[Mesa-dev] [PATCH 3/3] gallivm: Reenable PPC VSX (v2)

[Emil Velikov]

On 16 January 2017 at 23:38, Ben Crocker <bcrocker at redhat.com> wrote:
> Reenable the PPC64LE Vector-Scalar Extension for LLVM versions >= 3.8.1,
> now that LLVM bug 26775 and its corollary, 25503, are fixed.
>
> Amendment: remove extraneous spaces in macro def & invocations.
>
> Signed-off-by: Ben Crocker <bcrocker at redhat.com>
Stable ?

Cc: "12.0 13.0 17.0" <mesa-stable at lists.freedesktop.org>

> ---
>  src/gallium/auxiliary/gallivm/lp_bld_misc.cpp | 15 ++++++++++++++-
>  1 file changed, 14 insertions(+), 1 deletion(-)
>
> diff --git a/src/gallium/auxiliary/gallivm/lp_bld_misc.cpp b/src/gallium/auxiliary/gallivm/lp_bld_misc.cpp
> index cac81b9..ff6bbb9 100644
> --- a/src/gallium/auxiliary/gallivm/lp_bld_misc.cpp
> +++ b/src/gallium/auxiliary/gallivm/lp_bld_misc.cpp
> @@ -50,6 +50,8 @@
>
>  #include <stddef.h>
>
> +#define LLVM_VERSION(MAJOR_MINOR, PATCH_LEVEL) ((MAJOR_MINOR << 8) + PATCH_LEVEL)
> +
Don't think the extra macro brings much. We directly compare pretty
much anywhere in Mesa.

>  // Workaround http://llvm.org/PR23628
>  #if HAVE_LLVM >= 0x0307
>  #  pragma push_macro("DEBUG")
> @@ -614,7 +616,8 @@ lp_build_create_jit_compiler_for_module(LLVMExecutionEngineRef *OutJIT,
>
>  #if defined(PIPE_ARCH_PPC)
>     MAttrs.push_back(util_cpu_caps.has_altivec ? "+altivec" : "-altivec");
> -#if HAVE_LLVM >= 0x0304
> +#if (HAVE_LLVM >= 0x0304) && \
> +   (LLVM_VERSION(HAVE_LLVM, MESA_LLVM_VERSION_PATCH) <= LLVM_VERSION(0x0308, 0x00))
I've mentioned this on another unrelated thread, but it's also applicable here:

We want to remove build-time patch version checks and ask LLVM at
runtime about it. Reason being is that when using shared LLVM one can
easily update/downgrade between bugfix releases and the build time
decision (in this patch) will no longer hold true.

If there's no LLVM API can I ask you to follow with LLVM devs ? Until
that one is available, this patch will be good enough.

Thanks
Emil