--- /dev/null
+/* memrchr optimized with AVX2.
+ Copyright (C) 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/>. */
+
+#if IS_IN (libc)
+
+# include <sysdep.h>
+
+# ifndef VZEROUPPER
+# define VZEROUPPER vzeroupper
+# endif
+
+# define VEC_SIZE 32
+
+ .section .text.avx,"ax",@progbits
+ENTRY (__memrchr_avx2)
+ /* Broadcast CHAR to YMM0. */
+ vmovd %esi, %xmm0
+ vpbroadcastb %xmm0, %ymm0
+
+ subq $VEC_SIZE, %rdx
+ jbe L(last_vec_or_less)
+
+ addq %rdx, %rdi
+
+ /* Check the last VEC_SIZE bytes. */
+ vpcmpeqb (%rdi), %ymm0, %ymm1
+ vpmovmskb %ymm1, %eax
+ testl %eax, %eax
+ jnz L(last_vec_x0)
+
+ subq $(VEC_SIZE * 4), %rdi
+ movl %edi, %ecx
+ andl $(VEC_SIZE - 1), %ecx
+ jz L(aligned_more)
+
+ /* Align data for aligned loads in the loop. */
+ addq $VEC_SIZE, %rdi
+ addq $VEC_SIZE, %rdx
+ andq $-VEC_SIZE, %rdi
+ subq %rcx, %rdx
+
+ .p2align 4
+L(aligned_more):
+ subq $(VEC_SIZE * 4), %rdx
+ jbe L(last_4x_vec_or_less)
+
+ /* Check the last 4 * VEC_SIZE. Only one VEC_SIZE at a time
+ since data is only aligned to VEC_SIZE. */
+ vpcmpeqb (VEC_SIZE * 3)(%rdi), %ymm0, %ymm1
+ vpmovmskb %ymm1, %eax
+ testl %eax, %eax
+ jnz L(last_vec_x3)
+
+ vpcmpeqb (VEC_SIZE * 2)(%rdi), %ymm0, %ymm2
+ vpmovmskb %ymm2, %eax
+ testl %eax, %eax
+ jnz L(last_vec_x2)
+
+ vpcmpeqb VEC_SIZE(%rdi), %ymm0, %ymm3
+ vpmovmskb %ymm3, %eax
+ testl %eax, %eax
+ jnz L(last_vec_x1)
+
+ vpcmpeqb (%rdi), %ymm0, %ymm4
+ vpmovmskb %ymm4, %eax
+ testl %eax, %eax
+ jnz L(last_vec_x0)
+
+ /* Align data to 4 * VEC_SIZE for loop with fewer branches.
+ There are some overlaps with above if data isn't aligned
+ to 4 * VEC_SIZE. */
+ movl %edi, %ecx
+ andl $(VEC_SIZE * 4 - 1), %ecx
+ jz L(loop_4x_vec)
+
+ addq $(VEC_SIZE * 4), %rdi
+ addq $(VEC_SIZE * 4), %rdx
+ andq $-(VEC_SIZE * 4), %rdi
+ subq %rcx, %rdx
+
+ .p2align 4
+L(loop_4x_vec):
+ /* Compare 4 * VEC at a time forward. */
+ subq $(VEC_SIZE * 4), %rdi
+ subq $(VEC_SIZE * 4), %rdx
+ jbe L(last_4x_vec_or_less)
+
+ vmovdqa (%rdi), %ymm1
+ vmovdqa VEC_SIZE(%rdi), %ymm2
+ vmovdqa (VEC_SIZE * 2)(%rdi), %ymm3
+ vmovdqa (VEC_SIZE * 3)(%rdi), %ymm4
+
+ vpcmpeqb %ymm1, %ymm0, %ymm1
+ vpcmpeqb %ymm2, %ymm0, %ymm2
+ vpcmpeqb %ymm3, %ymm0, %ymm3
+ vpcmpeqb %ymm4, %ymm0, %ymm4
+
+ vpor %ymm1, %ymm2, %ymm5
+ vpor %ymm3, %ymm4, %ymm6
+ vpor %ymm5, %ymm6, %ymm5
+
+ vpmovmskb %ymm5, %eax
+ testl %eax, %eax
+ jz L(loop_4x_vec)
+
+ /* There is a match. */
+ vpmovmskb %ymm4, %eax
+ testl %eax, %eax
+ jnz L(last_vec_x3)
+
+ vpmovmskb %ymm3, %eax
+ testl %eax, %eax
+ jnz L(last_vec_x2)
+
+ vpmovmskb %ymm2, %eax
+ testl %eax, %eax
+ jnz L(last_vec_x1)
+
+ vpmovmskb %ymm1, %eax
+ bsrl %eax, %eax
+ addq %rdi, %rax
+ VZEROUPPER
+ ret
+
+ .p2align 4
+L(last_4x_vec_or_less):
+ addl $(VEC_SIZE * 4), %edx
+ cmpl $(VEC_SIZE * 2), %edx
+ jbe L(last_2x_vec)
+
+ vpcmpeqb (VEC_SIZE * 3)(%rdi), %ymm0, %ymm1
+ vpmovmskb %ymm1, %eax
+ testl %eax, %eax
+ jnz L(last_vec_x3)
+
+ vpcmpeqb (VEC_SIZE * 2)(%rdi), %ymm0, %ymm2
+ vpmovmskb %ymm2, %eax
+ testl %eax, %eax
+ jnz L(last_vec_x2)
+
+ vpcmpeqb VEC_SIZE(%rdi), %ymm0, %ymm3
+ vpmovmskb %ymm3, %eax
+ testl %eax, %eax
+ jnz L(last_vec_x1_check)
+ cmpl $(VEC_SIZE * 3), %edx
+ jbe L(zero)
+
+ vpcmpeqb (%rdi), %ymm0, %ymm4
+ vpmovmskb %ymm4, %eax
+ testl %eax, %eax
+ jz L(zero)
+ bsrl %eax, %eax
+ subq $(VEC_SIZE * 4), %rdx
+ addq %rax, %rdx
+ jl L(zero)
+ addq %rdi, %rax
+ VZEROUPPER
+ ret
+
+ .p2align 4
+L(last_2x_vec):
+ vpcmpeqb (VEC_SIZE * 3)(%rdi), %ymm0, %ymm1
+ vpmovmskb %ymm1, %eax
+ testl %eax, %eax
+ jnz L(last_vec_x3_check)
+ cmpl $VEC_SIZE, %edx
+ jbe L(zero)
+
+ vpcmpeqb (VEC_SIZE * 2)(%rdi), %ymm0, %ymm1
+ vpmovmskb %ymm1, %eax
+ testl %eax, %eax
+ jz L(zero)
+ bsrl %eax, %eax
+ subq $(VEC_SIZE * 2), %rdx
+ addq %rax, %rdx
+ jl L(zero)
+ addl $(VEC_SIZE * 2), %eax
+ addq %rdi, %rax
+ VZEROUPPER
+ ret
+
+ .p2align 4
+L(last_vec_x0):
+ bsrl %eax, %eax
+ addq %rdi, %rax
+ VZEROUPPER
+ ret
+
+ .p2align 4
+L(last_vec_x1):
+ bsrl %eax, %eax
+ addl $VEC_SIZE, %eax
+ addq %rdi, %rax
+ VZEROUPPER
+ ret
+
+ .p2align 4
+L(last_vec_x2):
+ bsrl %eax, %eax
+ addl $(VEC_SIZE * 2), %eax
+ addq %rdi, %rax
+ VZEROUPPER
+ ret
+
+ .p2align 4
+L(last_vec_x3):
+ bsrl %eax, %eax
+ addl $(VEC_SIZE * 3), %eax
+ addq %rdi, %rax
+ ret
+
+ .p2align 4
+L(last_vec_x1_check):
+ bsrl %eax, %eax
+ subq $(VEC_SIZE * 3), %rdx
+ addq %rax, %rdx
+ jl L(zero)
+ addl $VEC_SIZE, %eax
+ addq %rdi, %rax
+ VZEROUPPER
+ ret
+
+ .p2align 4
+L(last_vec_x3_check):
+ bsrl %eax, %eax
+ subq $VEC_SIZE, %rdx
+ addq %rax, %rdx
+ jl L(zero)
+ addl $(VEC_SIZE * 3), %eax
+ addq %rdi, %rax
+ VZEROUPPER
+ ret
+
+ .p2align 4
+L(zero):
+ VZEROUPPER
+L(null):
+ xorl %eax, %eax
+ ret
+
+ .p2align 4
+L(last_vec_or_less_aligned):
+ movl %edx, %ecx
+
+ vpcmpeqb (%rdi), %ymm0, %ymm1
+
+ movl $1, %edx
+ /* Support rdx << 32. */
+ salq %cl, %rdx
+ subq $1, %rdx
+
+ vpmovmskb %ymm1, %eax
+
+ /* Remove the trailing bytes. */
+ andl %edx, %eax
+ testl %eax, %eax
+ jz L(zero)
+
+ bsrl %eax, %eax
+ addq %rdi, %rax
+ VZEROUPPER
+ ret
+
+ .p2align 4
+L(last_vec_or_less):
+ addl $VEC_SIZE, %edx
+
+ /* Check for zero length. */
+ testl %edx, %edx
+ jz L(null)
+
+ movl %edi, %ecx
+ andl $(VEC_SIZE - 1), %ecx
+ jz L(last_vec_or_less_aligned)
+
+ movl %ecx, %esi
+ movl %ecx, %r8d
+ addl %edx, %esi
+ andq $-VEC_SIZE, %rdi
+
+ subl $VEC_SIZE, %esi
+ ja L(last_vec_2x_aligned)
+
+ /* Check the last VEC. */
+ vpcmpeqb (%rdi), %ymm0, %ymm1
+ vpmovmskb %ymm1, %eax
+
+ /* Remove the leading and trailing bytes. */
+ sarl %cl, %eax
+ movl %edx, %ecx
+
+ movl $1, %edx
+ sall %cl, %edx
+ subl $1, %edx
+
+ andl %edx, %eax
+ testl %eax, %eax
+ jz L(zero)
+
+ bsrl %eax, %eax
+ addq %rdi, %rax
+ addq %r8, %rax
+ VZEROUPPER
+ ret
+
+ .p2align 4
+L(last_vec_2x_aligned):
+ movl %esi, %ecx
+
+ /* Check the last VEC. */
+ vpcmpeqb VEC_SIZE(%rdi), %ymm0, %ymm1
+
+ movl $1, %edx
+ sall %cl, %edx
+ subl $1, %edx
+
+ vpmovmskb %ymm1, %eax
+
+ /* Remove the trailing bytes. */
+ andl %edx, %eax
+
+ testl %eax, %eax
+ jnz L(last_vec_x1)
+
+ /* Check the second last VEC. */
+ vpcmpeqb (%rdi), %ymm0, %ymm1
+
+ movl %r8d, %ecx
+
+ vpmovmskb %ymm1, %eax
+
+ /* Remove the leading bytes. Must use unsigned right shift for
+ bsrl below. */
+ shrl %cl, %eax
+ testl %eax, %eax
+ jz L(zero)
+
+ bsrl %eax, %eax
+ addq %rdi, %rax
+ addq %r8, %rax
+ VZEROUPPER
+ ret
+END (__memrchr_avx2)
+#endif
--- /dev/null
+/* Multiple versions of memrchr
+ All versions must be listed in ifunc-impl-list.c.
+ Copyright (C) 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/>. */
+
+/* Define multiple versions only for the definition in libc. */
+#if IS_IN (libc)
+# define memrchr __redirect_memrchr
+# include <string.h>
+# undef memrchr
+
+# define SYMBOL_NAME memrchr
+# include "ifunc-avx2.h"
+
+libc_ifunc_redirected (__redirect_memrchr, __memrchr, IFUNC_SELECTOR ());
+weak_alias (__memrchr, memrchr)
+#endif
git://sourceware.org / glibc.git / commitdiff