Index: lib/Transforms/Scalar/NewGVN.cpp =================================================================== --- lib/Transforms/Scalar/NewGVN.cpp +++ lib/Transforms/Scalar/NewGVN.cpp @@ -2753,6 +2753,7 @@ // Clone the instruction, create an expression from it that is // translated back into the predecessor, and see if we have a leader. Instruction *ValueOp = I->clone(); + SmallPtrSet CurrentDeps; if (MemAccess) TempToMemory.insert({ValueOp, MemAccess}); bool SafeForPHIOfOps = true; @@ -2764,7 +2765,7 @@ if (isa(Op)) { Op = Op->DoPHITranslation(PHIBlock, PredBB); if (Op != OrigOp && Op != I) - Deps.insert(Op); + CurrentDeps.insert(Op); } else if (auto *ValuePHI = RealToTemp.lookup(Op)) { if (getBlockForValue(ValuePHI) == PHIBlock) Op = ValuePHI->getIncomingValueForBlock(PredBB); @@ -2783,8 +2784,16 @@ : findLeaderForInst(ValueOp, Visited, MemAccess, I, PredBB); ValueOp->deleteValue(); - if (!FoundVal) + if (!FoundVal) { + // We failed to find a leader for the current ValueOp, but this might + // change in case of the translated operands change. + if (SafeForPHIOfOps) + for (auto Dep : CurrentDeps) + addAdditionalUsers(Dep, I); + return nullptr; + } + Deps.insert(CurrentDeps.begin(), CurrentDeps.end()); } else { DEBUG(dbgs() << "Skipping phi of ops operand for incoming block " << getBlockName(PredBB) Index: test/Transforms/NewGVN/pr35074.ll =================================================================== --- /dev/null +++ test/Transforms/NewGVN/pr35074.ll @@ -0,0 +1,62 @@ +; NOTE: Assertions have been autogenerated by utils/update_test_checks.py +; RUN: opt < %s -newgvn -S | FileCheck %s + +define void @sort(i64 %.16) { +; CHECK-LABEL: @sort( +; CHECK-NEXT: Entry: +; CHECK-NEXT: [[TMP0:%.*]] = extractvalue { i64, i1 } undef, 0 +; CHECK-NEXT: [[TMP1:%.*]] = lshr i64 [[TMP0]], 2 +; CHECK-NEXT: br i1 undef, label [[DIVZEROFAIL2_I:%.*]], label [[WHILEBODY_LR_PH:%.*]] +; CHECK: DivZeroFail2.i: +; CHECK-NEXT: unreachable +; CHECK: WhileBody.lr.ph: +; CHECK-NEXT: [[TMP2:%.*]] = udiv i64 [[DOT16:%.*]], [[TMP1]] +; CHECK-NEXT: br label [[WHILEBODY:%.*]] +; CHECK: WhileBody: +; CHECK-NEXT: [[ITERATOR:%.*]] = phi i64 [ 0, [[WHILEBODY_LR_PH]] ], [ [[TMP6:%.*]], [[BOUNDSCHECKOK276:%.*]] ] +; CHECK-NEXT: [[TMP3:%.*]] = tail call { i64, i1 } @llvm.uadd.with.overflow.i64(i64 [[ITERATOR]], i64 [[TMP2]]) +; CHECK-NEXT: [[TMP4:%.*]] = extractvalue { i64, i1 } [[TMP3]], 0 +; CHECK-NEXT: [[TMP5:%.*]] = tail call { i64, i1 } @llvm.uadd.with.overflow.i64(i64 [[TMP4]], i64 1) +; CHECK-NEXT: [[TMP6]] = extractvalue { i64, i1 } [[TMP5]], 0 +; CHECK-NEXT: br i1 false, label [[BOUNDSCHECKFAIL275:%.*]], label [[BOUNDSCHECKOK276]] +; CHECK: WhileEnd: +; CHECK-NEXT: ret void +; CHECK: BoundsCheckFail275: +; CHECK-NEXT: unreachable +; CHECK: BoundsCheckOk276: +; CHECK-NEXT: [[TMP7:%.*]] = icmp ult i64 [[TMP6]], [[DOT16]] +; CHECK-NEXT: br i1 [[TMP7]], label [[WHILEBODY]], label [[WHILEEND:%.*]] +; +Entry: + %0 = extractvalue { i64, i1 } undef, 0 + %1 = lshr i64 %0, 2 + br i1 undef, label %DivZeroFail2.i, label %WhileBody.lr.ph + +DivZeroFail2.i: ; preds = %Entry + unreachable + +WhileBody.lr.ph: ; preds = %Entry + %2 = udiv i64 %.16, %1 + br label %WhileBody + +WhileBody: ; preds = %BoundsCheckOk276, %WhileBody.lr.ph + %iterator = phi i64 [ 0, %WhileBody.lr.ph ], [ %6, %BoundsCheckOk276 ] + %3 = tail call { i64, i1 } @llvm.uadd.with.overflow.i64(i64 %iterator, i64 %2) + %4 = extractvalue { i64, i1 } %3, 0 + %5 = tail call { i64, i1 } @llvm.uadd.with.overflow.i64(i64 %4, i64 1) + %6 = extractvalue { i64, i1 } %5, 0 + %7 = icmp ugt i64 %iterator, %.16 + br i1 %7, label %BoundsCheckFail275, label %BoundsCheckOk276 + +WhileEnd: ; preds = %BoundsCheckOk276 + ret void + +BoundsCheckFail275: ; preds = %WhileBody + unreachable + +BoundsCheckOk276: ; preds = %WhileBody + %8 = icmp ult i64 %6, %.16 + br i1 %8, label %WhileBody, label %WhileEnd +} + +declare { i64, i1 } @llvm.uadd.with.overflow.i64(i64, i64)