Sub-Target specific math routines library
- On i386, GCC currently emits calls to libm math functions like f.i. sin(). This pessimizes code a lot if we are using SSE math, as we need to obey the standard i387 FP ABI. The sub-target specific math routines library will provide a way to present different ABI math routines to GCC, possibly featuring a faster sub-target specific implementation. This includes SSE(2) ABI and implementation transcendental functions and vectorized transcendental functions not currently in libm.
- Richard Guenther
- Stage 1 of 4.2. i386 specific implementation is ready, a better name than libsse2 has to be chosen and some sub-directory restructuring of the library needs to be made.
- GCC will create better (as in faster and smaller) code in the SSE math case on i386. Other targets may be able to benefit from the infrastructure laid.
- A new toplevel library will be introduced and the i386 backend will be made to emit calls to functions in this library instead of libm, if asked to do so.