mirror of
https://github.com/golang/go.git
synced 2025-12-08 06:10:04 +00:00
strings: add asm version of Index() for short strings on amd64
Currently we have special case for 1-byte strings, This extends this to strings shorter than 32 bytes on amd64. Results (broadwell): name old time/op new time/op delta IndexRune-4 57.4ns ± 0% 57.5ns ± 0% +0.10% (p=0.000 n=20+19) IndexRuneFastPath-4 20.4ns ± 0% 20.4ns ± 0% ~ (all samples are equal) Index-4 21.0ns ± 0% 21.8ns ± 0% +3.81% (p=0.000 n=20+20) LastIndex-4 7.07ns ± 1% 6.98ns ± 0% -1.21% (p=0.000 n=20+16) IndexByte-4 18.3ns ± 0% 18.3ns ± 0% ~ (all samples are equal) IndexHard1-4 1.46ms ± 0% 0.39ms ± 0% -73.06% (p=0.000 n=16+16) IndexHard2-4 1.46ms ± 0% 0.30ms ± 0% -79.55% (p=0.000 n=18+18) IndexHard3-4 1.46ms ± 0% 0.66ms ± 0% -54.68% (p=0.000 n=19+19) LastIndexHard1-4 1.46ms ± 0% 1.46ms ± 0% -0.01% (p=0.036 n=18+20) LastIndexHard2-4 1.46ms ± 0% 1.46ms ± 0% ~ (p=0.588 n=19+19) LastIndexHard3-4 1.46ms ± 0% 1.46ms ± 0% ~ (p=0.283 n=17+20) IndexTorture-4 11.1µs ± 0% 11.1µs ± 0% +0.01% (p=0.000 n=18+17) Change-Id: I892781549f558f698be4e41f9f568e3d0611efb5 Reviewed-on: https://go-review.googlesource.com/16430 Reviewed-by: Keith Randall <khr@golang.org> Run-TryBot: Ilya Tocar <ilya.tocar@intel.com>
This commit is contained in:
Ilya Tocar
Keith Randall
parent
1870572180
commit
95333aea53
5 changed files with 311 additions and 37 deletions
|
|
@ -1725,6 +1725,168 @@ big_loop_avx2_exit:
|
|||
JMP loop
|
||||
|
||||
|
||||
// TODO: Also use this in bytes.Index
|
||||
TEXT strings·indexShortStr(SB),NOSPLIT,$0-40
|
||||
MOVQ s+0(FP), DI
|
||||
MOVQ s_len+8(FP), CX
|
||||
MOVQ c+16(FP), AX
|
||||
MOVQ c_len+24(FP), BX
|
||||
CMPQ BX, CX
|
||||
JA fail
|
||||
CMPQ BX, $2
|
||||
JA _3_or_more
|
||||
MOVW (AX), AX
|
||||
LEAQ -1(DI)(CX*1), CX
|
||||
loop2:
|
||||
MOVW (DI), SI
|
||||
CMPW SI,AX
|
||||
JZ success
|
||||
ADDQ $1,DI
|
||||
CMPQ DI,CX
|
||||
JB loop2
|
||||
JMP fail
|
||||
_3_or_more:
|
||||
CMPQ BX, $3
|
||||
JA _4_or_more
|
||||
MOVW 1(AX), DX
|
||||
MOVW (AX), AX
|
||||
LEAQ -2(DI)(CX*1), CX
|
||||
loop3:
|
||||
MOVW (DI), SI
|
||||
CMPW SI,AX
|
||||
JZ partial_success3
|
||||
ADDQ $1,DI
|
||||
CMPQ DI,CX
|
||||
JB loop3
|
||||
JMP fail
|
||||
partial_success3:
|
||||
MOVW 1(DI), SI
|
||||
CMPW SI,DX
|
||||
JZ success
|
||||
ADDQ $1,DI
|
||||
CMPQ DI,CX
|
||||
JB loop3
|
||||
JMP fail
|
||||
_4_or_more:
|
||||
CMPQ BX, $4
|
||||
JA _5_or_more
|
||||
MOVL (AX), AX
|
||||
LEAQ -3(DI)(CX*1), CX
|
||||
loop4:
|
||||
MOVL (DI), SI
|
||||
CMPL SI,AX
|
||||
JZ success
|
||||
ADDQ $1,DI
|
||||
CMPQ DI,CX
|
||||
JB loop4
|
||||
JMP fail
|
||||
_5_or_more:
|
||||
CMPQ BX, $7
|
||||
JA _8_or_more
|
||||
LEAQ 1(DI)(CX*1), CX
|
||||
SUBQ BX, CX
|
||||
MOVL -4(AX)(BX*1), DX
|
||||
MOVL (AX), AX
|
||||
loop5to7:
|
||||
MOVL (DI), SI
|
||||
CMPL SI,AX
|
||||
JZ partial_success5to7
|
||||
ADDQ $1,DI
|
||||
CMPQ DI,CX
|
||||
JB loop5to7
|
||||
JMP fail
|
||||
partial_success5to7:
|
||||
MOVL -4(BX)(DI*1), SI
|
||||
CMPL SI,DX
|
||||
JZ success
|
||||
ADDQ $1,DI
|
||||
CMPQ DI,CX
|
||||
JB loop5to7
|
||||
JMP fail
|
||||
_8_or_more:
|
||||
CMPQ BX, $8
|
||||
JA _9_or_more
|
||||
MOVQ (AX), AX
|
||||
LEAQ -7(DI)(CX*1), CX
|
||||
loop8:
|
||||
MOVQ (DI), SI
|
||||
CMPQ SI,AX
|
||||
JZ success
|
||||
ADDQ $1,DI
|
||||
CMPQ DI,CX
|
||||
JB loop8
|
||||
JMP fail
|
||||
_9_or_more:
|
||||
CMPQ BX, $16
|
||||
JA _16_or_more
|
||||
LEAQ 1(DI)(CX*1), CX
|
||||
SUBQ BX, CX
|
||||
MOVQ -8(AX)(BX*1), DX
|
||||
MOVQ (AX), AX
|
||||
loop9to15:
|
||||
MOVQ (DI), SI
|
||||
CMPQ SI,AX
|
||||
JZ partial_success9to15
|
||||
ADDQ $1,DI
|
||||
CMPQ DI,CX
|
||||
JB loop9to15
|
||||
JMP fail
|
||||
partial_success9to15:
|
||||
MOVQ -8(BX)(DI*1), SI
|
||||
CMPQ SI,DX
|
||||
JZ success
|
||||
ADDQ $1,DI
|
||||
CMPQ DI,CX
|
||||
JB loop9to15
|
||||
JMP fail
|
||||
_16_or_more:
|
||||
CMPQ BX, $16
|
||||
JA _17_to_31
|
||||
MOVOU (AX), X1
|
||||
LEAQ -15(DI)(CX*1), CX
|
||||
loop16:
|
||||
MOVOU (DI), X2
|
||||
PCMPEQB X1, X2
|
||||
PMOVMSKB X2, SI
|
||||
CMPQ SI, $0xffff
|
||||
JE success
|
||||
ADDQ $1,DI
|
||||
CMPQ DI,CX
|
||||
JB loop16
|
||||
JMP fail
|
||||
_17_to_31:
|
||||
LEAQ 1(DI)(CX*1), CX
|
||||
SUBQ BX, CX
|
||||
MOVOU -16(AX)(BX*1), X0
|
||||
MOVOU (AX), X1
|
||||
loop17to31:
|
||||
MOVOU (DI), X2
|
||||
PCMPEQB X1,X2
|
||||
PMOVMSKB X2, SI
|
||||
CMPQ SI, $0xffff
|
||||
JE partial_success17to31
|
||||
ADDQ $1,DI
|
||||
CMPQ DI,CX
|
||||
JB loop17to31
|
||||
JMP fail
|
||||
partial_success17to31:
|
||||
MOVOU -16(BX)(DI*1), X3
|
||||
PCMPEQB X0, X3
|
||||
PMOVMSKB X3, SI
|
||||
CMPQ SI, $0xffff
|
||||
JE success
|
||||
ADDQ $1,DI
|
||||
CMPQ DI,CX
|
||||
JB loop17to31
|
||||
fail:
|
||||
MOVQ $-1, ret+32(FP)
|
||||
RET
|
||||
success:
|
||||
SUBQ s+0(FP), DI
|
||||
MOVQ DI, ret+32(FP)
|
||||
RET
|
||||
|
||||
|
||||
TEXT bytes·IndexByte(SB),NOSPLIT,$0-40
|
||||
MOVQ s+0(FP), SI
|
||||
MOVQ s_len+8(FP), BX
|
||||
|
|
|
|||
|
|
@ -143,43 +143,6 @@ func ContainsRune(s string, r rune) bool {
|
|||
return IndexRune(s, r) >= 0
|
||||
}
|
||||
|
||||
// Index returns the index of the first instance of sep in s, or -1 if sep is not present in s.
|
||||
func Index(s, sep string) int {
|
||||
n := len(sep)
|
||||
switch {
|
||||
case n == 0:
|
||||
return 0
|
||||
case n == 1:
|
||||
return IndexByte(s, sep[0])
|
||||
case n == len(s):
|
||||
if sep == s {
|
||||
return 0
|
||||
}
|
||||
return -1
|
||||
case n > len(s):
|
||||
return -1
|
||||
}
|
||||
// Rabin-Karp search
|
||||
hashsep, pow := hashStr(sep)
|
||||
var h uint32
|
||||
for i := 0; i < n; i++ {
|
||||
h = h*primeRK + uint32(s[i])
|
||||
}
|
||||
if h == hashsep && s[:n] == sep {
|
||||
return 0
|
||||
}
|
||||
for i := n; i < len(s); {
|
||||
h *= primeRK
|
||||
h += uint32(s[i])
|
||||
h -= pow * uint32(s[i-n])
|
||||
i++
|
||||
if h == hashsep && s[i-n:i] == sep {
|
||||
return i - n
|
||||
}
|
||||
}
|
||||
return -1
|
||||
}
|
||||
|
||||
// LastIndex returns the index of the last instance of sep in s, or -1 if sep is not present in s.
|
||||
func LastIndex(s, sep string) int {
|
||||
n := len(sep)
|
||||
|
|
|
|||
49
src/strings/strings_amd64.go
Normal file
49
src/strings/strings_amd64.go
Normal file
|
|
@ -0,0 +1,49 @@
|
|||
// Copyright 2015 The Go Authors. All rights reserved.
|
||||
// Use of this source code is governed by a BSD-style
|
||||
// license that can be found in the LICENSE file.
|
||||
|
||||
package strings
|
||||
|
||||
// indexShortStr returns the index of the first instance of c in s, or -1 if c is not present in s.
|
||||
// indexShortStr requires 2 <= len(c) <= shortStringLen
|
||||
func indexShortStr(s, c string) int // ../runtime/asm_$GOARCH.s
|
||||
const shortStringLen = 31
|
||||
|
||||
// Index returns the index of the first instance of sep in s, or -1 if sep is not present in s.
|
||||
func Index(s, sep string) int {
|
||||
n := len(sep)
|
||||
switch {
|
||||
case n == 0:
|
||||
return 0
|
||||
case n == 1:
|
||||
return IndexByte(s, sep[0])
|
||||
case n <= shortStringLen:
|
||||
return indexShortStr(s, sep)
|
||||
case n == len(s):
|
||||
if sep == s {
|
||||
return 0
|
||||
}
|
||||
return -1
|
||||
case n > len(s):
|
||||
return -1
|
||||
}
|
||||
// Rabin-Karp search
|
||||
hashsep, pow := hashStr(sep)
|
||||
var h uint32
|
||||
for i := 0; i < n; i++ {
|
||||
h = h*primeRK + uint32(s[i])
|
||||
}
|
||||
if h == hashsep && s[:n] == sep {
|
||||
return 0
|
||||
}
|
||||
for i := n; i < len(s); {
|
||||
h *= primeRK
|
||||
h += uint32(s[i])
|
||||
h -= pow * uint32(s[i-n])
|
||||
i++
|
||||
if h == hashsep && s[i-n:i] == sep {
|
||||
return i - n
|
||||
}
|
||||
}
|
||||
return -1
|
||||
}
|
||||
47
src/strings/strings_generic.go
Normal file
47
src/strings/strings_generic.go
Normal file
|
|
@ -0,0 +1,47 @@
|
|||
// Copyright 2015 The Go Authors. All rights reserved.
|
||||
// Use of this source code is governed by a BSD-style
|
||||
// license that can be found in the LICENSE file.
|
||||
|
||||
// +build !amd64
|
||||
|
||||
package strings
|
||||
|
||||
// TODO: implements short string optimization on non amd64 platforms
|
||||
// and get rid of strings_amd64.go
|
||||
|
||||
// Index returns the index of the first instance of sep in s, or -1 if sep is not present in s.
|
||||
func Index(s, sep string) int {
|
||||
n := len(sep)
|
||||
switch {
|
||||
case n == 0:
|
||||
return 0
|
||||
case n == 1:
|
||||
return IndexByte(s, sep[0])
|
||||
case n == len(s):
|
||||
if sep == s {
|
||||
return 0
|
||||
}
|
||||
return -1
|
||||
case n > len(s):
|
||||
return -1
|
||||
}
|
||||
// Rabin-Karp search
|
||||
hashsep, pow := hashStr(sep)
|
||||
var h uint32
|
||||
for i := 0; i < n; i++ {
|
||||
h = h*primeRK + uint32(s[i])
|
||||
}
|
||||
if h == hashsep && s[:n] == sep {
|
||||
return 0
|
||||
}
|
||||
for i := n; i < len(s); {
|
||||
h *= primeRK
|
||||
h += uint32(s[i])
|
||||
h -= pow * uint32(s[i-n])
|
||||
i++
|
||||
if h == hashsep && s[i-n:i] == sep {
|
||||
return i - n
|
||||
}
|
||||
}
|
||||
return -1
|
||||
}
|
||||
|
|
@ -59,6 +59,59 @@ var indexTests = []IndexTest{
|
|||
{"abc", "b", 1},
|
||||
{"abc", "c", 2},
|
||||
{"abc", "x", -1},
|
||||
// test special cases in Index() for short strings
|
||||
{"", "ab", -1},
|
||||
{"bc", "ab", -1},
|
||||
{"ab", "ab", 0},
|
||||
{"xab", "ab", 1},
|
||||
{"xab"[:2], "ab", -1},
|
||||
{"", "abc", -1},
|
||||
{"xbc", "abc", -1},
|
||||
{"abc", "abc", 0},
|
||||
{"xabc", "abc", 1},
|
||||
{"xabc"[:3], "abc", -1},
|
||||
{"xabxc", "abc", -1},
|
||||
{"", "abcd", -1},
|
||||
{"xbcd", "abcd", -1},
|
||||
{"abcd", "abcd", 0},
|
||||
{"xabcd", "abcd", 1},
|
||||
{"xyabcd"[:5], "abcd", -1},
|
||||
{"xbcqq", "abcqq", -1},
|
||||
{"abcqq", "abcqq", 0},
|
||||
{"xabcqq", "abcqq", 1},
|
||||
{"xyabcqq"[:6], "abcqq", -1},
|
||||
{"xabxcqq", "abcqq", -1},
|
||||
{"xabcqxq", "abcqq", -1},
|
||||
{"", "01234567", -1},
|
||||
{"32145678", "01234567", -1},
|
||||
{"01234567", "01234567", 0},
|
||||
{"x01234567", "01234567", 1},
|
||||
{"xx01234567"[:9], "01234567", -1},
|
||||
{"", "0123456789", -1},
|
||||
{"3214567844", "0123456789", -1},
|
||||
{"0123456789", "0123456789", 0},
|
||||
{"x0123456789", "0123456789", 1},
|
||||
{"xyz0123456789"[:12], "0123456789", -1},
|
||||
{"x01234567x89", "0123456789", -1},
|
||||
{"", "0123456789012345", -1},
|
||||
{"3214567889012345", "0123456789012345", -1},
|
||||
{"0123456789012345", "0123456789012345", 0},
|
||||
{"x0123456789012345", "0123456789012345", 1},
|
||||
{"", "01234567890123456789", -1},
|
||||
{"32145678890123456789", "01234567890123456789", -1},
|
||||
{"01234567890123456789", "01234567890123456789", 0},
|
||||
{"x01234567890123456789", "01234567890123456789", 1},
|
||||
{"xyz01234567890123456789"[:22], "01234567890123456789", -1},
|
||||
{"", "0123456789012345678901234567890", -1},
|
||||
{"321456788901234567890123456789012345678911", "0123456789012345678901234567890", -1},
|
||||
{"0123456789012345678901234567890", "0123456789012345678901234567890", 0},
|
||||
{"x0123456789012345678901234567890", "0123456789012345678901234567890", 1},
|
||||
{"xyz0123456789012345678901234567890"[:33], "0123456789012345678901234567890", -1},
|
||||
{"", "01234567890123456789012345678901", -1},
|
||||
{"32145678890123456789012345678901234567890211", "01234567890123456789012345678901", -1},
|
||||
{"01234567890123456789012345678901", "01234567890123456789012345678901", 0},
|
||||
{"x01234567890123456789012345678901", "01234567890123456789012345678901", 1},
|
||||
{"xyz01234567890123456789012345678901"[:34], "01234567890123456789012345678901", -1},
|
||||
}
|
||||
|
||||
var lastIndexTests = []IndexTest{
|
||||
|
|
|
|||
Loading…
Add table
Add a link
Reference in a new issue