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authorgVisor bot <gvisor-bot@google.com>2019-10-03 23:27:21 +0000
committergVisor bot <gvisor-bot@google.com>2019-10-03 23:27:21 +0000
commit2302defe592326ae081a9c54b90f5bcbd012672b (patch)
treee5e21c1edb44486fb050230ad6bdfb7824eeb2bc /pkg/bits
parent85367cc0cfe8f5b0f76f2fb2715cc79847c87dbd (diff)
parent135aadb5179c94972504910e66e9e2540c09d489 (diff)
Merge release-20190806.1-235-g135aadb (automated)
Diffstat (limited to 'pkg/bits')
-rwxr-xr-x[-rw-r--r--]pkg/bits/uint64_arch.go (renamed from pkg/bits/uint64_arch_amd64.go)2
-rwxr-xr-xpkg/bits/uint64_arch_arm64_asm.s33
-rw-r--r--pkg/bits/uint64_arch_generic.go2
3 files changed, 35 insertions, 2 deletions
diff --git a/pkg/bits/uint64_arch_amd64.go b/pkg/bits/uint64_arch.go
index faccaa61a..9f23eff77 100644..100755
--- a/pkg/bits/uint64_arch_amd64.go
+++ b/pkg/bits/uint64_arch.go
@@ -12,7 +12,7 @@
// See the License for the specific language governing permissions and
// limitations under the License.
-// +build amd64
+// +build amd64 arm64
package bits
diff --git a/pkg/bits/uint64_arch_arm64_asm.s b/pkg/bits/uint64_arch_arm64_asm.s
new file mode 100755
index 000000000..814ba562d
--- /dev/null
+++ b/pkg/bits/uint64_arch_arm64_asm.s
@@ -0,0 +1,33 @@
+// Copyright 2019 The gVisor Authors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// +build arm64
+
+TEXT ·TrailingZeros64(SB),$0-16
+ MOVD x+0(FP), R0
+ RBIT R0, R0
+ CLZ R0, R0 // return 64 if x == 0
+ MOVD R0, ret+8(FP)
+ RET
+
+TEXT ·MostSignificantOne64(SB),$0-16
+ MOVD x+0(FP), R0
+ CLZ R0, R0 // return 64 if x == 0
+ MOVD $63, R1
+ SUBS R0, R1, R0 // ret = 63 - CLZ
+ BPL end
+ MOVD $64, R0 // x == 0
+end:
+ MOVD R0, ret+8(FP)
+ RET
diff --git a/pkg/bits/uint64_arch_generic.go b/pkg/bits/uint64_arch_generic.go
index 7dd2d1480..9dd2098d1 100644
--- a/pkg/bits/uint64_arch_generic.go
+++ b/pkg/bits/uint64_arch_generic.go
@@ -12,7 +12,7 @@
// See the License for the specific language governing permissions and
// limitations under the License.
-// +build !amd64
+// +build !amd64,!arm64
package bits