cmd/compile: generates invalid instruction when using bit shifts on amd64 #38746
Description
What version of Go are you using (go version)?
$ go version go version go1.14.2 darwin/amd64
Does this issue reproduce with the latest release?
Yes
What operating system and processor architecture are you using (go env)?
go env Output
$ go env GO111MODULE="" GOARCH="amd64" GOBIN="/Users/steve/go/bin" GOCACHE="/Users/steve/Library/Caches/go-build" GOENV="/Users/steve/Library/Application Support/go/env" GOEXE="" GOFLAGS="" GOHOSTARCH="amd64" GOHOSTOS="darwin" GOINSECURE="" GONOPROXY="" GONOSUMDB="" GOOS="darwin" GOPATH="/Users/steve/go" GOPRIVATE="" GOPROXY="https://proxy.golang.org,direct" GOROOT="/usr/local/Cellar/go/1.14.2_1/libexec" GOSUMDB="sum.golang.org" GOTMPDIR="" GOTOOLDIR="/usr/local/Cellar/go/1.14.2_1/libexec/pkg/tool/darwin_amd64" GCCGO="gccgo" AR="ar" CC="clang" CXX="clang++" CGO_ENABLED="1" GOMOD="/Users/steve/Projects/kynrai/invalid_instruction/go.mod" CGO_CFLAGS="-g -O2" CGO_CPPFLAGS="" CGO_CXXFLAGS="-g -O2" CGO_FFLAGS="-g -O2" CGO_LDFLAGS="-g -O2" PKG_CONFIG="pkg-config" GOGCCFLAGS="-fPIC -m64 -pthread -fno-caret-diagnostics -Qunused-arguments -fmessage-length=0 -fdebug-prefix-map=/var/folders/sm/hgxsvgvx3h93cb_0cwyj39g80000gn/T/go-build850937365=/tmp/go-build -gno-record-gcc-switches -fno-common"
What did you do?
Using bit shifts to store data when a sequence of code causes a invalid instruction error:
invalid instruction: 00080 (invalid_test.go:22) ANDQ $9223372034707292159, CX
I have minimised the code example to the smallest amount of code that will reproduce the error.
package invalid
import (
"testing"
)
type ValuesMask uint64
func (v *ValuesMask) PrintBits() {
for i := 0; i < 64; i++ {
}
}
func TestMask(t *testing.T) {
v := ValuesMask(0)
v.PrintBits()
v &^= (1 << 31)
v |= 1 << 63
v &^= (1 << 63)
}What did you expect to see?
No error? or a pointer related error at worst
What did you see instead?
invalid instruction: 00080 (/Users/steve/Projects/kynrai/invalid_instruction/invalid_test.go:22) ANDQ $9223372034707292159, CX