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// Combine bitwise operation and bitwise inversion.
6(AND x (NOT y)) => (ANDN x y)
7(OR x (NOT y)) => (ORN x y)
8(XOR x (NOT y)) => (XNOR x y)
9(NOT (XOR x y)) => (XNOR x y)
10
11// Fold constant shift with extension.
12(SRAI [c] (MOVBreg x)) && c < 8 => (SRAI [56+c] (SLLI <typ.Int64> [56] x))
13(SRAI [c] (MOVHreg x)) && c < 16 => (SRAI [48+c] (SLLI <typ.Int64> [48] x))
14(SRAI [c] (MOVWreg x)) && c < 32 => (SRAI [32+c] (SLLI <typ.Int64> [32] x))
15(SRLI [c] (MOVBUreg x)) && c < 8 => (SRLI [56+c] (SLLI <typ.UInt64> [56] x))
16(SRLI [c] (MOVHUreg x)) && c < 16 => (SRLI [48+c] (SLLI <typ.UInt64> [48] x))
17(SRLI [c] (MOVWUreg x)) && c < 32 => (SRLI [32+c] (SLLI <typ.UInt64> [32] x))
18(SLLI [c] (MOVBUreg x)) && c <= 56 => (SRLI [56-c] (SLLI <typ.UInt64> [56] x))
19(SLLI [c] (MOVHUreg x)) && c <= 48 => (SRLI [48-c] (SLLI <typ.UInt64> [48] x))
20(SLLI [c] (MOVWUreg x)) && c <= 32 => (SRLI [32-c] (SLLI <typ.UInt64> [32] x))
21
22// Shift by zero.
23(SRAI [0] x) => x
24(SRLI [0] x) => x
25(SLLI [0] x) => x
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