Initial commit: Go 1.23 release state

test/codegen/stack.go

@@ -0,0 +1,144 @@
+// asmcheck
+
+// Copyright 2018 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
+
+import "runtime"
+
+// This file contains code generation tests related to the use of the
+// stack.
+
+// Check that stack stores are optimized away.
+
+// 386:"TEXT\t.*, [$]0-"
+// amd64:"TEXT\t.*, [$]0-"
+// arm:"TEXT\t.*, [$]-4-"
+// arm64:"TEXT\t.*, [$]0-"
+// mips:"TEXT\t.*, [$]-4-"
+// ppc64x:"TEXT\t.*, [$]0-"
+// s390x:"TEXT\t.*, [$]0-"
+func StackStore() int {
+	var x int
+	return *(&x)
+}
+
+type T struct {
+	A, B, C, D int // keep exported fields
+	x, y, z    int // reset unexported fields
+}
+
+// Check that large structs are cleared directly (issue #24416).
+
+// 386:"TEXT\t.*, [$]0-"
+// amd64:"TEXT\t.*, [$]0-"
+// arm:"TEXT\t.*, [$]0-" (spills return address)
+// arm64:"TEXT\t.*, [$]0-"
+// mips:"TEXT\t.*, [$]-4-"
+// ppc64x:"TEXT\t.*, [$]0-"
+// s390x:"TEXT\t.*, [$]0-"
+func ZeroLargeStruct(x *T) {
+	t := T{}
+	*x = t
+}
+
+// Check that structs are partially initialised directly (issue #24386).
+
+// Notes:
+// - 386 fails due to spilling a register
+// amd64:"TEXT\t.*, [$]0-"
+// arm:"TEXT\t.*, [$]0-" (spills return address)
+// arm64:"TEXT\t.*, [$]0-"
+// ppc64x:"TEXT\t.*, [$]0-"
+// s390x:"TEXT\t.*, [$]0-"
+// Note: that 386 currently has to spill a register.
+func KeepWanted(t *T) {
+	*t = T{A: t.A, B: t.B, C: t.C, D: t.D}
+}
+
+// Check that small array operations avoid using the stack (issue #15925).
+
+// Notes:
+// - 386 fails due to spilling a register
+// - arm & mips fail due to softfloat calls
+// amd64:"TEXT\t.*, [$]0-"
+// arm64:"TEXT\t.*, [$]0-"
+// ppc64x:"TEXT\t.*, [$]0-"
+// s390x:"TEXT\t.*, [$]0-"
+func ArrayAdd64(a, b [4]float64) [4]float64 {
+	return [4]float64{a[0] + b[0], a[1] + b[1], a[2] + b[2], a[3] + b[3]}
+}
+
+// Check that small array initialization avoids using the stack.
+
+// 386:"TEXT\t.*, [$]0-"
+// amd64:"TEXT\t.*, [$]0-"
+// arm:"TEXT\t.*, [$]0-" (spills return address)
+// arm64:"TEXT\t.*, [$]0-"
+// mips:"TEXT\t.*, [$]-4-"
+// ppc64x:"TEXT\t.*, [$]0-"
+// s390x:"TEXT\t.*, [$]0-"
+func ArrayInit(i, j int) [4]int {
+	return [4]int{i, 0, j, 0}
+}
+
+// Check that assembly output has matching offset and base register
+// (issue #21064).
+
+func check_asmout(b [2]int) int {
+	runtime.GC() // use some frame
+	// amd64:`.*b\+24\(SP\)`
+	// arm:`.*b\+4\(FP\)`
+	return b[1]
+}
+
+// Check that simple functions get promoted to nosplit, even when
+// they might panic in various ways. See issue 31219.
+// amd64:"TEXT\t.*NOSPLIT.*"
+func MightPanic(a []int, i, j, k, s int) {
+	_ = a[i]     // panicIndex
+	_ = a[i:j]   // panicSlice
+	_ = a[i:j:k] // also panicSlice
+	_ = i << s   // panicShift
+	_ = i / j    // panicDivide
+}
+
+// Put a defer in a loop, so second defer is not open-coded
+func Defer() {
+	for i := 0; i < 2; i++ {
+		defer func() {}()
+	}
+	// amd64:`CALL\truntime\.deferprocStack`
+	defer func() {}()
+}
+
+// Check that stack slots are shared among values of the same
+// type, but not pointer-identical types. See issue 65783.
+
+func spillSlotReuse() {
+	// The return values of getp1 and getp2 need to be
+	// spilled around the calls to nopInt. Make sure that
+	// spill slot gets reused.
+
+	//arm64:`.*autotmp_2-8\(SP\)`
+	getp1()[nopInt()] = 0
+	//arm64:`.*autotmp_2-8\(SP\)`
+	getp2()[nopInt()] = 0
+}
+
+//go:noinline
+func nopInt() int {
+	return 0
+}
+
+//go:noinline
+func getp1() *[4]int {
+	return nil
+}
+
+//go:noinline
+func getp2() *[4]int {
+	return nil
+}