cmd/compile: correct type of CvtBoolToUint8 values

Fixes #40772

Change-Id: I539f07d1f958dacee87d846171a8889d03182d25
Reviewed-on: https://go-review.googlesource.com/c/go/+/248397
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
Reviewed-on: https://go-review.googlesource.com/c/go/+/248401

diff --git a/src/cmd/compile/internal/ssa/phiopt.go b/src/cmd/compile/internal/ssa/phiopt.go
index 8643fa584c3839df2ceadb9ae15471b2ace6380c..db7b02275cf934c62d66a9e9434bc61d041fff38 100644 (file)
--- a/src/cmd/compile/internal/ssa/phiopt.go
+++ b/src/cmd/compile/internal/ssa/phiopt.go
@@ -154,7 +154,7 @@ func phioptint(v *Value, b0 *Block, reverse int) {
        }
        v.AddArg(a)
 
-       cvt := v.Block.NewValue1(v.Pos, OpCvtBoolToUint8, a.Type, a)
+       cvt := v.Block.NewValue1(v.Pos, OpCvtBoolToUint8, v.Block.Func.Config.Types.UInt8, a)
        switch v.Type.Size() {
        case 1:
                v.reset(OpCopy)

diff --git a/src/cmd/compile/internal/ssa/prove.go b/src/cmd/compile/internal/ssa/prove.go
index 6c6be39d34b60376e71874c3e2c2b016b18c01b9..ce7d689f935a3c910f6fd6606c538e690e3c0185 100644 (file)
--- a/src/cmd/compile/internal/ssa/prove.go
+++ b/src/cmd/compile/internal/ssa/prove.go
@@ -1334,7 +1334,7 @@ func removeBranch(b *Block, branch branch) {
 // isNonNegative reports whether v is known to be greater or equal to zero.
 func isNonNegative(v *Value) bool {
        if !v.Type.IsInteger() {
-               panic("isNonNegative bad type")
+               v.Fatalf("isNonNegative bad type: %v", v.Type)
        }
        // TODO: return true if !v.Type.IsSigned()
        // SSA isn't type-safe enough to do that now (issue 37753).

diff --git a/test/fixedbugs/issue40746.go b/test/fixedbugs/issue40746.go
new file mode 100644 (file)
index 0000000..235282f
--- /dev/null
+++ b/test/fixedbugs/issue40746.go
@@ -0,0 +1,19 @@
+// compile
+
+// Copyright 2020 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 p
+
+func f(x byte, b bool) byte {
+       var c byte
+       if b {
+               c = 1
+       }
+
+       if int8(c) < 0 {
+               x++
+       }
+       return x
+}