Index: llvm/lib/Transforms/Vectorize/LoopVectorizationLegality.cpp =================================================================== --- llvm/lib/Transforms/Vectorize/LoopVectorizationLegality.cpp +++ llvm/lib/Transforms/Vectorize/LoopVectorizationLegality.cpp @@ -1095,9 +1095,15 @@ return false; } - // We must have a single exiting block. - if (!Lp->getExitingBlock()) { - reportVectorizationFailure("The loop must have an exiting block", + // We currently must have a single "exit block" after the loop. Note that + // multiple "exiting blocks" inside the loop are allowed, provided they all + // reach the single exit block. + // TODO: This restriction can be relaxed in the near future, it's here solely + // to allow separation of changes for review. We need to generalize the phi + // update logic in a number of places. + BasicBlock *ExitBB = Lp->getUniqueExitBlock(); + if (!ExitBB) { + reportVectorizationFailure("The loop must have a unique exit block", "loop control flow is not understood by vectorizer", "CFGNotUnderstood", ORE, TheLoop); if (DoExtraAnalysis) @@ -1106,19 +1112,22 @@ return false; } - // We only handle bottom-tested loops, i.e. loop in which the condition is - // checked at the end of each iteration. With that we can assume that all - // instructions in the loop are executed the same number of times. - if (Lp->getExitingBlock() != Lp->getLoopLatch()) { - reportVectorizationFailure("The exiting block is not the loop latch", + // The existing code assumes that LCSSA implies that phis are single entry + // (which was true when we had at most a single exiting edge from the latch). + // In general, there's nothing which prevents an LCSSA phi in exit block from + // having two or more values if there are multiple exiting edges leading to + // the exit block. (TODO: implement general case) + if (!empty(ExitBB->phis()) && !ExitBB->getSinglePredecessor()) { + reportVectorizationFailure("The loop must have no live-out values if " + "it has more than one exiting block", "loop control flow is not understood by vectorizer", "CFGNotUnderstood", ORE, TheLoop); if (DoExtraAnalysis) Result = false; else return false; - } - + } + return Result; } Index: llvm/lib/Transforms/Vectorize/LoopVectorize.cpp =================================================================== --- llvm/lib/Transforms/Vectorize/LoopVectorize.cpp +++ llvm/lib/Transforms/Vectorize/LoopVectorize.cpp @@ -837,7 +837,8 @@ /// Middle Block between the vector and the scalar. BasicBlock *LoopMiddleBlock; - /// The ExitBlock of the scalar loop. + /// The (unique) ExitBlock of the scalar loop. Note that + /// there can be multiple exiting edges reaching this block. BasicBlock *LoopExitBlock; /// The vector loop body. @@ -1548,11 +1549,16 @@ return InterleaveInfo.getInterleaveGroup(Instr); } - /// Returns true if an interleaved group requires a scalar iteration - /// to handle accesses with gaps, and there is nothing preventing us from - /// creating a scalar epilogue. + /// Returns true if we're required to use a scalar epilogue for at least + /// the final iteration of the original loop. bool requiresScalarEpilogue() const { - return isScalarEpilogueAllowed() && InterleaveInfo.requiresScalarEpilogue(); + if (!isScalarEpilogueAllowed()) + return false; + // If we might exit from anywhere but the latch, must run the exiting + // iteration in scalar form. + if (TheLoop->getExitingBlock() != TheLoop->getLoopLatch()) + return true; + return InterleaveInfo.requiresScalarEpilogue(); } /// Returns true if a scalar epilogue is not allowed due to optsize or a @@ -2912,7 +2918,7 @@ Induction->addIncoming(Next, Latch); // Create the compare. Value *ICmp = Builder.CreateICmpEQ(Next, End); - Builder.CreateCondBr(ICmp, L->getExitBlock(), Header); + Builder.CreateCondBr(ICmp, L->getUniqueExitBlock(), Header); // Now we have two terminators. Remove the old one from the block. Latch->getTerminator()->eraseFromParent(); @@ -3000,13 +3006,17 @@ // unroll factor (number of SIMD instructions). Value *R = Builder.CreateURem(TC, Step, "n.mod.vf"); - // If there is a non-reversed interleaved group that may speculatively access - // memory out-of-bounds, we need to ensure that there will be at least one - // iteration of the scalar epilogue loop. Thus, if the step evenly divides + // There are two cases where we need to ensure (at least) the last iteration + // runs in the scalar remainder loop. Thus, if the step evenly divides // the trip count, we set the remainder to be equal to the step. If the step // does not evenly divide the trip count, no adjustment is necessary since // there will already be scalar iterations. Note that the minimum iterations - // check ensures that N >= Step. + // check ensures that N >= Step. The cases are: + // 1) If there is a non-reversed interleaved group that may speculatively + // access memory out-of-bounds. + // 2) If any instruction may follow a conditionally taken exit. That is, if + // the loop contains multiple exiting blocks, or a single exiting block + // which is not the latch. if (VF.isVector() && Cost->requiresScalarEpilogue()) { auto *IsZero = Builder.CreateICmpEQ(R, ConstantInt::get(R->getType(), 0)); R = Builder.CreateSelect(IsZero, Step, R); @@ -3301,7 +3311,7 @@ Loop *InnerLoopVectorizer::createVectorLoopSkeleton(StringRef Prefix) { LoopScalarBody = OrigLoop->getHeader(); LoopVectorPreHeader = OrigLoop->getLoopPreheader(); - LoopExitBlock = OrigLoop->getExitBlock(); + LoopExitBlock = OrigLoop->getUniqueExitBlock(); assert(LoopExitBlock && "Must have an exit block"); assert(LoopVectorPreHeader && "Invalid loop structure"); @@ -3567,7 +3577,7 @@ // value (the value that feeds into the phi from the loop latch). // We allow both, but they, obviously, have different values. - assert(OrigLoop->getExitBlock() && "Expected a single exit block"); + assert(OrigLoop->getUniqueExitBlock() && "Expected a single exit block"); DenseMap MissingVals; @@ -5485,11 +5495,28 @@ // for size. if (runtimeChecksRequired()) return None; + break; } - // Now try the tail folding + // The only loops we can vectorize without a scalar epilogue, are loops with + // a bottom-test and a single exiting block. We'd have to handle the fact + // that not every instruction executes on the last iteration. This will + // require a lane mask which varies through the vector loop body. (TODO) + if (TheLoop->getExitingBlock() != TheLoop->getLoopLatch()) { + // If there was a tail-folding hint/switch, but we can't fold the tail by + // masking, fallback to a vectorization with a scalar epilogue. + if (ScalarEpilogueStatus == CM_ScalarEpilogueNotNeededUsePredicate) { + LLVM_DEBUG(dbgs() << "LV: Cannot fold tail by masking: vectorize with a " + "scalar epilogue instead.\n"); + ScalarEpilogueStatus = CM_ScalarEpilogueAllowed; + return MaxVF; + } + return None; + } + // Now try the tail folding + // Invalidate interleave groups that require an epilogue if we can't mask // the interleave-group. if (!useMaskedInterleavedAccesses(TTI)) { @@ -7916,6 +7943,12 @@ if (!BI->isConditional() || BI->getSuccessor(0) == BI->getSuccessor(1)) return EdgeMaskCache[Edge] = SrcMask; + // If source is an exiting block, we know the exit edge is dynamically dead + // in the vector loop, and thus we don't need to restrict the mask. Avoid + // adding uses of an otherwise potentially dead instruction. + if (OrigLoop->isLoopExiting(Src)) + return EdgeMaskCache[Edge] = SrcMask; + VPValue *EdgeMask = Plan->getOrAddVPValue(BI->getCondition()); assert(EdgeMask && "No Edge Mask found for condition"); Index: llvm/test/Transforms/LoopVectorize/control-flow.ll =================================================================== --- llvm/test/Transforms/LoopVectorize/control-flow.ll +++ llvm/test/Transforms/LoopVectorize/control-flow.ll @@ -10,7 +10,7 @@ ; return 0; ; } -; CHECK: remark: source.cpp:5:9: loop not vectorized: loop control flow is not understood by vectorizer +; CHECK: remark: source.cpp:5:9: loop not vectorized: could not determine number of loop iterations ; CHECK: remark: source.cpp:5:9: loop not vectorized ; CHECK: _Z4testPii Index: llvm/test/Transforms/LoopVectorize/loop-form.ll =================================================================== --- llvm/test/Transforms/LoopVectorize/loop-form.ll +++ llvm/test/Transforms/LoopVectorize/loop-form.ll @@ -1,5 +1,7 @@ ; NOTE: Assertions have been autogenerated by utils/update_test_checks.py ; RUN: opt -S -loop-vectorize -force-vector-width=2 < %s | FileCheck %s +; RUN: opt -S -loop-vectorize -force-vector-width=2 -prefer-predicate-over-epilogue=predicate-dont-vectorize < %s | FileCheck --check-prefix TAILFOLD %s + target datalayout = "e-m:o-i64:64-f80:128-n8:16:32:64-S128" define void @bottom_tested(i16* %p, i32 %n) { @@ -42,6 +44,63 @@ ; CHECK: if.end: ; CHECK-NEXT: ret void ; +; TAILFOLD-LABEL: @bottom_tested( +; TAILFOLD-NEXT: entry: +; TAILFOLD-NEXT: [[TMP0:%.*]] = icmp sgt i32 [[N:%.*]], 0 +; TAILFOLD-NEXT: [[SMAX:%.*]] = select i1 [[TMP0]], i32 [[N]], i32 0 +; TAILFOLD-NEXT: [[TMP1:%.*]] = add nuw i32 [[SMAX]], 1 +; TAILFOLD-NEXT: br i1 false, label [[SCALAR_PH:%.*]], label [[VECTOR_PH:%.*]] +; TAILFOLD: vector.ph: +; TAILFOLD-NEXT: [[N_RND_UP:%.*]] = add i32 [[TMP1]], 1 +; TAILFOLD-NEXT: [[N_MOD_VF:%.*]] = urem i32 [[N_RND_UP]], 2 +; TAILFOLD-NEXT: [[N_VEC:%.*]] = sub i32 [[N_RND_UP]], [[N_MOD_VF]] +; TAILFOLD-NEXT: [[TRIP_COUNT_MINUS_1:%.*]] = sub i32 [[TMP1]], 1 +; TAILFOLD-NEXT: [[BROADCAST_SPLATINSERT:%.*]] = insertelement <2 x i32> undef, i32 [[TRIP_COUNT_MINUS_1]], i32 0 +; TAILFOLD-NEXT: [[BROADCAST_SPLAT:%.*]] = shufflevector <2 x i32> [[BROADCAST_SPLATINSERT]], <2 x i32> undef, <2 x i32> zeroinitializer +; TAILFOLD-NEXT: br label [[VECTOR_BODY:%.*]] +; TAILFOLD: vector.body: +; TAILFOLD-NEXT: [[INDEX:%.*]] = phi i32 [ 0, [[VECTOR_PH]] ], [ [[INDEX_NEXT:%.*]], [[PRED_STORE_CONTINUE2:%.*]] ] +; TAILFOLD-NEXT: [[VEC_IND:%.*]] = phi <2 x i32> [ , [[VECTOR_PH]] ], [ [[VEC_IND_NEXT:%.*]], [[PRED_STORE_CONTINUE2]] ] +; TAILFOLD-NEXT: [[TMP2:%.*]] = add i32 [[INDEX]], 0 +; TAILFOLD-NEXT: [[TMP3:%.*]] = add i32 [[INDEX]], 1 +; TAILFOLD-NEXT: [[TMP4:%.*]] = icmp ule <2 x i32> [[VEC_IND]], [[BROADCAST_SPLAT]] +; TAILFOLD-NEXT: [[TMP5:%.*]] = sext <2 x i32> [[VEC_IND]] to <2 x i64> +; TAILFOLD-NEXT: [[TMP6:%.*]] = extractelement <2 x i1> [[TMP4]], i32 0 +; TAILFOLD-NEXT: br i1 [[TMP6]], label [[PRED_STORE_IF:%.*]], label [[PRED_STORE_CONTINUE:%.*]] +; TAILFOLD: pred.store.if: +; TAILFOLD-NEXT: [[TMP7:%.*]] = extractelement <2 x i64> [[TMP5]], i32 0 +; TAILFOLD-NEXT: [[TMP8:%.*]] = getelementptr inbounds i16, i16* [[P:%.*]], i64 [[TMP7]] +; TAILFOLD-NEXT: store i16 0, i16* [[TMP8]], align 4 +; TAILFOLD-NEXT: br label [[PRED_STORE_CONTINUE]] +; TAILFOLD: pred.store.continue: +; TAILFOLD-NEXT: [[TMP9:%.*]] = extractelement <2 x i1> [[TMP4]], i32 1 +; TAILFOLD-NEXT: br i1 [[TMP9]], label [[PRED_STORE_IF1:%.*]], label [[PRED_STORE_CONTINUE2]] +; TAILFOLD: pred.store.if1: +; TAILFOLD-NEXT: [[TMP10:%.*]] = extractelement <2 x i64> [[TMP5]], i32 1 +; TAILFOLD-NEXT: [[TMP11:%.*]] = getelementptr inbounds i16, i16* [[P]], i64 [[TMP10]] +; TAILFOLD-NEXT: store i16 0, i16* [[TMP11]], align 4 +; TAILFOLD-NEXT: br label [[PRED_STORE_CONTINUE2]] +; TAILFOLD: pred.store.continue2: +; TAILFOLD-NEXT: [[INDEX_NEXT]] = add i32 [[INDEX]], 2 +; TAILFOLD-NEXT: [[VEC_IND_NEXT]] = add <2 x i32> [[VEC_IND]], +; TAILFOLD-NEXT: [[TMP12:%.*]] = icmp eq i32 [[INDEX_NEXT]], [[N_VEC]] +; TAILFOLD-NEXT: br i1 [[TMP12]], label [[MIDDLE_BLOCK:%.*]], label [[VECTOR_BODY]], [[LOOP0:!llvm.loop !.*]] +; TAILFOLD: middle.block: +; TAILFOLD-NEXT: br i1 true, label [[IF_END:%.*]], label [[SCALAR_PH]] +; TAILFOLD: scalar.ph: +; TAILFOLD-NEXT: [[BC_RESUME_VAL:%.*]] = phi i32 [ [[N_VEC]], [[MIDDLE_BLOCK]] ], [ 0, [[ENTRY:%.*]] ] +; TAILFOLD-NEXT: br label [[FOR_COND:%.*]] +; TAILFOLD: for.cond: +; TAILFOLD-NEXT: [[I:%.*]] = phi i32 [ [[BC_RESUME_VAL]], [[SCALAR_PH]] ], [ [[INC:%.*]], [[FOR_COND]] ] +; TAILFOLD-NEXT: [[IPROM:%.*]] = sext i32 [[I]] to i64 +; TAILFOLD-NEXT: [[B:%.*]] = getelementptr inbounds i16, i16* [[P]], i64 [[IPROM]] +; TAILFOLD-NEXT: store i16 0, i16* [[B]], align 4 +; TAILFOLD-NEXT: [[INC]] = add nsw i32 [[I]], 1 +; TAILFOLD-NEXT: [[CMP:%.*]] = icmp slt i32 [[I]], [[N]] +; TAILFOLD-NEXT: br i1 [[CMP]], label [[FOR_COND]], label [[IF_END]], [[LOOP2:!llvm.loop !.*]] +; TAILFOLD: if.end: +; TAILFOLD-NEXT: ret void +; entry: br label %for.cond @@ -61,6 +120,90 @@ define void @early_exit(i16* %p, i32 %n) { ; CHECK-LABEL: @early_exit( ; CHECK-NEXT: entry: +; CHECK-NEXT: [[TMP0:%.*]] = icmp sgt i32 [[N:%.*]], 0 +; CHECK-NEXT: [[SMAX:%.*]] = select i1 [[TMP0]], i32 [[N]], i32 0 +; CHECK-NEXT: [[TMP1:%.*]] = add nuw i32 [[SMAX]], 1 +; CHECK-NEXT: [[MIN_ITERS_CHECK:%.*]] = icmp ule i32 [[TMP1]], 2 +; CHECK-NEXT: br i1 [[MIN_ITERS_CHECK]], label [[SCALAR_PH:%.*]], label [[VECTOR_PH:%.*]] +; CHECK: vector.ph: +; CHECK-NEXT: [[N_MOD_VF:%.*]] = urem i32 [[TMP1]], 2 +; CHECK-NEXT: [[TMP2:%.*]] = icmp eq i32 [[N_MOD_VF]], 0 +; CHECK-NEXT: [[TMP3:%.*]] = select i1 [[TMP2]], i32 2, i32 [[N_MOD_VF]] +; CHECK-NEXT: [[N_VEC:%.*]] = sub i32 [[TMP1]], [[TMP3]] +; CHECK-NEXT: br label [[VECTOR_BODY:%.*]] +; CHECK: vector.body: +; CHECK-NEXT: [[INDEX:%.*]] = phi i32 [ 0, [[VECTOR_PH]] ], [ [[INDEX_NEXT:%.*]], [[VECTOR_BODY]] ] +; CHECK-NEXT: [[VEC_IND:%.*]] = phi <2 x i32> [ , [[VECTOR_PH]] ], [ [[VEC_IND_NEXT:%.*]], [[VECTOR_BODY]] ] +; CHECK-NEXT: [[TMP4:%.*]] = add i32 [[INDEX]], 0 +; CHECK-NEXT: [[TMP5:%.*]] = add i32 [[INDEX]], 1 +; CHECK-NEXT: [[TMP6:%.*]] = sext i32 [[TMP4]] to i64 +; CHECK-NEXT: [[TMP7:%.*]] = getelementptr inbounds i16, i16* [[P:%.*]], i64 [[TMP6]] +; CHECK-NEXT: [[TMP8:%.*]] = getelementptr inbounds i16, i16* [[TMP7]], i32 0 +; CHECK-NEXT: [[TMP9:%.*]] = bitcast i16* [[TMP8]] to <2 x i16>* +; CHECK-NEXT: store <2 x i16> zeroinitializer, <2 x i16>* [[TMP9]], align 4 +; CHECK-NEXT: [[INDEX_NEXT]] = add i32 [[INDEX]], 2 +; CHECK-NEXT: [[VEC_IND_NEXT]] = add <2 x i32> [[VEC_IND]], +; CHECK-NEXT: [[TMP10:%.*]] = icmp eq i32 [[INDEX_NEXT]], [[N_VEC]] +; CHECK-NEXT: br i1 [[TMP10]], label [[MIDDLE_BLOCK:%.*]], label [[VECTOR_BODY]], [[LOOP4:!llvm.loop !.*]] +; CHECK: middle.block: +; CHECK-NEXT: [[CMP_N:%.*]] = icmp eq i32 [[TMP1]], [[N_VEC]] +; CHECK-NEXT: br i1 [[CMP_N]], label [[IF_END:%.*]], label [[SCALAR_PH]] +; CHECK: scalar.ph: +; CHECK-NEXT: [[BC_RESUME_VAL:%.*]] = phi i32 [ [[N_VEC]], [[MIDDLE_BLOCK]] ], [ 0, [[ENTRY:%.*]] ] +; CHECK-NEXT: br label [[FOR_COND:%.*]] +; CHECK: for.cond: +; CHECK-NEXT: [[I:%.*]] = phi i32 [ [[BC_RESUME_VAL]], [[SCALAR_PH]] ], [ [[INC:%.*]], [[FOR_BODY:%.*]] ] +; CHECK-NEXT: [[CMP:%.*]] = icmp slt i32 [[I]], [[N]] +; CHECK-NEXT: br i1 [[CMP]], label [[FOR_BODY]], label [[IF_END]] +; CHECK: for.body: +; CHECK-NEXT: [[IPROM:%.*]] = sext i32 [[I]] to i64 +; CHECK-NEXT: [[B:%.*]] = getelementptr inbounds i16, i16* [[P]], i64 [[IPROM]] +; CHECK-NEXT: store i16 0, i16* [[B]], align 4 +; CHECK-NEXT: [[INC]] = add nsw i32 [[I]], 1 +; CHECK-NEXT: br label [[FOR_COND]], [[LOOP5:!llvm.loop !.*]] +; CHECK: if.end: +; CHECK-NEXT: ret void +; +; TAILFOLD-LABEL: @early_exit( +; TAILFOLD-NEXT: entry: +; TAILFOLD-NEXT: br label [[FOR_COND:%.*]] +; TAILFOLD: for.cond: +; TAILFOLD-NEXT: [[I:%.*]] = phi i32 [ 0, [[ENTRY:%.*]] ], [ [[INC:%.*]], [[FOR_BODY:%.*]] ] +; TAILFOLD-NEXT: [[CMP:%.*]] = icmp slt i32 [[I]], [[N:%.*]] +; TAILFOLD-NEXT: br i1 [[CMP]], label [[FOR_BODY]], label [[IF_END:%.*]] +; TAILFOLD: for.body: +; TAILFOLD-NEXT: [[IPROM:%.*]] = sext i32 [[I]] to i64 +; TAILFOLD-NEXT: [[B:%.*]] = getelementptr inbounds i16, i16* [[P:%.*]], i64 [[IPROM]] +; TAILFOLD-NEXT: store i16 0, i16* [[B]], align 4 +; TAILFOLD-NEXT: [[INC]] = add nsw i32 [[I]], 1 +; TAILFOLD-NEXT: br label [[FOR_COND]] +; TAILFOLD: if.end: +; TAILFOLD-NEXT: ret void +; +entry: + br label %for.cond + +for.cond: + %i = phi i32 [ 0, %entry ], [ %inc, %for.body ] + %cmp = icmp slt i32 %i, %n + br i1 %cmp, label %for.body, label %if.end + +for.body: + %iprom = sext i32 %i to i64 + %b = getelementptr inbounds i16, i16* %p, i64 %iprom + store i16 0, i16* %b, align 4 + %inc = add nsw i32 %i, 1 + br label %for.cond + +if.end: + ret void +} + +; Same as early_exit, but with optsize to prevent the use of +; a scalar epilogue. -- Can't vectorize this in either case. +define void @optsize(i16* %p, i32 %n) optsize { +; CHECK-LABEL: @optsize( +; CHECK-NEXT: entry: ; CHECK-NEXT: br label [[FOR_COND:%.*]] ; CHECK: for.cond: ; CHECK-NEXT: [[I:%.*]] = phi i32 [ 0, [[ENTRY:%.*]] ], [ [[INC:%.*]], [[FOR_BODY:%.*]] ] @@ -75,6 +218,22 @@ ; CHECK: if.end: ; CHECK-NEXT: ret void ; +; TAILFOLD-LABEL: @optsize( +; TAILFOLD-NEXT: entry: +; TAILFOLD-NEXT: br label [[FOR_COND:%.*]] +; TAILFOLD: for.cond: +; TAILFOLD-NEXT: [[I:%.*]] = phi i32 [ 0, [[ENTRY:%.*]] ], [ [[INC:%.*]], [[FOR_BODY:%.*]] ] +; TAILFOLD-NEXT: [[CMP:%.*]] = icmp slt i32 [[I]], [[N:%.*]] +; TAILFOLD-NEXT: br i1 [[CMP]], label [[FOR_BODY]], label [[IF_END:%.*]] +; TAILFOLD: for.body: +; TAILFOLD-NEXT: [[IPROM:%.*]] = sext i32 [[I]] to i64 +; TAILFOLD-NEXT: [[B:%.*]] = getelementptr inbounds i16, i16* [[P:%.*]], i64 [[IPROM]] +; TAILFOLD-NEXT: store i16 0, i16* [[B]], align 4 +; TAILFOLD-NEXT: [[INC]] = add nsw i32 [[I]], 1 +; TAILFOLD-NEXT: br label [[FOR_COND]] +; TAILFOLD: if.end: +; TAILFOLD-NEXT: ret void +; entry: br label %for.cond @@ -99,21 +258,70 @@ define void @multiple_unique_exit(i16* %p, i32 %n) { ; CHECK-LABEL: @multiple_unique_exit( ; CHECK-NEXT: entry: +; CHECK-NEXT: [[TMP0:%.*]] = icmp sgt i32 [[N:%.*]], 0 +; CHECK-NEXT: [[SMAX:%.*]] = select i1 [[TMP0]], i32 [[N]], i32 0 +; CHECK-NEXT: [[TMP1:%.*]] = icmp ult i32 [[SMAX]], 2096 +; CHECK-NEXT: [[UMIN:%.*]] = select i1 [[TMP1]], i32 [[SMAX]], i32 2096 +; CHECK-NEXT: [[TMP2:%.*]] = add nuw nsw i32 [[UMIN]], 1 +; CHECK-NEXT: [[MIN_ITERS_CHECK:%.*]] = icmp ule i32 [[TMP2]], 2 +; CHECK-NEXT: br i1 [[MIN_ITERS_CHECK]], label [[SCALAR_PH:%.*]], label [[VECTOR_PH:%.*]] +; CHECK: vector.ph: +; CHECK-NEXT: [[N_MOD_VF:%.*]] = urem i32 [[TMP2]], 2 +; CHECK-NEXT: [[TMP3:%.*]] = icmp eq i32 [[N_MOD_VF]], 0 +; CHECK-NEXT: [[TMP4:%.*]] = select i1 [[TMP3]], i32 2, i32 [[N_MOD_VF]] +; CHECK-NEXT: [[N_VEC:%.*]] = sub i32 [[TMP2]], [[TMP4]] +; CHECK-NEXT: br label [[VECTOR_BODY:%.*]] +; CHECK: vector.body: +; CHECK-NEXT: [[INDEX:%.*]] = phi i32 [ 0, [[VECTOR_PH]] ], [ [[INDEX_NEXT:%.*]], [[VECTOR_BODY]] ] +; CHECK-NEXT: [[VEC_IND:%.*]] = phi <2 x i32> [ , [[VECTOR_PH]] ], [ [[VEC_IND_NEXT:%.*]], [[VECTOR_BODY]] ] +; CHECK-NEXT: [[TMP5:%.*]] = add i32 [[INDEX]], 0 +; CHECK-NEXT: [[TMP6:%.*]] = add i32 [[INDEX]], 1 +; CHECK-NEXT: [[TMP7:%.*]] = sext i32 [[TMP5]] to i64 +; CHECK-NEXT: [[TMP8:%.*]] = getelementptr inbounds i16, i16* [[P:%.*]], i64 [[TMP7]] +; CHECK-NEXT: [[TMP9:%.*]] = getelementptr inbounds i16, i16* [[TMP8]], i32 0 +; CHECK-NEXT: [[TMP10:%.*]] = bitcast i16* [[TMP9]] to <2 x i16>* +; CHECK-NEXT: store <2 x i16> zeroinitializer, <2 x i16>* [[TMP10]], align 4 +; CHECK-NEXT: [[INDEX_NEXT]] = add i32 [[INDEX]], 2 +; CHECK-NEXT: [[VEC_IND_NEXT]] = add <2 x i32> [[VEC_IND]], +; CHECK-NEXT: [[TMP11:%.*]] = icmp eq i32 [[INDEX_NEXT]], [[N_VEC]] +; CHECK-NEXT: br i1 [[TMP11]], label [[MIDDLE_BLOCK:%.*]], label [[VECTOR_BODY]], [[LOOP6:!llvm.loop !.*]] +; CHECK: middle.block: +; CHECK-NEXT: [[CMP_N:%.*]] = icmp eq i32 [[TMP2]], [[N_VEC]] +; CHECK-NEXT: br i1 [[CMP_N]], label [[IF_END:%.*]], label [[SCALAR_PH]] +; CHECK: scalar.ph: +; CHECK-NEXT: [[BC_RESUME_VAL:%.*]] = phi i32 [ [[N_VEC]], [[MIDDLE_BLOCK]] ], [ 0, [[ENTRY:%.*]] ] ; CHECK-NEXT: br label [[FOR_COND:%.*]] ; CHECK: for.cond: -; CHECK-NEXT: [[I:%.*]] = phi i32 [ 0, [[ENTRY:%.*]] ], [ [[INC:%.*]], [[FOR_BODY:%.*]] ] -; CHECK-NEXT: [[CMP:%.*]] = icmp slt i32 [[I]], [[N:%.*]] -; CHECK-NEXT: br i1 [[CMP]], label [[FOR_BODY]], label [[IF_END:%.*]] +; CHECK-NEXT: [[I:%.*]] = phi i32 [ [[BC_RESUME_VAL]], [[SCALAR_PH]] ], [ [[INC:%.*]], [[FOR_BODY:%.*]] ] +; CHECK-NEXT: [[CMP:%.*]] = icmp slt i32 [[I]], [[N]] +; CHECK-NEXT: br i1 [[CMP]], label [[FOR_BODY]], label [[IF_END]] ; CHECK: for.body: ; CHECK-NEXT: [[IPROM:%.*]] = sext i32 [[I]] to i64 -; CHECK-NEXT: [[B:%.*]] = getelementptr inbounds i16, i16* [[P:%.*]], i64 [[IPROM]] +; CHECK-NEXT: [[B:%.*]] = getelementptr inbounds i16, i16* [[P]], i64 [[IPROM]] ; CHECK-NEXT: store i16 0, i16* [[B]], align 4 ; CHECK-NEXT: [[INC]] = add nsw i32 [[I]], 1 ; CHECK-NEXT: [[CMP2:%.*]] = icmp slt i32 [[I]], 2096 -; CHECK-NEXT: br i1 [[CMP2]], label [[FOR_COND]], label [[IF_END]] +; CHECK-NEXT: br i1 [[CMP2]], label [[FOR_COND]], label [[IF_END]], [[LOOP7:!llvm.loop !.*]] ; CHECK: if.end: ; CHECK-NEXT: ret void ; +; TAILFOLD-LABEL: @multiple_unique_exit( +; TAILFOLD-NEXT: entry: +; TAILFOLD-NEXT: br label [[FOR_COND:%.*]] +; TAILFOLD: for.cond: +; TAILFOLD-NEXT: [[I:%.*]] = phi i32 [ 0, [[ENTRY:%.*]] ], [ [[INC:%.*]], [[FOR_BODY:%.*]] ] +; TAILFOLD-NEXT: [[CMP:%.*]] = icmp slt i32 [[I]], [[N:%.*]] +; TAILFOLD-NEXT: br i1 [[CMP]], label [[FOR_BODY]], label [[IF_END:%.*]] +; TAILFOLD: for.body: +; TAILFOLD-NEXT: [[IPROM:%.*]] = sext i32 [[I]] to i64 +; TAILFOLD-NEXT: [[B:%.*]] = getelementptr inbounds i16, i16* [[P:%.*]], i64 [[IPROM]] +; TAILFOLD-NEXT: store i16 0, i16* [[B]], align 4 +; TAILFOLD-NEXT: [[INC]] = add nsw i32 [[I]], 1 +; TAILFOLD-NEXT: [[CMP2:%.*]] = icmp slt i32 [[I]], 2096 +; TAILFOLD-NEXT: br i1 [[CMP2]], label [[FOR_COND]], label [[IF_END]] +; TAILFOLD: if.end: +; TAILFOLD-NEXT: ret void +; entry: br label %for.cond @@ -154,6 +362,24 @@ ; CHECK-NEXT: [[I_LCSSA:%.*]] = phi i32 [ [[I]], [[FOR_BODY]] ], [ [[I]], [[FOR_COND]] ] ; CHECK-NEXT: ret i32 [[I_LCSSA]] ; +; TAILFOLD-LABEL: @multiple_unique_exit2( +; TAILFOLD-NEXT: entry: +; TAILFOLD-NEXT: br label [[FOR_COND:%.*]] +; TAILFOLD: for.cond: +; TAILFOLD-NEXT: [[I:%.*]] = phi i32 [ 0, [[ENTRY:%.*]] ], [ [[INC:%.*]], [[FOR_BODY:%.*]] ] +; TAILFOLD-NEXT: [[CMP:%.*]] = icmp slt i32 [[I]], [[N:%.*]] +; TAILFOLD-NEXT: br i1 [[CMP]], label [[FOR_BODY]], label [[IF_END:%.*]] +; TAILFOLD: for.body: +; TAILFOLD-NEXT: [[IPROM:%.*]] = sext i32 [[I]] to i64 +; TAILFOLD-NEXT: [[B:%.*]] = getelementptr inbounds i16, i16* [[P:%.*]], i64 [[IPROM]] +; TAILFOLD-NEXT: store i16 0, i16* [[B]], align 4 +; TAILFOLD-NEXT: [[INC]] = add nsw i32 [[I]], 1 +; TAILFOLD-NEXT: [[CMP2:%.*]] = icmp slt i32 [[I]], 2096 +; TAILFOLD-NEXT: br i1 [[CMP2]], label [[FOR_COND]], label [[IF_END]] +; TAILFOLD: if.end: +; TAILFOLD-NEXT: [[I_LCSSA:%.*]] = phi i32 [ [[I]], [[FOR_BODY]] ], [ [[I]], [[FOR_COND]] ] +; TAILFOLD-NEXT: ret i32 [[I_LCSSA]] +; entry: br label %for.cond @@ -194,6 +420,24 @@ ; CHECK-NEXT: [[EXIT:%.*]] = phi i32 [ 0, [[FOR_COND]] ], [ 1, [[FOR_BODY]] ] ; CHECK-NEXT: ret i32 [[EXIT]] ; +; TAILFOLD-LABEL: @multiple_unique_exit3( +; TAILFOLD-NEXT: entry: +; TAILFOLD-NEXT: br label [[FOR_COND:%.*]] +; TAILFOLD: for.cond: +; TAILFOLD-NEXT: [[I:%.*]] = phi i32 [ 0, [[ENTRY:%.*]] ], [ [[INC:%.*]], [[FOR_BODY:%.*]] ] +; TAILFOLD-NEXT: [[CMP:%.*]] = icmp slt i32 [[I]], [[N:%.*]] +; TAILFOLD-NEXT: br i1 [[CMP]], label [[FOR_BODY]], label [[IF_END:%.*]] +; TAILFOLD: for.body: +; TAILFOLD-NEXT: [[IPROM:%.*]] = sext i32 [[I]] to i64 +; TAILFOLD-NEXT: [[B:%.*]] = getelementptr inbounds i16, i16* [[P:%.*]], i64 [[IPROM]] +; TAILFOLD-NEXT: store i16 0, i16* [[B]], align 4 +; TAILFOLD-NEXT: [[INC]] = add nsw i32 [[I]], 1 +; TAILFOLD-NEXT: [[CMP2:%.*]] = icmp slt i32 [[I]], 2096 +; TAILFOLD-NEXT: br i1 [[CMP2]], label [[FOR_COND]], label [[IF_END]] +; TAILFOLD: if.end: +; TAILFOLD-NEXT: [[EXIT:%.*]] = phi i32 [ 0, [[FOR_COND]] ], [ 1, [[FOR_BODY]] ] +; TAILFOLD-NEXT: ret i32 [[EXIT]] +; entry: br label %for.cond @@ -236,6 +480,25 @@ ; CHECK: if.end2: ; CHECK-NEXT: ret i32 1 ; +; TAILFOLD-LABEL: @multiple_exit_blocks( +; TAILFOLD-NEXT: entry: +; TAILFOLD-NEXT: br label [[FOR_COND:%.*]] +; TAILFOLD: for.cond: +; TAILFOLD-NEXT: [[I:%.*]] = phi i32 [ 0, [[ENTRY:%.*]] ], [ [[INC:%.*]], [[FOR_BODY:%.*]] ] +; TAILFOLD-NEXT: [[CMP:%.*]] = icmp slt i32 [[I]], [[N:%.*]] +; TAILFOLD-NEXT: br i1 [[CMP]], label [[FOR_BODY]], label [[IF_END:%.*]] +; TAILFOLD: for.body: +; TAILFOLD-NEXT: [[IPROM:%.*]] = sext i32 [[I]] to i64 +; TAILFOLD-NEXT: [[B:%.*]] = getelementptr inbounds i16, i16* [[P:%.*]], i64 [[IPROM]] +; TAILFOLD-NEXT: store i16 0, i16* [[B]], align 4 +; TAILFOLD-NEXT: [[INC]] = add nsw i32 [[I]], 1 +; TAILFOLD-NEXT: [[CMP2:%.*]] = icmp slt i32 [[I]], 2096 +; TAILFOLD-NEXT: br i1 [[CMP2]], label [[FOR_COND]], label [[IF_END2:%.*]] +; TAILFOLD: if.end: +; TAILFOLD-NEXT: ret i32 0 +; TAILFOLD: if.end2: +; TAILFOLD-NEXT: ret i32 1 +; entry: br label %for.cond @@ -279,6 +542,23 @@ ; CHECK-NEXT: [[I_LCSSA:%.*]] = phi i32 [ [[I]], [[FOR_COND]] ], [ [[I]], [[FOR_COND]] ] ; CHECK-NEXT: ret i32 [[I_LCSSA]] ; +; TAILFOLD-LABEL: @multiple_exit_switch( +; TAILFOLD-NEXT: entry: +; TAILFOLD-NEXT: br label [[FOR_COND:%.*]] +; TAILFOLD: for.cond: +; TAILFOLD-NEXT: [[I:%.*]] = phi i32 [ 0, [[ENTRY:%.*]] ], [ [[INC:%.*]], [[FOR_COND]] ] +; TAILFOLD-NEXT: [[IPROM:%.*]] = sext i32 [[I]] to i64 +; TAILFOLD-NEXT: [[B:%.*]] = getelementptr inbounds i16, i16* [[P:%.*]], i64 [[IPROM]] +; TAILFOLD-NEXT: store i16 0, i16* [[B]], align 4 +; TAILFOLD-NEXT: [[INC]] = add nsw i32 [[I]], 1 +; TAILFOLD-NEXT: switch i32 [[I]], label [[FOR_COND]] [ +; TAILFOLD-NEXT: i32 2096, label [[IF_END:%.*]] +; TAILFOLD-NEXT: i32 2097, label [[IF_END]] +; TAILFOLD-NEXT: ] +; TAILFOLD: if.end: +; TAILFOLD-NEXT: [[I_LCSSA:%.*]] = phi i32 [ [[I]], [[FOR_COND]] ], [ [[I]], [[FOR_COND]] ] +; TAILFOLD-NEXT: ret i32 [[I_LCSSA]] +; entry: br label %for.cond @@ -318,6 +598,24 @@ ; CHECK: if.end2: ; CHECK-NEXT: ret i32 1 ; +; TAILFOLD-LABEL: @multiple_exit_switch2( +; TAILFOLD-NEXT: entry: +; TAILFOLD-NEXT: br label [[FOR_COND:%.*]] +; TAILFOLD: for.cond: +; TAILFOLD-NEXT: [[I:%.*]] = phi i32 [ 0, [[ENTRY:%.*]] ], [ [[INC:%.*]], [[FOR_COND]] ] +; TAILFOLD-NEXT: [[IPROM:%.*]] = sext i32 [[I]] to i64 +; TAILFOLD-NEXT: [[B:%.*]] = getelementptr inbounds i16, i16* [[P:%.*]], i64 [[IPROM]] +; TAILFOLD-NEXT: store i16 0, i16* [[B]], align 4 +; TAILFOLD-NEXT: [[INC]] = add nsw i32 [[I]], 1 +; TAILFOLD-NEXT: switch i32 [[I]], label [[FOR_COND]] [ +; TAILFOLD-NEXT: i32 2096, label [[IF_END:%.*]] +; TAILFOLD-NEXT: i32 2097, label [[IF_END2:%.*]] +; TAILFOLD-NEXT: ] +; TAILFOLD: if.end: +; TAILFOLD-NEXT: ret i32 0 +; TAILFOLD: if.end2: +; TAILFOLD-NEXT: ret i32 1 +; entry: br label %for.cond @@ -359,6 +657,25 @@ ; CHECK: for.end: ; CHECK-NEXT: ret i32 0 ; +; TAILFOLD-LABEL: @multiple_latch1( +; TAILFOLD-NEXT: entry: +; TAILFOLD-NEXT: br label [[FOR_BODY:%.*]] +; TAILFOLD: for.body: +; TAILFOLD-NEXT: [[I_02:%.*]] = phi i32 [ 0, [[ENTRY:%.*]] ], [ [[INC:%.*]], [[FOR_BODY_BACKEDGE:%.*]] ] +; TAILFOLD-NEXT: [[INC]] = add nsw i32 [[I_02]], 1 +; TAILFOLD-NEXT: [[CMP:%.*]] = icmp slt i32 [[INC]], 16 +; TAILFOLD-NEXT: br i1 [[CMP]], label [[FOR_BODY_BACKEDGE]], label [[FOR_SECOND:%.*]] +; TAILFOLD: for.second: +; TAILFOLD-NEXT: [[IPROM:%.*]] = sext i32 [[I_02]] to i64 +; TAILFOLD-NEXT: [[B:%.*]] = getelementptr inbounds i16, i16* [[P:%.*]], i64 [[IPROM]] +; TAILFOLD-NEXT: store i16 0, i16* [[B]], align 4 +; TAILFOLD-NEXT: [[CMPS:%.*]] = icmp sgt i32 [[INC]], 16 +; TAILFOLD-NEXT: br i1 [[CMPS]], label [[FOR_BODY_BACKEDGE]], label [[FOR_END:%.*]] +; TAILFOLD: for.body.backedge: +; TAILFOLD-NEXT: br label [[FOR_BODY]] +; TAILFOLD: for.end: +; TAILFOLD-NEXT: ret i32 0 +; entry: br label %for.body @@ -405,6 +722,25 @@ ; CHECK: for.end: ; CHECK-NEXT: ret i32 0 ; +; TAILFOLD-LABEL: @multiple_latch2( +; TAILFOLD-NEXT: entry: +; TAILFOLD-NEXT: br label [[FOR_BODY:%.*]] +; TAILFOLD: for.body: +; TAILFOLD-NEXT: [[I_02:%.*]] = phi i32 [ 0, [[ENTRY:%.*]] ], [ [[INC:%.*]], [[FOR_BODY_BACKEDGE:%.*]] ] +; TAILFOLD-NEXT: [[INC]] = add nsw i32 [[I_02]], 1 +; TAILFOLD-NEXT: [[CMP:%.*]] = icmp slt i32 [[INC]], 16 +; TAILFOLD-NEXT: br i1 [[CMP]], label [[FOR_BODY_BACKEDGE]], label [[FOR_SECOND:%.*]] +; TAILFOLD: for.body.backedge: +; TAILFOLD-NEXT: br label [[FOR_BODY]] +; TAILFOLD: for.second: +; TAILFOLD-NEXT: [[IPROM:%.*]] = sext i32 [[I_02]] to i64 +; TAILFOLD-NEXT: [[B:%.*]] = getelementptr inbounds i16, i16* [[P:%.*]], i64 [[IPROM]] +; TAILFOLD-NEXT: store i16 0, i16* [[B]], align 4 +; TAILFOLD-NEXT: [[CMPS:%.*]] = icmp sgt i32 [[INC]], 16 +; TAILFOLD-NEXT: br i1 [[CMPS]], label [[FOR_BODY_BACKEDGE]], label [[FOR_END:%.*]] +; TAILFOLD: for.end: +; TAILFOLD-NEXT: ret i32 0 +; entry: br label %for.body @@ -425,4 +761,111 @@ ret i32 0 } -declare void @foo() + +; Check interaction between block predication and early exits. We need the +; condition on the early exit to remain dead (i.e. not be used when forming +; the predicate mask). +define void @scalar_predication(float* %addr) { +; CHECK-LABEL: @scalar_predication( +; CHECK-NEXT: entry: +; CHECK-NEXT: br i1 false, label [[SCALAR_PH:%.*]], label [[VECTOR_PH:%.*]] +; CHECK: vector.ph: +; CHECK-NEXT: br label [[VECTOR_BODY:%.*]] +; CHECK: vector.body: +; CHECK-NEXT: [[INDEX:%.*]] = phi i64 [ 0, [[VECTOR_PH]] ], [ [[INDEX_NEXT:%.*]], [[PRED_STORE_CONTINUE2:%.*]] ] +; CHECK-NEXT: [[VEC_IND:%.*]] = phi <2 x i64> [ , [[VECTOR_PH]] ], [ [[VEC_IND_NEXT:%.*]], [[PRED_STORE_CONTINUE2]] ] +; CHECK-NEXT: [[TMP0:%.*]] = add i64 [[INDEX]], 0 +; CHECK-NEXT: [[TMP1:%.*]] = getelementptr float, float* [[ADDR:%.*]], i64 [[TMP0]] +; CHECK-NEXT: [[TMP2:%.*]] = getelementptr float, float* [[TMP1]], i32 0 +; CHECK-NEXT: [[TMP3:%.*]] = bitcast float* [[TMP2]] to <2 x float>* +; CHECK-NEXT: [[WIDE_LOAD:%.*]] = load <2 x float>, <2 x float>* [[TMP3]], align 4 +; CHECK-NEXT: [[TMP4:%.*]] = fcmp oeq <2 x float> [[WIDE_LOAD]], zeroinitializer +; CHECK-NEXT: [[TMP5:%.*]] = xor <2 x i1> [[TMP4]], +; CHECK-NEXT: [[TMP6:%.*]] = extractelement <2 x i1> [[TMP5]], i32 0 +; CHECK-NEXT: br i1 [[TMP6]], label [[PRED_STORE_IF:%.*]], label [[PRED_STORE_CONTINUE:%.*]] +; CHECK: pred.store.if: +; CHECK-NEXT: store float 1.000000e+01, float* [[TMP1]], align 4 +; CHECK-NEXT: br label [[PRED_STORE_CONTINUE]] +; CHECK: pred.store.continue: +; CHECK-NEXT: [[TMP7:%.*]] = extractelement <2 x i1> [[TMP5]], i32 1 +; CHECK-NEXT: br i1 [[TMP7]], label [[PRED_STORE_IF1:%.*]], label [[PRED_STORE_CONTINUE2]] +; CHECK: pred.store.if1: +; CHECK-NEXT: [[TMP8:%.*]] = add i64 [[INDEX]], 1 +; CHECK-NEXT: [[TMP9:%.*]] = getelementptr float, float* [[ADDR]], i64 [[TMP8]] +; CHECK-NEXT: store float 1.000000e+01, float* [[TMP9]], align 4 +; CHECK-NEXT: br label [[PRED_STORE_CONTINUE2]] +; CHECK: pred.store.continue2: +; CHECK-NEXT: [[INDEX_NEXT]] = add i64 [[INDEX]], 2 +; CHECK-NEXT: [[VEC_IND_NEXT]] = add <2 x i64> [[VEC_IND]], +; CHECK-NEXT: [[TMP10:%.*]] = icmp eq i64 [[INDEX_NEXT]], 200 +; CHECK-NEXT: br i1 [[TMP10]], label [[MIDDLE_BLOCK:%.*]], label [[VECTOR_BODY]], [[LOOP8:!llvm.loop !.*]] +; CHECK: middle.block: +; CHECK-NEXT: [[CMP_N:%.*]] = icmp eq i64 201, 200 +; CHECK-NEXT: br i1 [[CMP_N]], label [[EXIT:%.*]], label [[SCALAR_PH]] +; CHECK: scalar.ph: +; CHECK-NEXT: [[BC_RESUME_VAL:%.*]] = phi i64 [ 200, [[MIDDLE_BLOCK]] ], [ 0, [[ENTRY:%.*]] ] +; CHECK-NEXT: br label [[LOOP_HEADER:%.*]] +; CHECK: loop.header: +; CHECK-NEXT: [[IV:%.*]] = phi i64 [ [[BC_RESUME_VAL]], [[SCALAR_PH]] ], [ [[IV_NEXT:%.*]], [[LOOP_LATCH:%.*]] ] +; CHECK-NEXT: [[GEP:%.*]] = getelementptr float, float* [[ADDR]], i64 [[IV]] +; CHECK-NEXT: [[EXITCOND_NOT:%.*]] = icmp eq i64 [[IV]], 200 +; CHECK-NEXT: br i1 [[EXITCOND_NOT]], label [[EXIT]], label [[LOOP_BODY:%.*]] +; CHECK: loop.body: +; CHECK-NEXT: [[TMP11:%.*]] = load float, float* [[GEP]], align 4 +; CHECK-NEXT: [[PRED:%.*]] = fcmp oeq float [[TMP11]], 0.000000e+00 +; CHECK-NEXT: br i1 [[PRED]], label [[LOOP_LATCH]], label [[THEN:%.*]] +; CHECK: then: +; CHECK-NEXT: store float 1.000000e+01, float* [[GEP]], align 4 +; CHECK-NEXT: br label [[LOOP_LATCH]] +; CHECK: loop.latch: +; CHECK-NEXT: [[IV_NEXT]] = add nuw nsw i64 [[IV]], 1 +; CHECK-NEXT: br label [[LOOP_HEADER]], [[LOOP9:!llvm.loop !.*]] +; CHECK: exit: +; CHECK-NEXT: ret void +; +; TAILFOLD-LABEL: @scalar_predication( +; TAILFOLD-NEXT: entry: +; TAILFOLD-NEXT: br label [[LOOP_HEADER:%.*]] +; TAILFOLD: loop.header: +; TAILFOLD-NEXT: [[IV:%.*]] = phi i64 [ 0, [[ENTRY:%.*]] ], [ [[IV_NEXT:%.*]], [[LOOP_LATCH:%.*]] ] +; TAILFOLD-NEXT: [[GEP:%.*]] = getelementptr float, float* [[ADDR:%.*]], i64 [[IV]] +; TAILFOLD-NEXT: [[EXITCOND_NOT:%.*]] = icmp eq i64 [[IV]], 200 +; TAILFOLD-NEXT: br i1 [[EXITCOND_NOT]], label [[EXIT:%.*]], label [[LOOP_BODY:%.*]] +; TAILFOLD: loop.body: +; TAILFOLD-NEXT: [[TMP0:%.*]] = load float, float* [[GEP]], align 4 +; TAILFOLD-NEXT: [[PRED:%.*]] = fcmp oeq float [[TMP0]], 0.000000e+00 +; TAILFOLD-NEXT: br i1 [[PRED]], label [[LOOP_LATCH]], label [[THEN:%.*]] +; TAILFOLD: then: +; TAILFOLD-NEXT: store float 1.000000e+01, float* [[GEP]], align 4 +; TAILFOLD-NEXT: br label [[LOOP_LATCH]] +; TAILFOLD: loop.latch: +; TAILFOLD-NEXT: [[IV_NEXT]] = add nuw nsw i64 [[IV]], 1 +; TAILFOLD-NEXT: br label [[LOOP_HEADER]] +; TAILFOLD: exit: +; TAILFOLD-NEXT: ret void +; +entry: + br label %loop.header + +loop.header: + %iv = phi i64 [ 0, %entry ], [ %iv.next, %loop.latch ] + %gep = getelementptr float, float* %addr, i64 %iv + %exitcond.not = icmp eq i64 %iv, 200 + br i1 %exitcond.not, label %exit, label %loop.body + +loop.body: + %0 = load float, float* %gep, align 4 + %pred = fcmp oeq float %0, 0.0 + br i1 %pred, label %loop.latch, label %then + +then: + store float 10.0, float* %gep, align 4 + br label %loop.latch + +loop.latch: + %iv.next = add nuw nsw i64 %iv, 1 + br label %loop.header + +exit: + ret void +} Index: llvm/test/Transforms/LoopVectorize/loop-legality-checks.ll =================================================================== --- llvm/test/Transforms/LoopVectorize/loop-legality-checks.ll +++ llvm/test/Transforms/LoopVectorize/loop-legality-checks.ll @@ -1,30 +1,9 @@ ; RUN: opt < %s -loop-vectorize -debug-only=loop-vectorize -S -disable-output 2>&1 | FileCheck %s ; REQUIRES: asserts -; Make sure LV legal bails out when the exiting block != loop latch. -; CHECK-LABEL: "latch_is_not_exiting" -; CHECK: LV: Not vectorizing: The exiting block is not the loop latch. -define i32 @latch_is_not_exiting() { -entry: - br label %for.body - -for.body: - %i.02 = phi i32 [ 0, %entry ], [ %inc, %for.body ], [%inc, %for.second] - %inc = add nsw i32 %i.02, 1 - %cmp = icmp slt i32 %inc, 16 - br i1 %cmp, label %for.body, label %for.second - -for.second: - %cmps = icmp sgt i32 %inc, 16 - br i1 %cmps, label %for.body, label %for.end - -for.end: - ret i32 0 -} - ; Make sure LV legal bails out when there is no exiting block ; CHECK-LABEL: "no_exiting_block" -; CHECK: LV: Not vectorizing: The loop must have an exiting block. +; CHECK: LV: Not vectorizing: The loop must have a unique exit block. define i32 @no_exiting_block() { entry: br label %for.body