--- /dev/null
+/* SSE2 version of strlen and SSE4.1 version of wcslen.
+ Copyright (C) 2012-2021 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
+ <https://www.gnu.org/licenses/>. */
+
+#include <sysdep.h>
+
+#ifdef AS_WCSLEN
+# define PMINU pminud
+# define PCMPEQ pcmpeqd
+# define SHIFT_RETURN shrq $2, %rax
+#else
+# define PMINU pminub
+# define PCMPEQ pcmpeqb
+# define SHIFT_RETURN
+#endif
+
+/* Long lived register in strlen(s), strnlen(s, n) are:
+
+ %xmm3 - zero
+ %rdi - s
+ %r10 (s+n) & (~(64-1))
+ %r11 s+n
+*/
+
+
+.text
+ENTRY(strlen)
+
+/* Test 64 bytes from %rax for zero. Save result as bitmask in %rdx. */
+#define FIND_ZERO \
+ PCMPEQ (%rax), %xmm0; \
+ PCMPEQ 16(%rax), %xmm1; \
+ PCMPEQ 32(%rax), %xmm2; \
+ PCMPEQ 48(%rax), %xmm3; \
+ pmovmskb %xmm0, %esi; \
+ pmovmskb %xmm1, %edx; \
+ pmovmskb %xmm2, %r8d; \
+ pmovmskb %xmm3, %ecx; \
+ salq $16, %rdx; \
+ salq $16, %rcx; \
+ orq %rsi, %rdx; \
+ orq %r8, %rcx; \
+ salq $32, %rcx; \
+ orq %rcx, %rdx;
+
+#ifdef AS_STRNLEN
+/* Do not read anything when n==0. */
+ test %RSI_LP, %RSI_LP
+ jne L(n_nonzero)
+ xor %rax, %rax
+ ret
+L(n_nonzero):
+# ifdef AS_WCSLEN
+ shl $2, %RSI_LP
+# endif
+
+/* Initialize long lived registers. */
+
+ add %RDI_LP, %RSI_LP
+ mov %RSI_LP, %R10_LP
+ and $-64, %R10_LP
+ mov %RSI_LP, %R11_LP
+#endif
+
+ pxor %xmm0, %xmm0
+ pxor %xmm1, %xmm1
+ pxor %xmm2, %xmm2
+ pxor %xmm3, %xmm3
+ movq %rdi, %rax
+ movq %rdi, %rcx
+ andq $4095, %rcx
+/* Offsets 4032-4047 will be aligned into 4032 thus fit into page. */
+ cmpq $4047, %rcx
+/* We cannot unify this branching as it would be ~6 cycles slower. */
+ ja L(cross_page)
+
+#ifdef AS_STRNLEN
+/* Test if end is among first 64 bytes. */
+# define STRNLEN_PROLOG \
+ mov %r11, %rsi; \
+ subq %rax, %rsi; \
+ andq $-64, %rax; \
+ testq $-64, %rsi; \
+ je L(strnlen_ret)
+#else
+# define STRNLEN_PROLOG andq $-64, %rax;
+#endif
+
+/* Ignore bits in mask that come before start of string. */
+#define PROLOG(lab) \
+ movq %rdi, %rcx; \
+ xorq %rax, %rcx; \
+ STRNLEN_PROLOG; \
+ sarq %cl, %rdx; \
+ test %rdx, %rdx; \
+ je L(lab); \
+ bsfq %rdx, %rax; \
+ SHIFT_RETURN; \
+ ret
+
+#ifdef AS_STRNLEN
+ andq $-16, %rax
+ FIND_ZERO
+#else
+ /* Test first 16 bytes unaligned. */
+ movdqu (%rax), %xmm4
+ PCMPEQ %xmm0, %xmm4
+ pmovmskb %xmm4, %edx
+ test %edx, %edx
+ je L(next48_bytes)
+ bsf %edx, %eax /* If eax is zeroed 16bit bsf can be used. */
+ SHIFT_RETURN
+ ret
+
+L(next48_bytes):
+/* Same as FIND_ZERO except we do not check first 16 bytes. */
+ andq $-16, %rax
+ PCMPEQ 16(%rax), %xmm1
+ PCMPEQ 32(%rax), %xmm2
+ PCMPEQ 48(%rax), %xmm3
+ pmovmskb %xmm1, %edx
+ pmovmskb %xmm2, %r8d
+ pmovmskb %xmm3, %ecx
+ salq $16, %rdx
+ salq $16, %rcx
+ orq %r8, %rcx
+ salq $32, %rcx
+ orq %rcx, %rdx
+#endif
+
+ /* When no zero byte is found xmm1-3 are zero so we do not have to
+ zero them. */
+ PROLOG(loop)
+
+ .p2align 4
+L(cross_page):
+ andq $-64, %rax
+ FIND_ZERO
+ PROLOG(loop_init)
+
+#ifdef AS_STRNLEN
+/* We must do this check to correctly handle strnlen (s, -1). */
+L(strnlen_ret):
+ bts %rsi, %rdx
+ sarq %cl, %rdx
+ test %rdx, %rdx
+ je L(loop_init)
+ bsfq %rdx, %rax
+ SHIFT_RETURN
+ ret
+#endif
+ .p2align 4
+L(loop_init):
+ pxor %xmm1, %xmm1
+ pxor %xmm2, %xmm2
+ pxor %xmm3, %xmm3
+#ifdef AS_STRNLEN
+ .p2align 4
+L(loop):
+
+ addq $64, %rax
+ cmpq %rax, %r10
+ je L(exit_end)
+
+ movdqa (%rax), %xmm0
+ PMINU 16(%rax), %xmm0
+ PMINU 32(%rax), %xmm0
+ PMINU 48(%rax), %xmm0
+ PCMPEQ %xmm3, %xmm0
+ pmovmskb %xmm0, %edx
+ testl %edx, %edx
+ jne L(exit)
+ jmp L(loop)
+
+ .p2align 4
+L(exit_end):
+ cmp %rax, %r11
+ je L(first) /* Do not read when end is at page boundary. */
+ pxor %xmm0, %xmm0
+ FIND_ZERO
+
+L(first):
+ bts %r11, %rdx
+ bsfq %rdx, %rdx
+ addq %rdx, %rax
+ subq %rdi, %rax
+ SHIFT_RETURN
+ ret
+
+ .p2align 4
+L(exit):
+ pxor %xmm0, %xmm0
+ FIND_ZERO
+
+ bsfq %rdx, %rdx
+ addq %rdx, %rax
+ subq %rdi, %rax
+ SHIFT_RETURN
+ ret
+
+#else
+
+ /* Main loop. Unrolled twice to improve L2 cache performance on core2. */
+ .p2align 4
+L(loop):
+
+ movdqa 64(%rax), %xmm0
+ PMINU 80(%rax), %xmm0
+ PMINU 96(%rax), %xmm0
+ PMINU 112(%rax), %xmm0
+ PCMPEQ %xmm3, %xmm0
+ pmovmskb %xmm0, %edx
+ testl %edx, %edx
+ jne L(exit64)
+
+ subq $-128, %rax
+
+ movdqa (%rax), %xmm0
+ PMINU 16(%rax), %xmm0
+ PMINU 32(%rax), %xmm0
+ PMINU 48(%rax), %xmm0
+ PCMPEQ %xmm3, %xmm0
+ pmovmskb %xmm0, %edx
+ testl %edx, %edx
+ jne L(exit0)
+ jmp L(loop)
+
+ .p2align 4
+L(exit64):
+ addq $64, %rax
+L(exit0):
+ pxor %xmm0, %xmm0
+ FIND_ZERO
+
+ bsfq %rdx, %rdx
+ addq %rdx, %rax
+ subq %rdi, %rax
+ SHIFT_RETURN
+ ret
+
+#endif
+
+END(strlen)
-/* SSE2 version of strlen/wcslen.
- Copyright (C) 2012-2021 Free Software Foundation, Inc.
+/* SSE2 version of strlen.
+ Copyright (C) 2021 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
License along with the GNU C Library; if not, see
<https://www.gnu.org/licenses/>. */
-#include <sysdep.h>
+#include "multiarch/strlen-vec.S"
-#ifdef AS_WCSLEN
-# define PMINU pminud
-# define PCMPEQ pcmpeqd
-# define SHIFT_RETURN shrq $2, %rax
-#else
-# define PMINU pminub
-# define PCMPEQ pcmpeqb
-# define SHIFT_RETURN
-#endif
-
-/* Long lived register in strlen(s), strnlen(s, n) are:
-
- %xmm3 - zero
- %rdi - s
- %r10 (s+n) & (~(64-1))
- %r11 s+n
-*/
-
-
-.text
-ENTRY(strlen)
-
-/* Test 64 bytes from %rax for zero. Save result as bitmask in %rdx. */
-#define FIND_ZERO \
- PCMPEQ (%rax), %xmm0; \
- PCMPEQ 16(%rax), %xmm1; \
- PCMPEQ 32(%rax), %xmm2; \
- PCMPEQ 48(%rax), %xmm3; \
- pmovmskb %xmm0, %esi; \
- pmovmskb %xmm1, %edx; \
- pmovmskb %xmm2, %r8d; \
- pmovmskb %xmm3, %ecx; \
- salq $16, %rdx; \
- salq $16, %rcx; \
- orq %rsi, %rdx; \
- orq %r8, %rcx; \
- salq $32, %rcx; \
- orq %rcx, %rdx;
-
-#ifdef AS_STRNLEN
-/* Do not read anything when n==0. */
- test %RSI_LP, %RSI_LP
- jne L(n_nonzero)
- xor %rax, %rax
- ret
-L(n_nonzero):
-# ifdef AS_WCSLEN
- shl $2, %RSI_LP
-# endif
-
-/* Initialize long lived registers. */
-
- add %RDI_LP, %RSI_LP
- mov %RSI_LP, %R10_LP
- and $-64, %R10_LP
- mov %RSI_LP, %R11_LP
-#endif
-
- pxor %xmm0, %xmm0
- pxor %xmm1, %xmm1
- pxor %xmm2, %xmm2
- pxor %xmm3, %xmm3
- movq %rdi, %rax
- movq %rdi, %rcx
- andq $4095, %rcx
-/* Offsets 4032-4047 will be aligned into 4032 thus fit into page. */
- cmpq $4047, %rcx
-/* We cannot unify this branching as it would be ~6 cycles slower. */
- ja L(cross_page)
-
-#ifdef AS_STRNLEN
-/* Test if end is among first 64 bytes. */
-# define STRNLEN_PROLOG \
- mov %r11, %rsi; \
- subq %rax, %rsi; \
- andq $-64, %rax; \
- testq $-64, %rsi; \
- je L(strnlen_ret)
-#else
-# define STRNLEN_PROLOG andq $-64, %rax;
-#endif
-
-/* Ignore bits in mask that come before start of string. */
-#define PROLOG(lab) \
- movq %rdi, %rcx; \
- xorq %rax, %rcx; \
- STRNLEN_PROLOG; \
- sarq %cl, %rdx; \
- test %rdx, %rdx; \
- je L(lab); \
- bsfq %rdx, %rax; \
- SHIFT_RETURN; \
- ret
-
-#ifdef AS_STRNLEN
- andq $-16, %rax
- FIND_ZERO
-#else
- /* Test first 16 bytes unaligned. */
- movdqu (%rax), %xmm4
- PCMPEQ %xmm0, %xmm4
- pmovmskb %xmm4, %edx
- test %edx, %edx
- je L(next48_bytes)
- bsf %edx, %eax /* If eax is zeroed 16bit bsf can be used. */
- SHIFT_RETURN
- ret
-
-L(next48_bytes):
-/* Same as FIND_ZERO except we do not check first 16 bytes. */
- andq $-16, %rax
- PCMPEQ 16(%rax), %xmm1
- PCMPEQ 32(%rax), %xmm2
- PCMPEQ 48(%rax), %xmm3
- pmovmskb %xmm1, %edx
- pmovmskb %xmm2, %r8d
- pmovmskb %xmm3, %ecx
- salq $16, %rdx
- salq $16, %rcx
- orq %r8, %rcx
- salq $32, %rcx
- orq %rcx, %rdx
-#endif
-
- /* When no zero byte is found xmm1-3 are zero so we do not have to
- zero them. */
- PROLOG(loop)
-
- .p2align 4
-L(cross_page):
- andq $-64, %rax
- FIND_ZERO
- PROLOG(loop_init)
-
-#ifdef AS_STRNLEN
-/* We must do this check to correctly handle strnlen (s, -1). */
-L(strnlen_ret):
- bts %rsi, %rdx
- sarq %cl, %rdx
- test %rdx, %rdx
- je L(loop_init)
- bsfq %rdx, %rax
- SHIFT_RETURN
- ret
-#endif
- .p2align 4
-L(loop_init):
- pxor %xmm1, %xmm1
- pxor %xmm2, %xmm2
- pxor %xmm3, %xmm3
-#ifdef AS_STRNLEN
- .p2align 4
-L(loop):
-
- addq $64, %rax
- cmpq %rax, %r10
- je L(exit_end)
-
- movdqa (%rax), %xmm0
- PMINU 16(%rax), %xmm0
- PMINU 32(%rax), %xmm0
- PMINU 48(%rax), %xmm0
- PCMPEQ %xmm3, %xmm0
- pmovmskb %xmm0, %edx
- testl %edx, %edx
- jne L(exit)
- jmp L(loop)
-
- .p2align 4
-L(exit_end):
- cmp %rax, %r11
- je L(first) /* Do not read when end is at page boundary. */
- pxor %xmm0, %xmm0
- FIND_ZERO
-
-L(first):
- bts %r11, %rdx
- bsfq %rdx, %rdx
- addq %rdx, %rax
- subq %rdi, %rax
- SHIFT_RETURN
- ret
-
- .p2align 4
-L(exit):
- pxor %xmm0, %xmm0
- FIND_ZERO
-
- bsfq %rdx, %rdx
- addq %rdx, %rax
- subq %rdi, %rax
- SHIFT_RETURN
- ret
-
-#else
-
- /* Main loop. Unrolled twice to improve L2 cache performance on core2. */
- .p2align 4
-L(loop):
-
- movdqa 64(%rax), %xmm0
- PMINU 80(%rax), %xmm0
- PMINU 96(%rax), %xmm0
- PMINU 112(%rax), %xmm0
- PCMPEQ %xmm3, %xmm0
- pmovmskb %xmm0, %edx
- testl %edx, %edx
- jne L(exit64)
-
- subq $-128, %rax
-
- movdqa (%rax), %xmm0
- PMINU 16(%rax), %xmm0
- PMINU 32(%rax), %xmm0
- PMINU 48(%rax), %xmm0
- PCMPEQ %xmm3, %xmm0
- pmovmskb %xmm0, %edx
- testl %edx, %edx
- jne L(exit0)
- jmp L(loop)
-
- .p2align 4
-L(exit64):
- addq $64, %rax
-L(exit0):
- pxor %xmm0, %xmm0
- FIND_ZERO
-
- bsfq %rdx, %rdx
- addq %rdx, %rax
- subq %rdi, %rax
- SHIFT_RETURN
- ret
-
-#endif
-
-END(strlen)
libc_hidden_builtin_def (strlen)
projects / thirdparty / glibc.git / commitdiff
