[llvm-branch-commits] [llvm] 4b33b23 - Reapply "[LV] Vectorize (some) early and multiple exit loops"" w/fix for builder
Philip Reames via llvm-branch-commits
llvm-branch-commits at lists.llvm.org
Mon Dec 28 10:19:45 PST 2020
Author: Philip Reames
Date: 2020-12-28T10:13:28-08:00
New Revision: 4b33b2387787aef5020450cdcc8dde231eb0a5fc
URL: https://github.com/llvm/llvm-project/commit/4b33b2387787aef5020450cdcc8dde231eb0a5fc
DIFF: https://github.com/llvm/llvm-project/commit/4b33b2387787aef5020450cdcc8dde231eb0a5fc.diff
LOG: Reapply "[LV] Vectorize (some) early and multiple exit loops"" w/fix for builder
This reverts commit 4ffcd4fe9ac2ee948948f732baa16663eb63f1c7 thus restoring e4df6a40dad.
The only change from the original patch is to add "llvm::" before the call to empty(iterator_range). This is a speculative fix for the ambiguity reported on some builders.
Added:
Modified:
llvm/lib/Transforms/Vectorize/LoopVectorizationLegality.cpp
llvm/lib/Transforms/Vectorize/LoopVectorize.cpp
llvm/test/Transforms/LoopVectorize/control-flow.ll
llvm/test/Transforms/LoopVectorize/loop-form.ll
llvm/test/Transforms/LoopVectorize/loop-legality-checks.ll
Removed:
################################################################################
diff --git a/llvm/lib/Transforms/Vectorize/LoopVectorizationLegality.cpp b/llvm/lib/Transforms/Vectorize/LoopVectorizationLegality.cpp
index 60e1cc9a4a59..65b3132dc3f1 100644
--- a/llvm/lib/Transforms/Vectorize/LoopVectorizationLegality.cpp
+++ b/llvm/lib/Transforms/Vectorize/LoopVectorizationLegality.cpp
@@ -1095,9 +1095,15 @@ bool LoopVectorizationLegality::canVectorizeLoopCFG(Loop *Lp,
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)
@@ -1106,11 +1112,14 @@ bool LoopVectorizationLegality::canVectorizeLoopCFG(Loop *Lp,
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 (!llvm::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)
diff --git a/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp b/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp
index 5889d5e55339..c48b650c3c3e 100644
--- a/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp
+++ b/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp
@@ -837,7 +837,8 @@ class InnerLoopVectorizer {
/// 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 @@ class LoopVectorizationCostModel {
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 @@ PHINode *InnerLoopVectorizer::createInductionVariable(Loop *L, Value *Start,
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 @@ Value *InnerLoopVectorizer::getOrCreateVectorTripCount(Loop *L) {
// 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 @@ Value *InnerLoopVectorizer::emitTransformedIndex(
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");
@@ -3572,7 +3582,7 @@ void InnerLoopVectorizer::fixupIVUsers(PHINode *OrigPhi,
// value (the value that feeds into the phi from the loop latch).
// We allow both, but they, obviously, have
diff erent values.
- assert(OrigLoop->getExitBlock() && "Expected a single exit block");
+ assert(OrigLoop->getUniqueExitBlock() && "Expected a single exit block");
DenseMap<Value *, Value *> MissingVals;
@@ -5490,11 +5500,28 @@ LoopVectorizationCostModel::computeMaxVF(ElementCount UserVF, unsigned UserIC) {
// 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)) {
@@ -7921,6 +7948,12 @@ VPValue *VPRecipeBuilder::createEdgeMask(BasicBlock *Src, BasicBlock *Dst,
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");
diff --git a/llvm/test/Transforms/LoopVectorize/control-flow.ll b/llvm/test/Transforms/LoopVectorize/control-flow.ll
index 8d56a17994a0..7aa065e49f58 100644
--- a/llvm/test/Transforms/LoopVectorize/control-flow.ll
+++ b/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
diff --git a/llvm/test/Transforms/LoopVectorize/loop-form.ll b/llvm/test/Transforms/LoopVectorize/loop-form.ll
index 72f2215bb934..6f4af4650f80 100644
--- a/llvm/test/Transforms/LoopVectorize/loop-form.ll
+++ b/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 @@ define void @bottom_tested(i16* %p, i32 %n) {
; 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> [ <i32 0, i32 1>, [[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]], <i32 2, i32 2>
+; 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 @@ if.end:
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> [ <i32 0, i32 1>, [[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]], <i32 2, i32 2>
+; 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 @@ define void @early_exit(i16* %p, i32 %n) {
; 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 @@ if.end:
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> [ <i32 0, i32 1>, [[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]], <i32 2, i32 2>
+; 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 @@ define i32 @multiple_unique_exit2(i16* %p, i32 %n) {
; 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 @@ define i32 @multiple_unique_exit3(i16* %p, i32 %n) {
; 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 @@ define i32 @multiple_exit_blocks(i16* %p, i32 %n) {
; 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 @@ define i32 @multiple_exit_switch(i16* %p, i32 %n) {
; 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 @@ define i32 @multiple_exit_switch2(i16* %p, i32 %n) {
; 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 @@ define i32 @multiple_latch1(i16* %p) {
; 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 @@ define i32 @multiple_latch2(i16* %p) {
; 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 @@ for.end:
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> [ <i64 0, i64 1>, [[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]], <i1 true, i1 true>
+; 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]], <i64 2, i64 2>
+; 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
+}
diff --git a/llvm/test/Transforms/LoopVectorize/loop-legality-checks.ll b/llvm/test/Transforms/LoopVectorize/loop-legality-checks.ll
index 4e39181e53dd..a4a8e99b77ca 100644
--- a/llvm/test/Transforms/LoopVectorize/loop-legality-checks.ll
+++ b/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
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