cmd/internal/obj/arm: handle HAUTO etc. in addpool

HAUTO should be handled the same way as other stack offsets for
adding to constant pool. Add the missing cases.

Fixes #57955.

Change-Id: If7fc82cafb2bbf0a6121e73e353b8825cb36b5bc
Reviewed-on: https://go-review.googlesource.com/c/go/+/463138
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
Reviewed-by: Keith Randall <khr@google.com>
Run-TryBot: Cherry Mui <cherryyz@google.com>

src/cmd/internal/obj/arm/asm5.go

@@ -688,13 +688,16 @@ func (c *ctxt5) addpool(p *obj.Prog, a *obj.Addr) {
 			t.Rel = p
 		}
 
-	case C_SROREG,
-		C_LOREG,
-		C_ROREG,
+	case C_HOREG,
 		C_FOREG,
+		C_HFOREG,
 		C_SOREG,
-		C_HOREG,
+		C_ROREG,
+		C_SROREG,
+		C_LOREG,
+		C_HAUTO,
 		C_FAUTO,
+		C_HFAUTO,
 		C_SAUTO,
 		C_LAUTO,
 		C_LACON:

test/fixedbugs/issue57955.go

@@ -0,0 +1,43 @@
+// compile
+
+// 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.
+
+// Issue 57955: ARM assembler fails to handle certain cases.
+
+package main
+
+func main() {
+	Decode[int16](nil)
+	Decode[uint16](nil)
+	Decode[float64](nil)
+}
+
+func DecodeInt16(b []byte) (int16, int) {
+	return 0, 0
+}
+
+func DecodeUint16(b []byte) (uint16, int) {
+	return 0, 0
+}
+
+func DecodeFloat64(b []byte) (float64, int) {
+	return 0, 0
+}
+
+func Decode[T any](b []byte) (T, int) {
+	switch any(*new(T)).(type) {
+	case int16:
+		v, n := DecodeInt16(b)
+		return any(v).(T), n
+	case uint16:
+		v, n := DecodeUint16(b)
+		return any(v).(T), n
+	case float64:
+		v, n := DecodeFloat64(b)
+		return any(v).(T), n
+	default:
+		panic("")
+	}
+}