commit a655e0f991ba59f34fc24c44d04bbc56ff564c3e
author Philip Reames <listmail@philipreames.com> Mon Nov 29 14:31:50 2021 -0800
committer Philip Reames <listmail@philipreames.com> Mon Nov 29 14:33:14 2021 -0800
tree 70025dd93a6001eac753adb86cfe80c8eb70dfcd
parent a20987adf4f80e2657eb3032a5a91e13f58106a0

[unroll] Reduce scope of UnrollFactor variable in computeUnrollCount [NFC]

Suggested in review of D114453, done as a separate change to get all uses at once.

llvm/lib/Transforms/Scalar/LoopUnrollPass.cpp

diff --git a/llvm/lib/Transforms/Scalar/LoopUnrollPass.cpp b/llvm/lib/Transforms/Scalar/LoopUnrollPass.cpp
index f8e179e..293bb2c 100644
--- a/llvm/lib/Transforms/Scalar/LoopUnrollPass.cpp
+++ b/llvm/lib/Transforms/Scalar/LoopUnrollPass.cpp
@@ -899,7 +899,6 @@
     TargetTransformInfo::PeelingPreferences &PP, bool &UseUpperBound) {
 
   UnrollCostEstimator UCE(*L, LoopSize);
-  Optional<unsigned> UnrollFactor;
 
   const bool UserUnrollCount = UnrollCount.getNumOccurrences() > 0;
   const bool PragmaFullUnroll = hasUnrollFullPragma(L);
@@ -925,9 +924,8 @@
   // Check for explicit Count.
   // 1st priority is unroll count set by "unroll-count" option.
   // 2nd priority is unroll count set by pragma.
-  UnrollFactor = shouldPragmaUnroll(L, PInfo, TripMultiple, TripCount, UCE, UP);
-
-  if (UnrollFactor) {
+  if (auto UnrollFactor = shouldPragmaUnroll(L, PInfo, TripMultiple, TripCount,
+                                             UCE, UP)) {
     UP.Count = *UnrollFactor;
 
     if (UserUnrollCount || (PragmaCount > 0)) {
@@ -952,9 +950,8 @@
   UP.Count = 0;
   if (TripCount) {
     UP.Count = TripCount;
-    UnrollFactor =
-      shouldFullUnroll(L, TTI, DT, SE, EphValues, TripCount, UCE, UP);
-    if (UnrollFactor) {
+    if (auto UnrollFactor = shouldFullUnroll(L, TTI, DT, SE, EphValues,
+                                             TripCount, UCE, UP)) {
       UP.Count = *UnrollFactor;
       UseUpperBound = false;
       return ExplicitUnroll;
@@ -976,9 +973,8 @@
   if (!TripCount && MaxTripCount && (UP.UpperBound || MaxOrZero) &&
       MaxTripCount <= UnrollMaxUpperBound) {
     UP.Count = MaxTripCount;
-    UnrollFactor =
-      shouldFullUnroll(L, TTI, DT, SE, EphValues, MaxTripCount, UCE, UP);
-    if (UnrollFactor) {
+    if (auto UnrollFactor = shouldFullUnroll(L, TTI, DT, SE, EphValues,
+                                             MaxTripCount, UCE, UP)) {
       UP.Count = *UnrollFactor;
       UseUpperBound = true;
       return ExplicitUnroll;
@@ -1000,9 +996,7 @@
 
   // 6th priority is partial unrolling.
   // Try partial unroll only when TripCount could be statically calculated.
-  UnrollFactor = shouldPartialUnroll(LoopSize, TripCount, UCE, UP);
-
-  if (UnrollFactor) {
+  if (auto UnrollFactor = shouldPartialUnroll(LoopSize, TripCount, UCE, UP)) {
     UP.Count = *UnrollFactor;
 
     if ((PragmaFullUnroll || PragmaEnableUnroll) && TripCount &&