[llvm-commits] [llvm] r74041 - in /llvm/trunk: include/llvm/Analysis/ScalarEvolution.h lib/Analysis/ScalarEvolution.cpp lib/Target/ARM/AsmPrinter/ARMAsmPrinter.cpp

[Dan Gohman]

Author: djg
Date: Tue Jun 23 19:54:57 2009
New Revision: 74041

URL: http://llvm.org/viewvc/llvm-project?rev=74041&view=rev
Log:
Move the special cases for constants out of getUnknown and into
createSCEV. Also, recognize UndefValue in createSCEV.

Change getIntegerSCEV's comment to avoid mentioning FP types,
and re-implement it in terms of getConstant instead of getUnknown.

Modified:
    llvm/trunk/include/llvm/Analysis/ScalarEvolution.h
    llvm/trunk/lib/Analysis/ScalarEvolution.cpp
    llvm/trunk/lib/Target/ARM/AsmPrinter/ARMAsmPrinter.cpp

Modified: llvm/trunk/include/llvm/Analysis/ScalarEvolution.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/Analysis/ScalarEvolution.h?rev=74041&r1=74040&r2=74041&view=diff

==============================================================================
--- llvm/trunk/include/llvm/Analysis/ScalarEvolution.h (original)
+++ llvm/trunk/include/llvm/Analysis/ScalarEvolution.h Tue Jun 23 19:54:57 2009
@@ -462,7 +462,7 @@
     /// widening.
     const SCEV* getTruncateOrNoop(const SCEV* V, const Type *Ty);
 
-    /// getIntegerSCEV - Given an integer or FP type, create a constant for the
+    /// getIntegerSCEV - Given a SCEVable type, create a constant for the
     /// specified signed integer value and return a SCEV for the constant.
     const SCEV* getIntegerSCEV(int Val, const Type *Ty);
 

Modified: llvm/trunk/lib/Analysis/ScalarEvolution.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Analysis/ScalarEvolution.cpp?rev=74041&r1=74040&r2=74041&view=diff

==============================================================================
--- llvm/trunk/lib/Analysis/ScalarEvolution.cpp (original)
+++ llvm/trunk/lib/Analysis/ScalarEvolution.cpp Tue Jun 23 19:54:57 2009
@@ -1867,10 +1867,11 @@
 }
 
 const SCEV* ScalarEvolution::getUnknown(Value *V) {
-  if (ConstantInt *CI = dyn_cast<ConstantInt>(V))
-    return getConstant(CI);
-  if (isa<ConstantPointerNull>(V))
-    return getIntegerSCEV(0, V->getType());
+  // Don't attempt to do anything other than create a SCEVUnknown object
+  // here.  createSCEV only calls getUnknown after checking for all other
+  // interesting possibilities, and any other code that calls getUnknown
+  // is doing so in order to hide a value from SCEV canonicalization.
+
   SCEVUnknown *&Result = SCEVUnknowns[V];
   if (Result == 0) Result = new SCEVUnknown(V);
   return Result;
@@ -1948,19 +1949,11 @@
   return S;
 }
 
-/// getIntegerSCEV - Given an integer or FP type, create a constant for the
+/// getIntegerSCEV - Given a SCEVable type, create a constant for the
 /// specified signed integer value and return a SCEV for the constant.
 const SCEV* ScalarEvolution::getIntegerSCEV(int Val, const Type *Ty) {
-  Ty = getEffectiveSCEVType(Ty);
-  Constant *C;
-  if (Val == 0)
-    C = Constant::getNullValue(Ty);
-  else if (Ty->isFloatingPoint())
-    C = ConstantFP::get(APFloat(Ty==Type::FloatTy ? APFloat::IEEEsingle :
-                                APFloat::IEEEdouble, Val));
-  else
-    C = ConstantInt::get(Ty, Val);
-  return getUnknown(C);
+  const IntegerType *ITy = cast<IntegerType>(getEffectiveSCEVType(Ty));
+  return getConstant(ConstantInt::get(ITy, Val));
 }
 
 /// getNegativeSCEV - Return a SCEV corresponding to -V = -1*V
@@ -2429,6 +2422,12 @@
     Opcode = I->getOpcode();
   else if (ConstantExpr *CE = dyn_cast<ConstantExpr>(V))
     Opcode = CE->getOpcode();
+  else if (ConstantInt *CI = dyn_cast<ConstantInt>(V))
+    return getConstant(CI);
+  else if (isa<ConstantPointerNull>(V))
+    return getIntegerSCEV(0, V->getType());
+  else if (isa<UndefValue>(V))
+    return getIntegerSCEV(0, V->getType());
   else
     return getUnknown(V);
 

Modified: llvm/trunk/lib/Target/ARM/AsmPrinter/ARMAsmPrinter.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/ARM/AsmPrinter/ARMAsmPrinter.cpp?rev=74041&r1=74040&r2=74041&view=diff

==============================================================================
--- llvm/trunk/lib/Target/ARM/AsmPrinter/ARMAsmPrinter.cpp (original)
+++ llvm/trunk/lib/Target/ARM/AsmPrinter/ARMAsmPrinter.cpp Tue Jun 23 19:54:57 2009
@@ -644,7 +644,7 @@
   const MachineOperand &MO = MI->getOperand(Op);
   uint32_t v = ~MO.getImm();
   int32_t lsb = ffs (v) - 1;
-  int32_t width = fls (v) - lsb;
+  int32_t width = ffs (v) - lsb;
   assert(MO.isImm() && "Not a valid bf_inv_mask_imm value!");
   O << "#" << lsb << ", #" << width;
 }