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| author | Guillaume Gomez <guillaume1.gomez@gmail.com> | 2025-05-05 21:32:30 +0200 |
|---|---|---|
| committer | GitHub <noreply@github.com> | 2025-05-05 21:32:30 +0200 |
| commit | ab7623e93c9a063e4025b72a7aefc4362f790f96 (patch) | |
| tree | dee034175698ac3647381e3398efa77775e60108 /compiler/rustc_mir_transform/src/lib.rs | |
| parent | 677a5aca7f1e201b0168a8efbb77ca2e9ac700ea (diff) | |
| parent | 5881b7c68b353c3723133c43f209802b3a0c9621 (diff) | |
| download | rust-ab7623e93c9a063e4025b72a7aefc4362f790f96.tar.gz rust-ab7623e93c9a063e4025b72a7aefc4362f790f96.zip | |
Rollup merge of #140115 - dianqk:gvn-matchbr, r=oli-obk
mir-opt: execute MatchBranchSimplification after GVN
This can provide more opportunities for MatchBranchSimplification.
Currently, rustc does not optimize the following code into a single statement at mir-opt, and this PR fixes the first case.
```rust
pub fn match1(c: bool, v1: i32, v2: i32) -> i32 {
if c { v1 - v2 } else { v1 - v2 }
}
pub fn match2(c: bool, v1: i32) -> i32 {
if c { v1 - 1 } else { v1 - 1 }
}
```
https://rust.godbolt.org/z/Y8xPMjrfM
r? mir-opt
Diffstat (limited to 'compiler/rustc_mir_transform/src/lib.rs')
| -rw-r--r-- | compiler/rustc_mir_transform/src/lib.rs | 3 |
1 files changed, 1 insertions, 2 deletions
diff --git a/compiler/rustc_mir_transform/src/lib.rs b/compiler/rustc_mir_transform/src/lib.rs index 24f4c11a66d..dc0eacd3613 100644 --- a/compiler/rustc_mir_transform/src/lib.rs +++ b/compiler/rustc_mir_transform/src/lib.rs @@ -701,8 +701,6 @@ pub(crate) fn run_optimization_passes<'tcx>(tcx: TyCtxt<'tcx>, body: &mut Body<' // Now, we need to shrink the generated MIR. &ref_prop::ReferencePropagation, &sroa::ScalarReplacementOfAggregates, - &match_branches::MatchBranchSimplification, - // inst combine is after MatchBranchSimplification to clean up Ne(_1, false) &multiple_return_terminators::MultipleReturnTerminators, // After simplifycfg, it allows us to discover new opportunities for peephole // optimizations. @@ -711,6 +709,7 @@ pub(crate) fn run_optimization_passes<'tcx>(tcx: TyCtxt<'tcx>, body: &mut Body<' &dead_store_elimination::DeadStoreElimination::Initial, &gvn::GVN, &simplify::SimplifyLocals::AfterGVN, + &match_branches::MatchBranchSimplification, &dataflow_const_prop::DataflowConstProp, &single_use_consts::SingleUseConsts, &o1(simplify_branches::SimplifyConstCondition::AfterConstProp), |