APFloat: Add some missing function declarations

[tstellar]

Summary

Theses functions were added in fd1e5aa8dffa8b26e59fb340668b264b9ac80382
without a declaration.

[tstellar]

There were friend function declarations added for these functions to the DoubleAPFloat class, but no actual declarations.

[nikic]

Are these functions used anywhere? If not, I think we should just remove them.

[arsenm]

These should be used for constant folding of ldexp and frexp

[nikic]

In D154765#4486245, @arsenm wrote:

These should be used for constant folding of ldexp and frexp

We probably don't support constant folding for pcc_fp128. Or at least I don't see how it would work without the declarations.

[arsenm]

In D154765#4486268, @nikic wrote:

In D154765#4486245, @arsenm wrote:

These should be used for constant folding of ldexp and frexp

We probably don't support constant folding for pcc_fp128. Or at least I don't see how it would work without the declarations.

D149587 introduces the constant folding of ldexp. I haven't gotten around to posting the frexp patch yet

[nikic]

In D154765#4486295, @arsenm wrote:

In D154765#4486268, @nikic wrote:

In D154765#4486245, @arsenm wrote:

These should be used for constant folding of ldexp and frexp

We probably don't support constant folding for pcc_fp128. Or at least I don't see how it would work without the declarations.

D149587 introduces the constant folding of ldexp. I haven't gotten around to posting the frexp patch yet

This is working on APFloat though, not on DoubleAPFloat.

[arsenm]

In D154765#4486299, @nikic wrote:

In D154765#4486295, @arsenm wrote:

In D154765#4486268, @nikic wrote:

In D154765#4486245, @arsenm wrote:

These should be used for constant folding of ldexp and frexp

We probably don't support constant folding for pcc_fp128. Or at least I don't see how it would work without the declarations.

D149587 introduces the constant folding of ldexp. I haven't gotten around to posting the frexp patch yet

This is working on APFloat though, not on DoubleAPFloat.

There's supposed to be a APFLOAT_DISPATCH_ON_SEMANTICS wrapper around ~everything

[arsenm]

In D154765#4486303, @arsenm wrote:

In D154765#4486299, @nikic wrote:

In D154765#4486295, @arsenm wrote:

In D154765#4486268, @nikic wrote:

In D154765#4486245, @arsenm wrote:

These should be used for constant folding of ldexp and frexp

We probably don't support constant folding for pcc_fp128. Or at least I don't see how it would work without the declarations.

D149587 introduces the constant folding of ldexp. I haven't gotten around to posting the frexp patch yet

This is working on APFloat though, not on DoubleAPFloat.

There's supposed to be a APFLOAT_DISPATCH_ON_SEMANTICS wrapper around ~everything

Which we already have so now I'm confused

[nikic]

Oh, I see. I think the reason this works is ADL, which also finds friend declarations even if not declared at namespace level.

llvm/include/llvm/ADT/APFloat.h

1459

These declarations should probably be next to hash_code hash_value(const DoubleAPFloat &Arg); above, rather than these definitions.

[tstellar]

Move declarations up to be next to the hash_value declaration.

[nikic]

LGTM

llvm/include/llvm/ADT/APFloat.h

public:
   int getExactLog2Abs() const;
 
   friend DoubleAPFloat scalbn(const DoubleAPFloat &X, int Exp, roundingMode);
   friend DoubleAPFloat frexp(const DoubleAPFloat &X, int &Exp, roundingMode);
   friend hash_code hash_value(const DoubleAPFloat &Arg);
 };
 
 hash_code hash_value(const DoubleAPFloat &Arg);
+DoubleAPFloat scalbn(const DoubleAPFloat &Arg, int Exp, IEEEFloat::roundingMode RM);
+DoubleAPFloat frexp(const DoubleAPFloat &X, int &Exp, IEEEFloat::roundingMode);
 
 } // End detail namespace
 
 // This is a interface class that is currently forwarding functionalities from
 // detail::IEEEFloat.
 class APFloat : public APFloatBase {
   typedef detail::IEEEFloat IEEEFloat;
   typedef detail::DoubleAPFloat DoubleAPFloat;
DoubleAPFloat &DoubleAPFloat::operator=(DoubleAPFloat &&RHS) {
   return *this;
 }
 
 APFloat &DoubleAPFloat::getFirst() { return Floats[0]; }
 const APFloat &DoubleAPFloat::getFirst() const { return Floats[0]; }
 APFloat &DoubleAPFloat::getSecond() { return Floats[1]; }
 const APFloat &DoubleAPFloat::getSecond() const { return Floats[1]; }
 
 } // namespace detail
 
 } // namespace llvm
 
 #undef APFLOAT_DISPATCH_ON_SEMANTICS
 #endif // LLVM_ADT_APFLOAT_H