[LLVMdev] [Clang] Reasons for lack of -fsingle-precision-constant support? Alternatives?

[Rick Mann]

> On Jul 15, 2015, at 09:08 , ed at modk.it wrote:
> 
> Thanks for the response.  If we add the support would you accept the patch?  Seems like a pretty straightforward flag since it maps directly to NumericLiteralParser::NumericLiteralParser within LiteralSupport.cpp.  I understand the maintenance concern with flags that affect multiple points in code though.
> 
> Still trying to get the bottom of why we're crashing with double floating point literal.  It seems the fpu in question (fpv4-sp-d16) only supports 32 bit operations so this is somehow getting passed to a software wrapper and crashing there.  But to be fair this was crashing in gcc too which is why we added the -fsingle-precision-constant flag since we didn't care about the precision of the constants and we're using floats everywhere anyway for performance.

Shouldn't the code generator know to make the constants 32-bit if that's all the target supports? Or does it emulate 64-bit in software?

-- 
Rick Mann
rmann at latencyzero.com