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internal/bytealg: share code for equal functions on arm

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Move the shared code into byteal.memeqbody. This will allow to implement
optimizations (e.g. for #29001) in a single function.

Change-Id: Iaa34ddeb7068d92c35a8b4e581b7fd92da56535c
Reviewed-on: https://go-review.googlesource.com/c/go/+/166677
Run-TryBot: Tobias Klauser <tobias.klauser@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
This commit is contained in:
Tobias Klauser 2019-03-11 15:18:05 +01:00 committed by Tobias Klauser
parent 21a634e2e9
commit 14a58d65e3
2 changed files with 44 additions and 47 deletions
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1
src/cmd/vet/all/whitelist/arm.txt
View File

@ -12,3 +12,4 @@ runtime/tls_arm.s: [arm] load_g: function load_g missing Go declaration
runtime/tls_arm.s: [arm] _initcgo: function _initcgo missing Go declaration runtime/tls_arm.s: [arm] _initcgo: function _initcgo missing Go declaration
runtime/internal/atomic/asm_arm.s: [arm] cas: function cas missing Go declaration runtime/internal/atomic/asm_arm.s: [arm] cas: function cas missing Go declaration
internal/bytealg/equal_arm.s: [arm] Equal: invalid MOVW of ret+24(FP); bool is 1-byte value

90
src/internal/bytealg/equal_arm.s
View File

@ -5,7 +5,6 @@
#include "go_asm.h" #include "go_asm.h"
#include "textflag.h" #include "textflag.h"
// TODO: share code with memequal?
TEXT ·Equal(SB),NOSPLIT,$0-25 TEXT ·Equal(SB),NOSPLIT,$0-25
MOVW a_len+4(FP), R1 MOVW a_len+4(FP), R1
MOVW b_len+16(FP), R3 MOVW b_len+16(FP), R3
@ -15,8 +14,48 @@ TEXT ·Equal(SB),NOSPLIT,$0-25
MOVW a_base+0(FP), R0 MOVW a_base+0(FP), R0
MOVW b_base+12(FP), R2 MOVW b_base+12(FP), R2
ADD R0, R1 // end MOVW $ret+24(FP), R7
B memeqbody<>(SB)
notequal:
MOVW $0, R0
MOVBU R0, ret+24(FP)
RET
// memequal(a, b unsafe.Pointer, size uintptr) bool
TEXT runtime·memequal(SB),NOSPLIT|NOFRAME,$0-13
MOVW a+0(FP), R0
MOVW b+4(FP), R2
CMP R0, R2
B.EQ eq
MOVW size+8(FP), R1
MOVW $ret+12(FP), R7
B memeqbody<>(SB)
eq:
MOVW $1, R0
MOVB R0, ret+12(FP)
RET
// memequal_varlen(a, b unsafe.Pointer) bool
TEXT runtime·memequal_varlen(SB),NOSPLIT|NOFRAME,$0-9
MOVW a+0(FP), R0
MOVW b+4(FP), R2
CMP R0, R2
B.EQ eq
MOVW 4(R7), R1 // compiler stores size at offset 4 in the closure
MOVW $ret+8(FP), R7
B memeqbody<>(SB)
eq:
MOVW $1, R0
MOVB R0, ret+8(FP)
RET
// Input:
// R0: data of a
// R1: length
// R2: data of b
// R7: points to return value
TEXT memeqbody<>(SB),NOSPLIT|NOFRAME,$0-0
ADD R0, R1 // end
loop: loop:
CMP R0, R1 CMP R0, R1
B.EQ equal // reached the end B.EQ equal // reached the end
@ -24,54 +63,11 @@ loop:
MOVBU.P 1(R2), R5 MOVBU.P 1(R2), R5
CMP R4, R5 CMP R4, R5
B.EQ loop B.EQ loop
notequal: notequal:
MOVW $0, R0 MOVW $0, R0
MOVBU R0, ret+24(FP) MOVB R0, (R7)
RET RET
equal: equal:
MOVW $1, R0 MOVW $1, R0
MOVBU R0, ret+24(FP) MOVB R0, (R7)
RET
// memequal(a, b unsafe.Pointer, size uintptr) bool
TEXT runtime·memequal(SB),NOSPLIT|NOFRAME,$0-13
MOVW a+0(FP), R1
MOVW b+4(FP), R2
MOVW size+8(FP), R3
ADD R1, R3, R6
MOVW $1, R0
MOVB R0, ret+12(FP)
CMP R1, R2
RET.EQ
loop:
CMP R1, R6
RET.EQ
MOVBU.P 1(R1), R4
MOVBU.P 1(R2), R5
CMP R4, R5
BEQ loop
MOVW $0, R0
MOVB R0, ret+12(FP)
RET
// memequal_varlen(a, b unsafe.Pointer) bool
TEXT runtime·memequal_varlen(SB),NOSPLIT,$16-9
MOVW a+0(FP), R0
MOVW b+4(FP), R1
CMP R0, R1
BEQ eq
MOVW 4(R7), R2 // compiler stores size at offset 4 in the closure
MOVW R0, 4(R13)
MOVW R1, 8(R13)
MOVW R2, 12(R13)
BL runtime·memequal(SB)
MOVB 16(R13), R0
MOVB R0, ret+8(FP)
RET
eq:
MOVW $1, R0
MOVB R0, ret+8(FP)
RET RET