57c23b967e
In some cases natural use of abstraction in avo programs can lead to redundant move instructions, specifically self-moves such as MOVQ AX, AX. This does not produce incorrect code but it is incorrect and inelegant. This diff introduces a PruneSelfMoves pass that removes such unnecessary instructions. Closes #76
62 lines
1.3 KiB
Go
62 lines
1.3 KiB
Go
package pass_test
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import (
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"testing"
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"github.com/mmcloughlin/avo/ir"
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"github.com/mmcloughlin/avo/reg"
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"github.com/mmcloughlin/avo/pass"
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"github.com/mmcloughlin/avo/build"
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"github.com/mmcloughlin/avo/operand"
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)
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func TestLivenessBasic(t *testing.T) {
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// Build: a = 1, b = 2, a = a+b
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ctx := build.NewContext()
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ctx.Function("add")
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a := ctx.GP64()
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b := ctx.GP64()
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ctx.MOVQ(operand.U64(1), a)
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ctx.MOVQ(operand.U64(2), b)
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ctx.ADDQ(a, b)
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AssertLiveness(t, ctx,
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[][]reg.Register{
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{},
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{a},
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{a, b},
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},
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[][]reg.Register{
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{a},
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{a, b},
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{},
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},
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)
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}
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func AssertLiveness(t *testing.T, ctx *build.Context, in, out [][]reg.Register) {
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fn := ConstructLiveness(t, ctx)
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is := fn.Instructions()
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if len(in) != len(is) || len(out) != len(is) {
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t.Fatalf("%d instructions: %d/%d in/out expectations", len(is), len(in), len(out))
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}
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for idx, i := range is {
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AssertRegistersMatchSet(t, in[idx], i.LiveIn)
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AssertRegistersMatchSet(t, out[idx], i.LiveOut)
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}
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}
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func AssertRegistersMatchSet(t *testing.T, rs []reg.Register, s reg.Set) {
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if !s.Equals(reg.NewSetFromSlice(rs)) {
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t.Fatalf("register slice does not match set: %#v and %#v", rs, s)
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}
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}
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func ConstructLiveness(t *testing.T, ctx *build.Context) *ir.Function {
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return BuildFunction(t, ctx, pass.LabelTarget, pass.CFG, pass.Liveness)
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}
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