From 5567441de93575cf170e37a5f9dc13ccc448091d Mon Sep 17 00:00:00 2001
From: Chris Lattner <sabre@nondot.org>
Date: Sun, 12 Oct 2003 08:12:58 +0000
Subject: [PATCH] * Spell "necessary" correctly * Print floating point values
 using C99 hexadecimal style FP if possible.   This increases the number of
 floating point constants that may be emitted   inline, and improves precision
 for global variable initializers which   can not be emitted in integer form.

This fixes the Olden/Power benchmark with the CBE!!!!

llvm-svn: 9052
---
 lib/CWriter/Writer.cpp | 27 ++++++++++++++++++++++++---
 1 file changed, 24 insertions(+), 3 deletions(-)

diff --git a/lib/CWriter/Writer.cpp b/lib/CWriter/Writer.cpp
index d1bf8490722..33981245ced 100644
--- a/lib/CWriter/Writer.cpp
+++ b/lib/CWriter/Writer.cpp
@@ -23,6 +23,10 @@
 #include <algorithm>
 #include <sstream>
 
+
+/* FIXME: This should be autoconf'd! */
+#define HAS_C99_HEXADECIMAL_CONSTANTS 1
+
 namespace {
   class CWriter : public Pass, public InstVisitor<CWriter> {
     std::ostream &Out; 
@@ -337,6 +341,16 @@ void CWriter::printConstantArray(ConstantArray *CPA) {
 // only deal in IEEE FP).
 //
 static bool isFPCSafeToPrint(const ConstantFP *CFP) {
+#if HAS_C99_HEXADECIMAL_CONSTANTS
+  char Buffer[100];
+  sprintf(Buffer, "%a", CFP->getValue());
+
+  if (!strncmp(Buffer, "0x", 2) ||
+      !strncmp(Buffer, "-0x", 3) ||
+      !strncmp(Buffer, "+0x", 3))
+    return atof(Buffer) == CFP->getValue();
+  return false;
+#else
   std::string StrVal = ftostr(CFP->getValue());
 
   while (StrVal[0] == ' ')
@@ -350,6 +364,7 @@ static bool isFPCSafeToPrint(const ConstantFP *CFP) {
     // Reparse stringized version!
     return atof(StrVal.c_str()) == CFP->getValue();
   return false;
+#endif
 }
 
 // printConstant - The LLVM Constant to C Constant converter.
@@ -442,8 +457,14 @@ void CWriter::printConstant(Constant *CPV) {
       Out << "(*(" << (FPC->getType() == Type::FloatTy ? "float" : "double")
           << "*)&FPConstant" << I->second << ")";
     } else {
+#if HAS_C99_HEXADECIMAL_CONSTANTS
       // Print out the constant as a floating point number.
+      char Buffer[100];
+      sprintf(Buffer, "%a", FPC->getValue());
+      Out << Buffer << " /*" << FPC->getValue() << "*/ ";
+#else
       Out << ftostr(FPC->getValue());
+#endif
     }
     break;
   }
@@ -1018,7 +1039,7 @@ void CWriter::visitUnwindInst(UnwindInst &I) {
   emittedInvoke = true;
 }
 
-static bool isGotoCodeNeccessary(BasicBlock *From, BasicBlock *To) {
+static bool isGotoCodeNecessary(BasicBlock *From, BasicBlock *To) {
   // If PHI nodes need copies, we need the copy code...
   if (isa<PHINode>(To->front()) ||
       From->getNext() != To)      // Not directly successor, need goto
@@ -1051,14 +1072,14 @@ void CWriter::printBranchToBlock(BasicBlock *CurBB, BasicBlock *Succ,
 //
 void CWriter::visitBranchInst(BranchInst &I) {
   if (I.isConditional()) {
-    if (isGotoCodeNeccessary(I.getParent(), I.getSuccessor(0))) {
+    if (isGotoCodeNecessary(I.getParent(), I.getSuccessor(0))) {
       Out << "  if (";
       writeOperand(I.getCondition());
       Out << ") {\n";
       
       printBranchToBlock(I.getParent(), I.getSuccessor(0), 2);
       
-      if (isGotoCodeNeccessary(I.getParent(), I.getSuccessor(1))) {
+      if (isGotoCodeNecessary(I.getParent(), I.getSuccessor(1))) {
         Out << "  } else {\n";
         printBranchToBlock(I.getParent(), I.getSuccessor(1), 2);
       }