Hi, On Thu, Jul 26, 2012 at 2:39 PM, Diego Biurrun <di...@biurrun.de> wrote: > On Thu, Jul 26, 2012 at 01:50:17PM -0700, Ronald S. Bultje wrote: >> >> discussion thread. We currently use HAVE_SSSE3 and related macros to >> indicate that we want to compile these and that our compiler tools are >> good enough to know what to do with it. As a result, we currently use >> HAVE_AVX around all avx code (yasm only - we don't have any avx inline >> asm), HAVE_SSSE3 around some yasm and all inline asm code that uses >> ssse3 instructions, and sometimes HAVE_SSE/2 around inline asm using >> xmm regs. There is no HAVE_SSE4. HAVE_MMX2 is almost never used but >> does exist. > > Do we need HAVE_SSE4? It should be easy enough to add. > >> HAVE_MMX is something entirely different and is used as an >> alternative form of ARCH_X86. > > No, HAVE_MMX is just that. True, it's abused in some places where > ARCH_X86 would be better (when invoking init functions), but that > is an issue that needs to be addressed at some point. > >> In addition to that, we're using inline asm checks to test whether to >> enable HAVE_SSSE3 and HAVE_SSE2 (line 2850 of configure). >> >> Can we split these macros in something for yasm vs something for >> inline asm? This means e.g. that we can use ssse3 if yasm (but not >> inline asm) supports it, if inline asm is lacking, etc. > > What is your goal? Do you want to write something like > > #if HAVE_INLINE_SSSE3 > > instead of > > #if HAVE_SSSE3 && HAVE_INLINE_ASM > > ?
Right now, in practice: HAVE_SSSE3 means "we support inline ssse3" HAVE_SSE2 means "we support inline sse2" HAVE_AVX means "we support yasm avx" but depends on HAVE_SSSE3 I wonder whether it makes sense to have a "generic" HAVE_SSSE3 anyway - when would we use it, what would it mean? I think in practice, we probably want a HAVE_INLINE_SSSE3, as you said, because yes, there's compilers that don't support this, but do support HAVE_INLINE_ASM in general. Likewise, HAVE_AVX could be renamed HAVE_YASM_AVX or so. Having HAVE_YASM_SSSE3 seems pointless, I don't think we support any yasm/nasm version that doesn't understand ssse3, so it'd always be 1. However, this would make it clear that HAVE_SSSE3 and HAVE_AVX don't and shouldn't depend on each other. Ronald _______________________________________________ libav-devel mailing list libav-devel@libav.org https://lists.libav.org/mailman/listinfo/libav-devel
