9b06f76057
* LICM pass * Uses loop analysis to detect loop tree * For each loop (starting with the inner ones), create a pre-header and move there loop-invariant instructions * An instruction is loop invariant if it does not use as argument a value defined earlier in the loop * File tests to check LICM's correctness * Optimized pre-header creation If the loop already has a natural pre-header, we use it instead of creating a new one. The natural pre-header of a loop is the only predecessor of the header it doesn't dominate.
47 lines
930 B
Plaintext
47 lines
930 B
Plaintext
test licm
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function multiple_blocks(i32) -> i32 {
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ebb0(v0: i32):
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jump ebb1(v0)
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ebb1(v10: i32):
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v11 = iconst.i32 1
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v12 = iconst.i32 2
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v13 = iadd v11, v12
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brz v10, ebb2(v10)
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v15 = isub v10, v11
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brz v15, ebb3(v15)
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v14 = isub v10, v11
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jump ebb1(v14)
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ebb2(v20: i32):
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return v20
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ebb3(v30: i32):
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v31 = iadd v11, v13
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jump ebb1(v30)
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}
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; sameln:function multiple_blocks(i32) -> i32 {
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; nextln: ebb0(v0: i32):
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; nextln: v2 = iconst.i32 1
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; nextln: v3 = iconst.i32 2
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; nextln: v4 = iadd v2, v3
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; nextln: v9 = iadd v2, v4
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; nextln: jump ebb1(v0)
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; nextln:
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; nextln: ebb1(v1: i32):
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; nextln: brz v1, ebb2(v1)
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; nextln: v5 = isub v1, v2
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; nextln: brz v5, ebb3(v5)
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; nextln: v6 = isub v1, v2
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; nextln: jump ebb1(v6)
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; nextln:
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; nextln: ebb2(v7: i32):
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; nextln: return v7
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; nextln:
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; nextln: ebb3(v8: i32):
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; nextln: jump ebb1(v8)
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; nextln: }
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