Don't skip debug instructions when looking for the insertion point of
the cast. If we do, we can end up with
inst1
--------------- < Insertion point
dbg inst
new inst
instead of the desired
inst1
new inst
--------------- < Insertion point
dbg inst
Another option would be for InsertNoopCastOfTo (or its callers) to move the
insertion point and we would end up with
inst1
dbg inst
new inst
--------------- < Insertion point
but that complicates the callers. This fixes PR12018 (and firefox's build).
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@150884 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Analysis/ScalarEvolutionExpander.cpp b/lib/Analysis/ScalarEvolutionExpander.cpp
index f559889..58181fb 100644
--- a/lib/Analysis/ScalarEvolutionExpander.cpp
+++ b/lib/Analysis/ScalarEvolutionExpander.cpp
@@ -31,6 +31,12 @@
Value *SCEVExpander::ReuseOrCreateCast(Value *V, Type *Ty,
Instruction::CastOps Op,
BasicBlock::iterator IP) {
+ // All new or reused instructions must strictly dominate the Builder's
+ // InsertPt to ensure that the expression's expansion dominates its uses.
+ // Assert that the requested insertion point works at least for new
+ // instructions.
+ assert(SE.DT->dominates(IP, Builder.GetInsertPoint()));
+
// Check to see if there is already a cast!
for (Value::use_iterator UI = V->use_begin(), E = V->use_end();
UI != E; ++UI) {
@@ -38,9 +44,7 @@
if (U->getType() == Ty)
if (CastInst *CI = dyn_cast<CastInst>(U))
if (CI->getOpcode() == Op) {
- // If the cast isn't where we want it, fix it. All new or reused
- // instructions must strictly dominate the Builder's InsertPt to
- // ensure that the expression's expansion dominates its uses.
+ // If the cast isn't where we want it, fix it.
if (BasicBlock::iterator(CI) != IP
|| IP == Builder.GetInsertPoint()) {
// Create a new cast, and leave the old cast in place in case
@@ -124,8 +128,7 @@
BasicBlock::iterator IP = I; ++IP;
if (InvokeInst *II = dyn_cast<InvokeInst>(I))
IP = II->getNormalDest()->begin();
- while (isa<PHINode>(IP) || isa<DbgInfoIntrinsic>(IP) ||
- isa<LandingPadInst>(IP))
+ while (isa<PHINode>(IP) || isa<LandingPadInst>(IP))
++IP;
return ReuseOrCreateCast(I, Ty, Op, IP);
}