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23d27709a4
Similar to BZ#19387 and BZ#20971, both i686 memchr optimized assembly implementations (memchr-sse2-bsf and memchr-sse2) do not handle the size overflow correctly. It is shown by the new tests added by commit3daef2c8ee, where both implementation fails with size as SIZE_MAX. This patch uses a similar strategy used on3daef2c8ee, where saturared math is used for overflow case. Checked on i686-linux-gnu. [BZ #21014] * sysdeps/i386/i686/multiarch/memchr-sse2-bsf.S (MEMCHR): Avoid overflow in pointer addition. * sysdeps/i386/i686/multiarch/memchr-sse2.S (MEMCHR): Likewise.
503 lines
8.2 KiB
ArmAsm
503 lines
8.2 KiB
ArmAsm
/* Optimized memchr with sse2
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Copyright (C) 2011-2017 Free Software Foundation, Inc.
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Contributed by Intel Corporation.
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This file is part of the GNU C Library.
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The GNU C Library is free software; you can redistribute it and/or
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modify it under the terms of the GNU Lesser General Public
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License as published by the Free Software Foundation; either
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version 2.1 of the License, or (at your option) any later version.
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The GNU C Library is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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Lesser General Public License for more details.
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You should have received a copy of the GNU Lesser General Public
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License along with the GNU C Library; if not, see
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<http://www.gnu.org/licenses/>. */
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#if IS_IN (libc)
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# include <sysdep.h>
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# define CFI_PUSH(REG) \
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cfi_adjust_cfa_offset (4); \
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cfi_rel_offset (REG, 0)
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# define CFI_POP(REG) \
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cfi_adjust_cfa_offset (-4); \
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cfi_restore (REG)
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# define PUSH(REG) pushl REG; CFI_PUSH (REG)
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# define POP(REG) popl REG; CFI_POP (REG)
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# define PARMS 4
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# define STR1 PARMS
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# define STR2 STR1+4
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# ifndef USE_AS_RAWMEMCHR
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# define LEN STR2+4
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# define RETURN POP(%edi); ret; CFI_PUSH(%edi);
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# endif
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# ifndef MEMCHR
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# define MEMCHR __memchr_sse2_bsf
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# endif
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.text
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ENTRY (MEMCHR)
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mov STR1(%esp), %ecx
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movd STR2(%esp), %xmm1
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# ifndef USE_AS_RAWMEMCHR
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mov LEN(%esp), %edx
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test %edx, %edx
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jz L(return_null_1)
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# endif
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mov %ecx, %eax
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punpcklbw %xmm1, %xmm1
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punpcklbw %xmm1, %xmm1
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and $63, %ecx
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pshufd $0, %xmm1, %xmm1
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cmp $48, %ecx
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ja L(crosscache)
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movdqu (%eax), %xmm0
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pcmpeqb %xmm1, %xmm0
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/* Check if there is a match. */
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pmovmskb %xmm0, %ecx
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test %ecx, %ecx
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je L(unaligned_no_match_1)
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/* Check which byte is a match. */
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bsf %ecx, %ecx
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# ifndef USE_AS_RAWMEMCHR
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sub %ecx, %edx
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jbe L(return_null_1)
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# endif
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add %ecx, %eax
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ret
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.p2align 4
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L(unaligned_no_match_1):
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# ifndef USE_AS_RAWMEMCHR
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sub $16, %edx
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jbe L(return_null_1)
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PUSH (%edi)
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lea 16(%eax), %edi
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and $15, %eax
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and $-16, %edi
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add %eax, %edx
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# else
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lea 16(%eax), %edx
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and $-16, %edx
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# endif
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jmp L(loop_prolog)
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.p2align 4
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L(return_null_1):
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xor %eax, %eax
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ret
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# ifndef USE_AS_RAWMEMCHR
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CFI_POP (%edi)
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# endif
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.p2align 4
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L(crosscache):
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/* Handle unaligned string. */
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# ifndef USE_AS_RAWMEMCHR
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PUSH (%edi)
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mov %eax, %edi
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and $15, %ecx
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and $-16, %edi
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movdqa (%edi), %xmm0
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# else
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mov %eax, %edx
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and $15, %ecx
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and $-16, %edx
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movdqa (%edx), %xmm0
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# endif
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pcmpeqb %xmm1, %xmm0
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/* Check if there is a match. */
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pmovmskb %xmm0, %eax
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/* Remove the leading bytes. */
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sar %cl, %eax
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test %eax, %eax
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je L(unaligned_no_match)
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/* Check which byte is a match. */
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bsf %eax, %eax
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# ifndef USE_AS_RAWMEMCHR
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sub %eax, %edx
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jbe L(return_null)
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add %edi, %eax
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add %ecx, %eax
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RETURN
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# else
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add %edx, %eax
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add %ecx, %eax
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ret
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# endif
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.p2align 4
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L(unaligned_no_match):
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# ifndef USE_AS_RAWMEMCHR
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/* Calculate the last acceptable address and check for possible
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addition overflow by using satured math:
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edx = ecx + edx
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edx |= -(edx < ecx) */
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add %ecx, %edx
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sbb %eax, %eax
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or %eax, %edx
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sub $16, %edx
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jbe L(return_null)
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add $16, %edi
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# else
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add $16, %edx
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# endif
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.p2align 4
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/* Loop start on aligned string. */
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L(loop_prolog):
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# ifndef USE_AS_RAWMEMCHR
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sub $64, %edx
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jbe L(exit_loop)
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movdqa (%edi), %xmm0
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# else
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movdqa (%edx), %xmm0
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# endif
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pcmpeqb %xmm1, %xmm0
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pmovmskb %xmm0, %eax
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test %eax, %eax
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jnz L(matches)
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# ifndef USE_AS_RAWMEMCHR
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movdqa 16(%edi), %xmm2
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# else
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movdqa 16(%edx), %xmm2
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# endif
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pcmpeqb %xmm1, %xmm2
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pmovmskb %xmm2, %eax
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test %eax, %eax
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jnz L(matches16)
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# ifndef USE_AS_RAWMEMCHR
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movdqa 32(%edi), %xmm3
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# else
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movdqa 32(%edx), %xmm3
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# endif
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pcmpeqb %xmm1, %xmm3
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pmovmskb %xmm3, %eax
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test %eax, %eax
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jnz L(matches32)
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# ifndef USE_AS_RAWMEMCHR
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movdqa 48(%edi), %xmm4
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# else
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movdqa 48(%edx), %xmm4
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# endif
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pcmpeqb %xmm1, %xmm4
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# ifndef USE_AS_RAWMEMCHR
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add $64, %edi
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# else
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add $64, %edx
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# endif
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pmovmskb %xmm4, %eax
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test %eax, %eax
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jnz L(matches0)
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# ifndef USE_AS_RAWMEMCHR
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test $0x3f, %edi
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# else
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test $0x3f, %edx
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# endif
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jz L(align64_loop)
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# ifndef USE_AS_RAWMEMCHR
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sub $64, %edx
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jbe L(exit_loop)
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movdqa (%edi), %xmm0
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# else
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movdqa (%edx), %xmm0
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# endif
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pcmpeqb %xmm1, %xmm0
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pmovmskb %xmm0, %eax
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test %eax, %eax
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jnz L(matches)
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# ifndef USE_AS_RAWMEMCHR
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movdqa 16(%edi), %xmm2
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# else
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movdqa 16(%edx), %xmm2
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# endif
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pcmpeqb %xmm1, %xmm2
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pmovmskb %xmm2, %eax
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test %eax, %eax
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jnz L(matches16)
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# ifndef USE_AS_RAWMEMCHR
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movdqa 32(%edi), %xmm3
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# else
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movdqa 32(%edx), %xmm3
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# endif
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pcmpeqb %xmm1, %xmm3
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pmovmskb %xmm3, %eax
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test %eax, %eax
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jnz L(matches32)
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# ifndef USE_AS_RAWMEMCHR
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movdqa 48(%edi), %xmm3
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# else
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movdqa 48(%edx), %xmm3
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# endif
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pcmpeqb %xmm1, %xmm3
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pmovmskb %xmm3, %eax
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# ifndef USE_AS_RAWMEMCHR
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add $64, %edi
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# else
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add $64, %edx
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# endif
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test %eax, %eax
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jnz L(matches0)
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# ifndef USE_AS_RAWMEMCHR
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mov %edi, %ecx
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and $-64, %edi
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and $63, %ecx
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add %ecx, %edx
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# else
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and $-64, %edx
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# endif
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.p2align 4
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L(align64_loop):
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# ifndef USE_AS_RAWMEMCHR
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sub $64, %edx
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jbe L(exit_loop)
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movdqa (%edi), %xmm0
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movdqa 16(%edi), %xmm2
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movdqa 32(%edi), %xmm3
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movdqa 48(%edi), %xmm4
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# else
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movdqa (%edx), %xmm0
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movdqa 16(%edx), %xmm2
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movdqa 32(%edx), %xmm3
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movdqa 48(%edx), %xmm4
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# endif
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pcmpeqb %xmm1, %xmm0
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pcmpeqb %xmm1, %xmm2
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pcmpeqb %xmm1, %xmm3
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pcmpeqb %xmm1, %xmm4
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pmaxub %xmm0, %xmm3
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pmaxub %xmm2, %xmm4
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pmaxub %xmm3, %xmm4
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pmovmskb %xmm4, %eax
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# ifndef USE_AS_RAWMEMCHR
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add $64, %edi
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# else
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add $64, %edx
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# endif
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test %eax, %eax
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jz L(align64_loop)
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# ifndef USE_AS_RAWMEMCHR
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sub $64, %edi
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# else
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sub $64, %edx
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# endif
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pmovmskb %xmm0, %eax
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test %eax, %eax
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jnz L(matches)
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pmovmskb %xmm2, %eax
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test %eax, %eax
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jnz L(matches16)
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# ifndef USE_AS_RAWMEMCHR
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movdqa 32(%edi), %xmm3
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# else
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movdqa 32(%edx), %xmm3
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# endif
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pcmpeqb %xmm1, %xmm3
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# ifndef USE_AS_RAWMEMCHR
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pcmpeqb 48(%edi), %xmm1
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# else
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pcmpeqb 48(%edx), %xmm1
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# endif
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pmovmskb %xmm3, %eax
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test %eax, %eax
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jnz L(matches32)
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pmovmskb %xmm1, %eax
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bsf %eax, %eax
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# ifndef USE_AS_RAWMEMCHR
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lea 48(%edi, %eax), %eax
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RETURN
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# else
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lea 48(%edx, %eax), %eax
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ret
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# endif
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# ifndef USE_AS_RAWMEMCHR
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.p2align 4
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L(exit_loop):
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add $64, %edx
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cmp $32, %edx
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jbe L(exit_loop_32)
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movdqa (%edi), %xmm0
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pcmpeqb %xmm1, %xmm0
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pmovmskb %xmm0, %eax
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test %eax, %eax
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jnz L(matches)
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movdqa 16(%edi), %xmm2
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pcmpeqb %xmm1, %xmm2
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pmovmskb %xmm2, %eax
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test %eax, %eax
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jnz L(matches16)
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movdqa 32(%edi), %xmm3
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pcmpeqb %xmm1, %xmm3
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pmovmskb %xmm3, %eax
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test %eax, %eax
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jnz L(matches32_1)
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cmp $48, %edx
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jbe L(return_null)
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pcmpeqb 48(%edi), %xmm1
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pmovmskb %xmm1, %eax
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test %eax, %eax
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jnz L(matches48_1)
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xor %eax, %eax
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RETURN
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.p2align 4
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L(exit_loop_32):
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movdqa (%edi), %xmm0
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pcmpeqb %xmm1, %xmm0
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pmovmskb %xmm0, %eax
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test %eax, %eax
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jnz L(matches_1)
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cmp $16, %edx
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jbe L(return_null)
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pcmpeqb 16(%edi), %xmm1
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pmovmskb %xmm1, %eax
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test %eax, %eax
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jnz L(matches16_1)
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xor %eax, %eax
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RETURN
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# endif
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.p2align 4
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L(matches0):
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bsf %eax, %eax
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# ifndef USE_AS_RAWMEMCHR
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lea -16(%eax, %edi), %eax
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RETURN
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# else
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lea -16(%eax, %edx), %eax
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ret
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# endif
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.p2align 4
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L(matches):
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bsf %eax, %eax
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# ifndef USE_AS_RAWMEMCHR
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add %edi, %eax
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RETURN
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# else
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add %edx, %eax
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ret
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# endif
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.p2align 4
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L(matches16):
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bsf %eax, %eax
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# ifndef USE_AS_RAWMEMCHR
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lea 16(%eax, %edi), %eax
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RETURN
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# else
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lea 16(%eax, %edx), %eax
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ret
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# endif
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.p2align 4
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L(matches32):
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bsf %eax, %eax
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# ifndef USE_AS_RAWMEMCHR
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lea 32(%eax, %edi), %eax
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RETURN
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# else
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lea 32(%eax, %edx), %eax
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ret
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# endif
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# ifndef USE_AS_RAWMEMCHR
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.p2align 4
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L(matches_1):
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bsf %eax, %eax
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sub %eax, %edx
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jbe L(return_null)
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add %edi, %eax
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RETURN
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.p2align 4
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L(matches16_1):
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sub $16, %edx
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bsf %eax, %eax
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sub %eax, %edx
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jbe L(return_null)
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lea 16(%edi, %eax), %eax
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RETURN
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.p2align 4
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L(matches32_1):
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sub $32, %edx
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bsf %eax, %eax
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sub %eax, %edx
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jbe L(return_null)
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lea 32(%edi, %eax), %eax
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RETURN
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.p2align 4
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L(matches48_1):
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sub $48, %edx
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bsf %eax, %eax
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sub %eax, %edx
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jbe L(return_null)
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lea 48(%edi, %eax), %eax
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RETURN
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# endif
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.p2align 4
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L(return_null):
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xor %eax, %eax
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# ifndef USE_AS_RAWMEMCHR
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RETURN
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# else
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ret
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# endif
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END (MEMCHR)
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#endif
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