commit db7a91251c7f5f90e500c5c4e103a1cac2402ce6
author Philip Reames <listmail@philipreames.com> Thu Oct 17 23:49:46 2019 +0000
committer Philip Reames <listmail@philipreames.com> Thu Oct 17 23:49:46 2019 +0000
tree 36e74d840367af35a48a0235cd70cadf9adbedc6
parent 8aca037140b0a40a243704bfbdd8f332e3355b51

[IndVars] Factor out some common code into a utility function

As requested in review of D69009



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@375191 91177308-0d34-0410-b5e6-96231b3b80d8

lib/Transforms/Scalar/IndVarSimplify.cpp

diff --git a/lib/Transforms/Scalar/IndVarSimplify.cpp b/lib/Transforms/Scalar/IndVarSimplify.cpp
index a5edb80..6299dec 100644
--- a/lib/Transforms/Scalar/IndVarSimplify.cpp
+++ b/lib/Transforms/Scalar/IndVarSimplify.cpp
@@ -2717,10 +2717,19 @@
   if (isa<SCEVCouldNotCompute>(MaxExitCount))
     return false;
 
+  auto FoldExit = [&](BasicBlock *ExitingBB, bool IsTaken) {
+    BranchInst *BI = cast<BranchInst>(ExitingBB->getTerminator());
+    bool ExitIfTrue = !L->contains(*succ_begin(ExitingBB));
+    auto *OldCond = BI->getCondition();
+    auto *NewCond = ConstantInt::get(OldCond->getType(),
+                                     IsTaken ? ExitIfTrue : !ExitIfTrue);
+    BI->setCondition(NewCond);
+    if (OldCond->use_empty())
+      DeadInsts.push_back(OldCond);
+  };
+
   bool Changed = false;
   for (BasicBlock *ExitingBB : ExitingBlocks) {
-    BranchInst *BI = cast<BranchInst>(ExitingBB->getTerminator());
-
     const SCEV *ExitCount = SE->getExitCount(L, ExitingBB);
     assert(!isa<SCEVCouldNotCompute>(ExitCount) && "checked above");
     
@@ -2730,13 +2739,7 @@
     // TODO: Given we know the backedge can't be taken, we should go ahead
     // and break it.  Or at least, kill all the header phis and simplify.
     if (ExitCount->isZero()) {
-      bool ExitIfTrue = !L->contains(*succ_begin(ExitingBB));
-      auto *OldCond = BI->getCondition();
-      auto *NewCond = ExitIfTrue ? ConstantInt::getTrue(OldCond->getType()) :
-        ConstantInt::getFalse(OldCond->getType());
-      BI->setCondition(NewCond);
-      if (OldCond->use_empty())
-        DeadInsts.push_back(OldCond);
+      FoldExit(ExitingBB, true);
       Changed = true;
       continue;
     }
@@ -2758,13 +2761,7 @@
     // one?
     if (SE->isLoopEntryGuardedByCond(L, CmpInst::ICMP_ULT,
                                      MaxExitCount, ExitCount)) {
-      bool ExitIfTrue = !L->contains(*succ_begin(ExitingBB));
-      auto *OldCond = BI->getCondition();
-      auto *NewCond = ExitIfTrue ? ConstantInt::getFalse(OldCond->getType()) :
-        ConstantInt::getTrue(OldCond->getType());
-      BI->setCondition(NewCond);
-      if (OldCond->use_empty())
-        DeadInsts.push_back(OldCond);
+      FoldExit(ExitingBB, false);
       Changed = true;
       continue;
     }