Files
mesh-controller/vendor/github.com/klauspost/compress/internal/regmask/regmask.go
T
jochen e1f5d4fdf0 Vendor every dependency, so no build fetches the host's validator (hq to-be 45 D1)
The controller imports mesh-host/validate through a replace onto the forge
that holds it, and every build — the build agent's go build in a fresh
toolchain container, the Dockerfile's go mod download — would have fetched
it through the public proxy and checksum database at build time: a merge
breaking main on the network, the class Phase 1 removes. vendor/ is
committed; go builds from it with nothing fetched, and refuses to build
when it and go.mod disagree, so a pin moved without go mod vendor fails at
once. The Dockerfile copies vendor/ and builds with GOPROXY=off.
2026-10-06 10:29:10 +02:00

51 lines
1.8 KiB
Go

//go:build !386
// Package regmask provides masks for variable shift counts.
//
// Go defines a shift by more than the width of the shifted value as producing
// zero, so the compiler has to guard every variable shift against that: on
// amd64 with a CMP and an SBB, on arm64 with a CMP and a CSEL, and so on. When
// the count is known to be smaller than the width anyway, masking it with the
// width minus one lets the compiler drop the guard. The mask itself costs
// nothing on the architectures whose shift instructions already use only the
// low bits of the count, which the compiler knows about.
//
// Each constant is named for the width of the value being shifted and the type
// of the shift count, and may only be used where the count is always smaller
// than that width:
//
// x := y >> (n & regmask.Shift64ByUint) // y is 64 bits, n is a uint below 64
package regmask
const (
// ShiftNByUint8 - shifting an N bit value by a uint8
Shift8ByUint8 = 7
Shift16ByUint8 = 15
Shift32ByUint8 = 31
Shift64ByUint8 = 63
// ShiftNByUint16 - shifting an N bit value by a uint16
Shift8ByUint16 = Shift8ByUint8
Shift16ByUint16 = Shift16ByUint8
Shift32ByUint16 = Shift32ByUint8
Shift64ByUint16 = Shift64ByUint8
// ShiftNByUint32 - shifting an N bit value by a uint32
Shift8ByUint32 = Shift8ByUint8
Shift16ByUint32 = Shift16ByUint8
Shift32ByUint32 = Shift32ByUint8
Shift64ByUint32 = Shift64ByUint8
// ShiftNByUint64 - shifting an N bit value by a uint64
Shift8ByUint64 = Shift8ByUint8
Shift16ByUint64 = Shift16ByUint8
Shift32ByUint64 = Shift32ByUint8
Shift64ByUint64 = Shift64ByUint8
// ShiftNByUint - shifting an N bit value by a uint
Shift8ByUint = Shift8ByUint8
Shift16ByUint = Shift16ByUint8
Shift32ByUint = Shift32ByUint8
Shift64ByUint = Shift64ByUint8
)