Re: What is wrong with Bugzilla? [Was: Re: GCC and Floating-Point]

[Haren Visavadia <themis_hv at yahoo dot co dot uk>]

--- "Joseph S. Myers" wrote:

> On Sun, 29 May 2005, Giovanni Bajo wrote:
> 
> > You are mistaken, we think GCC isn't buggy about
> 323 because the C/C++
> > standards do not tell us to do better than this.
> If you have higher
> > expectations about floating point and C/C++, you
> should file a bugreport
> > against the C/C++ standards.
> 
> This is ignoring that there are specific
> requirements in the C99 standard 
> regarding the handling of excess precision which we
> do not implement, even 
> with -ffloat-store, which are genuine bugs. 
> Assignment, casts and 
> function call and return must discard excess
> precision, but we do not 
> discard excess precision on a cast of an expression
> to its own type.  
> Furthermore, the definition of FLT_EVAL_METHOD for
> i386
> 
> #define TARGET_FLT_EVAL_METHOD \
>   (TARGET_MIX_SSE_I387 ? -1 : TARGET_SSE_MATH ? 0 :
> 2)
> 
> is wrong when it is 2 because the way the i386 back
> end pretends to have 
> float and double (not just long double) 387
> operations means that 
> precision may get randomly reduced if an
> intermediate value is spilled (so 
> -1, not 2, is correct).  It is also incorrect
> because it is an assertion 
> about both arithmetic and evaluation of constants
> and we do not emulate 
> excess precision when evaluating constants and doing
> arithmetic on them.
> 

This makes it *bad* compiler claiming it implements a
standard when does not.

Giovanni Bajo stop telling lies about what GCC
implements.








	
	
		
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