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Diffstat (limited to 'sysdeps/powerpc/powerpc32/power4/memcmp.S')
| -rw-r--r-- | sysdeps/powerpc/powerpc32/power4/memcmp.S | 985 |
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) |