[indvars] Fix PR10946: SCEV cannot handle Vector IVs.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@140026 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Transforms/Utils/SimplifyIndVar.cpp b/lib/Transforms/Utils/SimplifyIndVar.cpp
index ffaad27..5ee1eb1 100644
--- a/lib/Transforms/Utils/SimplifyIndVar.cpp
+++ b/lib/Transforms/Utils/SimplifyIndVar.cpp
@@ -85,6 +85,8 @@
/// foldIVUser - Fold an IV operand into its use. This removes increments of an
/// aligned IV when used by a instruction that ignores the low bits.
///
+/// IVOperand is guaranteed SCEVable, but UseInst may not be.
+///
/// Return the operand of IVOperand for this induction variable if IVOperand can
/// be folded (in case more folding opportunities have been exposed).
/// Otherwise return null.
@@ -241,6 +243,7 @@
/// eliminateIVUser - Eliminate an operation that consumes a simple IV and has
/// no observable side-effect given the range of IV values.
+/// IVOperand is guaranteed SCEVable, but UseInst may not be.
bool SimplifyIndvar::eliminateIVUser(Instruction *UseInst,
Instruction *IVOperand) {
if (ICmpInst *ICmp = dyn_cast<ICmpInst>(UseInst)) {
@@ -324,6 +327,9 @@
/// Once DisableIVRewrite is default, LSR will be the only client of IVUsers.
///
void SimplifyIndvar::simplifyUsers(PHINode *CurrIV, IVVisitor *V) {
+ if (!SE->isSCEVable(CurrIV->getType()))
+ return;
+
// Instructions processed by SimplifyIndvar for CurrIV.
SmallPtrSet<Instruction*,16> Simplified;
diff --git a/test/Transforms/IndVarSimplify/2011-09-19-vectoriv.ll b/test/Transforms/IndVarSimplify/2011-09-19-vectoriv.ll
new file mode 100644
index 0000000..6a01012
--- /dev/null
+++ b/test/Transforms/IndVarSimplify/2011-09-19-vectoriv.ll
@@ -0,0 +1,16 @@
+; RUN: opt < %s -indvars -S | FileCheck %s
+; PR10946: Vector IVs are not SCEVable.
+; CHECK-NOT: phi
+define void @test() nounwind {
+allocas:
+ br i1 undef, label %cif_done, label %for_loop398
+
+cif_done: ; preds = %allocas
+ ret void
+
+for_loop398: ; preds = %for_loop398, %allocas
+ %storemerge35 = phi <4 x i32> [ %storemerge, %for_loop398 ], [ undef, %allocas ]
+ %bincmp431 = icmp sge <4 x i32> %storemerge35, <i32 5, i32 5, i32 5, i32 5>
+ %storemerge = bitcast <4 x float> undef to <4 x i32>
+ br label %for_loop398
+}
