Please answer these questions before submitting your issue. Thanks!

What version of Go are you using (go version)?

go version devel +324b2e9 Wed Aug 23 03:13:15 2017 +0000 linux/arm64

Does this issue reproduce with the latest release?

yes

What operating system and processor architecture are you using (go env)?

GOARCH="arm64"
GOBIN=""
GOEXE=""
GOHOSTARCH="arm64"
GOHOSTOS="linux"
GOOS="linux"
GOPATH="/home/fanzha02/go"
GORACE=""
GOROOT="/mnt/share/homes/fanzha02/push/asmforus/golang"
GOTOOLDIR="/mnt/share/homes/fanzha02/push/asmforus/golang/pkg/tool/linux_arm64"
GCCGO="gccgo"
CC="gcc"
GOGCCFLAGS="-fPIC -pthread -fmessage-length=0 -fdebug-prefix-map=/tmp/go-build043970017=/tmp/go-build -gno-record-gcc-switches"
CXX="g++"
CGO_ENABLED="1"
CGO_CFLAGS="-g -O2"
CGO_CPPFLAGS=""
CGO_CXXFLAGS="-g -O2"
CGO_FFLAGS="-g -O2"
CGO_LDFLAGS="-g -O2"
PKG_CONFIG="pkg-config"

What did you do?

cd src/cmd/asm/internal/asm
vi testdate/arm64enc.s
uncomment FCMP/FCMPE test cases
go test -run "ARM64Encoder"

If possible, provide a recipe for reproducing the error.
A complete runnable program is good.
A link on play.golang.org is best.

What did you expect to see?

go test successfully

What did you see instead?

the FCMP/FCMPE test cases are failed, and please refer to the detailed error information, as below.
(testdata/arm64enc.s:401) FCMPS F3, F17: have encoding 0020231e, want 2022231e
(testdata/arm64enc.s:402) FCMPS $(0.0), F8: have encoding 0020201e, want 0821201e
(testdata/arm64enc.s:403) FCMPD F11, F27: have encoding 00206b1e, want 60236b1e
(testdata/arm64enc.s:404) FCMPD $(0.0), F25: have encoding 0020601e, want 2823601e
(testdata/arm64enc.s:405) FCMPES F16, F30: have encoding 1020301e, want d023301e
(testdata/arm64enc.s:406) FCMPES $(0.0), F29: have encoding 1020201e, want b823201e
(testdata/arm64enc.s:407) FCMPED F13, F10: have encoding 10206d1e, want 50216d1e
(testdata/arm64enc.s:408) FCMPED $(0.0), F25: have encoding 1020601e, want 3823601e