// Copyright 2022 The Go Authors. All rights reserved. // Use of this source code is governed by a BSD-style // license that can be found in the LICENSE file. // Prefer SARX/SHLX/SHRX instruction because it has less register restriction on the shift input. (SAR(Q|L) x y) && buildcfg.GOAMD64 >= 3 => (SARX(Q|L) x y) (SHL(Q|L) x y) && buildcfg.GOAMD64 >= 3 => (SHLX(Q|L) x y) (SHR(Q|L) x y) && buildcfg.GOAMD64 >= 3 => (SHRX(Q|L) x y) // See comments in ARM64latelower.rules for why these are here. (MOVLQZX x) && zeroUpper32Bits(x,3) => x (MOVWQZX x) && zeroUpper48Bits(x,3) => x (MOVBQZX x) && zeroUpper56Bits(x,3) => x