[release-branch.go1.18] cmd/compile: fix wrong dict param when getting dict type

CL 338129 added getDictionaryType to get the dictionary type from the
specified dict param, but still using the one in info.dictParam, which
is wrong.

Fixes #51669

Change-Id: Ie13460c1e5751c4c5fc44479a44f6eed8b3b06e4
Reviewed-on: https://go-review.googlesource.com/c/go/+/391994
Trust: Cuong Manh Le <cuong.manhle.vn@gmail.com>
Run-TryBot: Cuong Manh Le <cuong.manhle.vn@gmail.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
Trust: Matthew Dempsky <mdempsky@google.com>
Reviewed-by: Keith Randall <khr@golang.org>
Reviewed-on: https://go-review.googlesource.com/c/go/+/392614

2 files changed, 85 insertions, 1 deletions

diff --git a/src/cmd/compile/internal/noder/stencil.go b/src/cmd/compile/internal/noder/stencil.go
index cd586cab78..c78a169d31 100644
--- a/src/cmd/compile/internal/noder/stencil.go
+++ b/src/cmd/compile/internal/noder/stencil.go
@@ -898,7 +898,7 @@ func getDictionaryType(info *instInfo, dictParam *ir.Name, pos src.XPos, i int)
 		base.Fatalf(fmt.Sprintf("bad dict index %d", i))
 	}
 
-	r := getDictionaryEntry(pos, info.dictParam, i, info.dictInfo.startSubDict)
+	r := getDictionaryEntry(pos, dictParam, i, info.dictInfo.startSubDict)
 	// change type of retrieved dictionary entry to *byte, which is the
 	// standard typing of a *runtime._type in the compiler
 	typed(types.Types[types.TUINT8].PtrTo(), r)
diff --git a/test/typeparam/mdempsky/13b.go b/test/typeparam/mdempsky/13b.go
new file mode 100644
index 0000000000..d152251d81
--- /dev/null
+++ b/test/typeparam/mdempsky/13b.go
@@ -0,0 +1,84 @@
+// run -gcflags="-G=3 -l"
+
+// Copyright 2021 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
+
+// Interface which will be used as a regular interface type and as a type bound.
+type Mer interface{
+	M()
+}
+
+// Interface that is a superset of Mer.
+type Mer2 interface {
+	M()
+	String() string
+}
+
+func F[T Mer](t T) {
+	T.M(t)
+	t.M()
+}
+
+type MyMer int
+
+func (MyMer) M() {}
+func (MyMer) String() string {
+	return "aa"
+}
+
+// Parameterized interface
+type Abs[T any] interface {
+	Abs() T
+}
+
+func G[T Abs[U], U any](t T) {
+	T.Abs(t)
+	t.Abs()
+}
+
+type MyInt int
+func (m MyInt) Abs() MyInt {
+	if m < 0 {
+		return -m
+	}
+	return m
+}
+
+type Abs2 interface {
+	Abs() MyInt
+}
+
+
+func main() {
+	mm := MyMer(3)
+	ms := struct{ Mer }{Mer: mm }
+
+	// Testing F with an interface type arg: Mer and Mer2
+	F[Mer](mm)
+	F[Mer2](mm)
+	F[struct{ Mer }](ms)
+	F[*struct{ Mer }](&ms)
+
+	ms2 := struct { MyMer }{MyMer: mm}
+	ms3 := struct { *MyMer }{MyMer: &mm}
+
+	// Testing F with a concrete type arg
+	F[MyMer](mm)
+	F[*MyMer](&mm)
+	F[struct{ MyMer }](ms2)
+	F[struct{ *MyMer }](ms3)
+	F[*struct{ MyMer }](&ms2)
+	F[*struct{ *MyMer }](&ms3)
+
+	// Testing G with a concrete type args
+	mi := MyInt(-3)
+	G[MyInt,MyInt](mi)
+
+	// Interface Abs[MyInt] holding an mi.
+	intMi := Abs[MyInt](mi)
+	// First type arg here is Abs[MyInt], an interface type.
+	G[Abs[MyInt],MyInt](intMi)
+}