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// 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
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