On 02/01/2013 08:47 AM, Simon Marlow wrote: > On 01/02/13 08:19, Geoffrey Mainland wrote: >> On 02/01/2013 08:03 AM, Simon Marlow wrote: >>> On 31/01/13 20:30, Geoffrey Mainland wrote: >>>> 2) SSE support is processor and platform dependent. What is the proper >>>> way for the programmer to know what SSE primitives are available? A CPP >>>> define? If so, what should it be called? >>>> >>>> Right now one can look at the TARGET_* and __GLASGOW_HASKELL_LLVM__ CPP >>>> macros and make a decision as to whether or not SSE primitives are >>>> available, but that's not a great solution. Also, what happens when we >>>> want to add AVX support? How do we control the inclusion of AVX support >>>> when building GHC, and how do we let the programmer know that the AVX >>>> primops/primtypes are available for use? >>> >>> We #define __SSE__: http://hackage.haskell.org/trac/ghc/ticket/7554 >>> >>> Similar things would need to happen for AVX. >> >> If I invoke ghc with -msse on a Win32 box then __SSE__ will be 1, but >> that doesn't mean I will be able to use SSE primops due to the stack >> alignment issue on that platform. > > I guess we should not allow -msse with -fllvm on Win32. Or perhaps > not -msse at all.
Hm, OK, but that would also means external C files could not be compiled with -msse when using the LLVM back-end on Win32 since we pass the flags through to the C compiler, right? >> Also, the decision as to whether or not SSE primops will be available at >> all needs to be made when GHC is itself built. How should we expose that >> knob? > > Why does it need to be decided at build time? Isn't it dependent on > -msse on x86-32, and always available on x86-64? The primops would need to be compiled in to GHC for -msse to be able expose them. In general, how would we make the set of primops and primtypes a function of dynflags? It's my understanding that this isn't possible right now. Or is it? And what about GHC.PrimopWrappers? >> As an aside, what's the proper way for me to test the ARM >> cross-compilation support? I'm afraid my patches may break things there. > > You could follow the instructions for building an RPi cross-compiler here: > > http://hackage.haskell.org/trac/ghc/wiki/Building/Preparation/RaspberryPi > > it should be fairly smooth. Thanks! Geoff _______________________________________________ ghc-devs mailing list ghc-devs@haskell.org http://www.haskell.org/mailman/listinfo/ghc-devs
