[release-branch.go1.17] cmd/compile: allow 128-bit values to be spilled

We sometimes use 16-byte load+store to move values around in memory.
In rare circumstances, the loaded value must be spilled because the
store can't happen yet.

In that case, we need to be able to spill the 16-byte value.

Fixes #53470

Change-Id: I09fd08e11a63c6ba3ef781d3f5ede237e9b0132e
Reviewed-on: https://go-review.googlesource.com/c/go/+/413294
Reviewed-by: Keith Randall <khr@golang.org>
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: David Chase <drchase@google.com>
Run-TryBot: Keith Randall <khr@golang.org>
Reviewed-by: Keith Randall <khr@google.com>
(cherry picked from commit c2d373d5d1802d7479f3c81dcf01d41bef3646dd)
Reviewed-on: https://go-review.googlesource.com/c/go/+/413456
Reviewed-by: Carlos Amedee <carlos@golang.org>

1 files changed, 89 insertions, 0 deletions

diff --git a/test/fixedbugs/issue53454.go b/test/fixedbugs/issue53454.go
new file mode 100644
index 00000000000..8b16d818398
--- /dev/null
+++ b/test/fixedbugs/issue53454.go
@@ -0,0 +1,89 @@
+// compile
+
+// 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.
+
+package main
+
+type T1 struct {
+	A T5
+	B T2
+	C T7
+	D T4
+}
+
+type T2 struct {
+	T3
+	A float64
+	E float64
+	C float64
+}
+
+type T3 struct {
+	F float64
+	G float64
+	H float64
+	I float64
+	J float64
+	K float64
+	L float64
+}
+
+type T4 struct {
+	M float64
+	N float64
+	O float64
+	P float64
+}
+
+type T5 struct {
+	Q float64
+	R float64
+	S float64
+	T float64
+	U float64
+	V float64
+}
+
+type T6 struct {
+	T9
+	C T10
+}
+
+type T7 struct {
+	T10
+	T11
+}
+
+type T8 struct {
+	T9
+	C T7
+}
+
+type T9 struct {
+	A T5
+	B T3
+	D T4
+}
+
+type T10 struct {
+	W float64
+}
+
+type T11 struct {
+	X float64
+	Y float64
+}
+
+func MainTest(x T1, y T8, z T6) float64 {
+	return Test(x.B, x.A, x.D, x.C, y.B, y.A, y.D, y.C, z.B, z.A, z.D,
+		T7{
+			T10: T10{
+				W: z.C.W,
+			},
+			T11: T11{},
+		},
+	)
+}
+func Test(a T2, b T5, c T4, d T7, e T3, f T5, g T4, h T7, i T3, j T5, k T4, l T7) float64