cmd/compile: upgrade ssa to do (int or float) -> complex

Generic instantiations can produce conversions from constant literal ints or floats to complex values. We could constant literals during instantiation, but it is just as easy to upgrade the code generator to do the conversions. Fixes #50193 Change-Id: I24bdc09226c8e868f6282e0e4057ba6c3ad5c41a Reviewed-on: https://go-review.googlesource.com/c/go/+/372514 Trust: Keith Randall <[email protected]> Run-TryBot: Keith Randall <[email protected]> Trust: Dan Scales <[email protected]> Reviewed-by: Dan Scales <[email protected]> Reviewed-by: Cherry Mui <[email protected]> TryBot-Result: Gopher Robot <[email protected]>
cloudflare · Dec 16, 2021 · d107aa2 · d107aa2
1 parent 6e7c691
commit d107aa2
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Showing 3 changed files with 70 additions and 25 deletions.
diff --git a/src/cmd/compile/internal/ssagen/ssa.go b/src/cmd/compile/internal/ssagen/ssa.go
@@ -2446,6 +2446,38 @@ func (s *state) conv(n ir.Node, v *ssa.Value, ft, tt *types.Type) *ssa.Value {
  return s.newValue1(op, tt, v)
  }
 
+ if ft.IsComplex() && tt.IsComplex() {
+ var op ssa.Op
+ if ft.Size() == tt.Size() {
+ switch ft.Size() {
+ case 8:
+ op = ssa.OpRound32F
+ case 16:
+ op = ssa.OpRound64F
+ default:
+ s.Fatalf("weird complex conversion %v -> %v", ft, tt)
+ }
+ } else if ft.Size() == 8 && tt.Size() == 16 {
+ op = ssa.OpCvt32Fto64F
+ } else if ft.Size() == 16 && tt.Size() == 8 {
+ op = ssa.OpCvt64Fto32F
+ } else {
+ s.Fatalf("weird complex conversion %v -> %v", ft, tt)
+ }
+ ftp := types.FloatForComplex(ft)
+ ttp := types.FloatForComplex(tt)
+ return s.newValue2(ssa.OpComplexMake, tt,
+ s.newValueOrSfCall1(op, ttp, s.newValue1(ssa.OpComplexReal, ftp, v)),
+ s.newValueOrSfCall1(op, ttp, s.newValue1(ssa.OpComplexImag, ftp, v)))
+ }
+
+ if tt.IsComplex() { // and ft is not complex
+ // Needed for generics support - can't happen in normal Go code.
+ et := types.FloatForComplex(tt)
+ v = s.conv(n, v, ft, et)
+ return s.newValue2(ssa.OpComplexMake, tt, v, s.zeroVal(et))
+ }
+
  if ft.IsFloat() || tt.IsFloat() {
  conv, ok := fpConvOpToSSA[twoTypes{s.concreteEtype(ft), s.concreteEtype(tt)}]
  if s.config.RegSize == 4 && Arch.LinkArch.Family != sys.MIPS && !s.softFloat {
@@ -2519,31 +2551,6 @@ func (s *state) conv(n ir.Node, v *ssa.Value, ft, tt *types.Type) *ssa.Value {
  return nil
  }
 
- if ft.IsComplex() && tt.IsComplex() {
- var op ssa.Op
- if ft.Size() == tt.Size() {
- switch ft.Size() {
- case 8:
- op = ssa.OpRound32F
- case 16:
- op = ssa.OpRound64F
- default:
- s.Fatalf("weird complex conversion %v -> %v", ft, tt)
- }
- } else if ft.Size() == 8 && tt.Size() == 16 {
- op = ssa.OpCvt32Fto64F
- } else if ft.Size() == 16 && tt.Size() == 8 {
- op = ssa.OpCvt64Fto32F
- } else {
- s.Fatalf("weird complex conversion %v -> %v", ft, tt)
- }
- ftp := types.FloatForComplex(ft)
- ttp := types.FloatForComplex(tt)
- return s.newValue2(ssa.OpComplexMake, tt,
- s.newValueOrSfCall1(op, ttp, s.newValue1(ssa.OpComplexReal, ftp, v)),
- s.newValueOrSfCall1(op, ttp, s.newValue1(ssa.OpComplexImag, ftp, v)))
- }
-
  s.Fatalf("unhandled OCONV %s -> %s", ft.Kind(), tt.Kind())
  return nil
 }

diff --git a/test/typeparam/issue50193.go b/test/typeparam/issue50193.go
@@ -0,0 +1,32 @@
+// run -gcflags=-G=3
+
+// 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
+
+import (
+ "constraints"
+ "fmt"
+)
+
+func zero[T constraints.Complex]() T {
+ return T(0)
+}
+func pi[T constraints.Complex]() T {
+ return T(3.14)
+}
+func sqrtN1[T constraints.Complex]() T {
+ return T(-1i)
+}
+
+func main() {
+ fmt.Println(zero[complex128]())
+ fmt.Println(pi[complex128]())
+ fmt.Println(sqrtN1[complex128]())
+ fmt.Println(zero[complex64]())
+ fmt.Println(pi[complex64]())
+ fmt.Println(sqrtN1[complex64]())
+}
+
diff --git a/test/typeparam/issue50193.out b/test/typeparam/issue50193.out
@@ -0,0 +1,6 @@
+(0+0i)
+(3.14+0i)
+(0-1i)
+(0+0i)
+(3.14+0i)
+(0-1i)