[ARM][MVE] Change VCTP operand

The VCTP instruction will calculate the predicate masked based upon
the number of elements that need to be processed. I had inserted the
sub before the vctp intrinsic and supplied it as the operand, but
this is incorrect as the phi should directly feed the vctp. The sub
is calculating the value for the next iteration.

Differential Revision: https://reviews.llvm.org/D67921

llvm-svn: 373188

1 files changed, 3 insertions, 3 deletions

diff --git a/llvm/lib/Target/ARM/MVETailPredication.cpp b/llvm/lib/Target/ARM/MVETailPredication.cpp
index 844eafbcb38..4db8ab17c49 100644
--- a/llvm/lib/Target/ARM/MVETailPredication.cpp
+++ b/llvm/lib/Target/ARM/MVETailPredication.cpp
@@ -491,13 +491,13 @@ bool MVETailPredication::TryConvert(Value *TripCount) {
     case 16: VCTPID = Intrinsic::arm_vctp8; break;
     }
     Function *VCTP = Intrinsic::getDeclaration(M, VCTPID);
-    // TODO: This add likely already exists in the loop.
-    Value *Remaining = Builder.CreateSub(Processed, Factor);
-    Value *TailPredicate = Builder.CreateCall(VCTP, Remaining);
+    Value *TailPredicate = Builder.CreateCall(VCTP, Processed);
     Predicate->replaceAllUsesWith(TailPredicate);
     NewPredicates[Predicate] = cast<Instruction>(TailPredicate);
 
     // Add the incoming value to the new phi.
+    // TODO: This add likely already exists in the loop.
+    Value *Remaining = Builder.CreateSub(Processed, Factor);
     Processed->addIncoming(Remaining, L->getLoopLatch());
     LLVM_DEBUG(dbgs() << "TP: Insert processed elements phi: "
                << *Processed << "\n"