| | // Copyright 2018 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. |
| |
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| | |
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| | // memequal(a, b unsafe.Pointer, size uintptr) bool |
| | TEXT runtime路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 |
| | CMP $0, R1 |
| | B.EQ eq // short path to handle 0-byte case |
| | 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路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 |
| | CMP $0, R1 |
| | B.EQ eq // short path to handle 0-byte case |
| | 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 |
| | // |
| | // On exit: |
| | // R4, R5 and R6 are clobbered |
| | TEXT memeqbody<>(SB),NOSPLIT|NOFRAME,$0-0 |
| | CMP $1, R1 |
| | B.EQ one // 1-byte special case for better performance |
| |
|
| | CMP $4, R1 |
| | ADD R0, R1 // R1 is the end of the range to compare |
| | B.LT byte_loop // length < 4 |
| | AND $3, R0, R6 |
| | CMP $0, R6 |
| | B.NE byte_loop // unaligned a, use byte-wise compare (TODO: try to align a) |
| | AND $3, R2, R6 |
| | CMP $0, R6 |
| | B.NE byte_loop // unaligned b, use byte-wise compare |
| | AND $0xfffffffc, R1, R6 |
| | // length >= 4 |
| | chunk4_loop: |
| | MOVW.P 4(R0), R4 |
| | MOVW.P 4(R2), R5 |
| | CMP R4, R5 |
| | B.NE notequal |
| | CMP R0, R6 |
| | B.NE chunk4_loop |
| | CMP R0, R1 |
| | B.EQ equal // reached the end |
| | byte_loop: |
| | MOVBU.P 1(R0), R4 |
| | MOVBU.P 1(R2), R5 |
| | CMP R4, R5 |
| | B.NE notequal |
| | CMP R0, R1 |
| | B.NE byte_loop |
| | equal: |
| | MOVW $1, R0 |
| | MOVB R0, (R7) |
| | RET |
| | one: |
| | MOVBU (R0), R4 |
| | MOVBU (R2), R5 |
| | CMP R4, R5 |
| | B.EQ equal |
| | notequal: |
| | MOVW $0, R0 |
| | MOVB R0, (R7) |
| | RET |
| |
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