[llvm-commits] CVS: llvm/lib/Transforms/Scalar/IndVarSimplify.cpp LoopStrengthReduce.cpp

Dan Gohman djg at cray.com
Fri Jun 15 07:38:39 PDT 2007



Changes in directory llvm/lib/Transforms/Scalar:

IndVarSimplify.cpp updated: 1.120 -> 1.121
LoopStrengthReduce.cpp updated: 1.140 -> 1.141
---
Log message:

Add a SCEV class and supporting code for sign-extend expressions.

This created an ambiguity for expandInTy to decide when to use
sign-extension or zero-extension, but it turns out that most of its callers
don't actually need a type conversion, now that LLVM types don't have
explicit signedness. Drop expandInTy in favor of plain expand, and change
the few places that actually need a type conversion to do it themselves.


---
Diffs of the changes:  (+23 -18)

 IndVarSimplify.cpp     |   13 +++++++------
 LoopStrengthReduce.cpp |   28 ++++++++++++++++------------
 2 files changed, 23 insertions(+), 18 deletions(-)


Index: llvm/lib/Transforms/Scalar/IndVarSimplify.cpp
diff -u llvm/lib/Transforms/Scalar/IndVarSimplify.cpp:1.120 llvm/lib/Transforms/Scalar/IndVarSimplify.cpp:1.121
--- llvm/lib/Transforms/Scalar/IndVarSimplify.cpp:1.120	Tue Jun  5 22:51:56 2007
+++ llvm/lib/Transforms/Scalar/IndVarSimplify.cpp	Fri Jun 15 09:38:12 2007
@@ -277,8 +277,7 @@
 
   // Expand the code for the iteration count into the preheader of the loop.
   BasicBlock *Preheader = L->getLoopPreheader();
-  Value *ExitCnt = RW.expandCodeFor(TripCount, Preheader->getTerminator(),
-                                    IndVar->getType());
+  Value *ExitCnt = RW.expandCodeFor(TripCount, Preheader->getTerminator());
 
   // Insert a new icmp_ne or icmp_eq instruction before the branch.
   ICmpInst::Predicate Opcode;
@@ -383,7 +382,7 @@
         // just reuse it.
         Value *&ExitVal = ExitValues[Inst];
         if (!ExitVal)
-          ExitVal = Rewriter.expandCodeFor(ExitValue, InsertPt,Inst->getType());
+          ExitVal = Rewriter.expandCodeFor(ExitValue, InsertPt);
         
         DOUT << "INDVARS: RLEV: AfterLoopVal = " << *ExitVal
              << "  LoopVal = " << *Inst << "\n";
@@ -519,9 +518,12 @@
   Changed = true;
   DOUT << "INDVARS: New CanIV: " << *IndVar;
 
-  if (!isa<SCEVCouldNotCompute>(IterationCount))
+  if (!isa<SCEVCouldNotCompute>(IterationCount)) {
+    if (IterationCount->getType() != LargestType)
+      IterationCount = SCEVZeroExtendExpr::get(IterationCount, LargestType);
     if (Instruction *DI = LinearFunctionTestReplace(L, IterationCount,Rewriter))
       DeadInsts.insert(DI);
+  }
 
   // Now that we have a canonical induction variable, we can rewrite any
   // recurrences in terms of the induction variable.  Start with the auxillary
@@ -555,8 +557,7 @@
   std::map<unsigned, Value*> InsertedSizes;
   while (!IndVars.empty()) {
     PHINode *PN = IndVars.back().first;
-    Value *NewVal = Rewriter.expandCodeFor(IndVars.back().second, InsertPt,
-                                           PN->getType());
+    Value *NewVal = Rewriter.expandCodeFor(IndVars.back().second, InsertPt);
     DOUT << "INDVARS: Rewrote IV '" << *IndVars.back().second << "' " << *PN
          << "   into = " << *NewVal << "\n";
     NewVal->takeName(PN);


Index: llvm/lib/Transforms/Scalar/LoopStrengthReduce.cpp
diff -u llvm/lib/Transforms/Scalar/LoopStrengthReduce.cpp:1.140 llvm/lib/Transforms/Scalar/LoopStrengthReduce.cpp:1.141
--- llvm/lib/Transforms/Scalar/LoopStrengthReduce.cpp:1.140	Thu Jun  7 16:42:15 2007
+++ llvm/lib/Transforms/Scalar/LoopStrengthReduce.cpp	Fri Jun 15 09:38:12 2007
@@ -555,8 +555,7 @@
   // If there is no immediate value, skip the next part.
   if (SCEVConstant *SC = dyn_cast<SCEVConstant>(Imm))
     if (SC->getValue()->isZero())
-      return Rewriter.expandCodeFor(NewBase, BaseInsertPt,
-                                    OperandValToReplace->getType());
+      return Rewriter.expandCodeFor(NewBase, BaseInsertPt);
 
   Value *Base = Rewriter.expandCodeFor(NewBase, BaseInsertPt);
 
@@ -567,8 +566,7 @@
   
   // Always emit the immediate (if non-zero) into the same block as the user.
   SCEVHandle NewValSCEV = SCEVAddExpr::get(SCEVUnknown::get(Base), Imm);
-  return Rewriter.expandCodeFor(NewValSCEV, IP,
-                                OperandValToReplace->getType());
+  return Rewriter.expandCodeFor(NewValSCEV, IP);
   
 }
 
@@ -598,6 +596,11 @@
       }
     }
     Value *NewVal = InsertCodeForBaseAtPosition(NewBase, Rewriter, InsertPt, L);
+    // Adjust the type back to match the Inst.
+    if (isa<PointerType>(OperandValToReplace->getType())) {
+      NewVal = new IntToPtrInst(NewVal, OperandValToReplace->getType(), "cast",
+                                InsertPt);
+    }
     // Replace the use of the operand Value with the new Phi we just created.
     Inst->replaceUsesOfWith(OperandValToReplace, NewVal);
     DOUT << "    CHANGED: IMM =" << *Imm;
@@ -644,6 +647,11 @@
         // Insert the code into the end of the predecessor block.
         Instruction *InsertPt = PN->getIncomingBlock(i)->getTerminator();
         Code = InsertCodeForBaseAtPosition(NewBase, Rewriter, InsertPt, L);
+
+        // Adjust the type back to match the PHI.
+        if (isa<PointerType>(PN->getType())) {
+          Code = new IntToPtrInst(Code, PN->getType(), "cast", InsertPt);
+        }
       }
       
       // Replace the use of the operand Value with the new Phi we just created.
@@ -1112,8 +1120,7 @@
 
   // Emit the initial base value into the loop preheader.
   Value *CommonBaseV
-    = PreheaderRewriter.expandCodeFor(CommonExprs, PreInsertPt,
-                                      ReplacedTy);
+    = PreheaderRewriter.expandCodeFor(CommonExprs, PreInsertPt);
 
   if (RewriteFactor == 0) {
     // Create a new Phi for this base, and stick it in the loop header.
@@ -1131,8 +1138,7 @@
       IncAmount = SCEV::getNegativeSCEV(Stride);
     
     // Insert the stride into the preheader.
-    Value *StrideV = PreheaderRewriter.expandCodeFor(IncAmount, PreInsertPt,
-                                                     ReplacedTy);
+    Value *StrideV = PreheaderRewriter.expandCodeFor(IncAmount, PreInsertPt);
     if (!isa<ConstantInt>(StrideV)) ++NumVariable;
 
     // Emit the increment of the base value before the terminator of the loop
@@ -1142,8 +1148,7 @@
       IncExp = SCEV::getNegativeSCEV(IncExp);
     IncExp = SCEVAddExpr::get(SCEVUnknown::get(NewPHI), IncExp);
   
-    IncV = Rewriter.expandCodeFor(IncExp, LatchBlock->getTerminator(),
-                                  ReplacedTy);
+    IncV = Rewriter.expandCodeFor(IncExp, LatchBlock->getTerminator());
     IncV->setName(NewPHI->getName()+".inc");
     NewPHI->addIncoming(IncV, LatchBlock);
 
@@ -1199,8 +1204,7 @@
     SCEVHandle Base = UsersToProcess.back().Base;
 
     // Emit the code for Base into the preheader.
-    Value *BaseV = PreheaderRewriter.expandCodeFor(Base, PreInsertPt,
-                                                   ReplacedTy);
+    Value *BaseV = PreheaderRewriter.expandCodeFor(Base, PreInsertPt);
 
     DOUT << "  INSERTING code for BASE = " << *Base << ":";
     if (BaseV->hasName())






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