diff options
Diffstat (limited to 'src/cmd/compile')
| -rw-r--r-- | src/cmd/compile/internal/ssa/_gen/MIPS.rules | 3 | ||||
| -rw-r--r-- | src/cmd/compile/internal/ssa/rewriteMIPS.go | 34 |
2 files changed, 37 insertions, 0 deletions
diff --git a/src/cmd/compile/internal/ssa/_gen/MIPS.rules b/src/cmd/compile/internal/ssa/_gen/MIPS.rules index 4471763462..a4899ac24d 100644 --- a/src/cmd/compile/internal/ssa/_gen/MIPS.rules +++ b/src/cmd/compile/internal/ssa/_gen/MIPS.rules @@ -614,11 +614,14 @@ // generic simplifications (ADD x (NEG y)) => (SUB x y) +(SUB x (NEG y)) => (ADD x y) (SUB x x) => (MOVWconst [0]) (SUB (MOVWconst [0]) x) => (NEG x) (AND x x) => x (OR x x) => x (XOR x x) => (MOVWconst [0]) +(NEG (SUB x y)) => (SUB y x) +(NEG (NEG x)) => x // miscellaneous patterns generated by dec64 (AND (SGTUconst [1] x) (SGTUconst [1] y)) => (SGTUconst [1] (OR <x.Type> x y)) diff --git a/src/cmd/compile/internal/ssa/rewriteMIPS.go b/src/cmd/compile/internal/ssa/rewriteMIPS.go index 1bc2cb6e6d..fe24f0fd0f 100644 --- a/src/cmd/compile/internal/ssa/rewriteMIPS.go +++ b/src/cmd/compile/internal/ssa/rewriteMIPS.go @@ -4096,6 +4096,28 @@ func rewriteValueMIPS_OpMIPSMUL(v *Value) bool { } func rewriteValueMIPS_OpMIPSNEG(v *Value) bool { v_0 := v.Args[0] + // match: (NEG (SUB x y)) + // result: (SUB y x) + for { + if v_0.Op != OpMIPSSUB { + break + } + y := v_0.Args[1] + x := v_0.Args[0] + v.reset(OpMIPSSUB) + v.AddArg2(y, x) + return true + } + // match: (NEG (NEG x)) + // result: x + for { + if v_0.Op != OpMIPSNEG { + break + } + x := v_0.Args[0] + v.copyOf(x) + return true + } // match: (NEG (MOVWconst [c])) // result: (MOVWconst [-c]) for { @@ -4748,6 +4770,18 @@ func rewriteValueMIPS_OpMIPSSUB(v *Value) bool { v.AddArg(x) return true } + // match: (SUB x (NEG y)) + // result: (ADD x y) + for { + x := v_0 + if v_1.Op != OpMIPSNEG { + break + } + y := v_1.Args[0] + v.reset(OpMIPSADD) + v.AddArg2(x, y) + return true + } // match: (SUB x x) // result: (MOVWconst [0]) for { |