diff options
Diffstat (limited to 'src/cmd/compile/internal/ssa/regalloc_test.go')
-rw-r--r-- | src/cmd/compile/internal/ssa/regalloc_test.go | 65 |
1 files changed, 65 insertions, 0 deletions
diff --git a/src/cmd/compile/internal/ssa/regalloc_test.go b/src/cmd/compile/internal/ssa/regalloc_test.go index cf8f452d12..d3d1891bcd 100644 --- a/src/cmd/compile/internal/ssa/regalloc_test.go +++ b/src/cmd/compile/internal/ssa/regalloc_test.go @@ -31,3 +31,68 @@ func TestLiveControlOps(t *testing.T) { regalloc(f.f) checkFunc(f.f) } + +func TestSpillMove(t *testing.T) { + // Test for issue 20472. We shouldn't move a spill out to exit blocks + // if there is an exit block where the spill is dead but the pre-spill + // value is live. + c := testConfig(t) + ptrType := &TypeImpl{Size_: 8, Ptr: true, Name: "testptr"} // dummy for testing + arg1Aux := c.fe.Auto(TypeInt64) + arg2Aux := c.fe.Auto(ptrType) + f := Fun(c, "entry", + Bloc("entry", + Valu("mem", OpInitMem, TypeMem, 0, nil), + Valu("x", OpArg, TypeInt64, 0, arg1Aux), + Valu("p", OpArg, ptrType, 0, arg2Aux), + Valu("a", OpAMD64TESTQ, TypeFlags, 0, nil, "x", "x"), + Goto("loop1"), + ), + Bloc("loop1", + Valu("y", OpAMD64MULQ, TypeInt64, 0, nil, "x", "x"), + Eq("a", "loop2", "exit1"), + ), + Bloc("loop2", + Eq("a", "loop1", "exit2"), + ), + Bloc("exit1", + // store before call, y is available in a register + Valu("mem2", OpAMD64MOVQstore, TypeMem, 0, nil, "p", "y", "mem"), + Valu("mem3", OpAMD64CALLstatic, TypeMem, 0, nil, "mem2"), + Exit("mem3"), + ), + Bloc("exit2", + // store after call, y must be loaded from a spill location + Valu("mem4", OpAMD64CALLstatic, TypeMem, 0, nil, "mem"), + Valu("mem5", OpAMD64MOVQstore, TypeMem, 0, nil, "p", "y", "mem4"), + Exit("mem5"), + ), + ) + flagalloc(f.f) + regalloc(f.f) + checkFunc(f.f) + // There should still be a spill in Loop1, and nowhere else. + if numSpills(f.blocks["loop1"]) != 1 { + t.Errorf("spill missing from loop1") + } + if numSpills(f.blocks["loop2"]) != 0 { + t.Errorf("spill present in loop2") + } + if numSpills(f.blocks["exit1"]) != 0 { + t.Errorf("spill present in exit1") + } + if numSpills(f.blocks["exit2"]) != 0 { + t.Errorf("spill present in exit2") + } + +} + +func numSpills(b *Block) int { + n := 0 + for _, v := range b.Values { + if v.Op == OpStoreReg { + n++ + } + } + return n +} |