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runtime: implement cmpstring and bytes.Compare in assembly for ppc64

Change-Id: I15bf55aa5ac3588c05f0a253f583c52bab209892
Reviewed-on: https://go-review.googlesource.com/14041
Reviewed-by: Dave Cheney <dave@cheney.net>
This commit is contained in:
Shenghou Ma 2015-08-28 23:59:04 -04:00 committed by Minux Ma
parent 5483761c13
commit 32d3b96e8b
2 changed files with 61 additions and 2 deletions

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@ -1115,6 +1115,65 @@ notfound:
MOVD R3, ret+24(FP)
RET
TEXT runtime·cmpstring(SB),NOSPLIT,$-4-40
MOVD s1_base+0(FP), R5
MOVD s1_len+8(FP), R3
MOVD s2_base+16(FP), R6
MOVD s2_len+24(FP), R4
MOVD $ret+32(FP), R7
BR runtime·cmpbody<>(SB)
TEXT bytes·Compare(SB),NOSPLIT,$-4-56
MOVD s1+0(FP), R5
MOVD s1+8(FP), R3
MOVD s2+24(FP), R6
MOVD s2+32(FP), R4
MOVD $ret+48(FP), R7
BR runtime·cmpbody<>(SB)
// On entry:
// R3 is the length of s1
// R4 is the length of s2
// R5 points to the start of s1
// R6 points to the start of s2
// R7 points to return value (-1/0/1 will be written here)
//
// On exit:
// R5, R6, R8, R9 and R10 are clobbered
TEXT runtime·cmpbody<>(SB),NOSPLIT,$-4-0
CMP R5, R6
BEQ samebytes // same starting pointers; compare lengths
SUB $1, R5
SUB $1, R6
MOVD R4, R8
CMP R3, R4
BGE 2(PC)
MOVD R3, R8 // R8 is min(R3, R4)
ADD R5, R8 // R5 is current byte in s1, R8 is last byte in s1 to compare
loop:
CMP R5, R8
BEQ samebytes // all compared bytes were the same; compare lengths
MOVBZU 1(R5), R9
MOVBZU 1(R6), R10
CMP R9, R10
BEQ loop
// bytes differed
MOVD $1, R4
BGT 2(PC)
NEG R4
MOVD R4, (R7)
RET
samebytes:
MOVD $1, R8
CMP R3, R4
BNE 3(PC)
MOVD R0, (R7)
RET
BGT 2(PC)
NEG R8
MOVD R8, (R7)
RET
TEXT runtime·fastrand1(SB), NOSPLIT, $0-4
MOVD g_m(g), R4
MOVWZ m_fastrand(R4), R3

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@ -2,9 +2,9 @@
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
// Routines that are implemented in assembly in asm_{amd64,386,arm,arm64}.s
// Routines that are implemented in assembly in asm_{amd64,386,arm,arm64,ppc64x}.s
// +build ppc64 ppc64le
// +build ignore
package runtime