go source for verification 2026-05-22

test/codegen/writebarrier.go

@@ -0,0 +1,103 @@
+// asmcheck
+
+// Copyright 2023 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.
+
+package codegen
+
+func combine2string(p *[2]string, a, b string) {
+	// amd64:`.*runtime[.]gcWriteBarrier4\(SB\)`
+	// arm64:`.*runtime[.]gcWriteBarrier4\(SB\)`
+	p[0] = a
+	// amd64:-`.*runtime[.]gcWriteBarrier`
+	// arm64:-`.*runtime[.]gcWriteBarrier`
+	p[1] = b
+}
+
+func combine4string(p *[4]string, a, b, c, d string) {
+	// amd64:`.*runtime[.]gcWriteBarrier8\(SB\)`
+	// arm64:`.*runtime[.]gcWriteBarrier8\(SB\)`
+	p[0] = a
+	// amd64:-`.*runtime[.]gcWriteBarrier`
+	// arm64:-`.*runtime[.]gcWriteBarrier`
+	p[1] = b
+	// amd64:-`.*runtime[.]gcWriteBarrier`
+	// arm64:-`.*runtime[.]gcWriteBarrier`
+	p[2] = c
+	// amd64:-`.*runtime[.]gcWriteBarrier`
+	// arm64:-`.*runtime[.]gcWriteBarrier`
+	p[3] = d
+}
+
+func combine2slice(p *[2][]byte, a, b []byte) {
+	// amd64:`.*runtime[.]gcWriteBarrier4\(SB\)`
+	// arm64:`.*runtime[.]gcWriteBarrier4\(SB\)`
+	p[0] = a
+	// amd64:-`.*runtime[.]gcWriteBarrier`
+	// arm64:-`.*runtime[.]gcWriteBarrier`
+	p[1] = b
+}
+
+func combine4slice(p *[4][]byte, a, b, c, d []byte) {
+	// amd64:`.*runtime[.]gcWriteBarrier8\(SB\)`
+	// arm64:`.*runtime[.]gcWriteBarrier8\(SB\)`
+	p[0] = a
+	// amd64:-`.*runtime[.]gcWriteBarrier`
+	// arm64:-`.*runtime[.]gcWriteBarrier`
+	p[1] = b
+	// amd64:-`.*runtime[.]gcWriteBarrier`
+	// arm64:-`.*runtime[.]gcWriteBarrier`
+	p[2] = c
+	// amd64:-`.*runtime[.]gcWriteBarrier`
+	// arm64:-`.*runtime[.]gcWriteBarrier`
+	p[3] = d
+}
+
+func trickyWriteNil(p *int, q **int) {
+	if p == nil {
+		// We change "= p" to "= 0" in the prove pass, which
+		// means we have one less pointer that needs to go
+		// into the write barrier buffer.
+		// amd64:`.*runtime[.]gcWriteBarrier1`
+		*q = p
+	}
+}
+
+type S struct {
+	a, b string
+	c    *int
+}
+
+var g1, g2 *int
+
+func issue71228(dst *S, ptr *int) {
+	// Make sure that the non-write-barrier write.
+	// "sp.c = ptr" happens before the large write
+	// barrier "*dst = *sp". We approximate testing
+	// that by ensuring that two global variable write
+	// barriers aren't combined.
+	_ = *dst
+	var s S
+	sp := &s
+	//amd64:`.*runtime[.]gcWriteBarrier1`
+	g1 = nil
+	sp.c = ptr // outside of any write barrier
+	//amd64:`.*runtime[.]gcWriteBarrier1`
+	g2 = nil
+	//amd64:`.*runtime[.]wbMove`
+	*dst = *sp
+}
+
+func writeDouble(p *[2]*int, x, y *int) {
+	// arm64: `LDP\s`, `STP\s\(R[0-9]+, R[0-9]+\), \(`,
+	p[0] = x
+	// arm64: `STP\s\(R[0-9]+, R[0-9]+\), 16\(`,
+	p[1] = y
+}
+
+func writeDoubleNil(p *[2]*int) {
+	// arm64: `LDP\s`, `STP\s\(R[0-9]+, R[0-9]+\),`, `STP\s\(ZR, ZR\),`
+	p[0] = nil
+	p[1] = nil
+}