v10 #endif vcmpequb. v7, v5, v4 bnl cr6, L(different1) cmpldi cr6, rN, 16 ble cr6, L(zeroLength) subfic r11, r11, 16 subf rN, r11, rN add rSTR1, rSTR1, r11 add rSTR2, rSTR2, r11 /* As s1 is QW aligned prepare for unaligned loop. */ .align 4 L(s1_align): #ifdef __LITTLE_ENDIAN__ lvsr v6, 0, rSTR2 #else lvsl v6, 0, rSTR2 #endif lvx v5, 0, rSTR2 srdi. r6, rN, 6 li r10, 32 li r11, 48 ble cr0, L(lessthan64_unalign) mtctr r6 li r9, 64 /* Unaligned vector loop. */ .align 4 L(unalign_qwloop): lvx v4, 0, rSTR1 lvx v10, rSTR2, r8 #ifdef __LITTLE_ENDIAN__ vperm v5, v10, v5, v6 #else vperm v5, v5, v10, v6 #endif vcmpequb. v7, v5, v4 bnl cr6, L(different2) vor v5, v10, v10 lvx v4, rSTR1, r8 lvx v10, rSTR2, r10 #ifdef __LITTLE_ENDIAN__ vperm v5, v10, v5, v6 #else vperm v5, v5, v10, v6 #endif vcmpequb. v7, v5, v4 bnl cr6, L(different2) vor v5, v10, v10 lvx v4, rSTR1, r10 lvx v10, rSTR2, r11 #ifdef __LITTLE_ENDIAN__ vperm v5, v10, v5, v6 #else vperm v5, v5, v10, v6 #endif vcmpequb. v7, v5, v4 bnl cr6, L(different2) vor v5, v10, v10 lvx v4, rSTR1, r11 lvx v10, rSTR2, r9 #ifdef __LITTLE_ENDIAN__ vperm v5, v10, v5, v6 #else vperm v5, v5, v10, v6 #endif vcmpequb. v7, v5, v4 bnl cr6, L(different2) vor v5, v10, v10 addi rSTR1, rSTR1, 64 addi rSTR2, rSTR2, 64 bdnz L(unalign_qwloop) clrldi rN, rN, 58 /* Handle remainder for unaligned loop. */ .align 4 L(lessthan64_unalign): mr r9, rSTR1 cmpdi cr6, rN, 0 li rSTR1, 0 blelr cr6 lvx v4, 0, r9 lvx v10, rSTR2, r8 #ifdef __LITTLE_ENDIAN__ vperm v5, v10, v5, v6 #else vperm v5, v5, v10, v6 #endif vcmpequb. v7, v5, v4 bnl cr6, L(different1) vor v5, v10, v10 addi rN, rN, -16 cmpdi cr6, rN, 0 blelr cr6 lvx v4, r9, r8 lvx v10, rSTR2, r10 #ifdef __LITTLE_ENDIAN__ vperm v5, v10, v5, v6 #else vperm v5, v5, v10, v6 #endif vcmpequb. v7, v5, v4 bnl cr6, L(different1) vor v5, v10, v10 addi rN, rN, -16 cmpdi cr6, rN, 0 blelr cr6 lvx v4, r9, r10 lvx v10, rSTR2, r11 #ifdef __LITTLE_ENDIAN__ vperm v5, v10, v5, v6 #else vperm v5, v5, v10, v6 #endif vcmpequb. v7, v5, v4 bnl cr6, L(different1) vor v5, v10, v10 addi rN, rN, -16 cmpdi cr6, rN, 0 blelr cr6 lvx v4, r9, r11 addi r11, r11, 16 lvx v10, rSTR2, r11 #ifdef __LITTLE_ENDIAN__ vperm v5, v10, v5, v6 #else vperm v5, v5, v10, v6 #endif vcmpequb. v7, v5, v4 bnl cr6, L(different1) blr /* Otherwise we know the two strings have the same alignment (but not yet DW). So we force the string addresses to the next lower DW boundary and special case this first DW using shift left to eliminate bits preceding the first byte. Since we want to join the normal (DW aligned) 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 ensures that the loop count is correct and the first DW (shifted) is in the expected register pair. */ .align 4 L(DW): std rWORD8, rWORD8SAVE(r1) std rWORD7, rWORD7SAVE(r1) std rOFF8, rOFF8SAVE(r1) std rOFF16, rOFF16SAVE(r1) std rOFF24, rOFF24SAVE(r1) std rOFF32, rOFF32SAVE(r1) cfi_offset(rWORD8, rWORD8SAVE) cfi_offset(rWORD7, rWORD7SAVE) cfi_offset(rOFF8, rOFF8SAVE) cfi_offset(rOFF16, rOFF16SAVE) cfi_offset(rOFF24, rOFF24SAVE) cfi_offset(rOFF32, rOFF32SAVE) li rOFF8,8 li rOFF16,16 li rOFF24,24 li rOFF32,32 clrrdi rSTR1, rSTR1, 3 clrrdi rSTR2, rSTR2, 3 beq cr5, L(DWaligned) add rN, rN, r12 sldi rWORD6, r12, 3 srdi r0, rN, 5 /* Divide by 32. */ andi. r12, rN, 24 /* Get the DW remainder. */ LD rWORD1, 0, rSTR1 LD rWORD2, 0, rSTR2 cmpldi cr1, r12, 16 cmpldi cr7, rN, 32 clrldi rN, rN, 61 beq L(dPs4) mtctr r0 bgt cr1, L(dPs3) beq cr1, L(dPs2) /* Remainder is 8. */ .align 3 L(dsP1): sld rWORD5, rWORD1, rWORD6 sld rWORD6, rWORD2, rWORD6 cmpld cr5, rWORD5, rWORD6 blt cr7, L(dP1x) /* Do something useful in this cycle since we have to branch anyway. */ LD rWORD1, rOFF8, rSTR1 LD rWORD2, rOFF8, rSTR2 cmpld cr7, rWORD1, rWORD2 b L(dP1e) /* Remainder is 16. */ .align 4 L(dPs2): sld rWORD5, rWORD1, rWORD6 sld rWORD6, rWORD2, rWORD6 cmpld cr6, rWORD5, rWORD6 blt cr7, L(dP2x) /* Do something useful in this cycle since we have to branch anyway. */ LD rWORD7, rOFF8, rSTR1 LD rWORD8, rOFF8, rSTR2 cmpld cr5, rWORD7, rWORD8 b L(dP2e) /* Remainder is 24. */ .align 4 L(dPs3): sld rWORD3, rWORD1, rWORD6 sld rWORD4, rWORD2, rWORD6 cmpld cr1, rWORD3, rWORD4 b L(dP3e) /* Count is a multiple of 32, remainder is 0. */ .align 4 L(dPs4): mtctr r0 sld rWORD1, rWORD1, rWORD6 sld rWORD2, rWORD2, rWORD6 cmpld cr7, rWORD1, rWORD2 b L(dP4e) /* At this point we know both strings are double word aligned and the compare length is at least 8 bytes. */ .align 4 L(DWaligned): andi. r12, rN, 24 /* Get the DW remainder. */ srdi r0, rN, 5 /* Divide by 32. */ cmpldi cr1, r12, 16 cmpldi cr7, rN, 32 clrldi rN, rN, 61 beq L(dP4) bgt cr1, L(dP3) beq cr1, L(dP2) /* Remainder is 8. */ .align 4 L(dP1): mtctr r0 /* 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. */ LD rWORD5, 0, rSTR1 LD rWORD6, 0, rSTR2 cmpld cr5, rWORD5, rWORD6 blt cr7, L(dP1x) LD rWORD1, rOFF8, rSTR1 LD rWORD2, rOFF8, rSTR2 cmpld cr7, rWORD1, rWORD2 L(dP1e): LD rWORD3, rOFF16, rSTR1 LD rWORD4, rOFF16, rSTR2 cmpld cr1, rWORD3, rWORD4 LD rWORD5, rOFF24, rSTR1 LD rWORD6, rOFF24, rSTR2 cmpld cr6, rWORD5, rWORD6 bne cr5, L(dLcr5x) bne cr7, L(dLcr7x) LD rWORD7, rOFF32, rSTR1 LD rWORD8, rOFF32, rSTR2 addi rSTR1, rSTR1, 32 addi rSTR2, rSTR2, 32 bne cr1, L(dLcr1) cmpld cr5, rWORD7, rWORD8 bdnz L(dLoop) bne cr6, L(dLcr6) ld rWORD8, rWORD8SAVE(r1) ld rWORD7, rWORD7SAVE(r1) .align 3 L(dP1x): sldi. r12, rN, 3 bne cr5, L(dLcr5x) subfic rN, r12, 64 /* Shift count is 64 - (rN * 8). */ bne L(d00) ld rOFF8, rOFF8SAVE(r1) ld rOFF16, rOFF16SAVE(r1) ld rOFF24, rOFF24SAVE(r1) ld rOFF32, rOFF32SAVE(r1) li rRTN, 0 blr /* Remainder is 16. */ .align 4 L(dP2): mtctr r0 LD rWORD5, 0, rSTR1 LD rWORD6, 0, rSTR2 cmpld cr6, rWORD5, rWORD6 blt cr7, L(dP2x) LD rWORD7, rOFF8, rSTR1 LD rWORD8, rOFF8, rSTR2 cmpld cr5, rWORD7, rWORD8 L(dP2e): LD rWORD1, rOFF16, rSTR1 LD rWORD2, rOFF16, rSTR2 cmpld cr7, rWORD1, rWORD2 LD rWORD3, rOFF24, rSTR1 LD rWORD4, rOFF24, rSTR2 cmpld cr1, rWORD3, rWORD4 addi rSTR1, rSTR1, 8 addi rSTR2, rSTR2, 8 bne cr6, L(dLcr6) bne cr5, L(dLcr5) b L(dLoop2) .align 4 L(dP2x): LD rWORD3, rOFF8, rSTR1 LD rWORD4, rOFF8, rSTR2 cmpld cr1, rWORD3, rWORD4 sldi. r12, rN, 3 bne cr6, L(dLcr6x) addi rSTR1, rSTR1, 8 addi rSTR2, rSTR2, 8 bne cr1, L(dLcr1x) subfic rN, r12, 64 /* Shift count is 64 - (rN * 8). */ bne L(d00) ld rOFF8, rOFF8SAVE(r1) ld rOFF16, rOFF16SAVE(r1) ld rOFF24, rOFF24SAVE(r1) ld rOFF32, rOFF32SAVE(r1) li rRTN, 0 blr /* Remainder is 24. */ .align 4 L(dP3): mtctr r0 LD rWORD3, 0, rSTR1 LD rWORD4, 0, rSTR2 cmpld cr1, rWORD3, rWORD4 L(dP3e): LD rWORD5, rOFF8, rSTR1 LD rWORD6, rOFF8, rSTR2 cmpld cr6, rWORD5, rWORD6 blt cr7, L(dP3x) LD rWORD7, rOFF16, rSTR1 LD rWORD8, rOFF16, rSTR2 cmpld cr5, rWORD7, rWORD8 LD rWORD1, rOFF24, rSTR1 LD rWORD2, rOFF24, rSTR2 cmpld cr7, rWORD1, rWORD2 addi rSTR1, rSTR1, 16 addi rSTR2, rSTR2, 16 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): LD rWORD1, rOFF16, rSTR1 LD rWORD2, rOFF16, rSTR2 cmpld cr7, rWORD1, rWORD2 sldi. r12, rN, 3 bne cr1, L(dLcr1x) addi rSTR1, rSTR1, 16 addi rSTR2, rSTR2, 16 bne cr6, L(dLcr6x) subfic rN, r12, 64 /* Shift count is 64 - (rN * 8). */ bne cr7, L(dLcr7x) bne L(d00) ld rOFF8, rOFF8SAVE(r1) ld rOFF16, rOFF16SAVE(r1) ld rOFF24, rOFF24SAVE(r1) ld rOFF32, rOFF32SAVE(r1) li rRTN, 0 blr /* Count is a multiple of 32, remainder is 0. */ .align 4 L(dP4): mtctr r0 LD rWORD1, 0, rSTR1 LD rWORD2, 0, rSTR2 cmpld cr7, rWORD1, rWORD2 L(dP4e): LD rWORD3, rOFF8, rSTR1 LD rWORD4, rOFF8, rSTR2 cmpld cr1, rWORD3, rWORD4 LD rWORD5, rOFF16, rSTR1 LD rWORD6, rOFF16, rSTR2 cmpld cr6, rWORD5, rWORD6 LD rWORD7, rOFF24, rSTR1 LD rWORD8, rOFF24, rSTR2 addi rSTR1, rSTR1, 24 addi rSTR2, rSTR2, 24 cmpld cr5, rWORD7, rWORD8 bne cr7, L(dLcr7) bne cr1, L(dLcr1) bdz- L(d24) /* Adjust CTR as we start with +4. */ /* This is the primary loop. */ .align 4 L(dLoop): LD rWORD1, rOFF8, rSTR1 LD rWORD2, rOFF8, rSTR2 cmpld cr1, rWORD3, rWORD4 bne cr6, L(dLcr6) L(dLoop1): LD rWORD3, rOFF16, rSTR1 LD rWORD4, rOFF16, rSTR2 cmpld cr6, rWORD5, rWORD6 bne cr5, L(dLcr5) L(dLoop2): LD rWORD5, rOFF24, rSTR1 LD rWORD6, rOFF24, rSTR2 cmpld cr5, rWORD7, rWORD8 bne cr7, L(dLcr7) L(dLoop3): LD rWORD7, rOFF32, rSTR1 LD rWORD8, rOFF32, rSTR2 addi rSTR1, rSTR1, 32 addi rSTR2, rSTR2, 32 bne cr1, L(dLcr1) cmpld cr7, rWORD1, rWORD2 bdnz L(dLoop) L(dL4): cmpld cr1, rWORD3, rWORD4 bne cr6, L(dLcr6) cmpld cr6, rWORD5, rWORD6 bne cr5, L(dLcr5) cmpld cr5, rWORD7, rWORD8 L(d44): bne cr7, L(dLcr7) L(d34): bne cr1, L(dLcr1) L(d24): bne cr6, L(dLcr6) L(d14): sldi. r12, rN, 3 bne cr5, L(dLcr5) L(d04): ld rWORD8, rWORD8SAVE(r1) ld rWORD7, rWORD7SAVE(r1) subfic rN, r12, 64 /* Shift count is 64 - (rN * 8). */ beq L(duzeroLength) /* At this point we have a remainder of 1 to 7 bytes to compare. Since we are aligned it is safe to load the whole double word, and use shift right double to eliminate bits beyond the compare length. */ L(d00): LD rWORD1, rOFF8, rSTR1 LD rWORD2, rOFF8, rSTR2 srd rWORD1, rWORD1, rN srd rWORD2, rWORD2, rN cmpld cr7, rWORD1, rWORD2 bne cr7, L(dLcr7x) ld rOFF8, rOFF8SAVE(r1) ld rOFF16, rOFF16SAVE(r1) ld rOFF24, rOFF24SAVE(r1) ld rOFF32, rOFF32SAVE(r1) li rRTN, 0 blr .align 4 L(dLcr7): ld rWORD8, rWORD8SAVE(r1) ld rWORD7, rWORD7SAVE(r1) L(dLcr7x): ld rOFF8, rOFF8SAVE(r1) ld rOFF16, rOFF16SAVE(r1) ld rOFF24, rOFF24SAVE(r1) ld rOFF32, rOFF32SAVE(r1) li rRTN, 1 bgtlr cr7 li rRTN, -1 blr .align 4 L(dLcr1): ld rWORD8, rWORD8SAVE(r1) ld rWORD7, rWORD7SAVE(r1) L(dLcr1x): ld rOFF8, rOFF8SAVE(r1) ld rOFF16, rOFF16SAVE(r1) ld rOFF24, rOFF24SAVE(r1) ld rOFF32, rOFF32SAVE(r1) li rRTN, 1 bgtlr cr1 li rRTN, -1 blr .align 4 L(dLcr6): ld rWORD8, rWORD8SAVE(r1) ld rWORD7, rWORD7SAVE(r1) L(dLcr6x): ld rOFF8, rOFF8SAVE(r1) ld rOFF16, rOFF16SAVE(r1) ld rOFF24, rOFF24SAVE(r1) ld rOFF32, rOFF32SAVE(r1) li rRTN, 1 bgtlr cr6 li rRTN, -1 blr .align 4 L(dLcr5): ld rWORD8, rWORD8SAVE(r1) ld rWORD7, rWORD7SAVE(r1) L(dLcr5x): ld rOFF8, rOFF8SAVE(r1) ld rOFF16, rOFF16SAVE(r1) ld rOFF24, rOFF24SAVE(r1) ld rOFF32, rOFF32SAVE(r1) li rRTN, 1 bgtlr cr5 li rRTN, -1 blr .align 4 L(bytealigned): mtctr rN /* 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) cmpld cr7, rWORD1, rWORD2 lbz rWORD3, 1(rSTR1) lbz rWORD4, 1(rSTR2) bdz L(b12) cmpld 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 cr7, L(bLcr7) cmpld cr6, rWORD5, rWORD6 bdz L(b3i) lbzu rWORD3, 1(rSTR1) lbzu rWORD4, 1(rSTR2) bne cr1, L(bLcr1) cmpld cr7, rWORD1, rWORD2 bdz L(b2i) lbzu rWORD5, 1(rSTR1) lbzu rWORD6, 1(rSTR2) bne cr6, L(bLcr6) cmpld 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 cr7, L(bLcr7) bne cr1, L(bLcr1) b L(bx56) .align 4 L(b2i): bne cr6, L(bLcr6) bne cr7, L(bLcr7) b L(bx34) .align 4 L(b3i): bne cr1, L(bLcr1) bne cr6, L(bLcr6) b L(bx12) .align 4 L(bLcr7): li rRTN, 1 bgtlr cr7 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 cr7, L(bx12) bne cr1, L(bx34) L(bx56): sub rRTN, rWORD5, rWORD6 blr nop L(b12): bne cr7, L(bx12) L(bx34): sub rRTN, rWORD3, rWORD4 blr L(b11): L(bx12): sub rRTN, rWORD1, rWORD2 blr .align 4 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. r12 contains the low order 3 bits of rSTR1 and cr5 contains the result of the logical compare of r12 to 0. If r12 == 0 then rStr1 is double word aligned and can perform the DWunaligned loop. Otherwise we know that rSTR1 is not already DW aligned yet. So we can force the string addresses to the next lower DW boundary and special case this first DW using shift left to eliminate bits preceding 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 ensures that the loop count is correct and the first DW (shifted) is in the expected resister pair. */ L(unaligned): std rWORD8, rWORD8SAVE(r1) std rWORD7, rWORD7SAVE(r1) std rOFF8, rOFF8SAVE(r1) std rOFF16, rOFF16SAVE(r1) std rOFF24, rOFF24SAVE(r1) std rOFF32, rOFF32SAVE(r1) cfi_offset(rWORD8, rWORD8SAVE) cfi_offset(rWORD7, rWORD7SAVE) cfi_offset(rOFF8, rOFF8SAVE) cfi_offset(rOFF16, rOFF16SAVE) cfi_offset(rOFF24, rOFF24SAVE) cfi_offset(rOFF32, rOFF32SAVE) li rOFF8,8 li rOFF16,16 li rOFF24,24 li rOFF32,32 std rSHL, rSHLSAVE(r1) cfi_offset(rSHL, rSHLSAVE) clrldi rSHL, rSTR2, 61 beq cr6, L(duzeroLength) std rSHR, rSHRSAVE(r1) cfi_offset(rSHR, rSHRSAVE) beq cr5, L(DWunaligned) std rWORD8_SHIFT, rWORD8SHIFTSAVE(r1) cfi_offset(rWORD8_SHIFT, rWORD8SHIFTSAVE) /* Adjust the logical start of rSTR2 to compensate for the extra bits in the 1st rSTR1 DW. */ sub rWORD8_SHIFT, rSTR2, r12 /* But do not attempt to address the DW before that DW that contains the actual start of rSTR2. */ clrrdi rSTR2, rSTR2, 3 std rWORD2_SHIFT, rWORD2SHIFTSAVE(r1) /* Compute the left/right shift counts for the unaligned rSTR2, compensating for the logical (DW aligned) start of rSTR1. */ clrldi rSHL, rWORD8_SHIFT, 61 clrrdi rSTR1, rSTR1, 3 std rWORD4_SHIFT, rWORD4SHIFTSAVE(r1) sldi rSHL, rSHL, 3 cmpld cr5, rWORD8_SHIFT, rSTR2 add rN, rN, r12 sldi rWORD6, r12, 3 std rWORD6_SHIFT, rWORD6SHIFTSAVE(r1) cfi_offset(rWORD2_SHIFT, rWORD2SHIFTSAVE) cfi_offset(rWORD4_SHIFT, rWORD4SHIFTSAVE) cfi_offset(rWORD6_SHIFT, rWORD6SHIFTSAVE) subfic rSHR, rSHL, 64 srdi r0, rN, 5 /* Divide by 32. */ andi. r12, 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 addi rSTR2, rSTR2, 8 sld rWORD8, rWORD8, rSHL L(dus0): LD rWORD1, 0, rSTR1 LD rWORD2, 0, rSTR2 cmpldi cr1, r12, 16 cmpldi cr7, rN, 32 srd r12, rWORD2, rSHR clrldi rN, rN, 61 beq L(duPs4) mtctr r0 or rWORD8, r12, rWORD8 bgt cr1, L(duPs3) beq cr1, L(duPs2) /* Remainder is 8. */ .align 4 L(dusP1): sld rWORD8_SHIFT, rWORD2, rSHL sld rWORD7, rWORD1, rWORD6 sld rWORD8, rWORD8, rWORD6 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 r0, 0 ble cr7, L(dutrim) LD rWORD2, rOFF8, rSTR2 srd r0, rWORD2, rSHR b L(dutrim) /* Remainder is 16. */ .align 4 L(duPs2): sld rWORD6_SHIFT, rWORD2, rSHL sld rWORD5, rWORD1, rWORD6 sld rWORD6, rWORD8, rWORD6 b L(duP2e) /* Remainder is 24. */ .align 4 L(duPs3): sld rWORD4_SHIFT, rWORD2, rSHL sld rWORD3, rWORD1, rWORD6 sld rWORD4, rWORD8, rWORD6 b L(duP3e) /* Count is a multiple of 32, remainder is 0. */ .align 4 L(duPs4): mtctr r0 or rWORD8, r12, rWORD8 sld rWORD2_SHIFT, rWORD2, rSHL sld rWORD1, rWORD1, rWORD6 sld rWORD2, rWORD8, rWORD6 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 rWORD8_SHIFT, rWORD8SHIFTSAVE(r1) clrrdi rSTR2, rSTR2, 3 std rWORD2_SHIFT, rWORD2SHIFTSAVE(r1) srdi r0, rN, 5 /* Divide by 32. */ std rWORD4_SHIFT, rWORD4SHIFTSAVE(r1) andi. r12, rN, 24 /* Get the DW remainder. */ std rWORD6_SHIFT, rWORD6SHIFTSAVE(r1) cfi_offset(rWORD8_SHIFT, rWORD8SHIFTSAVE) cfi_offset(rWORD2_SHIFT, rWORD2SHIFTSAVE) cfi_offset(rWORD4_SHIFT, rWORD4SHIFTSAVE) cfi_offset(rWORD6_SHIFT, rWORD6SHIFTSAVE) sldi rSHL, rSHL, 3 LD rWORD6, 0, rSTR2 LD rWORD8, rOFF8, rSTR2 addi rSTR2, rSTR2, 8 cmpldi cr1, r12, 16 cmpldi cr7, rN, 32 clrldi rN, rN, 61 subfic rSHR, rSHL, 64 sld rWORD6_SHIFT, rWORD6, rSHL beq L(duP4) mtctr r0 bgt cr1, L(duP3) beq cr1, L(duP2) /* Remainder is 8. */ .align 4 L(duP1): srd r12, rWORD8, rSHR LD rWORD7, 0, rSTR1 sld rWORD8_SHIFT, rWORD8, rSHL or rWORD8, r12, rWORD6_SHIFT blt cr7, L(duP1x) L(duP1e): LD rWORD1, rOFF8, rSTR1 LD rWORD2, rOFF8, rSTR2 cmpld cr5, rWORD7, rWORD8 srd r0, rWORD2, rSHR sld rWORD2_SHIFT, rWORD2, rSHL or rWORD2, r0, rWORD8_SHIFT LD rWORD3, rOFF16, rSTR1 LD rWORD4, rOFF16, rSTR2 cmpld cr7, rWORD1, rWORD2 srd r12, rWORD4, rSHR sld rWORD4_SHIFT, rWORD4, rSHL bne cr5, L(duLcr5) or rWORD4, r12, rWORD2_SHIFT LD rWORD5, rOFF24, rSTR1 LD rWORD6, rOFF24, rSTR2 cmpld cr1, rWORD3, rWORD4 srd r0, rWORD6, rSHR sld rWORD6_SHIFT, rWORD6, rSHL bne cr7, L(duLcr7) or rWORD6, r0, rWORD4_SHIFT 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 r0, 0 ble cr7, L(dutrim) LD rWORD2, rOFF8, rSTR2 srd r0, rWORD2, rSHR b L(dutrim) /* Remainder is 16. */ .align 4 L(duP2): srd r0, rWORD8, rSHR LD rWORD5, 0, rSTR1 or rWORD6, r0, rWORD6_SHIFT sld rWORD6_SHIFT, rWORD8, rSHL L(duP2e): LD rWORD7, rOFF8, rSTR1 LD rWORD8, rOFF8, rSTR2 cmpld cr6, rWORD5, rWORD6 srd r12, rWORD8, rSHR sld rWORD8_SHIFT, rWORD8, rSHL or rWORD8, r12, rWORD6_SHIFT blt cr7, L(duP2x) LD rWORD1, rOFF16, rSTR1 LD rWORD2, rOFF16, rSTR2 cmpld cr5, rWORD7, rWORD8 bne cr6, L(duLcr6) srd r0, rWORD2, rSHR sld rWORD2_SHIFT, rWORD2, rSHL or rWORD2, r0, rWORD8_SHIFT LD rWORD3, rOFF24, rSTR1 LD rWORD4, rOFF24, rSTR2 cmpld cr7, rWORD1, rWORD2 bne cr5, L(duLcr5) srd r12, rWORD4, rSHR sld rWORD4_SHIFT, rWORD4, rSHL or rWORD4, r12, rWORD2_SHIFT 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 r0, 0 ble cr7, L(dutrim) LD rWORD2, rOFF8, rSTR2 srd r0, rWORD2, rSHR b L(dutrim) /* Remainder is 24. */ .align 4 L(duP3): srd r12, rWORD8, rSHR LD rWORD3, 0, rSTR1 sld rWORD4_SHIFT, rWORD8, rSHL or rWORD4, r12, rWORD6_SHIFT L(duP3e): LD rWORD5, rOFF8, rSTR1 LD rWORD6, rOFF8, rSTR2 cmpld cr1, rWORD3, rWORD4 srd r0, rWORD6, rSHR sld rWORD6_SHIFT, rWORD6, rSHL or rWORD6, r0, rWORD4_SHIFT LD rWORD7, rOFF16, rSTR1 LD rWORD8, rOFF16, rSTR2 cmpld cr6, rWORD5, rWORD6 bne cr1, L(duLcr1) srd r12, rWORD8, rSHR sld rWORD8_SHIFT, rWORD8, rSHL or rWORD8, r12, rWORD6_SHIFT blt cr7, L(duP3x) LD rWORD1, rOFF24, rSTR1 LD rWORD2, rOFF24, rSTR2 cmpld cr5, rWORD7, rWORD8 bne cr6, L(duLcr6) srd r0, rWORD2, rSHR sld rWORD2_SHIFT, rWORD2, rSHL or rWORD2, r0, rWORD8_SHIFT addi rSTR1, rSTR1, 16 addi rSTR2, rSTR2, 16 cmpld cr7, rWORD1, rWORD2 b L(duLoop1) .align 4 L(duP3x): addi rSTR1, rSTR1, 16 addi rSTR2, rSTR2, 16 cmpld cr5, rWORD7, rWORD8 bne cr6, L(duLcr6) sldi. rN, rN, 3 bne cr5, L(duLcr5) cmpld cr7, rN, rSHR beq L(duZeroReturn) li r0, 0 ble cr7, L(dutrim) LD rWORD2, rOFF8, rSTR2 srd r0, rWORD2, rSHR b L(dutrim) /* Count is a multiple of 32, remainder is 0. */ .align 4 L(duP4): mtctr r0 srd r0, rWORD8, rSHR LD rWORD1, 0, rSTR1 sld rWORD2_SHIFT, rWORD8, rSHL or rWORD2, r0, rWORD6_SHIFT L(duP4e): LD rWORD3, rOFF8, rSTR1 LD rWORD4, rOFF8, rSTR2 cmpld cr7, rWORD1, rWORD2 srd r12, rWORD4, rSHR sld rWORD4_SHIFT, rWORD4, rSHL or rWORD4, r12, rWORD2_SHIFT LD rWORD5, rOFF16, rSTR1 LD rWORD6, rOFF16, rSTR2 cmpld cr1, rWORD3, rWORD4 bne cr7, L(duLcr7) srd r0, rWORD6, rSHR sld rWORD6_SHIFT, rWORD6, rSHL or rWORD6, r0, rWORD4_SHIFT LD rWORD7, rOFF24, rSTR1 LD rWORD8, rOFF24, rSTR2 addi rSTR1, rSTR1, 24 addi rSTR2, rSTR2, 24 cmpld cr6, rWORD5, rWORD6 bne cr1, L(duLcr1) srd r12, rWORD8, rSHR sld rWORD8_SHIFT, rWORD8, rSHL or rWORD8, r12, rWORD6_SHIFT 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, rOFF8, rSTR1 LD rWORD2, rOFF8, rSTR2 cmpld cr1, rWORD3, rWORD4 bne cr6, L(duLcr6) srd r0, rWORD2, rSHR sld rWORD2_SHIFT, rWORD2, rSHL or rWORD2, r0, rWORD8_SHIFT L(duLoop1): LD rWORD3, rOFF16, rSTR1 LD rWORD4, rOFF16, rSTR2 cmpld cr6, rWORD5, rWORD6 bne cr5, L(duLcr5) srd r12, rWORD4, rSHR sld rWORD4_SHIFT, rWORD4, rSHL or rWORD4, r12, rWORD2_SHIFT L(duLoop2): LD rWORD5, rOFF24, rSTR1 LD rWORD6, rOFF24, rSTR2 cmpld cr5, rWORD7, rWORD8 bne cr7, L(duLcr7) srd r0, rWORD6, rSHR sld rWORD6_SHIFT, rWORD6, rSHL or rWORD6, r0, rWORD4_SHIFT L(duLoop3): LD rWORD7, rOFF32, rSTR1 LD rWORD8, rOFF32, rSTR2 addi rSTR1, rSTR1, 32 addi rSTR2, rSTR2, 32 cmpld cr7, rWORD1, rWORD2 bne cr1, L(duLcr1) srd r12, rWORD8, rSHR sld rWORD8_SHIFT, rWORD8, rSHL or rWORD8, r12, rWORD6_SHIFT bdnz L(duLoop) L(duL4): cmpld cr1, rWORD3, rWORD4 bne cr6, L(duLcr6) cmpld cr6, rWORD5, rWORD6 bne cr5, L(duLcr5) cmpld cr5, rWORD7, rWORD8 L(du44): bne cr7, L(duLcr7) 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 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 rWORD8_SHIFT). */ cmpld cr7, rN, rSHR beq L(duZeroReturn) li r0, 0 ble cr7, L(dutrim) LD rWORD2, rOFF8, rSTR2 srd r0, rWORD2, rSHR .align 4 L(dutrim): LD rWORD1, rOFF8, rSTR1 ld rWORD8, -8(r1) subfic rN, rN, 64 /* Shift count is 64 - (rN * 8). */ or rWORD2, r0, rWORD8_SHIFT ld rWORD7, rWORD7SAVE(r1) ld rSHL, rSHLSAVE(r1) srd rWORD1, rWORD1, rN srd rWORD2, rWORD2, rN ld rSHR, rSHRSAVE(r1) ld rWORD8_SHIFT, rWORD8SHIFTSAVE(r1) li rRTN, 0 cmpld cr7, rWORD1, rWORD2 ld rWORD2_SHIFT, rWORD2SHIFTSAVE(r1) ld rWORD4_SHIFT, rWORD4SHIFTSAVE(r1) beq cr7, L(dureturn24) li rRTN, 1 ld rWORD6_SHIFT, rWORD6SHIFTSAVE(r1) ld rOFF8, rOFF8SAVE(r1) ld rOFF16, rOFF16SAVE(r1) ld rOFF24, rOFF24SAVE(r1) ld rOFF32, rOFF32SAVE(r1) bgtlr cr7 li rRTN, -1 blr .align 4 L(duLcr7): ld rWORD8, rWORD8SAVE(r1) ld rWORD7, rWORD7SAVE(r1) li rRTN, 1 bgt cr7, L(dureturn29) ld rSHL, rSHLSAVE(r1) ld rSHR, rSHRSAVE(r1) li rRTN, -1 b L(dureturn27) .align 4 L(duLcr1): ld rWORD8, rWORD8SAVE(r1) ld rWORD7, rWORD7SAVE(r1) li rRTN, 1 bgt cr1, L(dureturn29) ld rSHL, rSHLSAVE(r1) ld rSHR, rSHRSAVE(r1) li rRTN, -1 b L(dureturn27) .align 4 L(duLcr6): ld rWORD8, rWORD8SAVE(r1) ld rWORD7, rWORD7SAVE(r1) li rRTN, 1 bgt cr6, L(dureturn29) ld rSHL, rSHLSAVE(r1) ld rSHR, rSHRSAVE(r1) li rRTN, -1 b L(dureturn27) .align 4 L(duLcr5): ld rWORD8, rWORD8SAVE(r1) ld rWORD7, rWORD7SAVE(r1) li rRTN, 1 bgt cr5, L(dureturn29) ld rSHL, rSHLSAVE(r1) ld rSHR, rSHRSAVE(r1) li rRTN, -1 b L(dureturn27) .align 3 L(duZeroReturn): li rRTN, 0 .align 4 L(dureturn): ld rWORD8, rWORD8SAVE(r1) ld rWORD7, rWORD7SAVE(r1) L(dureturn29): ld rSHL, rSHLSAVE(r1) ld rSHR, rSHRSAVE(r1) L(dureturn27): ld rWORD8_SHIFT, rWORD8SHIFTSAVE(r1) ld rWORD2_SHIFT, rWORD2SHIFTSAVE(r1) ld rWORD4_SHIFT, rWORD4SHIFTSAVE(r1) L(dureturn24): ld rWORD6_SHIFT, rWORD6SHIFTSAVE(r1) ld rOFF8, rOFF8SAVE(r1) ld rOFF16, rOFF16SAVE(r1) ld rOFF24, rOFF24SAVE(r1) ld rOFF32, rOFF32SAVE(r1) blr L(duzeroLength): ld rOFF8, rOFF8SAVE(r1) ld rOFF16, rOFF16SAVE(r1) ld rOFF24, rOFF24SAVE(r1) ld rOFF32, rOFF32SAVE(r1) li rRTN, 0 blr END (MEMCMP) libc_hidden_builtin_def (memcmp) weak_alias (memcmp, bcmp)