@@ -35,7 +35,6 @@
# define CHAR_SIZE 4
# define VPCMP vpcmpd
# define VPMIN vpminud
-# define VPCOMPRESS vpcompressd
# define VPTESTN vptestnmd
# define VPTEST vptestmd
# define VPBROADCAST vpbroadcastd
@@ -46,7 +45,6 @@
# define CHAR_SIZE 1
# define VPCMP vpcmpb
# define VPMIN vpminub
-# define VPCOMPRESS vpcompressb
# define VPTESTN vptestnmb
# define VPTEST vptestmb
# define VPBROADCAST vpbroadcastb
@@ -71,7 +69,7 @@ ENTRY_P2ALIGN(STRRCHR, 6)
andl $(PAGE_SIZE - 1), %eax
cmpl $(PAGE_SIZE - VEC_SIZE), %eax
jg L(cross_page_boundary)
-
+L(page_cross_continue):
VMOVU (%rdi), %VMM(1)
/* k0 has a 1 for each zero CHAR in YMM1. */
VPTESTN %VMM(1), %VMM(1), %k0
@@ -79,7 +77,7 @@ ENTRY_P2ALIGN(STRRCHR, 6)
test %VGPR(rsi), %VGPR(rsi)
jz L(aligned_more)
/* fallthrough: zero CHAR in first VEC. */
-L(page_cross_return):
+
/* K1 has a 1 for each search CHAR match in VEC(1). */
VPCMPEQ %VMATCH, %VMM(1), %k1
KMOV %k1, %VGPR(rax)
@@ -167,7 +165,6 @@ L(first_vec_x1_return):
.p2align 4,, 12
L(aligned_more):
-L(page_cross_continue):
/* Need to keep original pointer incase VEC(1) has last match. */
movq %rdi, %rsi
andq $-VEC_SIZE, %rdi
@@ -340,34 +337,49 @@ L(return_new_match_ret):
leaq (VEC_SIZE * 2)(%rdi, %rax, CHAR_SIZE), %rax
ret
- .p2align 4,, 4
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 (guaranteed 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
- mov $-1, %VRDX
- VMOVU (PAGE_SIZE - VEC_SIZE)(%rax), %VMM(6)
- VPTESTN %VMM(6), %VMM(6), %k0
+ VMOVU (PAGE_SIZE - VEC_SIZE)(%rax), %VMM(1)
+ VPTESTN %VMM(1), %VMM(1), %k0
KMOV %k0, %VRSI
+ /* Shift out zero CHAR matches that are before the beginning of
+ src (rdi). */
# ifdef USE_AS_WCSRCHR
movl %edi, %ecx
- and $(VEC_SIZE - 1), %ecx
+ andl $(VEC_SIZE - 1), %ecx
shrl $2, %ecx
# endif
- shlx %SHIFT_REG, %VRDX, %VRDX
-
-# ifdef USE_AS_WCSRCHR
- kmovw %edx, %k1
-# else
- KMOV %VRDX, %k1
-# endif
-
- VPCOMPRESS %VMM(6), %VMM(1){%k1}{z}
- /* We could technically just jmp back after the vpcompress but
- it doesn't save any 16-byte blocks. */
shrx %SHIFT_REG, %VRSI, %VRSI
+
test %VRSI, %VRSI
- jnz L(page_cross_return)
- jmp L(page_cross_continue)
- /* 1-byte from cache line. */
+ jz L(page_cross_continue)
+
+ /* Found zero CHAR so need to test for search CHAR. */
+ VPCMP $0, %VMATCH, %VMM(1), %k1
+ KMOV %k1, %VRAX
+ /* Shift out search CHAR matches that are before the beginning of
+ src (rdi). */
+ shrx %SHIFT_REG, %VRAX, %VRAX
+ /* Check if any search CHAR match in range. */
+ blsmsk %VRSI, %VRSI
+ and %VRSI, %VRAX
+ jz L(ret2)
+ bsr %VRAX, %VRAX
+# ifdef USE_AS_WCSRCHR
+ leaq (%rdi, %rax, CHAR_SIZE), %rax
+# else
+ addq %rdi, %rax
+# endif
+L(ret2):
+ ret
+ /* 3 bytes from cache-line for evex.
+ Crosses cache line for evex512. */
END(STRRCHR)
#endif
strrchr-evex-base used `vpcompress{b|d}` in the page cross logic but was missing the CPU_FEATURE checks for VBMI2 in the ifunc/ifunc-impl-list. The fix is either to add those checks or change the logic to not use `vpcompress{b|d}`. Choosing the latter here so that the strrchr-evex implementation is usable on SKX. New implementation is a bit slower, but this is in a cold path so its probably okay. --- sysdeps/x86_64/multiarch/strrchr-evex-base.S | 60 ++++++++++++-------- 1 file changed, 36 insertions(+), 24 deletions(-)