writebarrier_test.go

Documentation: cmd/compile/internal/ssa

     1  // Copyright 2016 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  package ssa
     6  
     7  import (
     8  	"cmd/compile/internal/types"
     9  	"testing"
    10  )
    11  
    12  func TestWriteBarrierStoreOrder(t *testing.T) {
    13  	// Make sure writebarrier phase works even StoreWB ops are not in dependency order
    14  	c := testConfig(t)
    15  	ptrType := c.config.Types.BytePtr
    16  	fun := c.Fun("entry",
    17  		Bloc("entry",
    18  			Valu("start", OpInitMem, types.TypeMem, 0, nil),
    19  			Valu("sb", OpSB, c.config.Types.Uintptr, 0, nil),
    20  			Valu("sp", OpSP, c.config.Types.Uintptr, 0, nil),
    21  			Valu("v", OpConstNil, ptrType, 0, nil),
    22  			Valu("addr1", OpAddr, ptrType, 0, nil, "sb"),
    23  			Valu("wb2", OpStore, types.TypeMem, 0, ptrType, "addr1", "v", "wb1"),
    24  			Valu("wb1", OpStore, types.TypeMem, 0, ptrType, "addr1", "v", "start"), // wb1 and wb2 are out of order
    25  			Goto("exit")),
    26  		Bloc("exit",
    27  			Exit("wb2")))
    28  
    29  	CheckFunc(fun.f)
    30  	writebarrier(fun.f)
    31  	CheckFunc(fun.f)
    32  }
    33  
    34  func TestWriteBarrierPhi(t *testing.T) {
    35  	// Make sure writebarrier phase works for single-block loop, where
    36  	// a Phi op takes the store in the same block as argument.
    37  	// See issue #19067.
    38  	c := testConfig(t)
    39  	ptrType := c.config.Types.BytePtr
    40  	fun := c.Fun("entry",
    41  		Bloc("entry",
    42  			Valu("start", OpInitMem, types.TypeMem, 0, nil),
    43  			Valu("sb", OpSB, c.config.Types.Uintptr, 0, nil),
    44  			Valu("sp", OpSP, c.config.Types.Uintptr, 0, nil),
    45  			Goto("loop")),
    46  		Bloc("loop",
    47  			Valu("phi", OpPhi, types.TypeMem, 0, nil, "start", "wb"),
    48  			Valu("v", OpConstNil, ptrType, 0, nil),
    49  			Valu("addr", OpAddr, ptrType, 0, nil, "sb"),
    50  			Valu("wb", OpStore, types.TypeMem, 0, ptrType, "addr", "v", "phi"), // has write barrier
    51  			Goto("loop")))
    52  
    53  	CheckFunc(fun.f)
    54  	writebarrier(fun.f)
    55  	CheckFunc(fun.f)
    56  }
    57
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