# define STRRCHR __strrchr_evex
# endif
-# define VMOVU vmovdqu64
-# define VMOVA vmovdqa64
+# define VMOVU vmovdqu64
+# define VMOVA vmovdqa64
# ifdef USE_AS_WCSRCHR
+# define SHIFT_REG esi
+
+# define kunpck kunpckbw
+# define kmov_2x kmovd
+# define maskz_2x ecx
+# define maskm_2x eax
+# define CHAR_SIZE 4
+# define VPMIN vpminud
+# define VPTESTN vptestnmd
# define VPBROADCAST vpbroadcastd
-# define VPCMP vpcmpd
-# define SHIFT_REG r8d
+# define VPCMP vpcmpd
# else
+# define SHIFT_REG edi
+
+# define kunpck kunpckdq
+# define kmov_2x kmovq
+# define maskz_2x rcx
+# define maskm_2x rax
+
+# define CHAR_SIZE 1
+# define VPMIN vpminub
+# define VPTESTN vptestnmb
# define VPBROADCAST vpbroadcastb
-# define VPCMP vpcmpb
-# define SHIFT_REG ecx
+# define VPCMP vpcmpb
# endif
# define XMMZERO xmm16
# define YMMZERO ymm16
# define YMMMATCH ymm17
-# define YMM1 ymm18
+# define YMMSAVE ymm18
+
+# define YMM1 ymm19
+# define YMM2 ymm20
+# define YMM3 ymm21
+# define YMM4 ymm22
+# define YMM5 ymm23
+# define YMM6 ymm24
+# define YMM7 ymm25
+# define YMM8 ymm26
-# define VEC_SIZE 32
- .section .text.evex,"ax",@progbits
-ENTRY (STRRCHR)
- movl %edi, %ecx
+# define VEC_SIZE 32
+# define PAGE_SIZE 4096
+ .section .text.evex, "ax", @progbits
+ENTRY(STRRCHR)
+ movl %edi, %eax
/* Broadcast CHAR to YMMMATCH. */
VPBROADCAST %esi, %YMMMATCH
- vpxorq %XMMZERO, %XMMZERO, %XMMZERO
-
- /* Check if we may cross page boundary with one vector load. */
- andl $(2 * VEC_SIZE - 1), %ecx
- cmpl $VEC_SIZE, %ecx
- ja L(cros_page_boundary)
+ andl $(PAGE_SIZE - 1), %eax
+ cmpl $(PAGE_SIZE - VEC_SIZE), %eax
+ jg L(cross_page_boundary)
+L(page_cross_continue):
VMOVU (%rdi), %YMM1
-
- /* Each bit in K0 represents a null byte in YMM1. */
- VPCMP $0, %YMMZERO, %YMM1, %k0
- /* Each bit in K1 represents a CHAR in YMM1. */
- VPCMP $0, %YMMMATCH, %YMM1, %k1
+ /* k0 has a 1 for each zero CHAR in YMM1. */
+ VPTESTN %YMM1, %YMM1, %k0
kmovd %k0, %ecx
- kmovd %k1, %eax
-
- addq $VEC_SIZE, %rdi
-
- testl %eax, %eax
- jnz L(first_vec)
-
testl %ecx, %ecx
- jnz L(return_null)
-
- andq $-VEC_SIZE, %rdi
- xorl %edx, %edx
- jmp L(aligned_loop)
-
- .p2align 4
-L(first_vec):
- /* Check if there is a null byte. */
- testl %ecx, %ecx
- jnz L(char_and_nul_in_first_vec)
-
- /* Remember the match and keep searching. */
- movl %eax, %edx
- movq %rdi, %rsi
- andq $-VEC_SIZE, %rdi
- jmp L(aligned_loop)
-
- .p2align 4
-L(cros_page_boundary):
- andl $(VEC_SIZE - 1), %ecx
- andq $-VEC_SIZE, %rdi
+ jz L(aligned_more)
+ /* fallthrough: zero CHAR in first VEC. */
+ /* K1 has a 1 for each search CHAR match in YMM1. */
+ VPCMP $0, %YMMMATCH, %YMM1, %k1
+ kmovd %k1, %eax
+ /* Build mask up until first zero CHAR (used to mask of
+ potential search CHAR matches past the end of the string).
+ */
+ blsmskl %ecx, %ecx
+ andl %ecx, %eax
+ jz L(ret0)
+ /* Get last match (the `andl` removed any out of bounds
+ matches). */
+ bsrl %eax, %eax
# ifdef USE_AS_WCSRCHR
- /* NB: Divide shift count by 4 since each bit in K1 represent 4
- bytes. */
- movl %ecx, %SHIFT_REG
- sarl $2, %SHIFT_REG
+ leaq (%rdi, %rax, CHAR_SIZE), %rax
+# else
+ addq %rdi, %rax
# endif
+L(ret0):
+ ret
- VMOVA (%rdi), %YMM1
-
- /* Each bit in K0 represents a null byte in YMM1. */
- VPCMP $0, %YMMZERO, %YMM1, %k0
- /* Each bit in K1 represents a CHAR in YMM1. */
+ /* Returns for first vec x1/x2/x3 have hard coded backward
+ search path for earlier matches. */
+ .p2align 4,, 6
+L(first_vec_x1):
+ VPCMP $0, %YMMMATCH, %YMM2, %k1
+ kmovd %k1, %eax
+ blsmskl %ecx, %ecx
+ /* eax non-zero if search CHAR in range. */
+ andl %ecx, %eax
+ jnz L(first_vec_x1_return)
+
+ /* fallthrough: no match in YMM2 then need to check for earlier
+ matches (in YMM1). */
+ .p2align 4,, 4
+L(first_vec_x0_test):
VPCMP $0, %YMMMATCH, %YMM1, %k1
- kmovd %k0, %edx
kmovd %k1, %eax
-
- shrxl %SHIFT_REG, %edx, %edx
- shrxl %SHIFT_REG, %eax, %eax
- addq $VEC_SIZE, %rdi
-
- /* Check if there is a CHAR. */
testl %eax, %eax
- jnz L(found_char)
-
- testl %edx, %edx
- jnz L(return_null)
-
- jmp L(aligned_loop)
-
- .p2align 4
-L(found_char):
- testl %edx, %edx
- jnz L(char_and_nul)
-
- /* Remember the match and keep searching. */
- movl %eax, %edx
- leaq (%rdi, %rcx), %rsi
+ jz L(ret1)
+ bsrl %eax, %eax
+# ifdef USE_AS_WCSRCHR
+ leaq (%rsi, %rax, CHAR_SIZE), %rax
+# else
+ addq %rsi, %rax
+# endif
+L(ret1):
+ ret
- .p2align 4
-L(aligned_loop):
- VMOVA (%rdi), %YMM1
- addq $VEC_SIZE, %rdi
+ .p2align 4,, 10
+L(first_vec_x1_or_x2):
+ VPCMP $0, %YMM3, %YMMMATCH, %k3
+ VPCMP $0, %YMM2, %YMMMATCH, %k2
+ /* K2 and K3 have 1 for any search CHAR match. Test if any
+ matches between either of them. Otherwise check YMM1. */
+ kortestd %k2, %k3
+ jz L(first_vec_x0_test)
+
+ /* Guranteed that YMM2 and YMM3 are within range so merge the
+ two bitmasks then get last result. */
+ kunpck %k2, %k3, %k3
+ kmovq %k3, %rax
+ bsrq %rax, %rax
+ leaq (VEC_SIZE)(%r8, %rax, CHAR_SIZE), %rax
+ ret
- /* Each bit in K0 represents a null byte in YMM1. */
- VPCMP $0, %YMMZERO, %YMM1, %k0
- /* Each bit in K1 represents a CHAR in YMM1. */
- VPCMP $0, %YMMMATCH, %YMM1, %k1
- kmovd %k0, %ecx
+ .p2align 4,, 6
+L(first_vec_x3):
+ VPCMP $0, %YMMMATCH, %YMM4, %k1
kmovd %k1, %eax
- orl %eax, %ecx
- jnz L(char_nor_null)
+ blsmskl %ecx, %ecx
+ /* If no search CHAR match in range check YMM1/YMM2/YMM3. */
+ andl %ecx, %eax
+ jz L(first_vec_x1_or_x2)
+ bsrl %eax, %eax
+ leaq (VEC_SIZE * 3)(%rdi, %rax, CHAR_SIZE), %rax
+ ret
- VMOVA (%rdi), %YMM1
- add $VEC_SIZE, %rdi
+ .p2align 4,, 6
+L(first_vec_x0_x1_test):
+ VPCMP $0, %YMMMATCH, %YMM2, %k1
+ kmovd %k1, %eax
+ /* Check YMM2 for last match first. If no match try YMM1. */
+ testl %eax, %eax
+ jz L(first_vec_x0_test)
+ .p2align 4,, 4
+L(first_vec_x1_return):
+ bsrl %eax, %eax
+ leaq (VEC_SIZE)(%rdi, %rax, CHAR_SIZE), %rax
+ ret
- /* Each bit in K0 represents a null byte in YMM1. */
- VPCMP $0, %YMMZERO, %YMM1, %k0
- /* Each bit in K1 represents a CHAR in YMM1. */
- VPCMP $0, %YMMMATCH, %YMM1, %k1
- kmovd %k0, %ecx
+ .p2align 4,, 10
+L(first_vec_x2):
+ VPCMP $0, %YMMMATCH, %YMM3, %k1
kmovd %k1, %eax
- orl %eax, %ecx
- jnz L(char_nor_null)
+ blsmskl %ecx, %ecx
+ /* Check YMM3 for last match first. If no match try YMM2/YMM1.
+ */
+ andl %ecx, %eax
+ jz L(first_vec_x0_x1_test)
+ bsrl %eax, %eax
+ leaq (VEC_SIZE * 2)(%rdi, %rax, CHAR_SIZE), %rax
+ ret
- VMOVA (%rdi), %YMM1
- addq $VEC_SIZE, %rdi
- /* Each bit in K0 represents a null byte in YMM1. */
- VPCMP $0, %YMMZERO, %YMM1, %k0
- /* Each bit in K1 represents a CHAR in YMM1. */
- VPCMP $0, %YMMMATCH, %YMM1, %k1
+ .p2align 4
+L(aligned_more):
+ /* Need to keep original pointer incase YMM1 has last match. */
+ movq %rdi, %rsi
+ andq $-VEC_SIZE, %rdi
+ VMOVU VEC_SIZE(%rdi), %YMM2
+ VPTESTN %YMM2, %YMM2, %k0
kmovd %k0, %ecx
- kmovd %k1, %eax
- orl %eax, %ecx
- jnz L(char_nor_null)
+ testl %ecx, %ecx
+ jnz L(first_vec_x1)
- VMOVA (%rdi), %YMM1
- addq $VEC_SIZE, %rdi
+ VMOVU (VEC_SIZE * 2)(%rdi), %YMM3
+ VPTESTN %YMM3, %YMM3, %k0
+ kmovd %k0, %ecx
+ testl %ecx, %ecx
+ jnz L(first_vec_x2)
- /* Each bit in K0 represents a null byte in YMM1. */
- VPCMP $0, %YMMZERO, %YMM1, %k0
- /* Each bit in K1 represents a CHAR in YMM1. */
- VPCMP $0, %YMMMATCH, %YMM1, %k1
+ VMOVU (VEC_SIZE * 3)(%rdi), %YMM4
+ VPTESTN %YMM4, %YMM4, %k0
kmovd %k0, %ecx
- kmovd %k1, %eax
- orl %eax, %ecx
- jz L(aligned_loop)
+ movq %rdi, %r8
+ testl %ecx, %ecx
+ jnz L(first_vec_x3)
+ andq $-(VEC_SIZE * 2), %rdi
.p2align 4
-L(char_nor_null):
- /* Find a CHAR or a null byte in a loop. */
+L(first_aligned_loop):
+ /* Preserve YMM1, YMM2, YMM3, and YMM4 until we can gurantee
+ they don't store a match. */
+ VMOVA (VEC_SIZE * 4)(%rdi), %YMM5
+ VMOVA (VEC_SIZE * 5)(%rdi), %YMM6
+
+ VPCMP $0, %YMM5, %YMMMATCH, %k2
+ vpxord %YMM6, %YMMMATCH, %YMM7
+
+ VPMIN %YMM5, %YMM6, %YMM8
+ VPMIN %YMM8, %YMM7, %YMM7
+
+ VPTESTN %YMM7, %YMM7, %k1
+ subq $(VEC_SIZE * -2), %rdi
+ kortestd %k1, %k2
+ jz L(first_aligned_loop)
+
+ VPCMP $0, %YMM6, %YMMMATCH, %k3
+ VPTESTN %YMM8, %YMM8, %k1
+ ktestd %k1, %k1
+ jz L(second_aligned_loop_prep)
+
+ kortestd %k2, %k3
+ jnz L(return_first_aligned_loop)
+
+ .p2align 4,, 6
+L(first_vec_x1_or_x2_or_x3):
+ VPCMP $0, %YMM4, %YMMMATCH, %k4
+ kmovd %k4, %eax
testl %eax, %eax
- jnz L(match)
-L(return_value):
- testl %edx, %edx
- jz L(return_null)
- movl %edx, %eax
- movq %rsi, %rdi
+ jz L(first_vec_x1_or_x2)
bsrl %eax, %eax
-# ifdef USE_AS_WCSRCHR
- /* NB: Multiply wchar_t count by 4 to get the number of bytes. */
- leaq -VEC_SIZE(%rdi, %rax, 4), %rax
-# else
- leaq -VEC_SIZE(%rdi, %rax), %rax
-# endif
+ leaq (VEC_SIZE * 3)(%r8, %rax, CHAR_SIZE), %rax
ret
- .p2align 4
-L(match):
- /* Find a CHAR. Check if there is a null byte. */
- kmovd %k0, %ecx
- testl %ecx, %ecx
- jnz L(find_nul)
+ .p2align 4,, 8
+L(return_first_aligned_loop):
+ VPTESTN %YMM5, %YMM5, %k0
+ kunpck %k0, %k1, %k0
+ kmov_2x %k0, %maskz_2x
+
+ blsmsk %maskz_2x, %maskz_2x
+ kunpck %k2, %k3, %k3
+ kmov_2x %k3, %maskm_2x
+ and %maskz_2x, %maskm_2x
+ jz L(first_vec_x1_or_x2_or_x3)
- /* Remember the match and keep searching. */
- movl %eax, %edx
+ bsr %maskm_2x, %maskm_2x
+ leaq (VEC_SIZE * 2)(%rdi, %rax, CHAR_SIZE), %rax
+ ret
+
+ .p2align 4
+ /* We can throw away the work done for the first 4x checks here
+ as we have a later match. This is the 'fast' path persay.
+ */
+L(second_aligned_loop_prep):
+L(second_aligned_loop_set_furthest_match):
movq %rdi, %rsi
- jmp L(aligned_loop)
+ kunpck %k2, %k3, %k4
.p2align 4
-L(find_nul):
- /* Mask out any matching bits after the null byte. */
- movl %ecx, %r8d
- subl $1, %r8d
- xorl %ecx, %r8d
- andl %r8d, %eax
- testl %eax, %eax
- /* If there is no CHAR here, return the remembered one. */
- jz L(return_value)
- bsrl %eax, %eax
+L(second_aligned_loop):
+ VMOVU (VEC_SIZE * 4)(%rdi), %YMM1
+ VMOVU (VEC_SIZE * 5)(%rdi), %YMM2
+
+ VPCMP $0, %YMM1, %YMMMATCH, %k2
+ vpxord %YMM2, %YMMMATCH, %YMM3
+
+ VPMIN %YMM1, %YMM2, %YMM4
+ VPMIN %YMM3, %YMM4, %YMM3
+
+ VPTESTN %YMM3, %YMM3, %k1
+ subq $(VEC_SIZE * -2), %rdi
+ kortestd %k1, %k2
+ jz L(second_aligned_loop)
+
+ VPCMP $0, %YMM2, %YMMMATCH, %k3
+ VPTESTN %YMM4, %YMM4, %k1
+ ktestd %k1, %k1
+ jz L(second_aligned_loop_set_furthest_match)
+
+ kortestd %k2, %k3
+ /* branch here because there is a significant advantage interms
+ of output dependency chance in using edx. */
+ jnz L(return_new_match)
+L(return_old_match):
+ kmovq %k4, %rax
+ bsrq %rax, %rax
+ leaq (VEC_SIZE * 2)(%rsi, %rax, CHAR_SIZE), %rax
+ ret
+
+L(return_new_match):
+ VPTESTN %YMM1, %YMM1, %k0
+ kunpck %k0, %k1, %k0
+ kmov_2x %k0, %maskz_2x
+
+ blsmsk %maskz_2x, %maskz_2x
+ kunpck %k2, %k3, %k3
+ kmov_2x %k3, %maskm_2x
+ and %maskz_2x, %maskm_2x
+ jz L(return_old_match)
+
+ bsr %maskm_2x, %maskm_2x
+ leaq (VEC_SIZE * 2)(%rdi, %rax, CHAR_SIZE), %rax
+ ret
+
+L(cross_page_boundary):
+ /* eax contains all the page offset bits of src (rdi). `xor rdi,
+ rax` sets pointer will all page offset bits cleared so
+ offset of (PAGE_SIZE - VEC_SIZE) will get last aligned VEC
+ before page cross (guranteed to be safe to read). Doing this
+ as opposed to `movq %rdi, %rax; andq $-VEC_SIZE, %rax` saves
+ a bit of code size. */
+ xorq %rdi, %rax
+ VMOVU (PAGE_SIZE - VEC_SIZE)(%rax), %YMM1
+ VPTESTN %YMM1, %YMM1, %k0
+ kmovd %k0, %ecx
+
+ /* Shift out zero CHAR matches that are before the begining of
+ src (rdi). */
# ifdef USE_AS_WCSRCHR
- /* NB: Multiply wchar_t count by 4 to get the number of bytes. */
- leaq -VEC_SIZE(%rdi, %rax, 4), %rax
-# else
- leaq -VEC_SIZE(%rdi, %rax), %rax
+ movl %edi, %esi
+ andl $(VEC_SIZE - 1), %esi
+ shrl $2, %esi
# endif
- ret
+ shrxl %SHIFT_REG, %ecx, %ecx
- .p2align 4
-L(char_and_nul):
- /* Find both a CHAR and a null byte. */
- addq %rcx, %rdi
- movl %edx, %ecx
-L(char_and_nul_in_first_vec):
- /* Mask out any matching bits after the null byte. */
- movl %ecx, %r8d
- subl $1, %r8d
- xorl %ecx, %r8d
- andl %r8d, %eax
- testl %eax, %eax
- /* Return null pointer if the null byte comes first. */
- jz L(return_null)
+ testl %ecx, %ecx
+ jz L(page_cross_continue)
+
+ /* Found zero CHAR so need to test for search CHAR. */
+ VPCMP $0, %YMMMATCH, %YMM1, %k1
+ kmovd %k1, %eax
+ /* Shift out search CHAR matches that are before the begining of
+ src (rdi). */
+ shrxl %SHIFT_REG, %eax, %eax
+
+ /* Check if any search CHAR match in range. */
+ blsmskl %ecx, %ecx
+ andl %ecx, %eax
+ jz L(ret3)
bsrl %eax, %eax
# ifdef USE_AS_WCSRCHR
- /* NB: Multiply wchar_t count by 4 to get the number of bytes. */
- leaq -VEC_SIZE(%rdi, %rax, 4), %rax
+ leaq (%rdi, %rax, CHAR_SIZE), %rax
# else
- leaq -VEC_SIZE(%rdi, %rax), %rax
+ addq %rdi, %rax
# endif
+L(ret3):
ret
- .p2align 4
-L(return_null):
- xorl %eax, %eax
- ret
-
-END (STRRCHR)
+END(STRRCHR)
#endif
projects / thirdparty / glibc.git / commitdiff
