diff --git a/llvm/lib/Transforms/Scalar/LoopInterchange.cpp b/llvm/lib/Transforms/Scalar/LoopInterchange.cpp --- a/llvm/lib/Transforms/Scalar/LoopInterchange.cpp +++ b/llvm/lib/Transforms/Scalar/LoopInterchange.cpp @@ -1339,7 +1339,8 @@ // Move Lcssa PHIs to the right place. static void moveLCSSAPhis(BasicBlock *InnerExit, BasicBlock *InnerHeader, BasicBlock *InnerLatch, BasicBlock *OuterHeader, - BasicBlock *OuterLatch, BasicBlock *OuterExit) { + BasicBlock *OuterLatch, BasicBlock *OuterExit, + Loop *InnerLoop, LoopInfo *LI) { // Deal with LCSSA PHI nodes in the exit block of the inner loop, that are // defined either in the header or latch. Those blocks will become header and @@ -1394,19 +1395,17 @@ P->moveBefore(InnerExit->getFirstNonPHI()); // Deal with LCSSA PHI nodes in the loop nest exit block. For PHIs that have - // incoming values from the outer latch or header, we have to add a new PHI + // incoming values defined in the outer loop, we have to add a new PHI // in the inner loop latch, which became the exit block of the outer loop, // after interchanging. if (OuterExit) { for (PHINode &P : OuterExit->phis()) { if (P.getNumIncomingValues() != 1) continue; - // Skip Phis with incoming values not defined in the outer loop's header - // and latch. Also skip incoming phis defined in the latch. Those should + // Skip Phis with incoming values defined in the inner loop. Those should // already have been updated. auto I = dyn_cast(P.getIncomingValue(0)); - if (!I || ((I->getParent() != OuterLatch || isa(I)) && - I->getParent() != OuterHeader)) + if (!I || LI->getLoopFor(I->getParent()) == InnerLoop) continue; PHINode *NewPhi = dyn_cast(P.clone()); @@ -1520,7 +1519,8 @@ OuterLoopPreHeader); moveLCSSAPhis(InnerLoopLatchSuccessor, InnerLoopHeader, InnerLoopLatch, - OuterLoopHeader, OuterLoopLatch, InnerLoop->getExitBlock()); + OuterLoopHeader, OuterLoopLatch, InnerLoop->getExitBlock(), + InnerLoop, LI); // For PHIs in the exit block of the outer loop, outer's latch has been // replaced by Inners'. OuterLoopLatchSuccessor->replacePhiUsesWith(OuterLoopLatch, InnerLoopLatch); diff --git a/llvm/test/Transforms/LoopInterchange/pr43797-lcssa-for-multiple-outer-loop-blocks.ll b/llvm/test/Transforms/LoopInterchange/pr43797-lcssa-for-multiple-outer-loop-blocks.ll new file mode 100644 --- /dev/null +++ b/llvm/test/Transforms/LoopInterchange/pr43797-lcssa-for-multiple-outer-loop-blocks.ll @@ -0,0 +1,150 @@ +; NOTE: Assertions have been autogenerated by utils/update_test_checks.py +; RUN: opt -loop-interchange -verify-loop-lcssa -S %s | FileCheck %s + +; Tests for PR43797. + +@wdtdr = external dso_local global [5 x [5 x double]], align 16 + +define void @test1() { +; CHECK-LABEL: @test1( +; CHECK-NEXT: entry: +; CHECK-NEXT: br label [[INNER_HEADER_PREHEADER:%.*]] +; CHECK: outer.header.preheader: +; CHECK-NEXT: br label [[OUTER_HEADER:%.*]] +; CHECK: outer.header: +; CHECK-NEXT: [[OUTER_IDX:%.*]] = phi i64 [ [[OUTER_IDX_INC:%.*]], [[OUTER_LATCH:%.*]] ], [ 0, [[OUTER_HEADER_PREHEADER:%.*]] ] +; CHECK-NEXT: [[ARRAYIDX8:%.*]] = getelementptr inbounds [5 x [5 x double]], [5 x [5 x double]]* @wdtdr, i64 0, i64 0, i64 [[OUTER_IDX]] +; CHECK-NEXT: br label [[INNER_HEADER_SPLIT:%.*]] +; CHECK: inner.header.preheader: +; CHECK-NEXT: br label [[INNER_HEADER:%.*]] +; CHECK: inner.header: +; CHECK-NEXT: [[INNER_IDX:%.*]] = phi i64 [ [[TMP3:%.*]], [[INNER_LATCH_SPLIT:%.*]] ], [ 0, [[INNER_HEADER_PREHEADER]] ] +; CHECK-NEXT: br label [[OUTER_HEADER_PREHEADER]] +; CHECK: inner.header.split: +; CHECK-NEXT: [[TMP0:%.*]] = load double, double* [[ARRAYIDX8]], align 8 +; CHECK-NEXT: store double undef, double* [[ARRAYIDX8]], align 8 +; CHECK-NEXT: br label [[INNER_LATCH:%.*]] +; CHECK: inner.latch: +; CHECK-NEXT: [[INNER_IDX_INC:%.*]] = add nsw i64 [[INNER_IDX]], 1 +; CHECK-NEXT: br label [[INNER_EXIT:%.*]] +; CHECK: inner.latch.split: +; CHECK-NEXT: [[TMP1:%.*]] = phi i64 [ [[OUTER_V:%.*]], [[OUTER_LATCH]] ] +; CHECK-NEXT: [[TMP2:%.*]] = phi i64 [ [[OUTER_IDX_INC]], [[OUTER_LATCH]] ] +; CHECK-NEXT: [[TMP3]] = add nsw i64 [[INNER_IDX]], 1 +; CHECK-NEXT: br i1 false, label [[INNER_HEADER]], label [[OUTER_EXIT:%.*]] +; CHECK: inner.exit: +; CHECK-NEXT: [[OUTER_V]] = add nsw i64 [[OUTER_IDX]], 1 +; CHECK-NEXT: br label [[OUTER_LATCH]] +; CHECK: outer.latch: +; CHECK-NEXT: [[OUTER_IDX_INC]] = add nsw i64 [[OUTER_IDX]], 1 +; CHECK-NEXT: br i1 false, label [[OUTER_HEADER]], label [[INNER_LATCH_SPLIT]] +; CHECK: outer.exit: +; CHECK-NEXT: [[EXIT1_LCSSA:%.*]] = phi i64 [ [[TMP1]], [[INNER_LATCH_SPLIT]] ] +; CHECK-NEXT: [[EXIT2_LCSSA:%.*]] = phi i64 [ [[TMP2]], [[INNER_LATCH_SPLIT]] ] +; CHECK-NEXT: ret void +; +entry: + br label %outer.header + +outer.header: ; preds = %for.inc27, %entry + %outer.idx = phi i64 [ 0, %entry ], [ %outer.idx.inc, %outer.latch ] + %arrayidx8 = getelementptr inbounds [5 x [5 x double]], [5 x [5 x double]]* @wdtdr, i64 0, i64 0, i64 %outer.idx + br label %inner.header + +inner.header: ; preds = %for.inc, %for.body + %inner.idx = phi i64 [ 0, %outer.header ], [ %inner.idx.inc, %inner.latch] + %0 = load double, double* %arrayidx8, align 8 + store double undef, double* %arrayidx8, align 8 + br label %inner.latch + +inner.latch: ; preds = %for.body6 + %inner.idx.inc = add nsw i64 %inner.idx, 1 + br i1 undef, label %inner.header, label %inner.exit + +inner.exit: ; preds = %for.inc + %outer.v = add nsw i64 %outer.idx, 1 + br label %outer.latch + +outer.latch: ; preds = %for.end + %outer.idx.inc = add nsw i64 %outer.idx, 1 + br i1 undef, label %outer.header, label %outer.exit + +outer.exit: ; preds = %for.inc27 + %exit1.lcssa = phi i64 [ %outer.v, %outer.latch ] + %exit2.lcssa = phi i64 [ %outer.idx.inc, %outer.latch ] + ret void +} + +define void @test2(i1 %cond) { +; CHECK-LABEL: @test2( +; CHECK-NEXT: entry: +; CHECK-NEXT: br i1 [[COND:%.*]], label [[INNER_HEADER_PREHEADER:%.*]], label [[OUTER_EXIT:%.*]] +; CHECK: outer.header.preheader: +; CHECK-NEXT: br label [[OUTER_HEADER:%.*]] +; CHECK: outer.header: +; CHECK-NEXT: [[OUTER_IDX:%.*]] = phi i64 [ [[OUTER_IDX_INC:%.*]], [[OUTER_LATCH:%.*]] ], [ 0, [[OUTER_HEADER_PREHEADER:%.*]] ] +; CHECK-NEXT: [[ARRAYIDX8:%.*]] = getelementptr inbounds [5 x [5 x double]], [5 x [5 x double]]* @wdtdr, i64 0, i64 0, i64 [[OUTER_IDX]] +; CHECK-NEXT: br label [[INNER_HEADER_SPLIT:%.*]] +; CHECK: inner.header.preheader: +; CHECK-NEXT: br label [[INNER_HEADER:%.*]] +; CHECK: inner.header: +; CHECK-NEXT: [[INNER_IDX:%.*]] = phi i64 [ [[TMP3:%.*]], [[INNER_LATCH_SPLIT:%.*]] ], [ 0, [[INNER_HEADER_PREHEADER]] ] +; CHECK-NEXT: br label [[OUTER_HEADER_PREHEADER]] +; CHECK: inner.header.split: +; CHECK-NEXT: [[TMP0:%.*]] = load double, double* [[ARRAYIDX8]], align 8 +; CHECK-NEXT: store double undef, double* [[ARRAYIDX8]], align 8 +; CHECK-NEXT: br label [[INNER_LATCH:%.*]] +; CHECK: inner.latch: +; CHECK-NEXT: [[INNER_IDX_INC:%.*]] = add nsw i64 [[INNER_IDX]], 1 +; CHECK-NEXT: br label [[INNER_EXIT:%.*]] +; CHECK: inner.latch.split: +; CHECK-NEXT: [[TMP1:%.*]] = phi i64 [ [[OUTER_IDX_INC]], [[OUTER_LATCH]] ] +; CHECK-NEXT: [[TMP2:%.*]] = phi i64 [ [[OUTER_V:%.*]], [[OUTER_LATCH]] ] +; CHECK-NEXT: [[TMP3]] = add nsw i64 [[INNER_IDX]], 1 +; CHECK-NEXT: br i1 false, label [[INNER_HEADER]], label [[OUTER_EXIT_LOOPEXIT:%.*]] +; CHECK: inner.exit: +; CHECK-NEXT: [[OUTER_V]] = add nsw i64 [[OUTER_IDX]], 1 +; CHECK-NEXT: br label [[OUTER_LATCH]] +; CHECK: outer.latch: +; CHECK-NEXT: [[OUTER_IDX_INC]] = add nsw i64 [[OUTER_IDX]], 1 +; CHECK-NEXT: br i1 false, label [[OUTER_HEADER]], label [[INNER_LATCH_SPLIT]] +; CHECK: outer.exit.loopexit: +; CHECK-NEXT: [[OUTER_IDX_INC_LCSSA:%.*]] = phi i64 [ [[TMP1]], [[INNER_LATCH_SPLIT]] ] +; CHECK-NEXT: [[OUTER_V_LCSSA:%.*]] = phi i64 [ [[TMP2]], [[INNER_LATCH_SPLIT]] ] +; CHECK-NEXT: br label [[OUTER_EXIT]] +; CHECK: outer.exit: +; CHECK-NEXT: [[EXIT1_LCSSA:%.*]] = phi i64 [ 0, [[ENTRY:%.*]] ], [ [[OUTER_V_LCSSA]], [[OUTER_EXIT_LOOPEXIT]] ] +; CHECK-NEXT: [[EXIT2_LCSSA:%.*]] = phi i64 [ 0, [[ENTRY]] ], [ [[OUTER_IDX_INC_LCSSA]], [[OUTER_EXIT_LOOPEXIT]] ] +; CHECK-NEXT: ret void +; +entry: + br i1 %cond, label %outer.header, label %outer.exit + +outer.header: ; preds = %for.inc27, %entry + %outer.idx = phi i64 [ 0, %entry ], [ %outer.idx.inc, %outer.latch ] + %arrayidx8 = getelementptr inbounds [5 x [5 x double]], [5 x [5 x double]]* @wdtdr, i64 0, i64 0, i64 %outer.idx + br label %inner.header + +inner.header: ; preds = %for.inc, %for.body + %inner.idx = phi i64 [ 0, %outer.header ], [ %inner.idx.inc, %inner.latch] + %0 = load double, double* %arrayidx8, align 8 + store double undef, double* %arrayidx8, align 8 + br label %inner.latch + +inner.latch: ; preds = %for.body6 + %inner.idx.inc = add nsw i64 %inner.idx , 1 + br i1 undef, label %inner.header, label %inner.exit + +inner.exit: ; preds = %for.inc + %outer.v = add nsw i64 %outer.idx, 1 + br label %outer.latch + +outer.latch: ; preds = %for.end + %outer.idx.inc = add nsw i64 %outer.idx, 1 + br i1 undef, label %outer.header, label %outer.exit + +outer.exit: ; preds = %for.inc27 + %exit1.lcssa = phi i64 [ 0, %entry ], [ %outer.v, %outer.latch ] + %exit2.lcssa = phi i64 [ 0, %entry ], [ %outer.idx.inc, %outer.latch ] + ret void +}