| /* Optimized memcmp implementation for POWER7/PowerPC64. |
| Copyright (C) 2010 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]) */ |
| |
| .machine power7 |
| EALIGN (BP_SYM(memcmp),4,0) |
| CALL_MCOUNT 3 |
| |
| #define rTMP r0 |
| #define rRTN r3 |
| #define rSTR1 r3 /* first string arg */ |
| #define rSTR2 r4 /* second string arg */ |
| #define rN r5 /* max string length */ |
| /* Note: The Bounded pointer support in this code is broken. This code |
| was inherited from PPC32 and and that support was never completed. |
| Current PPC gcc does not support -fbounds-check or -fbounded-pointers. */ |
| #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 |
| cmpldi cr6,rN,0 |
| cmpldi cr1,rN,12 |
| clrldi. rTMP,rTMP,61 |
| clrldi rBITDIF,rSTR1,61 |
| cmpldi cr5,rBITDIF,0 |
| beq- cr6,L(zeroLength) |
| dcbt 0,rSTR1 |
| dcbt 0,rSTR2 |
| /* If less than 8 bytes or not aligned, use the unalligned |
| byte loop. */ |
| blt cr1,L(bytealigned) |
| std rWORD8,-8(r1) |
| cfi_offset(rWORD8,-8) |
| std rWORD7,-16(r1) |
| cfi_offset(rWORD7,-16) |
| bne L(unaligned) |
| /* At this point we know both strings have the same 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 we are already double word |
| aligned and can perform the DWaligned loop. |
| |
| Otherwise we know the two strings have the same alignment (but not |
| yet DW). 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. */ |
| .align 4 |
| L(samealignment): |
| clrrdi rSTR1,rSTR1,3 |
| clrrdi rSTR2,rSTR2,3 |
| beq cr5,L(DWaligned) |
| add rN,rN,rBITDIF |
| sldi r11,rBITDIF,3 |
| srdi rTMP,rN,5 /* Divide by 32 */ |
| andi. rBITDIF,rN,24 /* Get the DW remainder */ |
| ld rWORD1,0(rSTR1) |
| ld rWORD2,0(rSTR2) |
| cmpldi cr1,rBITDIF,16 |
| cmpldi cr7,rN,32 |
| clrldi rN,rN,61 |
| beq L(dPs4) |
| mtctr rTMP |
| bgt cr1,L(dPs3) |
| beq cr1,L(dPs2) |
| |
| /* Remainder is 8 */ |
| .align 3 |
| L(dsP1): |
| sld rWORD5,rWORD1,r11 |
| sld rWORD6,rWORD2,r11 |
| cmpld cr5,rWORD5,rWORD6 |
| blt cr7,L(dP1x) |
| /* Do something useful in this cycle since we have to branch anyway. */ |
| ld rWORD1,8(rSTR1) |
| ld rWORD2,8(rSTR2) |
| cmpld cr0,rWORD1,rWORD2 |
| b L(dP1e) |
| /* Remainder is 16 */ |
| .align 4 |
| L(dPs2): |
| sld rWORD5,rWORD1,r11 |
| sld rWORD6,rWORD2,r11 |
| cmpld cr6,rWORD5,rWORD6 |
| blt cr7,L(dP2x) |
| /* Do something useful in this cycle since we have to branch anyway. */ |
| ld rWORD7,8(rSTR1) |
| ld rWORD8,8(rSTR2) |
| cmpld cr5,rWORD7,rWORD8 |
| b L(dP2e) |
| /* Remainder is 24 */ |
| .align 4 |
| L(dPs3): |
| sld rWORD3,rWORD1,r11 |
| sld rWORD4,rWORD2,r11 |
| cmpld cr1,rWORD3,rWORD4 |
| b L(dP3e) |
| /* Count is a multiple of 32, remainder is 0 */ |
| .align 4 |
| L(dPs4): |
| mtctr rTMP |
| sld rWORD1,rWORD1,r11 |
| sld rWORD2,rWORD2,r11 |
| cmpld cr0,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. rBITDIF,rN,24 /* Get the DW remainder */ |
| srdi rTMP,rN,5 /* Divide by 32 */ |
| cmpldi cr1,rBITDIF,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 rTMP |
| /* Normally we'd use rWORD7/rWORD8 here, but since we might exit early |
| (8-15 byte compare), we want to use only volitile registers. This |
| means we can avoid restoring non-volitile 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 rWORD1,8(rSTR1) |
| ld rWORD2,8(rSTR2) |
| cmpld cr0,rWORD1,rWORD2 |
| L(dP1e): |
| ld rWORD3,16(rSTR1) |
| ld rWORD4,16(rSTR2) |
| cmpld cr1,rWORD3,rWORD4 |
| ld rWORD5,24(rSTR1) |
| ld rWORD6,24(rSTR2) |
| cmpld cr6,rWORD5,rWORD6 |
| bne cr5,L(dLcr5) |
| bne cr0,L(dLcr0) |
| |
| ldu rWORD7,32(rSTR1) |
| ldu rWORD8,32(rSTR2) |
| bne cr1,L(dLcr1) |
| cmpld cr5,rWORD7,rWORD8 |
| bdnz L(dLoop) |
| bne cr6,L(dLcr6) |
| ld rWORD8,-8(r1) |
| ld rWORD7,-16(r1) |
| .align 3 |
| L(dP1x): |
| sldi. r12,rN,3 |
| bne cr5,L(dLcr5) |
| subfic rN,r12,64 /* Shift count is 64 - (rN * 8). */ |
| bne L(d00) |
| li rRTN,0 |
| blr |
| |
| /* Remainder is 16 */ |
| .align 4 |
| L(dP2): |
| mtctr rTMP |
| ld rWORD5,0(rSTR1) |
| ld rWORD6,0(rSTR2) |
| cmpld cr6,rWORD5,rWORD6 |
| blt cr7,L(dP2x) |
| ld rWORD7,8(rSTR1) |
| ld rWORD8,8(rSTR2) |
| cmpld cr5,rWORD7,rWORD8 |
| L(dP2e): |
| ld rWORD1,16(rSTR1) |
| ld rWORD2,16(rSTR2) |
| cmpld cr0,rWORD1,rWORD2 |
| ld rWORD3,24(rSTR1) |
| ld rWORD4,24(rSTR2) |
| cmpld cr1,rWORD3,rWORD4 |
| addi rSTR1,rSTR1,8 |
| addi rSTR2,rSTR2,8 |
| 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 volitile registers and avoid restoring non-volitile |
| registers. */ |
| .align 4 |
| L(dP2x): |
| ld rWORD3,8(rSTR1) |
| ld rWORD4,8(rSTR2) |
| cmpld cr5,rWORD3,rWORD4 |
| sldi. r12,rN,3 |
| bne cr6,L(dLcr6) |
| addi rSTR1,rSTR1,8 |
| addi rSTR2,rSTR2,8 |
| bne cr5,L(dLcr5) |
| subfic rN,r12,64 /* Shift count is 64 - (rN * 8). */ |
| bne L(d00) |
| li rRTN,0 |
| blr |
| |
| /* Remainder is 24 */ |
| .align 4 |
| L(dP3): |
| mtctr rTMP |
| ld rWORD3,0(rSTR1) |
| ld rWORD4,0(rSTR2) |
| cmpld cr1,rWORD3,rWORD4 |
| L(dP3e): |
| ld rWORD5,8(rSTR1) |
| ld rWORD6,8(rSTR2) |
| cmpld cr6,rWORD5,rWORD6 |
| blt cr7,L(dP3x) |
| ld rWORD7,16(rSTR1) |
| ld rWORD8,16(rSTR2) |
| cmpld cr5,rWORD7,rWORD8 |
| ld rWORD1,24(rSTR1) |
| ld rWORD2,24(rSTR2) |
| cmpld cr0,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 volitile registers and avoid restoring non-volitile |
| registers. */ |
| .align 4 |
| L(dP3x): |
| ld rWORD1,16(rSTR1) |
| ld rWORD2,16(rSTR2) |
| cmpld cr5,rWORD1,rWORD2 |
| sldi. r12,rN,3 |
| bne cr1,L(dLcr1) |
| addi rSTR1,rSTR1,16 |
| addi rSTR2,rSTR2,16 |
| bne cr6,L(dLcr6) |
| subfic rN,r12,64 /* Shift count is 64 - (rN * 8). */ |
| bne cr5,L(dLcr5) |
| bne L(d00) |
| li rRTN,0 |
| blr |
| |
| /* Count is a multiple of 32, remainder is 0 */ |
| .align 4 |
| L(dP4): |
| mtctr rTMP |
| ld rWORD1,0(rSTR1) |
| ld rWORD2,0(rSTR2) |
| cmpld cr0,rWORD1,rWORD2 |
| L(dP4e): |
| ld rWORD3,8(rSTR1) |
| ld rWORD4,8(rSTR2) |
| cmpld cr1,rWORD3,rWORD4 |
| ld rWORD5,16(rSTR1) |
| ld rWORD6,16(rSTR2) |
| cmpld cr6,rWORD5,rWORD6 |
| ldu rWORD7,24(rSTR1) |
| ldu rWORD8,24(rSTR2) |
| cmpld 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): |
| ld rWORD1,8(rSTR1) |
| ld rWORD2,8(rSTR2) |
| cmpld cr1,rWORD3,rWORD4 |
| bne cr6,L(dLcr6) |
| L(dLoop1): |
| ld rWORD3,16(rSTR1) |
| ld rWORD4,16(rSTR2) |
| cmpld cr6,rWORD5,rWORD6 |
| bne cr5,L(dLcr5) |
| L(dLoop2): |
| ld rWORD5,24(rSTR1) |
| ld rWORD6,24(rSTR2) |
| cmpld cr5,rWORD7,rWORD8 |
| bne cr0,L(dLcr0) |
| L(dLoop3): |
| ldu rWORD7,32(rSTR1) |
| ldu rWORD8,32(rSTR2) |
| bne cr1,L(dLcr1) |
| cmpld cr0,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 cr0,L(dLcr0) |
| 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,-8(r1) |
| ld rWORD7,-16(r1) |
| subfic rN,r12,64 /* Shift count is 64 - (rN * 8). */ |
| beq L(zeroLength) |
| /* 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 elliminate bits beyond the compare length. */ |
| L(d00): |
| ld rWORD1,8(rSTR1) |
| ld rWORD2,8(rSTR2) |
| srd rWORD1,rWORD1,rN |
| srd rWORD2,rWORD2,rN |
| cmpld cr5,rWORD1,rWORD2 |
| bne cr5,L(dLcr5x) |
| li rRTN,0 |
| blr |
| .align 4 |
| L(dLcr0): |
| ld rWORD8,-8(r1) |
| ld rWORD7,-16(r1) |
| li rRTN,1 |
| bgtlr cr0 |
| li rRTN,-1 |
| blr |
| .align 4 |
| L(dLcr1): |
| ld rWORD8,-8(r1) |
| ld rWORD7,-16(r1) |
| li rRTN,1 |
| bgtlr cr1 |
| li rRTN,-1 |
| blr |
| .align 4 |
| L(dLcr6): |
| ld rWORD8,-8(r1) |
| ld rWORD7,-16(r1) |
| li rRTN,1 |
| bgtlr cr6 |
| li rRTN,-1 |
| blr |
| .align 4 |
| L(dLcr5): |
| ld rWORD8,-8(r1) |
| ld rWORD7,-16(r1) |
| L(dLcr5x): |
| li rRTN,1 |
| bgtlr cr5 |
| li rRTN,-1 |
| blr |
| |
| .align 4 |
| L(bytealigned): |
| mtctr rN |
| beq cr6,L(zeroLength) |
| |
| /* 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 cr0,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 cr0,L(bLcr0) |
| |
| cmpld cr6,rWORD5,rWORD6 |
| bdz L(b3i) |
| |
| lbzu rWORD3,1(rSTR1) |
| lbzu rWORD4,1(rSTR2) |
| bne cr1,L(bLcr1) |
| |
| cmpld cr0,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 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): |
| 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) |