draw: do not use draw_get_option_use_llvm() inside draw execution paths

1c73e919a4 made it possible to not allocate
the tgsi machine if llvm was used. However, draw_get_option_use_llvm() is
not reliable after draw context creation, since drivers can explicitly
request a non-llvm draw context even if draw_get_option_use_llvm() would
return true (and softpipe does just that) which leads to crashes.
Thus use draw->llvm to determine if we're using llvm or not instead (and
make draw->llvm available even if HAVE_LLVM is false so we don't have to put
even more ifdefs).

Cc: "10.2" <mesa-stable@lists.freedesktop.org>
Reviewed-by: Brian Paul <brianp@vmware.com>
(cherry picked from commit 9af68e9b1d)

src/gallium/auxiliary/draw/draw_context.c

@@ -1000,6 +1000,8 @@ draw_get_shader_param_no_llvm(unsigned shader, enum pipe_shader_cap param)
 /**
  * XXX: Results for PIPE_SHADER_CAP_MAX_TEXTURE_SAMPLERS because there are two
  * different ways of setting textures, and drivers typically only support one.
+ * Drivers requesting a draw context explicitly without llvm must call
+ * draw_get_shader_param_no_llvm instead.
  */
 int
 draw_get_shader_param(unsigned shader, enum pipe_shader_cap param)

src/gallium/auxiliary/draw/draw_gs.c

@@ -597,7 +597,7 @@ int draw_geometry_shader_run(struct draw_geometry_shader *shader,
 
 
 #ifdef HAVE_LLVM
-   if (draw_get_option_use_llvm()) {
+   if (shader->draw->llvm) {
       shader->gs_output = output_verts->verts;
       if (max_out_prims > shader->max_out_prims) {
          unsigned i;
@@ -674,7 +674,7 @@ int draw_geometry_shader_run(struct draw_geometry_shader *shader,
 void draw_geometry_shader_prepare(struct draw_geometry_shader *shader,
                                   struct draw_context *draw)
 {
-   boolean use_llvm = draw_get_option_use_llvm();
+   boolean use_llvm = draw->llvm != NULL;
    if (!use_llvm && shader && shader->machine->Tokens != shader->state.tokens) {
       tgsi_exec_machine_bind_shader(shader->machine,
                                     shader->state.tokens,
@@ -686,7 +686,7 @@ void draw_geometry_shader_prepare(struct draw_geometry_shader *shader,
 boolean
 draw_gs_init( struct draw_context *draw )
 {
-   if (!draw_get_option_use_llvm()) {
+   if (!draw->llvm) {
       draw->gs.tgsi.machine = tgsi_exec_machine_create();
       if (!draw->gs.tgsi.machine)
          return FALSE;
@@ -715,7 +715,7 @@ draw_create_geometry_shader(struct draw_context *draw,
                             const struct pipe_shader_state *state)
 {
 #ifdef HAVE_LLVM
-   boolean use_llvm = draw_get_option_use_llvm();
+   boolean use_llvm = draw->llvm != NULL;
    struct llvm_geometry_shader *llvm_gs;
 #endif
    struct draw_geometry_shader *gs;
@@ -870,7 +870,7 @@ void draw_delete_geometry_shader(struct draw_context *draw,
       return;
    }
 #ifdef HAVE_LLVM
-   if (draw_get_option_use_llvm()) {
+   if (draw->llvm) {
       struct llvm_geometry_shader *shader = llvm_geometry_shader(dgs);
       struct draw_gs_llvm_variant_list_item *li;
 

src/gallium/auxiliary/draw/draw_private.h

@@ -47,7 +47,6 @@
 #include "tgsi/tgsi_scan.h"
 
 #ifdef HAVE_LLVM
-struct draw_llvm;
 struct gallivm_state;
 #endif
 
@@ -69,6 +68,7 @@ struct tgsi_exec_machine;
 struct tgsi_sampler;
 struct draw_pt_front_end;
 struct draw_assembler;
+struct draw_llvm;
 
 
 /**
@@ -318,9 +318,7 @@ struct draw_context
    unsigned start_instance;
    unsigned start_index;
 
-#ifdef HAVE_LLVM
    struct draw_llvm *llvm;
-#endif
 
    /** Texture sampler and sampler view state.
     * Note that we have arrays indexed by shader type.  At this time

src/gallium/auxiliary/draw/draw_vs.c

@@ -149,7 +149,7 @@ draw_vs_init( struct draw_context *draw )
 {
    draw->dump_vs = debug_get_option_gallium_dump_vs();
 
-   if (!draw_get_option_use_llvm()) {
+   if (!draw->llvm) {
       draw->vs.tgsi.machine = tgsi_exec_machine_create();
       if (!draw->vs.tgsi.machine)
          return FALSE;
@@ -175,7 +175,7 @@ draw_vs_destroy( struct draw_context *draw )
    if (draw->vs.emit_cache)
       translate_cache_destroy(draw->vs.emit_cache);
 
-   if (!draw_get_option_use_llvm())
+   if (!draw->llvm)
       tgsi_exec_machine_destroy(draw->vs.tgsi.machine);
 }
 

src/gallium/auxiliary/draw/draw_vs_exec.c

@@ -63,7 +63,7 @@ vs_exec_prepare( struct draw_vertex_shader *shader,
 {
    struct exec_vertex_shader *evs = exec_vertex_shader(shader);
 
-   debug_assert(!draw_get_option_use_llvm());
+   debug_assert(!draw->llvm);
    /* Specify the vertex program to interpret/execute.
     * Avoid rebinding when possible.
     */
@@ -97,7 +97,7 @@ vs_exec_run_linear( struct draw_vertex_shader *shader,
    unsigned slot;
    boolean clamp_vertex_color = shader->draw->rasterizer->clamp_vertex_color;
 
-   debug_assert(!draw_get_option_use_llvm());
+   debug_assert(!shader->draw->llvm);
    tgsi_exec_set_constant_buffers(machine, PIPE_MAX_CONSTANT_BUFFERS,
                                   constants, const_size);