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To not break TBAA rules, use a union. 

llvm-svn: 19280
This commit is contained in:
Chris Lattner 2005-01-04 01:56:57 +00:00
parent 623bacf418
commit 472cc1062d
1 changed files with 9 additions and 5 deletions
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14
llvm/lib/VMCore/AsmWriter.cpp
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@ -421,7 +421,8 @@ static void WriteConstantInt(std::ostream &Out, const Constant *CV,
(StrVal[1] >= '0' && StrVal[1] <= '9')))
// Reparse stringized version!
if (atof(StrVal.c_str()) == CFP->getValue()) {
Out << StrVal; return;
Out << StrVal;
return;
}
// Otherwise we could not reparse it to exactly the same value, so we must
@ -430,11 +431,14 @@ static void WriteConstantInt(std::ostream &Out, const Constant *CV,
// Behave nicely in the face of C TBAA rules... see:
// http://www.nullstone.com/htmls/category/aliastyp.htm
//
double Val = CFP->getValue();
char *Ptr = (char*)&Val;
assert(sizeof(double) == sizeof(uint64_t) && sizeof(double) == 8 &&
union {
double D;
uint64_t U;
} V;
V.D = CFP->getValue();
assert(sizeof(double) == sizeof(uint64_t) &&
"assuming that double is 64 bits!");
Out << "0x" << utohexstr(*(uint64_t*)Ptr);
Out << "0x" << utohexstr(V.U);
} else if (isa<ConstantAggregateZero>(CV)) {
Out << "zeroinitializer";