/* strchr with SSE2 with bsf Copyright (C) 2011-2014 Free Software Foundation, Inc. Contributed by Intel Corporation. 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 . */ #if IS_IN (libc) # include # define CFI_PUSH(REG) \ cfi_adjust_cfa_offset (4); \ cfi_rel_offset (REG, 0) # define CFI_POP(REG) \ cfi_adjust_cfa_offset (-4); \ cfi_restore (REG) # define PUSH(REG) pushl REG; CFI_PUSH (REG) # define POP(REG) popl REG; CFI_POP (REG) # define PARMS 8 # define ENTRANCE PUSH(%edi) # define RETURN POP(%edi); ret; CFI_PUSH(%edi); # define STR1 PARMS # define STR2 STR1+4 .text ENTRY (__strchr_sse2_bsf) ENTRANCE mov STR1(%esp), %ecx movd STR2(%esp), %xmm1 pxor %xmm2, %xmm2 mov %ecx, %edi punpcklbw %xmm1, %xmm1 punpcklbw %xmm1, %xmm1 /* ECX has OFFSET. */ and $15, %ecx pshufd $0, %xmm1, %xmm1 je L(loop) /* Handle unaligned string. */ and $-16, %edi movdqa (%edi), %xmm0 pcmpeqb %xmm0, %xmm2 pcmpeqb %xmm1, %xmm0 /* Find where NULL is. */ pmovmskb %xmm2, %edx /* Check if there is a match. */ pmovmskb %xmm0, %eax /* Remove the leading bytes. */ sarl %cl, %edx sarl %cl, %eax test %eax, %eax je L(unaligned_no_match) /* Check which byte is a match. */ bsf %eax, %eax /* Is there a NULL? */ test %edx, %edx je L(unaligned_match) bsf %edx, %edx cmpl %edx, %eax /* Return NULL if NULL comes first. */ ja L(return_null) L(unaligned_match): add %edi, %eax add %ecx, %eax RETURN .p2align 4 L(unaligned_no_match): test %edx, %edx jne L(return_null) pxor %xmm2, %xmm2 add $16, %edi .p2align 4 /* Loop start on aligned string. */ L(loop): movdqa (%edi), %xmm0 pcmpeqb %xmm0, %xmm2 add $16, %edi pcmpeqb %xmm1, %xmm0 pmovmskb %xmm2, %edx pmovmskb %xmm0, %eax or %eax, %edx jnz L(matches) movdqa (%edi), %xmm0 pcmpeqb %xmm0, %xmm2 add $16, %edi pcmpeqb %xmm1, %xmm0 pmovmskb %xmm2, %edx pmovmskb %xmm0, %eax or %eax, %edx jnz L(matches) movdqa (%edi), %xmm0 pcmpeqb %xmm0, %xmm2 add $16, %edi pcmpeqb %xmm1, %xmm0 pmovmskb %xmm2, %edx pmovmskb %xmm0, %eax or %eax, %edx jnz L(matches) movdqa (%edi), %xmm0 pcmpeqb %xmm0, %xmm2 add $16, %edi pcmpeqb %xmm1, %xmm0 pmovmskb %xmm2, %edx pmovmskb %xmm0, %eax or %eax, %edx jnz L(matches) jmp L(loop) L(matches): pmovmskb %xmm2, %edx test %eax, %eax jz L(return_null) bsf %eax, %eax /* There is a match. First find where NULL is. */ test %edx, %edx je L(match) bsf %edx, %ecx /* Check if NULL comes first. */ cmpl %ecx, %eax ja L(return_null) L(match): sub $16, %edi add %edi, %eax RETURN /* Return NULL. */ .p2align 4 L(return_null): xor %eax, %eax RETURN END (__strchr_sse2_bsf) #endif