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Diffstat (limited to 'sysdeps/powerpc/powerpc64/power8/strncpy.S')
| -rw-r--r-- | sysdeps/powerpc/powerpc64/power8/strncpy.S | 465 |
1 files changed, 0 insertions, 465 deletions
diff --git a/sysdeps/powerpc/powerpc64/power8/strncpy.S b/sysdeps/powerpc/powerpc64/power8/strncpy.S deleted file mode 100644 index 6d40f30ff7..0000000000 --- a/sysdeps/powerpc/powerpc64/power8/strncpy.S +++ /dev/null @@ -1,465 +0,0 @@ -/* Optimized strncpy/stpncpy implementation for PowerPC64/POWER8. - Copyright (C) 2015-2017 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 - <http://www.gnu.org/licenses/>. */ - -#include <sysdep.h> - -#ifdef USE_AS_STPNCPY -# ifndef STPNCPY -# define FUNC_NAME __stpncpy -# else -# define FUNC_NAME STPNCPY -# endif -#else -# ifndef STRNCPY -# define FUNC_NAME strncpy -# else -# define FUNC_NAME STRNCPY -# endif -#endif /* !USE_AS_STPNCPY */ - -#ifndef MEMSET -/* For builds without IFUNC support, local calls should be made to internal - GLIBC symbol (created by libc_hidden_builtin_def). */ -# ifdef SHARED -# define MEMSET __GI_memset -# else -# define MEMSET memset -# endif -#endif - -#define FRAMESIZE (FRAME_MIN_SIZE+48) - -/* Implements the function - - char * [r3] strncpy (char *dest [r3], const char *src [r4], size_t n [r5]) - - or - - char * [r3] stpncpy (char *dest [r3], const char *src [r4], size_t n [r5]) - - if USE_AS_STPCPY is defined. - - The implementation uses unaligned doubleword access to avoid specialized - code paths depending of data alignment. Although recent powerpc64 uses - 64K as default, the page cross handling assumes minimum page size of - 4k. */ - - .machine power7 -EALIGN (FUNC_NAME, 4, 0) - - /* Check if the [src]+15 will cross a 4K page by checking if the bit - indicating the page size changes. Basically: - - uint64_t srcin = (uint64_t)src; - uint64_t ob = srcin & 4096UL; - uint64_t nb = (srcin+15UL) & 4096UL; - if (ob ^ nb) - goto pagecross; */ - - addi r10,r4,16 - rlwinm r9,r4,0,19,19 - - /* Save some non-volatile registers on the stack. */ - std r26,-48(r1) - std r27,-40(r1) - - rlwinm r8,r10,0,19,19 - - std r28,-32(r1) - std r29,-24(r1) - - cmpld cr7,r9,r8 - - std r30,-16(r1) - std r31,-8(r1) - - /* Update CFI. */ - cfi_offset(r26, -48) - cfi_offset(r27, -40) - cfi_offset(r28, -32) - cfi_offset(r29, -24) - cfi_offset(r30, -16) - cfi_offset(r31, -8) - - beq cr7,L(unaligned_lt_16) - rldicl r9,r4,0,61 - subfic r8,r9,8 - cmpld cr7,r5,r8 - bgt cr7,L(pagecross) - - /* At this points there is 1 to 15 bytes to check and write. Since it could - be either from first unaligned 16 bytes access or from bulk copy, the code - uses an unrolled byte read/write instead of trying to analyze the cmpb - results. */ -L(short_path): - mr r9,r3 -L(short_path_1): - /* Return if there are no more bytes to be written. */ - cmpdi cr7,r5,0 - beq cr7,L(short_path_loop_end_1) -L(short_path_2): - /* Copy one char from src (r4) and write it to dest (r9). If it is the - end-of-string, start the null padding. Continue, otherwise. */ - lbz r10,0(r4) - cmpdi cr7,r10,0 - stb r10,0(r9) - beq cr7,L(zero_pad_start_1) - /* If there are no more bytes to be written, return. */ - cmpdi cr0,r5,1 - addi r8,r9,1 - addi r6,r5,-1 - beq cr0,L(short_path_loop_end_0) - /* Copy another char from src (r4) to dest (r9). Check again if it is - the end-of-string. If so, start the null padding. */ - lbz r10,1(r4) - cmpdi cr7,r10,0 - stb r10,1(r9) - beq cr7,L(zero_pad_start_prepare_1) - /* Eagerly decrement r5 by 3, which is the number of bytes already - written, plus one write that will be performed later on. */ - addi r10,r5,-3 - b L(short_path_loop_1) - - .align 4 -L(short_path_loop): - /* At this point, the induction variable, r5, as well as the pointers - to dest and src (r9 and r4, respectivelly) have been updated. - - Note: The registers r7 and r10 are induction variables derived from - r5. They are used to determine if the total number of writes has - been reached at every other write. - - Copy one char from src (r4) and write it to dest (r9). If it is the - end-of-string, start the null padding. Continue, otherwise. */ - lbz r8,0(r4) - addi r7,r10,-2 - cmpdi cr5,r8,0 - stb r8,0(r9) - beq cr5,L(zero_pad_start_1) - beq cr7,L(short_path_loop_end_0) - /* Copy another char from src (r4) to dest (r9). Check again if it is - the end-of-string. If so, start the null padding. */ - lbz r8,1(r4) - cmpdi cr7,r8,0 - stb r8,1(r9) - beq cr7,L(zero_pad_start) - mr r10,r7 -L(short_path_loop_1): - /* This block is reached after two chars have been already written to - dest. Nevertheless, r5 (the induction variable), r9 (the pointer to - dest), and r4 (the pointer to src) have not yet been updated. - - At this point: - r5 holds the count of bytes yet to be written plus 2. - r9 points to the last two chars that were already written to dest. - r4 points to the last two chars that were already copied from src. - - The algorithm continues by decrementing r5, the induction variable, - so that it reflects the last two writes. The pointers to dest (r9) - and to src (r4) are increment by two, for the same reason. - - Note: Register r10 is another induction variable, derived from r5, - which determines if the total number of writes has been reached. */ - addic. r5,r5,-2 - addi r9,r9,2 - cmpdi cr7,r10,0 /* Eagerly check if the next write is the last. */ - addi r4,r4,2 - addi r6,r9,1 - bne cr0,L(short_path_loop) /* Check if the total number of writes - has been reached at every other - write. */ -#ifdef USE_AS_STPNCPY - mr r3,r9 - b L(short_path_loop_end) -#endif - -L(short_path_loop_end_0): -#ifdef USE_AS_STPNCPY - addi r3,r9,1 - b L(short_path_loop_end) -#endif -L(short_path_loop_end_1): -#ifdef USE_AS_STPNCPY - mr r3,r9 -#endif -L(short_path_loop_end): - /* Restore non-volatile registers. */ - ld r26,-48(r1) - ld r27,-40(r1) - ld r28,-32(r1) - ld r29,-24(r1) - ld r30,-16(r1) - ld r31,-8(r1) - blr - - /* This code pads the remainder of dest with NULL bytes. The algorithm - calculates the remaining size and calls memset. */ - .align 4 -L(zero_pad_start): - mr r5,r10 - mr r9,r6 -L(zero_pad_start_1): - /* At this point: - - r5 holds the number of bytes that still have to be written to - dest. - - r9 points to the position, in dest, where the first null byte - will be written. - The above statements are true both when control reaches this label - from a branch or when falling through the previous lines. */ -#ifndef USE_AS_STPNCPY - mr r30,r3 /* Save the return value of strncpy. */ -#endif - /* Prepare the call to memset. */ - mr r3,r9 /* Pointer to the area to be zero-filled. */ - li r4,0 /* Byte to be written (zero). */ - - /* We delayed the creation of the stack frame, as well as the saving of - the link register, because only at this point, we are sure that - doing so is actually needed. */ - - /* Save the link register. */ - mflr r0 - std r0,16(r1) - cfi_offset(lr, 16) - - /* Create the stack frame. */ - stdu r1,-FRAMESIZE(r1) - cfi_adjust_cfa_offset(FRAMESIZE) - - bl MEMSET - nop - - /* Restore the stack frame. */ - addi r1,r1,FRAMESIZE - cfi_adjust_cfa_offset(-FRAMESIZE) - /* Restore the link register. */ - ld r0,16(r1) - mtlr r0 - -#ifndef USE_AS_STPNCPY - mr r3,r30 /* Restore the return value of strncpy, i.e.: - dest. For stpncpy, the return value is the - same as return value of memset. */ -#endif - - /* Restore non-volatile registers and return. */ - ld r26,-48(r1) - ld r27,-40(r1) - ld r28,-32(r1) - ld r29,-24(r1) - ld r30,-16(r1) - ld r31,-8(r1) - blr - - /* The common case where [src]+16 will not cross a 4K page boundary. - In this case the code fast check the first 16 bytes by using doubleword - read/compares and update destiny if neither total size or null byte - is found in destiny. */ - .align 4 -L(unaligned_lt_16): - cmpldi cr7,r5,7 - ble cr7,L(short_path) - ld r7,0(r4) - li r8,0 - cmpb r8,r7,r8 - cmpdi cr7,r8,0 - bne cr7,L(short_path_prepare_2) - addi r6,r5,-8 - std r7,0(r3) - addi r9,r3,8 - cmpldi cr7,r6,7 - addi r7,r4,8 - ble cr7,L(short_path_prepare_1_1) - ld r4,8(r4) - cmpb r8,r4,r8 - cmpdi cr7,r8,0 - bne cr7,L(short_path_prepare_2_1) - std r4,8(r3) - addi r29,r3,16 - addi r5,r5,-16 - /* Neither the null byte was found or total length was reached, - align to 16 bytes and issue a bulk copy/compare. */ - b L(align_to_16b) - - /* In the case of 4k page boundary cross, the algorithm first align - the address to a doubleword, calculate a mask based on alignment - to ignore the bytes and continue using doubleword. */ - .align 4 -L(pagecross): - rldicr r11,r4,0,59 /* Align the address to 8 bytes boundary. */ - li r6,-1 /* MASK = 0xffffffffffffffffUL. */ - sldi r9,r9,3 /* Calculate padding. */ - ld r7,0(r11) /* Load doubleword from memory. */ -#ifdef __LITTLE_ENDIAN__ - sld r9,r6,r9 /* MASK = MASK << padding. */ -#else - srd r9,r6,r9 /* MASK = MASK >> padding. */ -#endif - orc r9,r7,r9 /* Mask bits that are not part of the - string. */ - li r7,0 - cmpb r9,r9,r7 /* Check for null bytes in DWORD1. */ - cmpdi cr7,r9,0 - bne cr7,L(short_path_prepare_2) - subf r8,r8,r5 /* Adjust total length. */ - cmpldi cr7,r8,8 /* Check if length was reached. */ - ble cr7,L(short_path_prepare_2) - - /* For next checks we have aligned address, so we check for more - three doublewords to make sure we can read 16 unaligned bytes - to start the bulk copy with 16 aligned addresses. */ - ld r7,8(r11) - cmpb r9,r7,r9 - cmpdi cr7,r9,0 - bne cr7,L(short_path_prepare_2) - addi r7,r8,-8 - cmpldi cr7,r7,8 - ble cr7,L(short_path_prepare_2) - ld r7,16(r11) - cmpb r9,r7,r9 - cmpdi cr7,r9,0 - bne cr7,L(short_path_prepare_2) - addi r8,r8,-16 - cmpldi cr7,r8,8 - ble cr7,L(short_path_prepare_2) - ld r8,24(r11) - cmpb r9,r8,r9 - cmpdi cr7,r9,0 - bne cr7,L(short_path_prepare_2) - - /* No null byte found in the 32 bytes readed and length not reached, - read source again using unaligned loads and store them. */ - ld r9,0(r4) - addi r29,r3,16 - addi r5,r5,-16 - std r9,0(r3) - ld r9,8(r4) - std r9,8(r3) - - /* Align source to 16 bytes and adjust destiny and size. */ -L(align_to_16b): - rldicl r9,r10,0,60 - rldicr r28,r10,0,59 - add r12,r5,r9 - subf r29,r9,r29 - - /* The bulk read/compare/copy loads two doublewords, compare and merge - in a single register for speed. This is an attempt to speed up the - null-checking process for bigger strings. */ - - cmpldi cr7,r12,15 - ble cr7,L(short_path_prepare_1_2) - - /* Main loop for large sizes, unrolled 2 times to get better use of - pipeline. */ - ld r8,0(28) - ld r10,8(28) - li r9,0 - cmpb r7,r8,r9 - cmpb r9,r10,r9 - or. r6,r9,r7 - bne cr0,L(short_path_prepare_2_3) - addi r5,r12,-16 - addi r4,r28,16 - std r8,0(r29) - std r10,8(r29) - cmpldi cr7,r5,15 - addi r9,r29,16 - ble cr7,L(short_path_1) - mr r11,r28 - mr r6,r29 - li r30,0 - subfic r26,r4,48 - subfic r27,r9,48 - - b L(loop_16b) - - .align 4 -L(loop_start): - ld r31,0(r11) - ld r10,8(r11) - cmpb r0,r31,r7 - cmpb r8,r10,r7 - or. r7,r0,r8 - addi r5,r5,-32 - cmpldi cr7,r5,15 - add r4,r4,r26 - add r9,r9,r27 - bne cr0,L(short_path_prepare_2_2) - add r4,r28,r4 - std r31,0(r6) - add r9,r29,r9 - std r10,8(r6) - ble cr7,L(short_path_1) - -L(loop_16b): - ld r10,16(r11) - ld r0,24(r11) - cmpb r8,r10,r30 - cmpb r7,r0,r30 - or. r7,r8,r7 - addi r12,r12,-32 - cmpldi cr7,r12,15 - addi r11,r11,32 - bne cr0,L(short_path_2) - std r10,16(r6) - addi r6,r6,32 - std r0,-8(r6) - bgt cr7,L(loop_start) - - mr r5,r12 - mr r4,r11 - mr r9,r6 - b L(short_path_1) - - .align 4 -L(short_path_prepare_1_1): - mr r5,r6 - mr r4,r7 - b L(short_path_1) -L(short_path_prepare_1_2): - mr r5,r12 - mr r4,r28 - mr r9,r29 - b L(short_path_1) -L(short_path_prepare_2): - mr r9,r3 - b L(short_path_2) -L(short_path_prepare_2_1): - mr r5,r6 - mr r4,r7 - b L(short_path_2) -L(short_path_prepare_2_2): - mr r5,r12 - mr r4,r11 - mr r9,r6 - b L(short_path_2) -L(short_path_prepare_2_3): - mr r5,r12 - mr r4,r28 - mr r9,r29 - b L(short_path_2) -L(zero_pad_start_prepare_1): - mr r5,r6 - mr r9,r8 - b L(zero_pad_start_1) -END (FUNC_NAME) - -#ifndef USE_AS_STPNCPY -libc_hidden_builtin_def (strncpy) -#endif |