================ @@ -16,11 +16,15 @@ define i32 @test_asr(i32 %a, i32 %b) { ; CHECK-NEXT: [[C:%.*]] = icmp slt i32 [[A]], 0 ; CHECK-NEXT: br i1 [[C]], label [[BB2:%.*]], label [[BB3:%.*]] ; CHECK: bb2: +; CHECK-NEXT: [[NOT:%.*]] = xor i32 [[A]], -1 +; CHECK-NEXT: [[D:%.*]] = lshr i32 [[NOT]], [[B]] +; CHECK-NEXT: [[NOT2:%.*]] = xor i32 [[D]], -1 ---------------- nikic wrote:
However, the remaining pattern is already handled by an extra simplifycfg+instcombine run, because we have this select fold: https://github.com/llvm/llvm-project/blob/d222fa4521531cc4ac14b8e157d231c108c003be/llvm/lib/Transforms/InstCombine/InstCombineSelect.cpp#L656 I've adjusted the test to check for the combination of the three passes, to show that it folds in that case. But I'd also be open to add a variant of this fold for phi nodes rather than selects, if you think it's necessary. https://github.com/llvm/llvm-project/pull/73662 _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits