6502/llvm-6502
1
0
Fork 0
mirror of https://github.com/c64scene-ar/llvm-6502.git synced 2025-07-25 13:24:46 +00:00
Code Issues Projects Releases Wiki Activity

Make it possible to indicate relaxed floating point requirements at the IR level

Browse Source 
through the use of 'fpmath' metadata.  Currently this only provides a 'fpaccuracy'
value, which may be a number in ULPs or the keyword 'fast', however the intent is
that this will be extended with additional information about NaN's, infinities
etc later.  No optimizations have been hooked up to this so far.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@154822 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Duncan Sands
2012-04-16 16:28:59 +00:00
parent 9e67db4af1
commit 8883c43ddc
10 changed files with 282 additions and 86 deletions
Download Patch File Download Diff File Expand all files Collapse all files

38
lib/VMCore/Instructions.cpp
View File

@@ -2002,6 +2002,44 @@ bool BinaryOperator::isExact() const {
return cast<PossiblyExactOperator>(this)->isExact();
}
//===----------------------------------------------------------------------===//
// FPMathOperator Class
//===----------------------------------------------------------------------===//
/// getFPAccuracy - Get the maximum error permitted by this operation in ULPs.
/// An accuracy of 0.0 means that the operation should be performed with the
/// default precision. A huge value is returned if the accuracy is 'fast'.
float FPMathOperator::getFPAccuracy() const {
const MDNode *MD =
cast<Instruction>(this)->getMetadata(LLVMContext::MD_fpmath);
if (!MD)
return 0.0;
Value *Op = MD->getOperand(0);
if (const ConstantFP *Accuracy = dyn_cast<ConstantFP>(Op))
return Accuracy->getValueAPF().convertToFloat();
// If it's not a floating point number then it must be 'fast'.
assert(isa<MDString>(Op) && cast<MDString>(Op)->getString() == "fast" &&
"Expected the 'fast' keyword!");
return HUGE_VALF;
}
/// isFastFPAccuracy - Return true if the accuracy is 'fast'. This says that
/// speed is more important than accuracy.
bool FPMathOperator::isFastFPAccuracy() const {
const MDNode *MD =
cast<Instruction>(this)->getMetadata(LLVMContext::MD_fpmath);
if (!MD)
return false;
Value *Op = MD->getOperand(0);
if (isa<ConstantFP>(Op))
return false;
// If it's not a floating point number then it must be 'fast'.
assert(isa<MDString>(Op) && cast<MDString>(Op)->getString() == "fast" &&
"Expected the 'fast' keyword!");
return true;
}
//===----------------------------------------------------------------------===//
// CastInst Class
//===----------------------------------------------------------------------===//