1 files changed, 88 insertions, 0 deletions
diff --git a/src/internal/bytealg/compare_mips64x.s b/src/internal/bytealg/compare_mips64x.s
new file mode 100644
index 0000000..117a9ef
--- /dev/null
+++ b/src/internal/bytealg/compare_mips64x.s
@@ -0,0 +1,88 @@
+// Copyright 2019 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.
+
+//go:build mips64 || mips64le
+
+#include "go_asm.h"
+#include "textflag.h"
+
+TEXT ·Compare(SB),NOSPLIT,$0-56
+	MOVV	a_base+0(FP), R3
+	MOVV	b_base+24(FP), R4
+	MOVV	a_len+8(FP), R1
+	MOVV	b_len+32(FP), R2
+	MOVV	$ret+48(FP), R9
+	JMP	cmpbody<>(SB)
+
+TEXT runtime·cmpstring(SB),NOSPLIT,$0-40
+	MOVV	a_base+0(FP), R3
+	MOVV	b_base+16(FP), R4
+	MOVV	a_len+8(FP), R1
+	MOVV	b_len+24(FP), R2
+	MOVV	$ret+32(FP), R9
+	JMP	cmpbody<>(SB)
+
+// On entry:
+// R1 length of a
+// R2 length of b
+// R3 points to the start of a
+// R4 points to the start of b
+// R9 points to the return value (-1/0/1)
+TEXT cmpbody<>(SB),NOSPLIT|NOFRAME,$0
+	BEQ	R3, R4, samebytes // same start of a and b
+
+	SGTU	R1, R2, R7
+	BNE	R0, R7, r2_lt_r1
+	MOVV	R1, R10
+	JMP	entry
+r2_lt_r1:
+	MOVV	R2, R10	// R10 is min(R1, R2)
+entry:
+	ADDV	R3, R10, R8	// R3 start of a, R8 end of a
+	BEQ	R3, R8, samebytes // length is 0
+
+	SRLV	$4, R10		// R10 is number of chunks
+	BEQ	R0, R10, byte_loop
+
+	// make sure both a and b are aligned.
+	OR	R3, R4, R11
+	AND	$7, R11
+	BNE	R0, R11, byte_loop
+
+chunk16_loop:
+	BEQ	R0, R10, byte_loop
+	MOVV	(R3), R6
+	MOVV	(R4), R7
+	BNE	R6, R7, byte_loop
+	MOVV	8(R3), R13
+	MOVV	8(R4), R14
+	ADDV	$16, R3
+	ADDV	$16, R4
+	SUBVU	$1, R10
+	BEQ	R13, R14, chunk16_loop
+	SUBV	$8, R3
+	SUBV	$8, R4
+
+byte_loop:
+	BEQ	R3, R8, samebytes
+	MOVBU	(R3), R6
+	ADDVU	$1, R3
+	MOVBU	(R4), R7
+	ADDVU	$1, R4
+	BEQ	R6, R7, byte_loop
+
+byte_cmp:
+	SGTU	R6, R7, R8 // R8 = 1 if (R6 > R7)
+	BNE	R0, R8, ret
+	MOVV	$-1, R8
+	JMP	ret
+
+samebytes:
+	SGTU	R1, R2, R6
+	SGTU	R2, R1, R7
+	SUBV	R7, R6, R8
+
+ret:
+	MOVV	R8, (R9)
+	RET