[Mesa-dev] [RFC libdrm 0/2] Replace the build system with meson

Jonathan Gray jsg at jsg.id.au
Tue Mar 21 05:00:37 UTC 2017 

On Tue, Mar 21, 2017 at 08:28:22AM +1100, Timothy Arceri wrote:
> 
> 
> On 21/03/17 06:39, Emil Velikov wrote:
> > On 20 March 2017 at 18:30, Matt Turner <mattst88 at gmail.com> wrote:
> > > On Mon, Mar 20, 2017 at 6:55 AM, Emil Velikov <emil.l.velikov at gmail.com> wrote:
> > > > Seems like we ended up all over the place, so let me try afresh.
> > > > 
> > > > Above all:
> > > >  - Saying "I don't care" about your users is arrogant - let us _not_
> > > > do that, please ?
> > > 
> > > Let's be honest, the OpenBSD is subjecting itself to some pretty
> > > arbitrary restrictions caused including Mesa in its core: 10+ year old
> > > GCC,
> > IIRC Brian was using old MinGW GCC, which was one of the blockers - it
> > wasn't OpenBSD to blame here ;-)
> 
> Sorry Emil I probably wasn't clear in our discussion. I sent out patches to
> switch to GCC 4.8 last Sept (I believe this was needed by RHEL6) [1].
> 
> Brain jumped in and said "I'm still using the MinGW gcc 4.6 compiler. I'd
> rather not go through the upgrade hassle if I don't have to."
> 
> Followed by Jose "We're internally building and shipping Mesa compiled with
> GCC 4.4 (more specifically 4.4.3).
> 
> It's fine if you require GCC 4.8 on automake, but please leave support
> for GCC 4.4.x in SCons."
> 
> By this point I got bored and moved on. But OpenBSDs GCC is a fork with
> various features backported, from what I understand Mesa would not build on
> a real GCC 4.2 release and we should not be using it as a min version. IMO
> if OpenBSD want to maintain a GCC fork they can handle a patch to downgrade
> the min GCC version.
> 
> I believe Jonathan would like us to stick with 4.2 as min but is prepared to
> deal with it if we move on.

I would like to see Mesa test features it uses in configure rather than
arbitary versions that are what a certain linux distribution ships with.
The zlib change for instance didn't reference any specific problems with
older versions or interfaces required from newer versions.

We have one platform using clang/lld now (arm64) and are likely to move
others in future where possible.  libtool has to be patched and the Mesa
configure script regenerated to make this work or Mesa won't build due
to libtool.m4 looking for specific strings in ld -v produced by bfd
binutils or gold...

And yes if you change the configure script to check for a newer version
I'll revert it locally like I did with the zlib one.

As I get the impression no one cares about patches for older GCC I've
not being sending them to the list, ie

commit d3d340d6026e516cc405a2eb1d925a7a7a467480
Author: Jonathan Gray <jsg at jsg.id.au>
Date:   Thu Mar 16 00:30:07 2017 +1100

    i965: don't use designated array initialisation
    
    Don't use a form of designated array initialisation that breaks gcc 4.2.1.
    
    compiler/brw_vec4_gs_visitor.cpp:589: error: expected primary-expression before '[' token
    compiler/brw_vec4_gs_visitor.cpp:590: error: expected primary-expression before '[' token
    compiler/brw_vec4_gs_visitor.cpp:591: error: expected primary-expression before '[' token
    compiler/brw_vec4_gs_visitor.cpp:592: error: expected primary-expression before '[' token
    compiler/brw_vec4_gs_visitor.cpp:593: error: expected primary-expression before '[' token
    compiler/brw_vec4_gs_visitor.cpp:594: error: expected primary-expression before '[' token
    compiler/brw_vec4_gs_visitor.cpp:595: error: expected primary-expression before '[' token
    compiler/brw_vec4_gs_visitor.cpp:596: error: expected primary-expression before '[' token
    compiler/brw_vec4_gs_visitor.cpp:597: error: expected primary-expression before '[' token
    compiler/brw_vec4_gs_visitor.cpp:598: error: expected primary-expression before '[' token
    compiler/brw_vec4_gs_visitor.cpp:599: error: expected primary-expression before '[' token
    compiler/brw_vec4_gs_visitor.cpp:600: error: expected primary-expression before '[' token
    compiler/brw_vec4_gs_visitor.cpp:601: error: expected primary-expression before '[' token
    compiler/brw_vec4_gs_visitor.cpp:602: error: expected primary-expression before '[' token
    
    Signed-off-by: Jonathan Gray <jsg at jsg.id.au>

diff --git a/src/intel/compiler/brw_vec4_gs_visitor.cpp b/src/intel/compiler/brw_vec4_gs_visitor.cpp
index 4a8b5be30e..e7a502306e 100644
--- a/src/intel/compiler/brw_vec4_gs_visitor.cpp
+++ b/src/intel/compiler/brw_vec4_gs_visitor.cpp
@@ -585,23 +585,6 @@ vec4_gs_visitor::gs_end_primitive()
    emit(OR(dst_reg(this->control_data_bits), this->control_data_bits, mask));
 }
 
-static const GLuint gl_prim_to_hw_prim[GL_TRIANGLE_STRIP_ADJACENCY+1] = {
-   [GL_POINTS] =_3DPRIM_POINTLIST,
-   [GL_LINES] = _3DPRIM_LINELIST,
-   [GL_LINE_LOOP] = _3DPRIM_LINELOOP,
-   [GL_LINE_STRIP] = _3DPRIM_LINESTRIP,
-   [GL_TRIANGLES] = _3DPRIM_TRILIST,
-   [GL_TRIANGLE_STRIP] = _3DPRIM_TRISTRIP,
-   [GL_TRIANGLE_FAN] = _3DPRIM_TRIFAN,
-   [GL_QUADS] = _3DPRIM_QUADLIST,
-   [GL_QUAD_STRIP] = _3DPRIM_QUADSTRIP,
-   [GL_POLYGON] = _3DPRIM_POLYGON,
-   [GL_LINES_ADJACENCY] = _3DPRIM_LINELIST_ADJ,
-   [GL_LINE_STRIP_ADJACENCY] = _3DPRIM_LINESTRIP_ADJ,
-   [GL_TRIANGLES_ADJACENCY] = _3DPRIM_TRILIST_ADJ,
-   [GL_TRIANGLE_STRIP_ADJACENCY] = _3DPRIM_TRISTRIP_ADJ,
-};
-
 extern "C" const unsigned *
 brw_compile_gs(const struct brw_compiler *compiler, void *log_data,
                void *mem_ctx,
@@ -814,9 +797,51 @@ brw_compile_gs(const struct brw_compiler *compiler, void *log_data,
    else
       prog_data->base.urb_entry_size = ALIGN(output_size_bytes, 128) / 128;
 
-   assert(shader->info->gs.output_primitive < ARRAY_SIZE(gl_prim_to_hw_prim));
-   prog_data->output_topology =
-      gl_prim_to_hw_prim[shader->info->gs.output_primitive];
+   assert(shader->info->gs.output_primitive < (GL_TRIANGLE_STRIP_ADJACENCY+1));
+   switch (shader->info->gs.output_primitive) {
+   case GL_POINTS:
+      prog_data->output_topology =_3DPRIM_POINTLIST;
+      break;
+   case GL_LINES:
+      prog_data->output_topology = _3DPRIM_LINELIST;
+      break;
+   case GL_LINE_LOOP:
+      prog_data->output_topology = _3DPRIM_LINELOOP;
+      break;
+   case GL_LINE_STRIP:
+      prog_data->output_topology = _3DPRIM_LINESTRIP;
+      break;
+   case GL_TRIANGLES:
+      prog_data->output_topology = _3DPRIM_TRILIST;
+      break;
+   case GL_TRIANGLE_STRIP:
+      prog_data->output_topology = _3DPRIM_TRISTRIP;
+      break;
+   case GL_TRIANGLE_FAN:
+      prog_data->output_topology = _3DPRIM_TRIFAN;
+      break;
+   case GL_QUADS:
+      prog_data->output_topology = _3DPRIM_QUADLIST;
+      break;
+   case GL_QUAD_STRIP:
+      prog_data->output_topology = _3DPRIM_QUADSTRIP;
+      break;
+   case GL_POLYGON:
+      prog_data->output_topology = _3DPRIM_POLYGON;
+      break;
+   case GL_LINES_ADJACENCY:
+      prog_data->output_topology = _3DPRIM_LINELIST_ADJ;
+      break;
+   case GL_LINE_STRIP_ADJACENCY:
+      prog_data->output_topology = _3DPRIM_LINESTRIP_ADJ;
+      break;
+   case GL_TRIANGLES_ADJACENCY:
+      prog_data->output_topology = _3DPRIM_TRILIST_ADJ;
+      break;
+   case GL_TRIANGLE_STRIP_ADJACENCY:
+      prog_data->output_topology = _3DPRIM_TRISTRIP_ADJ;
+      break;
+   }
 
    prog_data->vertices_in = shader->info->gs.vertices_in;

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