[llvm] 25755a0 - [NFC] Add flag to disable IV widening in indvar instance

[Max Kazantsev via llvm-commits]

Author: Max Kazantsev
Date: 2020-11-10T15:10:44+07:00
New Revision: 25755a0159a2a69cb84dbd2b7bcbb5db9b482a40

URL: https://github.com/llvm/llvm-project/commit/25755a0159a2a69cb84dbd2b7bcbb5db9b482a40
DIFF: https://github.com/llvm/llvm-project/commit/25755a0159a2a69cb84dbd2b7bcbb5db9b482a40.diff

LOG: [NFC] Add flag to disable IV widening in indvar instance

This allows us to have control over IV widening in the pipeline.

Added: 
    

Modified: 
    llvm/include/llvm/Transforms/Scalar/IndVarSimplify.h
    llvm/lib/Transforms/Scalar/IndVarSimplify.cpp

Removed: 
    


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diff  --git a/llvm/include/llvm/Transforms/Scalar/IndVarSimplify.h b/llvm/include/llvm/Transforms/Scalar/IndVarSimplify.h
index 3c20537ab76a..b5d544f1149c 100644
--- a/llvm/include/llvm/Transforms/Scalar/IndVarSimplify.h
+++ b/llvm/include/llvm/Transforms/Scalar/IndVarSimplify.h
@@ -23,7 +23,11 @@ class Loop;
 class LPMUpdater;
 
 class IndVarSimplifyPass : public PassInfoMixin<IndVarSimplifyPass> {
+  /// Perform IV widening during the pass.
+  bool WidenIndVars;
+
 public:
+  IndVarSimplifyPass(bool WidenIndVars = true) : WidenIndVars(WidenIndVars) {}
   PreservedAnalyses run(Loop &L, LoopAnalysisManager &AM,
                         LoopStandardAnalysisResults &AR, LPMUpdater &U);
 };

diff  --git a/llvm/lib/Transforms/Scalar/IndVarSimplify.cpp b/llvm/lib/Transforms/Scalar/IndVarSimplify.cpp
index 83e783cfa763..f0b5d7954508 100644
--- a/llvm/lib/Transforms/Scalar/IndVarSimplify.cpp
+++ b/llvm/lib/Transforms/Scalar/IndVarSimplify.cpp
@@ -149,6 +149,7 @@ class IndVarSimplify {
   std::unique_ptr<MemorySSAUpdater> MSSAU;
 
   SmallVector<WeakTrackingVH, 16> DeadInsts;
+  bool WidenIndVars;
 
   bool handleFloatingPointIV(Loop *L, PHINode *PH);
   bool rewriteNonIntegerIVs(Loop *L);
@@ -171,8 +172,9 @@ class IndVarSimplify {
 public:
   IndVarSimplify(LoopInfo *LI, ScalarEvolution *SE, DominatorTree *DT,
                  const DataLayout &DL, TargetLibraryInfo *TLI,
-                 TargetTransformInfo *TTI, MemorySSA *MSSA)
-      : LI(LI), SE(SE), DT(DT), DL(DL), TLI(TLI), TTI(TTI) {
+                 TargetTransformInfo *TTI, MemorySSA *MSSA, bool WidenIndVars)
+      : LI(LI), SE(SE), DT(DT), DL(DL), TLI(TLI), TTI(TTI),
+        WidenIndVars(WidenIndVars) {
     if (MSSA)
       MSSAU = std::make_unique<MemorySSAUpdater>(MSSA);
   }
@@ -630,7 +632,7 @@ bool IndVarSimplify::simplifyAndExtend(Loop *L,
     } while(!LoopPhis.empty());
 
     // Continue if we disallowed widening.
-    if (!AllowIVWidening)
+    if (!WidenIndVars)
       continue;
 
     for (; !WideIVs.empty(); WideIVs.pop_back()) {
@@ -1898,7 +1900,8 @@ PreservedAnalyses IndVarSimplifyPass::run(Loop &L, LoopAnalysisManager &AM,
   Function *F = L.getHeader()->getParent();
   const DataLayout &DL = F->getParent()->getDataLayout();
 
-  IndVarSimplify IVS(&AR.LI, &AR.SE, &AR.DT, DL, &AR.TLI, &AR.TTI, AR.MSSA);
+  IndVarSimplify IVS(&AR.LI, &AR.SE, &AR.DT, DL, &AR.TLI, &AR.TTI, AR.MSSA,
+                     WidenIndVars && AllowIVWidening);
   if (!IVS.run(&L))
     return PreservedAnalyses::all();
 
@@ -1935,7 +1938,7 @@ struct IndVarSimplifyLegacyPass : public LoopPass {
     if (MSSAAnalysis)
       MSSA = &MSSAAnalysis->getMSSA();
 
-    IndVarSimplify IVS(LI, SE, DT, DL, TLI, TTI, MSSA);
+    IndVarSimplify IVS(LI, SE, DT, DL, TLI, TTI, MSSA, AllowIVWidening);
     return IVS.run(L);
   }