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Prototypes for builtin functions
- From: "Paulo Matos" <pmatos at broadcom dot com>
- To: "gcc at gcc dot gnu dot org" <gcc at gcc dot gnu dot org>
- Date: Thu, 29 Aug 2013 10:44:06 +0000
- Subject: Prototypes for builtin functions
- Authentication-results: sourceware.org; auth=none
Hi,
I would like to hear how other architectures organize their builtin/intrinsic headers.
Until recently we had a header that would look like:
/* Types */
typedef char V8B __attribute__ ((vector_size (8)));
...
/* Prototypes */
extern V8B __vec_put_v8b (V8B B, char C, unsigned char D);
...
The problem with this approach (I found out) is that GCC after seeing the prototype changes the location of the definition of the builtin from BUILTINS_LOCATION to the headerfile/linenumber and then when calling DECL_IS_BUILTIN on __vec_put_v8b tree it returns 0. This blocks a few optimizations (I noticed this when specifically checking why some functions were not being unrolled properly).
So, I commented out the prototypes from the intrinsics header and left only the type definitions, however, tests on intrinsics fail because if I do:
V8B put_v8b_test (V8B a, char value, char index)
{
V8B b = __vec_put_v8b (a, value, index);
return b;
}
GCC complains with:
error: incompatible type for argument 1 of '__vec_put_v8b'
note: expected '__vector(8) signed char' but argument is of type 'V8B'
What's the correct way to create the intrinsics header?
--
Paulo Matos