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| author | Marc Glisse <marc.glisse@inria.fr> | 2020-08-10 12:50:42 +0200 |
|---|---|---|
| committer | Marc Glisse <marc.glisse@inria.fr> | 2020-08-10 12:53:01 +0200 |
| commit | 287522613d661b4c5ba8403b051eb470c1674cba (patch) | |
| tree | f9c3ea8dfe1d1a8e89a20f898746d93f96a9de4d /gcc/fortran/frontend-passes.c | |
| parent | 9939be5758b52ed2fe1a7e56b94ce6d0f4d81580 (diff) | |
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Simplify X * C1 == C2 with wrapping overflow
Odd numbers are invertible in Z / 2^n Z, so X * C1 == C2 can be rewritten
as X == C2 * inv(C1) when overflow wraps.
mod_inv should probably be updated to better match the other wide_int
functions, but that's a separate issue.
2020-08-10 Marc Glisse <marc.glisse@inria.fr>
PR tree-optimization/95433
* match.pd (X * C1 == C2): Handle wrapping overflow.
* expr.c (maybe_optimize_mod_cmp): Qualify call to mod_inv.
(mod_inv): Move...
* wide-int.cc (mod_inv): ... here.
* wide-int.h (mod_inv): Declare it.
* gcc.dg/tree-ssa/pr95433-2.c: New file.
Diffstat (limited to 'gcc/fortran/frontend-passes.c')
0 files changed, 0 insertions, 0 deletions