e47f4a49fb
* 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.
32 lines
611 B
Plaintext
32 lines
611 B
Plaintext
test licm
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function simple_loop(i32) -> i32 {
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ebb1(v0: i32):
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v1 = iconst.i32 1
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v2 = iconst.i32 2
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v3 = iadd v1, v2
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brz v0, ebb2(v0)
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v4 = isub v0, v1
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jump ebb1(v4)
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ebb2(v5: i32):
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return v5
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}
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; sameln: function simple_loop(i32) -> i32 {
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; nextln: ebb2(v6: i32):
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; nextln: v1 = iconst.i32 1
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; nextln: v2 = iconst.i32 2
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; nextln: v3 = iadd v1, v2
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; nextln: jump ebb0(v6)
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; nextln:
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; nextln: ebb0(v0: i32):
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; nextln: brz v0, ebb1(v0)
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; nextln: v4 = isub v0, v1
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; nextln: jump ebb0(v4)
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; nextln:
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; nextln: ebb1(v5: i32):
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; nextln: return v5
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; nextln: }
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