| /* Optimized 64-bit memset implementation for POWER6. |
| Copyright (C) 1997-2018 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 |
| <http://www.gnu.org/licenses/>. */ |
| |
| #include <sysdep.h> |
| |
| /* void * [r3] memset (void *s [r3], int c [r4], size_t n [r5])); |
| Returns 's'. |
| |
| The memset is done in three sizes: byte (8 bits), word (32 bits), |
| cache line (256 bits). There is a special case for setting cache lines |
| to 0, to take advantage of the dcbz instruction. */ |
| |
| #ifndef MEMSET |
| # define MEMSET memset |
| #endif |
| .machine power6 |
| ENTRY_TOCLESS (MEMSET, 7) |
| CALL_MCOUNT 3 |
| |
| #define rTMP r0 |
| #define rRTN r3 /* Initial value of 1st argument. */ |
| #define rMEMP0 r3 /* Original value of 1st arg. */ |
| #define rCHR r4 /* Char to set in each byte. */ |
| #define rLEN r5 /* Length of region to set. */ |
| #define rMEMP r6 /* Address at which we are storing. */ |
| #define rALIGN r7 /* Number of bytes we are setting now (when aligning). */ |
| #define rMEMP2 r8 |
| #define rMEMP3 r9 /* Alt mem pointer. */ |
| L(_memset): |
| /* Take care of case for size <= 4. */ |
| cmpldi cr1, rLEN, 8 |
| andi. rALIGN, rMEMP0, 7 |
| mr rMEMP, rMEMP0 |
| ble cr1, L(small) |
| |
| /* Align to doubleword boundary. */ |
| cmpldi cr5, rLEN, 31 |
| insrdi rCHR, rCHR, 8, 48 /* Replicate byte to halfword. */ |
| beq+ L(aligned2) |
| mtcrf 0x01, rMEMP0 |
| subfic rALIGN, rALIGN, 8 |
| cror 28,30,31 /* Detect odd word aligned. */ |
| add rMEMP, rMEMP, rALIGN |
| sub rLEN, rLEN, rALIGN |
| insrdi rCHR, rCHR, 16, 32 /* Replicate halfword to word. */ |
| bt 29, L(g4) |
| /* Process the even word of doubleword. */ |
| bf+ 31, L(g2) |
| stb rCHR, 0(rMEMP0) |
| bt 30, L(g4x) |
| L(g2): |
| sth rCHR, -6(rMEMP) |
| L(g4x): |
| stw rCHR, -4(rMEMP) |
| b L(aligned) |
| /* Process the odd word of doubleword. */ |
| L(g4): |
| bf 28, L(g4x) /* If false, word aligned on odd word. */ |
| bf+ 31, L(g0) |
| stb rCHR, 0(rMEMP0) |
| bt 30, L(aligned) |
| L(g0): |
| sth rCHR, -2(rMEMP) |
| |
| /* Handle the case of size < 31. */ |
| L(aligned2): |
| insrdi rCHR, rCHR, 16, 32 /* Replicate halfword to word. */ |
| L(aligned): |
| mtcrf 0x01, rLEN |
| ble cr5, L(medium) |
| /* Align to 32-byte boundary. */ |
| andi. rALIGN, rMEMP, 0x18 |
| subfic rALIGN, rALIGN, 0x20 |
| insrdi rCHR, rCHR, 32, 0 /* Replicate word to double word. */ |
| beq L(caligned) |
| mtcrf 0x01, rALIGN |
| add rMEMP, rMEMP, rALIGN |
| sub rLEN, rLEN, rALIGN |
| cmplwi cr1, rALIGN, 0x10 |
| mr rMEMP2, rMEMP |
| bf 28, L(a1) |
| stdu rCHR, -8(rMEMP2) |
| L(a1): blt cr1, L(a2) |
| std rCHR, -8(rMEMP2) |
| stdu rCHR, -16(rMEMP2) |
| L(a2): |
| |
| /* Now aligned to a 32 byte boundary. */ |
| .align 4 |
| L(caligned): |
| cmpldi cr1, rCHR, 0 |
| clrrdi. rALIGN, rLEN, 5 |
| mtcrf 0x01, rLEN |
| beq cr1, L(zloopstart) /* Special case for clearing memory using dcbz. */ |
| beq L(medium) /* We may not actually get to do a full line. */ |
| .align 4 |
| /* Storing a non-zero "c" value. We are aligned at a sector (32-byte) |
| boundary may not be at cache line (128-byte) boundary. */ |
| L(nzloopstart): |
| /* memset in 32-byte chunks until we get to a cache line boundary. |
| If rLEN is less than the distance to the next cache-line boundary use |
| cacheAligned1 code to finish the tail. */ |
| cmpldi cr1,rLEN,128 |
| |
| andi. rTMP,rMEMP,127 |
| blt cr1,L(cacheAligned1) |
| addi rMEMP3,rMEMP,32 |
| beq L(nzCacheAligned) |
| addi rLEN,rLEN,-32 |
| std rCHR,0(rMEMP) |
| std rCHR,8(rMEMP) |
| std rCHR,16(rMEMP) |
| addi rMEMP,rMEMP,32 |
| andi. rTMP,rMEMP3,127 |
| std rCHR,-8(rMEMP3) |
| |
| beq L(nzCacheAligned) |
| addi rLEN,rLEN,-32 |
| std rCHR,0(rMEMP3) |
| addi rMEMP,rMEMP,32 |
| std rCHR,8(rMEMP3) |
| andi. rTMP,rMEMP,127 |
| std rCHR,16(rMEMP3) |
| std rCHR,24(rMEMP3) |
| |
| beq L(nzCacheAligned) |
| addi rLEN,rLEN,-32 |
| std rCHR,32(rMEMP3) |
| addi rMEMP,rMEMP,32 |
| cmpldi cr1,rLEN,128 |
| std rCHR,40(rMEMP3) |
| cmpldi cr6,rLEN,256 |
| li rMEMP2,128 |
| std rCHR,48(rMEMP3) |
| std rCHR,56(rMEMP3) |
| blt cr1,L(cacheAligned1) |
| b L(nzCacheAligned128) |
| |
| /* Now we are aligned to the cache line and can use dcbtst. */ |
| .align 4 |
| L(nzCacheAligned): |
| cmpldi cr1,rLEN,128 |
| blt cr1,L(cacheAligned1) |
| b L(nzCacheAligned128) |
| .align 5 |
| L(nzCacheAligned128): |
| cmpldi cr1,rLEN,256 |
| addi rMEMP3,rMEMP,64 |
| std rCHR,0(rMEMP) |
| std rCHR,8(rMEMP) |
| std rCHR,16(rMEMP) |
| std rCHR,24(rMEMP) |
| std rCHR,32(rMEMP) |
| std rCHR,40(rMEMP) |
| std rCHR,48(rMEMP) |
| std rCHR,56(rMEMP) |
| addi rMEMP,rMEMP3,64 |
| addi rLEN,rLEN,-128 |
| std rCHR,0(rMEMP3) |
| std rCHR,8(rMEMP3) |
| std rCHR,16(rMEMP3) |
| std rCHR,24(rMEMP3) |
| std rCHR,32(rMEMP3) |
| std rCHR,40(rMEMP3) |
| std rCHR,48(rMEMP3) |
| std rCHR,56(rMEMP3) |
| bge cr1,L(nzCacheAligned128) |
| dcbtst 0,rMEMP |
| b L(cacheAligned1) |
| .align 5 |
| /* Storing a zero "c" value. We are aligned at a sector (32-byte) |
| boundary but may not be at cache line (128-byte) boundary. If the |
| remaining length spans a full cache line we can use the Data cache |
| block zero instruction. */ |
| L(zloopstart): |
| /* memset in 32-byte chunks until we get to a cache line boundary. |
| If rLEN is less than the distance to the next cache-line boundary use |
| cacheAligned1 code to finish the tail. */ |
| cmpldi cr1,rLEN,128 |
| beq L(medium) |
| L(getCacheAligned): |
| andi. rTMP,rMEMP,127 |
| nop |
| blt cr1,L(cacheAligned1) |
| addi rMEMP3,rMEMP,32 |
| beq L(cacheAligned) |
| addi rLEN,rLEN,-32 |
| std rCHR,0(rMEMP) |
| std rCHR,8(rMEMP) |
| std rCHR,16(rMEMP) |
| addi rMEMP,rMEMP,32 |
| andi. rTMP,rMEMP3,127 |
| std rCHR,-8(rMEMP3) |
| L(getCacheAligned2): |
| beq L(cacheAligned) |
| addi rLEN,rLEN,-32 |
| std rCHR,0(rMEMP3) |
| std rCHR,8(rMEMP3) |
| addi rMEMP,rMEMP,32 |
| andi. rTMP,rMEMP,127 |
| std rCHR,16(rMEMP3) |
| std rCHR,24(rMEMP3) |
| L(getCacheAligned3): |
| beq L(cacheAligned) |
| addi rLEN,rLEN,-32 |
| std rCHR,32(rMEMP3) |
| addi rMEMP,rMEMP,32 |
| cmpldi cr1,rLEN,128 |
| std rCHR,40(rMEMP3) |
| cmpldi cr6,rLEN,256 |
| li rMEMP2,128 |
| std rCHR,48(rMEMP3) |
| std rCHR,56(rMEMP3) |
| blt cr1,L(cacheAligned1) |
| blt cr6,L(cacheAligned128) |
| b L(cacheAlignedx) |
| |
| /* Now we are aligned to the cache line and can use dcbz. */ |
| .align 5 |
| L(cacheAligned): |
| cmpldi cr1,rLEN,128 |
| cmpldi cr6,rLEN,256 |
| blt cr1,L(cacheAligned1) |
| li rMEMP2,128 |
| L(cacheAlignedx): |
| cmpldi cr5,rLEN,640 |
| blt cr6,L(cacheAligned128) |
| bgt cr5,L(cacheAligned512) |
| cmpldi cr6,rLEN,512 |
| dcbz 0,rMEMP |
| cmpldi cr1,rLEN,384 |
| dcbz rMEMP2,rMEMP |
| addi rMEMP,rMEMP,256 |
| addi rLEN,rLEN,-256 |
| blt cr1,L(cacheAligned1) |
| blt cr6,L(cacheAligned128) |
| b L(cacheAligned256) |
| .align 5 |
| /* A simple loop for the longer (>640 bytes) lengths. This form limits |
| the branch miss-predicted to exactly 1 at loop exit.*/ |
| L(cacheAligned512): |
| cmpldi cr1,rLEN,128 |
| blt cr1,L(cacheAligned1) |
| dcbz 0,rMEMP |
| addi rLEN,rLEN,-128 |
| addi rMEMP,rMEMP,128 |
| b L(cacheAligned512) |
| .align 5 |
| L(cacheAligned256): |
| |
| cmpldi cr6,rLEN,512 |
| |
| dcbz 0,rMEMP |
| cmpldi cr1,rLEN,384 |
| dcbz rMEMP2,rMEMP |
| addi rMEMP,rMEMP,256 |
| addi rLEN,rLEN,-256 |
| |
| bge cr6,L(cacheAligned256) |
| |
| blt cr1,L(cacheAligned1) |
| .align 4 |
| L(cacheAligned128): |
| dcbz 0,rMEMP |
| addi rMEMP,rMEMP,128 |
| addi rLEN,rLEN,-128 |
| nop |
| L(cacheAligned1): |
| cmpldi cr1,rLEN,32 |
| blt cr1,L(handletail32) |
| addi rMEMP3,rMEMP,32 |
| addi rLEN,rLEN,-32 |
| std rCHR,0(rMEMP) |
| std rCHR,8(rMEMP) |
| std rCHR,16(rMEMP) |
| addi rMEMP,rMEMP,32 |
| cmpldi cr1,rLEN,32 |
| std rCHR,-8(rMEMP3) |
| L(cacheAligned2): |
| blt cr1,L(handletail32) |
| addi rLEN,rLEN,-32 |
| std rCHR,0(rMEMP3) |
| std rCHR,8(rMEMP3) |
| addi rMEMP,rMEMP,32 |
| cmpldi cr1,rLEN,32 |
| std rCHR,16(rMEMP3) |
| std rCHR,24(rMEMP3) |
| nop |
| L(cacheAligned3): |
| blt cr1,L(handletail32) |
| addi rMEMP,rMEMP,32 |
| addi rLEN,rLEN,-32 |
| std rCHR,32(rMEMP3) |
| std rCHR,40(rMEMP3) |
| std rCHR,48(rMEMP3) |
| std rCHR,56(rMEMP3) |
| |
| /* We are here because the length or remainder (rLEN) is less than the |
| cache line/sector size and does not justify aggressive loop unrolling. |
| So set up the preconditions for L(medium) and go there. */ |
| .align 3 |
| L(handletail32): |
| cmpldi cr1,rLEN,0 |
| beqlr cr1 |
| b L(medium) |
| |
| .align 5 |
| L(small): |
| /* Memset of 8 bytes or less. */ |
| cmpldi cr6, rLEN, 4 |
| cmpldi cr5, rLEN, 1 |
| ble cr6,L(le4) |
| subi rLEN, rLEN, 4 |
| stb rCHR,0(rMEMP) |
| stb rCHR,1(rMEMP) |
| stb rCHR,2(rMEMP) |
| stb rCHR,3(rMEMP) |
| addi rMEMP,rMEMP, 4 |
| cmpldi cr5, rLEN, 1 |
| L(le4): |
| cmpldi cr1, rLEN, 3 |
| bltlr cr5 |
| stb rCHR, 0(rMEMP) |
| beqlr cr5 |
| stb rCHR, 1(rMEMP) |
| bltlr cr1 |
| stb rCHR, 2(rMEMP) |
| beqlr cr1 |
| stb rCHR, 3(rMEMP) |
| blr |
| |
| /* Memset of 0-31 bytes. */ |
| .align 5 |
| L(medium): |
| insrdi rCHR, rCHR, 32, 0 /* Replicate word to double word. */ |
| cmpldi cr1, rLEN, 16 |
| L(medium_tail2): |
| add rMEMP, rMEMP, rLEN |
| L(medium_tail): |
| bt- 31, L(medium_31t) |
| bt- 30, L(medium_30t) |
| L(medium_30f): |
| bt 29, L(medium_29t) |
| L(medium_29f): |
| bge cr1, L(medium_27t) |
| bflr 28 |
| std rCHR, -8(rMEMP) |
| blr |
| |
| L(medium_31t): |
| stbu rCHR, -1(rMEMP) |
| bf- 30, L(medium_30f) |
| L(medium_30t): |
| sthu rCHR, -2(rMEMP) |
| bf- 29, L(medium_29f) |
| L(medium_29t): |
| stwu rCHR, -4(rMEMP) |
| blt cr1, L(medium_27f) |
| L(medium_27t): |
| std rCHR, -8(rMEMP) |
| stdu rCHR, -16(rMEMP) |
| L(medium_27f): |
| bflr 28 |
| L(medium_28t): |
| std rCHR, -8(rMEMP) |
| blr |
| END_GEN_TB (MEMSET,TB_TOCLESS) |
| libc_hidden_builtin_def (memset) |
| |
| /* Copied from bzero.S to prevent the linker from inserting a stub |
| between bzero and memset. */ |
| ENTRY_TOCLESS (__bzero) |
| CALL_MCOUNT 3 |
| mr r5,r4 |
| li r4,0 |
| b L(_memset) |
| END (__bzero) |
| #ifndef __bzero |
| weak_alias (__bzero, bzero) |
| #endif |
