Actually, this code doesn't have to be quite so conservative in
the no-TLI case. But it should still default to declining the
transformation.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@96152 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Transforms/Scalar/LoopStrengthReduce.cpp b/lib/Transforms/Scalar/LoopStrengthReduce.cpp
index 0c65e33..b6ef718 100644
--- a/lib/Transforms/Scalar/LoopStrengthReduce.cpp
+++ b/lib/Transforms/Scalar/LoopStrengthReduce.cpp
@@ -1503,11 +1503,7 @@
// Conservatively avoid trying to use the post-inc value in non-latch
// exits if there may be pre-inc users in intervening blocks.
- if (LatchBlock != ExitingBlock) {
- // Without target lowering, we won't be able to query about valid reuse.
- if (!TLI)
- continue;
-
+ if (LatchBlock != ExitingBlock)
for (IVUsers::const_iterator UI = IU.begin(), E = IU.end(); UI != E; ++UI)
// Test if the use is reachable from the exiting block. This dominator
// query is a conservative approximation of reachability.
@@ -1535,6 +1531,10 @@
if (D->getValue()->getValue().getMinSignedBits() >= 64 ||
D->getValue()->getValue().isMinSignedValue())
goto decline_post_inc;
+ // Without TLI, assume that any stride might be valid, and so any
+ // use might be shared.
+ if (!TLI)
+ goto decline_post_inc;
// Check for possible scaled-address reuse.
const Type *AccessTy = getAccessType(UI->getUser());
TargetLowering::AddrMode AM;
@@ -1546,7 +1546,6 @@
goto decline_post_inc;
}
}
- }
DEBUG(dbgs() << " Change loop exiting icmp to use postinc iv: "
<< *Cond << '\n');