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| author | Michael Schmidt <github@mschmidt.me> | 2017-12-05 14:48:18 +0100 |
|---|---|---|
| committer | Xavier Leroy <xavierleroy@users.noreply.github.com> | 2017-12-05 14:48:18 +0100 |
| commit | 90b76a0842b7f080893dd70a7c0c6bc878f4056b (patch) | |
| tree | 277edd1eecf7bc7574a4b4dc3b925e3479dab8fd /powerpc/ConstpropOp.vp | |
| parent | 442e82e6ffc6958192f73382d2270e926ead9c80 (diff) | |
| download | compcert-kvx-90b76a0842b7f080893dd70a7c0c6bc878f4056b.tar.gz compcert-kvx-90b76a0842b7f080893dd70a7c0c6bc878f4056b.zip | |
Optimization for division by one during constant propagation (#39)
Signed and unsigned divisions by literal 1 are already optimized away during the Selection phase. This pull request also optimizes those divisions when the 1 divisor is produced by constant propagation.
Diffstat (limited to 'powerpc/ConstpropOp.vp')
| -rw-r--r-- | powerpc/ConstpropOp.vp | 15 |
1 files changed, 9 insertions, 6 deletions
diff --git a/powerpc/ConstpropOp.vp b/powerpc/ConstpropOp.vp index 0ed92e90..f18a72e9 100644 --- a/powerpc/ConstpropOp.vp +++ b/powerpc/ConstpropOp.vp @@ -124,12 +124,15 @@ Definition make_mulimm (n: int) (r1 r2: reg) := end. Definition make_divimm (n: int) (r1 r2: reg) := - match Int.is_power2 n with - | Some l => if Int.ltu l (Int.repr 31) - then (Oshrximm l, r1 :: nil) - else (Odiv, r1 :: r2 :: nil) - | None => (Odiv, r1 :: r2 :: nil) - end. + if Int.eq n Int.one then + (Omove, r1 :: nil) + else + match Int.is_power2 n with + | Some l => if Int.ltu l (Int.repr 31) + then (Oshrximm l, r1 :: nil) + else (Odiv, r1 :: r2 :: nil) + | None => (Odiv, r1 :: r2 :: nil) + end. Definition make_divuimm (n: int) (r1 r2: reg) := match Int.is_power2 n with |