| // 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. |
| |
| // Combine bitwise operation and bitwise inversion. |
| (AND x (NOT y)) => (ANDN x y) |
| (OR x (NOT y)) => (ORN x y) |
| (XOR x (NOT y)) => (XNOR x y) |
| (NOT (XOR x y)) => (XNOR x y) |
| |
| // Fold constant shift with extension. |
| (SRAI [c] (MOVBreg x)) && c < 8 => (SRAI [56+c] (SLLI <typ.Int64> [56] x)) |
| (SRAI [c] (MOVHreg x)) && c < 16 => (SRAI [48+c] (SLLI <typ.Int64> [48] x)) |
| (SRAI [c] (MOVWreg x)) && c < 32 => (SRAI [32+c] (SLLI <typ.Int64> [32] x)) |
| (SRLI [c] (MOVBUreg x)) && c < 8 => (SRLI [56+c] (SLLI <typ.UInt64> [56] x)) |
| (SRLI [c] (MOVHUreg x)) && c < 16 => (SRLI [48+c] (SLLI <typ.UInt64> [48] x)) |
| (SRLI [c] (MOVWUreg x)) && c < 32 => (SRLI [32+c] (SLLI <typ.UInt64> [32] x)) |
| (SLLI [c] (MOVBUreg x)) && c <= 56 => (SRLI [56-c] (SLLI <typ.UInt64> [56] x)) |
| (SLLI [c] (MOVHUreg x)) && c <= 48 => (SRLI [48-c] (SLLI <typ.UInt64> [48] x)) |
| (SLLI [c] (MOVWUreg x)) && c <= 32 => (SRLI [32-c] (SLLI <typ.UInt64> [32] x)) |
| |
| // Shift by zero. |
| (SRAI [0] x) => x |
| (SRLI [0] x) => x |
| (SLLI [0] x) => x |
