Enhance hasConstantValue to ignore undef values in phi nodes. This allows it

[oota-llvm.git] / lib / Transforms / Utils / Local.cpp

diff --git a/lib/Transforms/Utils/Local.cpp b/lib/Transforms/Utils/Local.cpp
index 64cd1037a98a80652da7faf684adbf424a6443a4..b188884a4052333b6ba36229f0744ecc92460759 100644 (file)
--- a/lib/Transforms/Utils/Local.cpp
+++ b/lib/Transforms/Utils/Local.cpp
@@ -12,9 +12,11 @@
 //
 //===----------------------------------------------------------------------===//
 
+#include "llvm/Support/MathExtras.h"
 #include "llvm/Transforms/Utils/Local.h"
 #include "llvm/Constants.h"
 #include "llvm/Instructions.h"
+#include "llvm/Intrinsics.h"
 #include <cerrno>
 #include <cmath>
 using namespace llvm;
@@ -234,8 +236,24 @@ bool llvm::ConstantFoldTerminator(BasicBlock *BB) {
 /// the specified function.
 bool llvm::canConstantFoldCallTo(Function *F) {
   const std::string &Name = F->getName();
+
+  switch (F->getIntrinsicID()) {
+  case Intrinsic::isunordered: return true;
+  default: break;
+  }
+
   return Name == "sin" || Name == "cos" || Name == "tan" || Name == "sqrt" ||
-         Name == "log" || Name == "log10" || Name == "exp" || Name == "pow";
+         Name == "log" || Name == "log10" || Name == "exp" || Name == "pow" ||
+         Name == "acos" || Name == "asin" || Name == "atan" || Name == "fmod";
+}
+
+static Constant *ConstantFoldFP(double (*NativeFP)(double), double V,
+                                const Type *Ty) {
+  errno = 0;
+  V = NativeFP(V);
+  if (errno == 0)
+    return ConstantFP::get(Ty, V);
+  return 0;
 }
 
 /// ConstantFoldCall - Attempt to constant fold a call to the specified function
@@ -245,49 +263,50 @@ Constant *llvm::ConstantFoldCall(Function *F,
   const std::string &Name = F->getName();
   const Type *Ty = F->getReturnType();
 
-  if (Name == "sin") {
-    if (Operands.size() == 1)
-      if (ConstantFP *CFP = dyn_cast<ConstantFP>(Operands[0]))
-        return ConstantFP::get(Ty, sin(CFP->getValue()));
-    
-  } else if (Name == "cos") {
-    if (Operands.size() == 1)
-      if (ConstantFP *CFP = dyn_cast<ConstantFP>(Operands[0]))
-        return ConstantFP::get(Ty, cos(CFP->getValue()));
-
-  } else if (Name == "tan") {
-    if (Operands.size() == 1)
-      if (ConstantFP *CFP = dyn_cast<ConstantFP>(Operands[0]))
-        return ConstantFP::get(Ty, tan(CFP->getValue()));
-
-  } else if (Name == "sqrt") {
-    if (Operands.size() == 1)
-      if (ConstantFP *CFP = dyn_cast<ConstantFP>(Operands[0]))
-        if (CFP->getValue() >= 0)
-          return ConstantFP::get(Ty, sqrt(CFP->getValue()));
-  } else if (Name == "exp") {
-    if (Operands.size() == 1)
-      if (ConstantFP *CFP = dyn_cast<ConstantFP>(Operands[0]))
-        return ConstantFP::get(Ty, exp(CFP->getValue()));
-  } else if (Name == "log") {
-    if (Operands.size() == 1)
-      if (ConstantFP *CFP = dyn_cast<ConstantFP>(Operands[0]))
-        if (CFP->getValue() > 0)
-          return ConstantFP::get(Ty, log(CFP->getValue()));
-  } else if (Name == "log10") {
-    if (Operands.size() == 1)
-      if (ConstantFP *CFP = dyn_cast<ConstantFP>(Operands[0]))
-        if (CFP->getValue() > 0)
-          return ConstantFP::get(Ty, log10(CFP->getValue()));
-  } else if (Name == "pow") {
-    if (Operands.size() == 2)
-      if (ConstantFP *Op1 = dyn_cast<ConstantFP>(Operands[0]))
-        if (ConstantFP *Op2 = dyn_cast<ConstantFP>(Operands[1])) {
+  if (Operands.size() == 1) {
+    if (ConstantFP *Op = dyn_cast<ConstantFP>(Operands[0])) {
+      double V = Op->getValue();
+      if (Name == "sin")
+        return ConstantFP::get(Ty, sin(V));
+      else if (Name == "cos")
+        return ConstantFP::get(Ty, cos(V));
+      else if (Name == "tan")
+        return ConstantFP::get(Ty, tan(V));
+      else if (Name == "sqrt" && V >= 0)
+        return ConstantFP::get(Ty, sqrt(V));
+      else if (Name == "exp")
+        return ConstantFP::get(Ty, exp(V));
+      else if (Name == "log" && V > 0)
+        return ConstantFP::get(Ty, log(V));
+      else if (Name == "log10")
+        return ConstantFoldFP(log10, V, Ty);
+      else if (Name == "acos")
+        return ConstantFoldFP(acos, V, Ty);
+      else if (Name == "asin")
+        return ConstantFoldFP(asin, V, Ty);
+      else if (Name == "atan")
+        return ConstantFP::get(Ty, atan(V));
+    }
+  } else if (Operands.size() == 2) {
+    if (ConstantFP *Op1 = dyn_cast<ConstantFP>(Operands[0]))
+      if (ConstantFP *Op2 = dyn_cast<ConstantFP>(Operands[1])) {
+        double Op1V = Op1->getValue(), Op2V = Op2->getValue();
+
+        if (Name == "llvm.isunordered")
+          return ConstantBool::get(IsNAN(Op1V) || IsNAN(Op2V));
+        else 
+        if (Name == "pow") {
+          errno = 0;
+          double V = pow(Op1V, Op2V);
+          if (errno == 0)
+            return ConstantFP::get(Ty, V);
+        } else if (Name == "fmod") {
           errno = 0;
-          double V = pow(Op1->getValue(), Op2->getValue());
+          double V = fmod(Op1V, Op2V);
           if (errno == 0)
             return ConstantFP::get(Ty, V);
         }
+      }
   }
   return 0;
 }
@@ -334,7 +353,8 @@ Value *llvm::hasConstantValue(PHINode *PN) {
   //
   Value *InVal = 0;
   for (unsigned i = 0, e = PN->getNumIncomingValues(); i != e; ++i)
-    if (PN->getIncomingValue(i) != PN)  // Not the PHI node itself...
+    if (PN->getIncomingValue(i) != PN &&  // Not the PHI node itself...
+        !isa<UndefValue>(PN->getIncomingValue(i)))
       if (InVal && PN->getIncomingValue(i) != InVal)
         return 0;  // Not the same, bail out.
       else
@@ -344,7 +364,7 @@ Value *llvm::hasConstantValue(PHINode *PN) {
   // that only has entries for itself.  In this case, there is no entry into the
   // loop, so kill the PHI.
   //
-  if (InVal == 0) InVal = Constant::getNullValue(PN->getType());
+  if (InVal == 0) InVal = UndefValue::get(PN->getType());
 
   // All of the incoming values are the same, return the value now.
   return InVal;