Culling out use of unions for converting FP to bits and vice versa.

llvm-svn: 22838

3 files changed, 16 insertions, 44 deletions

diff --git a/llvm/lib/CodeGen/AsmPrinter.cpp b/llvm/lib/CodeGen/AsmPrinter.cpp
index 497e9c89fab..d907d67b5a2 100644
--- a/llvm/lib/CodeGen/AsmPrinter.cpp
+++ b/llvm/lib/CodeGen/AsmPrinter.cpp
@@ -15,6 +15,7 @@
 #include "llvm/Constants.h"
 #include "llvm/Instruction.h"
 #include "llvm/Support/Mangler.h"
+#include "llvm/Support/MathExtras.h"
 #include "llvm/Target/TargetMachine.h"
 using namespace llvm;
 
@@ -222,39 +223,27 @@ void AsmPrinter::emitGlobalConstant(const Constant *CV) {
     // precision...
     double Val = CFP->getValue();
     if (CFP->getType() == Type::DoubleTy) {
-      union DU {                            // Abide by C TBAA rules
-        double FVal;
-        uint64_t UVal;
-      } U;
-      U.FVal = Val;
-
       if (Data64bitsDirective)
-        O << Data64bitsDirective << U.UVal << "\t" << CommentString
+        O << Data64bitsDirective << DoubleToBits(Val) << "\t" << CommentString
           << " double value: " << Val << "\n";
       else if (TD.isBigEndian()) {
-        O << Data32bitsDirective << unsigned(U.UVal >> 32)
+        O << Data32bitsDirective << unsigned(DoubleToBits(Val) >> 32)
           << "\t" << CommentString << " double most significant word "
           << Val << "\n";
-        O << Data32bitsDirective << unsigned(U.UVal)
+        O << Data32bitsDirective << unsigned(DoubleToBits(Val))
           << "\t" << CommentString << " double least significant word "
           << Val << "\n";
       } else {
-        O << Data32bitsDirective << unsigned(U.UVal)
+        O << Data32bitsDirective << unsigned(DoubleToBits(Val))
           << "\t" << CommentString << " double least significant word " << Val
           << "\n";
-        O << Data32bitsDirective << unsigned(U.UVal >> 32)
+        O << Data32bitsDirective << unsigned(DoubleToBits(Val) >> 32)
           << "\t" << CommentString << " double most significant word " << Val
           << "\n";
       }
       return;
     } else {
-      union FU {                            // Abide by C TBAA rules
-        float FVal;
-        int32_t UVal;
-      } U;
-      U.FVal = (float)Val;
-
-      O << Data32bitsDirective << U.UVal << "\t" << CommentString
+      O << Data32bitsDirective << FloatToBits(Val) << "\t" << CommentString
         << " float " << Val << "\n";
       return;
     }
diff --git a/llvm/lib/CodeGen/SelectionDAG/LegalizeDAG.cpp b/llvm/lib/CodeGen/SelectionDAG/LegalizeDAG.cpp
index ab070301b08..2c01982df2b 100644
--- a/llvm/lib/CodeGen/SelectionDAG/LegalizeDAG.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/LegalizeDAG.cpp
@@ -975,23 +975,17 @@ SDOperand SelectionDAGLegalize::LegalizeOp(SDOperand Op) {
     // Turn 'store float 1.0, Ptr' -> 'store int 0x12345678, Ptr'
     if (ConstantFPSDNode *CFP =dyn_cast<ConstantFPSDNode>(Node->getOperand(1))){
       if (CFP->getValueType(0) == MVT::f32) {
-        union {
-          unsigned I;
-          float    F;
-        } V;
-        V.F = CFP->getValue();
         Result = DAG.getNode(ISD::STORE, MVT::Other, Tmp1,
-                             DAG.getConstant(V.I, MVT::i32), Tmp2,
+                             DAG.getConstant(FloatToBits(CFP->getValue()),
+                                             MVT::i32),
+                             Tmp2,
                              Node->getOperand(3));
       } else {
         assert(CFP->getValueType(0) == MVT::f64 && "Unknown FP type!");
-        union {
-          uint64_t I;
-          double   F;
-        } V;
-        V.F = CFP->getValue();
         Result = DAG.getNode(ISD::STORE, MVT::Other, Tmp1,
-                             DAG.getConstant(V.I, MVT::i64), Tmp2,
+                             DAG.getConstant(DoubleToBits(CFP->getValue()),
+                                             MVT::i64),
+                             Tmp2,
                              Node->getOperand(3));
       }
       Node = Result.Val;
diff --git a/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp b/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
index 6afa9d08947..81b08039a47 100644
--- a/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
@@ -224,12 +224,8 @@ void SelectionDAG::RemoveNodeFromCSEMaps(SDNode *N) {
                                          N->getValueType(0)));
     break;
   case ISD::ConstantFP: {
-    union {
-      double DV;
-      uint64_t IV;
-    };
-    DV = cast<ConstantFPSDNode>(N)->getValue();
-    ConstantFPs.erase(std::make_pair(IV, N->getValueType(0)));
+    uint64_t V = DoubleToBits(cast<ConstantFPSDNode>(N)->getValue());
+    ConstantFPs.erase(std::make_pair(V, N->getValueType(0)));
     break;
   }
   case ISD::CONDCODE:
@@ -385,14 +381,7 @@ SDOperand SelectionDAG::getConstantFP(double Val, MVT::ValueType VT) {
   // Do the map lookup using the actual bit pattern for the floating point
   // value, so that we don't have problems with 0.0 comparing equal to -0.0, and
   // we don't have issues with SNANs.
-  union {
-    double DV;
-    uint64_t IV;
-  };
-
-  DV = Val;
-
-  SDNode *&N = ConstantFPs[std::make_pair(IV, VT)];
+  SDNode *&N = ConstantFPs[std::make_pair(DoubleToBits(Val), VT)];
   if (N) return SDOperand(N, 0);
   N = new ConstantFPSDNode(Val, VT);
   AllNodes.push_back(N);