From a26276b9498843218ee78c956c478ceebb819ad8 Mon Sep 17 00:00:00 2001 From: Haibo Xu Date: Tue, 20 Aug 2019 09:44:05 +0000 Subject: Enable pkg/bits support on arm64. Signed-off-by: Haibo Xu Change-Id: I490716f0e6204f0b3a43f71931b10d1ca541e128 --- pkg/bits/BUILD | 3 ++- pkg/bits/uint64_arch.go | 36 ++++++++++++++++++++++++++++++++++++ pkg/bits/uint64_arch_amd64.go | 36 ------------------------------------ pkg/bits/uint64_arch_arm64_asm.s | 33 +++++++++++++++++++++++++++++++++ pkg/bits/uint64_arch_generic.go | 2 +- 5 files changed, 72 insertions(+), 38 deletions(-) create mode 100644 pkg/bits/uint64_arch.go delete mode 100644 pkg/bits/uint64_arch_amd64.go create mode 100644 pkg/bits/uint64_arch_arm64_asm.s diff --git a/pkg/bits/BUILD b/pkg/bits/BUILD index 51967b811..1b5dac99a 100644 --- a/pkg/bits/BUILD +++ b/pkg/bits/BUILD @@ -11,8 +11,9 @@ go_library( "bits.go", "bits32.go", "bits64.go", - "uint64_arch_amd64.go", + "uint64_arch.go", "uint64_arch_amd64_asm.s", + "uint64_arch_arm64_asm.s", "uint64_arch_generic.go", ], importpath = "gvisor.dev/gvisor/pkg/bits", diff --git a/pkg/bits/uint64_arch.go b/pkg/bits/uint64_arch.go new file mode 100644 index 000000000..9f23eff77 --- /dev/null +++ b/pkg/bits/uint64_arch.go @@ -0,0 +1,36 @@ +// Copyright 2018 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 amd64 arm64 + +package bits + +// TrailingZeros64 returns the number of bits before the least significant 1 +// bit in x; in other words, it returns the index of the least significant 1 +// bit in x. If x is 0, TrailingZeros64 returns 64. +func TrailingZeros64(x uint64) int + +// MostSignificantOne64 returns the index of the most significant 1 bit in +// x. If x is 0, MostSignificantOne64 returns 64. +func MostSignificantOne64(x uint64) int + +// ForEachSetBit64 calls f once for each set bit in x, with argument i equal to +// the set bit's index. +func ForEachSetBit64(x uint64, f func(i int)) { + for x != 0 { + i := TrailingZeros64(x) + f(i) + x &^= MaskOf64(i) + } +} diff --git a/pkg/bits/uint64_arch_amd64.go b/pkg/bits/uint64_arch_amd64.go deleted file mode 100644 index faccaa61a..000000000 --- a/pkg/bits/uint64_arch_amd64.go +++ /dev/null @@ -1,36 +0,0 @@ -// Copyright 2018 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 amd64 - -package bits - -// TrailingZeros64 returns the number of bits before the least significant 1 -// bit in x; in other words, it returns the index of the least significant 1 -// bit in x. If x is 0, TrailingZeros64 returns 64. -func TrailingZeros64(x uint64) int - -// MostSignificantOne64 returns the index of the most significant 1 bit in -// x. If x is 0, MostSignificantOne64 returns 64. -func MostSignificantOne64(x uint64) int - -// ForEachSetBit64 calls f once for each set bit in x, with argument i equal to -// the set bit's index. -func ForEachSetBit64(x uint64, f func(i int)) { - for x != 0 { - i := TrailingZeros64(x) - f(i) - x &^= MaskOf64(i) - } -} diff --git a/pkg/bits/uint64_arch_arm64_asm.s b/pkg/bits/uint64_arch_arm64_asm.s new file mode 100644 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 -- cgit v1.2.3