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>
diff --git a/src/runtime/asm_ppc64x.s b/src/runtime/asm_ppc64x.s
index 60e6b8c..6646dd8 100644
--- a/src/runtime/asm_ppc64x.s
+++ b/src/runtime/asm_ppc64x.s
@@ -1115,6 +1115,65 @@
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
diff --git a/src/runtime/noasm.go b/src/runtime/noasm.go
index 218e121b..30fa31c 100644
--- a/src/runtime/noasm.go
+++ b/src/runtime/noasm.go
@@ -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
