llvm dev - Jul 2013 - [LLVMdev] arch-specific predefines in LLVM's source

> ----- Original Message -----
>> Hi all,
>>  	My recent commit r187027 fixed a simple oversight of forgetting to
>> check for __ppc__ (only checking __powerpc__), which broke my
>> powerpc-apple-darwin8 stage1 tests, since the system gcc only
>> provided
>> __ppc__.  I was wondering if this justifies using simpler macros like
>>
>> #define LLVM_PPC	(defined(__ppc__) || defined(__powerpc__) ...)
>> #define LLVM_PPC64	(defined(__ppc64__) || defined(__powerpc64__) ...)
>
> A general note: Given all of the compiler variance out there regarding
whether the 32-bit macros are also defined on the 64-bit systems, I really think
that you'll need to arrange these as:
>
> #define LLVM_PPC64	(defined(__ppc64__) || defined(__powerpc64__) ...)
> #define LLVM_PPC	!LLVM_PPC64 && (defined(__ppc__) ||
defined(__powerpc__) ...)
or define more clearly:

#define	LLVM_PPC32	(((defined(__ppc__) || defined(__powerpc__)) &&
!LLVM_PPC64)
#define	LLVM_PPC_ANY	(LLVM_PPC32 || LLVM_PPC64)

or

#define	LLVM_PPC_ANY	(defined(__ppc__) || defined(__powerpc__))
#define	LLVM_PPC32	(LLVM_PPC_ANY && !LLVM_PPC64)

?
>> I've even seen __POWERPC__, _POWER, _ARCH_PPC being tested in
>> conditionals.
>>
>> These proposed standardized macros would only be used in LLVM project
>> sources; there's no reason to exported them.
>> The standardized macros would simplify conditionals and make their
>> use
>> less error-prone.
>>
>> What predefines do other architectures use?
>
> Would all uses of these macros be restricted to the PPC backend, or 
> would they appear elsewhere as well?
One place I see these predefines outside of the PPC backend is
lib/Support/Host.cpp

Fang
> -Hal
>
>>
>> What would be a suitable place for these proposed macros?
>> include/llvm/Support/Compiler.h?
>> include/llvm/Support/Arch.h (new)?
>>
>> Fang

-- 
David Fang
http://www.csl.cornell.edu/~fang/

----- Original Message -----
> > ----- Original Message -----
> >> Hi all,
> >>  	My recent commit r187027 fixed a simple oversight of forgetting
> >>  	to
> >> check for __ppc__ (only checking __powerpc__), which broke my
> >> powerpc-apple-darwin8 stage1 tests, since the system gcc only
> >> provided
> >> __ppc__.  I was wondering if this justifies using simpler macros
> >> like
> >>
> >> #define LLVM_PPC	(defined(__ppc__) || defined(__powerpc__) ...)
> >> #define LLVM_PPC64	(defined(__ppc64__) || defined(__powerpc64__)
> >> ...)
> >
> > A general note: Given all of the compiler variance out there
> > regarding whether the 32-bit macros are also defined on the 64-bit
> > systems, I really think that you'll need to arrange these as:
> >
> > #define LLVM_PPC64	(defined(__ppc64__) || defined(__powerpc64__)
> > ...)
> > #define LLVM_PPC	!LLVM_PPC64 && (defined(__ppc__) ||
> > defined(__powerpc__) ...)
> 
> or define more clearly:
> 
> #define	LLVM_PPC32	(((defined(__ppc__) || defined(__powerpc__)) &&
> !LLVM_PPC64)
> #define	LLVM_PPC_ANY	(LLVM_PPC32 || LLVM_PPC64)
> 
> or
> 
> #define	LLVM_PPC_ANY	(defined(__ppc__) || defined(__powerpc__))
> #define	LLVM_PPC32	(LLVM_PPC_ANY && !LLVM_PPC64)
I thought that you had discovered that on Darwin __ppc__, etc. are defined only
for 32-bit builds. Is that correct?

 -Hal
> 
> ?
> 
> >> I've even seen __POWERPC__, _POWER, _ARCH_PPC being tested in
> >> conditionals.
> >>
> >> These proposed standardized macros would only be used in LLVM
> >> project
> >> sources; there's no reason to exported them.
> >> The standardized macros would simplify conditionals and make their
> >> use
> >> less error-prone.
> >>
> >> What predefines do other architectures use?
> >
> > Would all uses of these macros be restricted to the PPC backend, or
> > would they appear elsewhere as well?
> 
> One place I see these predefines outside of the PPC backend is
> lib/Support/Host.cpp
> 
> Fang
> 
> > -Hal
> >
> >>
> >> What would be a suitable place for these proposed macros?
> >> include/llvm/Support/Compiler.h?
> >> include/llvm/Support/Arch.h (new)?
> >>
> >> Fang
> 
> 
> --
> David Fang
> http://www.csl.cornell.edu/~fang/
> 
> 
-- 
Hal Finkel
Assistant Computational Scientist
Leadership Computing Facility
Argonne National Laboratory

Hi,
> ----- Original Message -----
>>> ----- Original Message -----
>>>> Hi all,
>>>>  	My recent commit r187027 fixed a simple oversight of
forgetting
>>>>  	to
>>>> check for __ppc__ (only checking __powerpc__), which broke my
>>>> powerpc-apple-darwin8 stage1 tests, since the system gcc only
>>>> provided
>>>> __ppc__.  I was wondering if this justifies using simpler
macros
>>>> like
>>>>
>>>> #define LLVM_PPC	(defined(__ppc__) || defined(__powerpc__) ...)
>>>> #define LLVM_PPC64	(defined(__ppc64__) ||
defined(__powerpc64__)
>>>> ...)
>> or define more clearly:
>>
>> #define	LLVM_PPC32	(((defined(__ppc__) || defined(__powerpc__))
&&
>> !LLVM_PPC64)
>> #define	LLVM_PPC_ANY	(LLVM_PPC32 || LLVM_PPC64)
>>
>> or
>>
>> #define	LLVM_PPC_ANY	(defined(__ppc__) || defined(__powerpc__))
>> #define	LLVM_PPC32	(LLVM_PPC_ANY && !LLVM_PPC64)
>
> I thought that you had discovered that on Darwin __ppc__, etc. are defined
only for 32-bit builds. Is that correct?
>
> -Hal
 	Ah yes, with apple-gcc-4.0.1 (powerpc)

-m32 only defines __ppc__
-m64 only defines __ppc64__

So a more correct set of definitions would be:

#define	LLVM_PPC32	((defined(__ppc__) || (defined(__powerpc__) &&
!defined(__powerpc64__)))
#define	LLVM_PPC64	(defined(__ppc64__) || defined(__powerpc64__))
#define	LLVM_PPC_ANY	(LLVM_PPC32 || LLVM_PPC64)

Fang
>>>> I've even seen __POWERPC__, _POWER, _ARCH_PPC being tested
in
>>>> conditionals.
>>>>
>>>> These proposed standardized macros would only be used in LLVM
>>>> project
>>>> sources; there's no reason to exported them.
>>>> The standardized macros would simplify conditionals and make
their
>>>> use
>>>> less error-prone.
>>>>
>>>> What predefines do other architectures use?
>>>
>>> Would all uses of these macros be restricted to the PPC backend, or
>>> would they appear elsewhere as well?
>>
>> One place I see these predefines outside of the PPC backend is
>> lib/Support/Host.cpp
>>
>> Fang
>>
>>> -Hal
>>>
>>>>
>>>> What would be a suitable place for these proposed macros?
>>>> include/llvm/Support/Compiler.h?
>>>> include/llvm/Support/Arch.h (new)?
>>>>
>>>> Fang
>>
>>
>> --
>> David Fang
>> http://www.csl.cornell.edu/~fang/
>>
>>
>
>
-- 
David Fang
http://www.csl.cornell.edu/~fang/