1 // Copyright 2022 The Go Authors. All rights reserved.
2 // Use of this source code is governed by a BSD-style
3 // license that can be found in the LICENSE file.
4
5 // Prefer SARX/SHLX/SHRX instruction because it has less register restriction on the shift input.
6 (SAR(Q|L) x y) && buildcfg.GOAMD64 >= 3 => (SARX(Q|L) x y)
7 (SHL(Q|L) x y) && buildcfg.GOAMD64 >= 3 => (SHLX(Q|L) x y)
8 (SHR(Q|L) x y) && buildcfg.GOAMD64 >= 3 => (SHRX(Q|L) x y)
9
10 // See comments in ARM64latelower.rules for why these are here.
11 (MOVLQZX x) && zeroUpper32Bits(x,3) => x
12 (MOVWQZX x) && zeroUpper48Bits(x,3) => x
13 (MOVBQZX x) && zeroUpper56Bits(x,3) => x
14
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