Adding upstream version 1.21.8.upstream/1.21.8

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 107 insertions, 0 deletions

diff --git a/src/runtime/memmove_loong64.s b/src/runtime/memmove_loong64.s
new file mode 100644
index 0000000..0f139bc
--- /dev/null
+++ b/src/runtime/memmove_loong64.s
@@ -0,0 +1,107 @@
+// Copyright 2022 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.
+
+#include "textflag.h"
+
+// See memmove Go doc for important implementation constraints.
+
+// func memmove(to, from unsafe.Pointer, n uintptr)
+TEXT runtime·memmove(SB), NOSPLIT|NOFRAME, $0-24
+	MOVV	to+0(FP), R4
+	MOVV	from+8(FP), R5
+	MOVV	n+16(FP), R6
+	BNE	R6, check
+	RET
+
+check:
+	SGTU	R4, R5, R7
+	BNE	R7, backward
+
+	ADDV	R4, R6, R9 // end pointer
+
+	// if the two pointers are not of same alignments, do byte copying
+	SUBVU	R5, R4, R7
+	AND	$7, R7
+	BNE	R7, out
+
+	// if less than 8 bytes, do byte copying
+	SGTU	$8, R6, R7
+	BNE	R7, out
+
+	// do one byte at a time until 8-aligned
+	AND	$7, R4, R8
+	BEQ	R8, words
+	MOVB	(R5), R7
+	ADDV	$1, R5
+	MOVB	R7, (R4)
+	ADDV	$1, R4
+	JMP	-6(PC)
+
+words:
+	// do 8 bytes at a time if there is room
+	ADDV	$-7, R9, R6 // R6 is end pointer-7
+
+	PCALIGN	$16
+	SGTU	R6, R4, R8
+	BEQ	R8, out
+	MOVV	(R5), R7
+	ADDV	$8, R5
+	MOVV	R7, (R4)
+	ADDV	$8, R4
+	JMP	-6(PC)
+
+out:
+	BEQ	R4, R9, done
+	MOVB	(R5), R7
+	ADDV	$1, R5
+	MOVB	R7, (R4)
+	ADDV	$1, R4
+	JMP	-5(PC)
+done:
+	RET
+
+backward:
+	ADDV	R6, R5 // from-end pointer
+	ADDV	R4, R6, R9 // to-end pointer
+
+	// if the two pointers are not of same alignments, do byte copying
+	SUBVU	R9, R5, R7
+	AND	$7, R7
+	BNE	R7, out1
+
+	// if less than 8 bytes, do byte copying
+	SGTU	$8, R6, R7
+	BNE	R7, out1
+
+	// do one byte at a time until 8-aligned
+	AND	$7, R9, R8
+	BEQ	R8, words1
+	ADDV	$-1, R5
+	MOVB	(R5), R7
+	ADDV	$-1, R9
+	MOVB	R7, (R9)
+	JMP	-6(PC)
+
+words1:
+	// do 8 bytes at a time if there is room
+	ADDV	$7, R4, R6 // R6 is start pointer+7
+
+	PCALIGN	$16
+	SGTU	R9, R6, R8
+	BEQ	R8, out1
+	ADDV	$-8, R5
+	MOVV	(R5), R7
+	ADDV	$-8, R9
+	MOVV	R7, (R9)
+	JMP	-6(PC)
+
+out1:
+	BEQ	R4, R9, done1
+	ADDV	$-1, R5
+	MOVB	(R5), R7
+	ADDV	$-1, R9
+	MOVB	R7, (R9)
+	JMP	-5(PC)
+done1:
+	RET