| // Copyright 2015 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. |
| |
| package ssa |
| |
| import ( |
| "cmd/compile/internal/types" |
| "cmd/internal/src" |
| "testing" |
| ) |
| |
| func TestDeadStore(t *testing.T) { |
| c := testConfig(t) |
| ptrType := c.config.Types.BytePtr |
| t.Logf("PTRTYPE %v", ptrType) |
| fun := c.Fun("entry", |
| Bloc("entry", |
| Valu("start", OpInitMem, types.TypeMem, 0, nil), |
| Valu("sb", OpSB, c.config.Types.Uintptr, 0, nil), |
| Valu("v", OpConstBool, c.config.Types.Bool, 1, nil), |
| Valu("addr1", OpAddr, ptrType, 0, nil, "sb"), |
| Valu("addr2", OpAddr, ptrType, 0, nil, "sb"), |
| Valu("addr3", OpAddr, ptrType, 0, nil, "sb"), |
| Valu("zero1", OpZero, types.TypeMem, 1, c.config.Types.Bool, "addr3", "start"), |
| Valu("store1", OpStore, types.TypeMem, 0, c.config.Types.Bool, "addr1", "v", "zero1"), |
| Valu("store2", OpStore, types.TypeMem, 0, c.config.Types.Bool, "addr2", "v", "store1"), |
| Valu("store3", OpStore, types.TypeMem, 0, c.config.Types.Bool, "addr1", "v", "store2"), |
| Valu("store4", OpStore, types.TypeMem, 0, c.config.Types.Bool, "addr3", "v", "store3"), |
| Goto("exit")), |
| Bloc("exit", |
| Exit("store3"))) |
| |
| CheckFunc(fun.f) |
| dse(fun.f) |
| CheckFunc(fun.f) |
| |
| v1 := fun.values["store1"] |
| if v1.Op != OpCopy { |
| t.Errorf("dead store not removed") |
| } |
| |
| v2 := fun.values["zero1"] |
| if v2.Op != OpCopy { |
| t.Errorf("dead store (zero) not removed") |
| } |
| } |
| |
| func TestDeadStorePhi(t *testing.T) { |
| // make sure we don't get into an infinite loop with phi values. |
| c := testConfig(t) |
| ptrType := c.config.Types.BytePtr |
| fun := c.Fun("entry", |
| Bloc("entry", |
| Valu("start", OpInitMem, types.TypeMem, 0, nil), |
| Valu("sb", OpSB, c.config.Types.Uintptr, 0, nil), |
| Valu("v", OpConstBool, c.config.Types.Bool, 1, nil), |
| Valu("addr", OpAddr, ptrType, 0, nil, "sb"), |
| Goto("loop")), |
| Bloc("loop", |
| Valu("phi", OpPhi, types.TypeMem, 0, nil, "start", "store"), |
| Valu("store", OpStore, types.TypeMem, 0, c.config.Types.Bool, "addr", "v", "phi"), |
| If("v", "loop", "exit")), |
| Bloc("exit", |
| Exit("store"))) |
| |
| CheckFunc(fun.f) |
| dse(fun.f) |
| CheckFunc(fun.f) |
| } |
| |
| func TestDeadStoreTypes(t *testing.T) { |
| // Make sure a narrow store can't shadow a wider one. We test an even |
| // stronger restriction, that one store can't shadow another unless the |
| // types of the address fields are identical (where identicalness is |
| // decided by the CSE pass). |
| c := testConfig(t) |
| t1 := c.config.Types.UInt64.PtrTo() |
| t2 := c.config.Types.UInt32.PtrTo() |
| fun := c.Fun("entry", |
| Bloc("entry", |
| Valu("start", OpInitMem, types.TypeMem, 0, nil), |
| Valu("sb", OpSB, c.config.Types.Uintptr, 0, nil), |
| Valu("v", OpConstBool, c.config.Types.Bool, 1, nil), |
| Valu("addr1", OpAddr, t1, 0, nil, "sb"), |
| Valu("addr2", OpAddr, t2, 0, nil, "sb"), |
| Valu("store1", OpStore, types.TypeMem, 0, c.config.Types.Bool, "addr1", "v", "start"), |
| Valu("store2", OpStore, types.TypeMem, 0, c.config.Types.Bool, "addr2", "v", "store1"), |
| Goto("exit")), |
| Bloc("exit", |
| Exit("store2"))) |
| |
| CheckFunc(fun.f) |
| cse(fun.f) |
| dse(fun.f) |
| CheckFunc(fun.f) |
| |
| v := fun.values["store1"] |
| if v.Op == OpCopy { |
| t.Errorf("store %s incorrectly removed", v) |
| } |
| } |
| |
| func TestDeadStoreUnsafe(t *testing.T) { |
| // Make sure a narrow store can't shadow a wider one. The test above |
| // covers the case of two different types, but unsafe pointer casting |
| // can get to a point where the size is changed but type unchanged. |
| c := testConfig(t) |
| ptrType := c.config.Types.UInt64.PtrTo() |
| fun := c.Fun("entry", |
| Bloc("entry", |
| Valu("start", OpInitMem, types.TypeMem, 0, nil), |
| Valu("sb", OpSB, c.config.Types.Uintptr, 0, nil), |
| Valu("v", OpConstBool, c.config.Types.Bool, 1, nil), |
| Valu("addr1", OpAddr, ptrType, 0, nil, "sb"), |
| Valu("store1", OpStore, types.TypeMem, 0, c.config.Types.Int64, "addr1", "v", "start"), // store 8 bytes |
| Valu("store2", OpStore, types.TypeMem, 0, c.config.Types.Bool, "addr1", "v", "store1"), // store 1 byte |
| Goto("exit")), |
| Bloc("exit", |
| Exit("store2"))) |
| |
| CheckFunc(fun.f) |
| cse(fun.f) |
| dse(fun.f) |
| CheckFunc(fun.f) |
| |
| v := fun.values["store1"] |
| if v.Op == OpCopy { |
| t.Errorf("store %s incorrectly removed", v) |
| } |
| } |
| |
| func TestDeadStoreSmallStructInit(t *testing.T) { |
| c := testConfig(t) |
| ptrType := c.config.Types.BytePtr |
| typ := types.NewStruct([]*types.Field{ |
| types.NewField(src.NoXPos, &types.Sym{Name: "A"}, c.config.Types.Int), |
| types.NewField(src.NoXPos, &types.Sym{Name: "B"}, c.config.Types.Int), |
| }) |
| name := c.Temp(typ) |
| fun := c.Fun("entry", |
| Bloc("entry", |
| Valu("start", OpInitMem, types.TypeMem, 0, nil), |
| Valu("sp", OpSP, c.config.Types.Uintptr, 0, nil), |
| Valu("zero", OpConst64, c.config.Types.Int, 0, nil), |
| Valu("v6", OpLocalAddr, ptrType, 0, name, "sp", "start"), |
| Valu("v3", OpOffPtr, ptrType, 8, nil, "v6"), |
| Valu("v22", OpOffPtr, ptrType, 0, nil, "v6"), |
| Valu("zerostore1", OpStore, types.TypeMem, 0, c.config.Types.Int, "v22", "zero", "start"), |
| Valu("zerostore2", OpStore, types.TypeMem, 0, c.config.Types.Int, "v3", "zero", "zerostore1"), |
| Valu("v8", OpLocalAddr, ptrType, 0, name, "sp", "zerostore2"), |
| Valu("v23", OpOffPtr, ptrType, 8, nil, "v8"), |
| Valu("v25", OpOffPtr, ptrType, 0, nil, "v8"), |
| Valu("zerostore3", OpStore, types.TypeMem, 0, c.config.Types.Int, "v25", "zero", "zerostore2"), |
| Valu("zerostore4", OpStore, types.TypeMem, 0, c.config.Types.Int, "v23", "zero", "zerostore3"), |
| Goto("exit")), |
| Bloc("exit", |
| Exit("zerostore4"))) |
| |
| fun.f.Name = "smallstructinit" |
| CheckFunc(fun.f) |
| cse(fun.f) |
| dse(fun.f) |
| CheckFunc(fun.f) |
| |
| v1 := fun.values["zerostore1"] |
| if v1.Op != OpCopy { |
| t.Errorf("dead store not removed") |
| } |
| v2 := fun.values["zerostore2"] |
| if v2.Op != OpCopy { |
| t.Errorf("dead store not removed") |
| } |
| } |