diff options
| -rw-r--r-- | llvm/lib/Transforms/Utils/LoopUnroll.cpp | 8 | ||||
| -rw-r--r-- | llvm/test/Transforms/LoopUnroll/unroll-header-exiting-with-phis.ll | 107 |
2 files changed, 112 insertions, 3 deletions
diff --git a/llvm/lib/Transforms/Utils/LoopUnroll.cpp b/llvm/lib/Transforms/Utils/LoopUnroll.cpp index e39ade52371..4a1edb3700c 100644 --- a/llvm/lib/Transforms/Utils/LoopUnroll.cpp +++ b/llvm/lib/Transforms/Utils/LoopUnroll.cpp @@ -711,7 +711,7 @@ LoopUnrollResult llvm::UnrollLoop(Loop *L, UnrollLoopOptions ULO, LoopInfo *LI, auto setDest = [LoopExit, ContinueOnTrue](BasicBlock *Src, BasicBlock *Dest, ArrayRef<BasicBlock *> NextBlocks, - BasicBlock *CurrentHeader, + BasicBlock *BlockInLoop, bool NeedConditional) { auto *Term = cast<BranchInst>(Src->getTerminator()); if (NeedConditional) { @@ -723,7 +723,9 @@ LoopUnrollResult llvm::UnrollLoop(Loop *L, UnrollLoopOptions ULO, LoopInfo *LI, if (Dest != LoopExit) { BasicBlock *BB = Src; for (BasicBlock *Succ : successors(BB)) { - if (Succ == CurrentHeader) + // Preserve the incoming value from BB if we are jumping to the block + // in the current loop. + if (Succ == BlockInLoop) continue; for (PHINode &Phi : Succ->phis()) Phi.removeIncomingValue(BB, false); @@ -794,7 +796,7 @@ LoopUnrollResult llvm::UnrollLoop(Loop *L, UnrollLoopOptions ULO, LoopInfo *LI, // unconditional branch for some iterations. NeedConditional = false; - setDest(Headers[i], Dest, Headers, Headers[i], NeedConditional); + setDest(Headers[i], Dest, Headers, HeaderSucc[i], NeedConditional); } // Set up latches to branch to the new header in the unrolled iterations or diff --git a/llvm/test/Transforms/LoopUnroll/unroll-header-exiting-with-phis.ll b/llvm/test/Transforms/LoopUnroll/unroll-header-exiting-with-phis.ll new file mode 100644 index 00000000000..e1fba5f6689 --- /dev/null +++ b/llvm/test/Transforms/LoopUnroll/unroll-header-exiting-with-phis.ll @@ -0,0 +1,107 @@ +; NOTE: Assertions have been autogenerated by utils/update_test_checks.py +; RUN: opt < %s -S -loop-unroll -unroll-allow-partial | FileCheck %s + +; The phi which acts as input to func should not be undef. It should +; have its loop-carried value (the load in for.cond) replaced accordingly +; after unrolling the loop. + +define i16 @full_unroll(i16* %A) { +; CHECK-LABEL: @full_unroll( +; CHECK-NEXT: entry: +; CHECK-NEXT: br label [[FOR_COND:%.*]] +; CHECK: for.cond: +; CHECK-NEXT: [[TMP2:%.*]] = load i16, i16* [[A:%.*]] +; CHECK-NEXT: br label [[FOR_COND_CLEANUP3:%.*]] +; CHECK: for.cond.cleanup: +; CHECK-NEXT: [[DOTLCSSA10_LCSSA:%.*]] = phi i16 [ [[TMP2_2:%.*]], [[FOR_COND_CLEANUP3_2:%.*]] ] +; CHECK-NEXT: [[TMP3:%.*]] = call i16 @func(i16 [[DOTLCSSA10_LCSSA]]) +; CHECK-NEXT: ret i16 0 +; CHECK: for.cond.cleanup3: +; CHECK-NEXT: [[PTR_1:%.*]] = getelementptr inbounds i16, i16* [[A]], i64 1 +; CHECK-NEXT: [[TMP2_1:%.*]] = load i16, i16* [[PTR_1]] +; CHECK-NEXT: br label [[FOR_COND_CLEANUP3_1:%.*]] +; CHECK: for.cond.cleanup3.1: +; CHECK-NEXT: [[PTR_2:%.*]] = getelementptr inbounds i16, i16* [[A]], i64 2 +; CHECK-NEXT: [[TMP2_2]] = load i16, i16* [[PTR_2]] +; CHECK-NEXT: br label [[FOR_COND_CLEANUP3_2]] +; CHECK: for.cond.cleanup3.2: +; CHECK-NEXT: [[PTR_3:%.*]] = getelementptr inbounds i16, i16* [[A]], i64 3 +; CHECK-NEXT: [[TMP2_3:%.*]] = load i16, i16* [[PTR_3]] +; CHECK-NEXT: br i1 false, label [[FOR_COND_CLEANUP3_3:%.*]], label [[FOR_COND_CLEANUP:%.*]] +; CHECK: for.cond.cleanup3.3: +; CHECK-NEXT: unreachable +; +entry: + br label %for.cond + +for.cond: ; preds = %for.cond.cleanup3, %entry + %.lcssa10 = phi i16 [ 123, %entry ], [ %.lcssa, %for.cond.cleanup3 ] + %i.0 = phi i64 [ 0, %entry ], [ %inc9, %for.cond.cleanup3 ] + %ptr = getelementptr inbounds i16, i16* %A, i64 %i.0 + %tmp2 = load i16, i16* %ptr + %cmp = icmp ult i64 %i.0, 3 + br i1 %cmp, label %for.cond.cleanup3, label %for.cond.cleanup + +for.cond.cleanup: ; preds = %for.cond + %.lcssa10.lcssa = phi i16 [ %.lcssa10, %for.cond ] + %tmp3 = call i16 (i16) @func(i16 %.lcssa10.lcssa) + ret i16 0 + +for.cond.cleanup3: ; preds = %for.cond + %.lcssa = phi i16 [ %tmp2, %for.cond ] + %inc9 = add i64 %i.0, 1 + br label %for.cond +} + +define i16 @partial_unroll(i16* %A) { +; CHECK-LABEL: @partial_unroll( +; CHECK-NEXT: entry: +; CHECK-NEXT: br label [[FOR_COND:%.*]] +; CHECK: for.cond: +; CHECK-NEXT: [[I_0:%.*]] = phi i64 [ 0, [[ENTRY:%.*]] ], [ [[INC9_2:%.*]], [[FOR_COND_CLEANUP3_2:%.*]] ] +; CHECK-NEXT: [[PTR:%.*]] = getelementptr inbounds i16, i16* [[A:%.*]], i64 [[I_0]] +; CHECK-NEXT: [[TMP2:%.*]] = load i16, i16* [[PTR]] +; CHECK-NEXT: br label [[FOR_COND_CLEANUP3:%.*]] +; CHECK: for.cond.cleanup: +; CHECK-NEXT: [[DOTLCSSA10_LCSSA:%.*]] = phi i16 [ [[TMP2_1:%.*]], [[FOR_COND_CLEANUP3_1:%.*]] ] +; CHECK-NEXT: [[TMP3:%.*]] = call i16 @func(i16 [[DOTLCSSA10_LCSSA]]) +; CHECK-NEXT: ret i16 0 +; CHECK: for.cond.cleanup3: +; CHECK-NEXT: [[INC9:%.*]] = add nuw nsw i64 [[I_0]], 1 +; CHECK-NEXT: [[PTR_1:%.*]] = getelementptr inbounds i16, i16* [[A]], i64 [[INC9]] +; CHECK-NEXT: [[TMP2_1]] = load i16, i16* [[PTR_1]] +; CHECK-NEXT: br label [[FOR_COND_CLEANUP3_1]] +; CHECK: for.cond.cleanup3.1: +; CHECK-NEXT: [[INC9_1:%.*]] = add nuw nsw i64 [[INC9]], 1 +; CHECK-NEXT: [[PTR_2:%.*]] = getelementptr inbounds i16, i16* [[A]], i64 [[INC9_1]] +; CHECK-NEXT: [[TMP2_2:%.*]] = load i16, i16* [[PTR_2]] +; CHECK-NEXT: [[CMP_2:%.*]] = icmp ult i64 [[INC9_1]], 200 +; CHECK-NEXT: br i1 [[CMP_2]], label [[FOR_COND_CLEANUP3_2]], label [[FOR_COND_CLEANUP:%.*]] +; CHECK: for.cond.cleanup3.2: +; CHECK-NEXT: [[INC9_2]] = add nuw nsw i64 [[INC9_1]], 1 +; CHECK-NEXT: br label [[FOR_COND]] +; +entry: + br label %for.cond + +for.cond: ; preds = %for.cond.cleanup3, %entry + %.lcssa10 = phi i16 [ 123, %entry ], [ %.lcssa, %for.cond.cleanup3 ] + %i.0 = phi i64 [ 0, %entry ], [ %inc9, %for.cond.cleanup3 ] + %ptr = getelementptr inbounds i16, i16* %A, i64 %i.0 + %tmp2 = load i16, i16* %ptr + %cmp = icmp ult i64 %i.0, 200 + br i1 %cmp, label %for.cond.cleanup3, label %for.cond.cleanup + +for.cond.cleanup: ; preds = %for.cond + %.lcssa10.lcssa = phi i16 [ %.lcssa10, %for.cond ] + %tmp3 = call i16 (i16) @func(i16 %.lcssa10.lcssa) + ret i16 0 + +for.cond.cleanup3: ; preds = %for.cond + %.lcssa = phi i16 [ %tmp2, %for.cond ] + %inc9 = add i64 %i.0, 1 + br label %for.cond +} + +declare i16 @func(i16) + |
