go/test/fixedbugs/issue27961.go
Cherry Zhang c96e3bcc97 cmd/compile: fix type of OffPtr in some optimization rules
In some optimization rules the type of generated OffPtr was
incorrectly set to the type of the pointee, instead of the
pointer. When the OffPtr value is spilled, this may generate
a spill of the wrong type, e.g. a floating point spill of an
integer (pointer) value. On Wasm, this leads to invalid
bytecode.

Fixes #27961.

Change-Id: I5d464847eb900ed90794105c0013a1a7330756cc
Reviewed-on: https://go-review.googlesource.com/c/139257
Run-TryBot: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
Reviewed-by: Richard Musiol <neelance@gmail.com>
2018-10-03 15:01:47 +00:00

36 lines
596 B
Go

// run
// Copyright 2018 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 27961: some optimizations generate OffPtr with wrong
// types, which causes invalid bytecode on Wasm.
package main
import "math"
type Vec2 [2]float64
func main() {
var a Vec2
a.A().B().C().D()
}
func (v Vec2) A() Vec2 {
return Vec2{v[0], v[0]}
}
func (v Vec2) B() Vec2 {
return Vec2{1.0 / v.D(), 0}
}
func (v Vec2) C() Vec2 {
return Vec2{v[0], v[0]}
}
func (v Vec2) D() float64 {
return math.Sqrt(v[0])
}