draw/llvm: fix generation of the VS with GS present

draw_current_shader_* functions return a final output when considering
both the geometry shader and the vertex shader. But when code generating
vertex shader we can not be using output slots from the geometry shader
because, obviously, those can be completely different. This fixes a
number of very non-obvious crashes.
A side-effect of this bug was that sometimes the vertex shading code
could save some random outputs as position/clip when the geometry
shader was writing them and vertex shader had different outputs at
those slots (sometimes writing garbage and sometimes something correct).

Signed-off-by: Zack Rusin <zackr@vmware.com>
Reviewed-by: José Fonseca <jfonseca@vmware.com>
Reviewed-by: Roland Scheidegger <sroland@vmware.com>
Reviewed-by: Matthew McClure <mcclurem@vmware.com>

diff --git a/src/gallium/auxiliary/draw/draw_llvm.c b/src/gallium/auxiliary/draw/draw_llvm.c
index 0bbb6804984e86519ccd4a97be59f4541582b115..53d13f3cb40a6ae192faea5cbf3d4c1abf243e9d 100644 (file)
--- a/src/gallium/auxiliary/draw/draw_llvm.c
+++ b/src/gallium/auxiliary/draw/draw_llvm.c
@@ -1104,7 +1104,7 @@ generate_viewport(struct draw_llvm_variant *variant,
    int i;
    struct gallivm_state *gallivm = variant->gallivm;
    struct lp_type f32_type = vs_type;
-   const unsigned pos = draw_current_shader_position_output(variant->llvm->draw);
+   const unsigned pos = variant->llvm->draw->vs.position_output;
    LLVMTypeRef vs_type_llvm = lp_build_vec_type(gallivm, vs_type);
    LLVMValueRef out3 = LLVMBuildLoad(builder, outputs[pos][3], ""); /*w0 w1 .. wn*/
    LLVMValueRef const1 = lp_build_const_vec(gallivm, f32_type, 1.0);       /*1.0 1.0 1.0 1.0*/
@@ -1173,14 +1173,14 @@ generate_clipmask(struct draw_llvm *llvm,
    LLVMValueRef plane1, planes, plane_ptr, sum;
    struct lp_type f32_type = vs_type;
    struct lp_type i32_type = lp_int_type(vs_type);
-   const unsigned pos = draw_current_shader_position_output(llvm->draw);
-   const unsigned cv = draw_current_shader_clipvertex_output(llvm->draw);
+   const unsigned pos = llvm->draw->vs.position_output;
+   const unsigned cv = llvm->draw->vs.clipvertex_output;
    int num_written_clipdistance = llvm->draw->vs.vertex_shader->info.num_written_clipdistance;
    bool have_cd = false;
    unsigned cd[2];
 
-   cd[0] = draw_current_shader_clipdistance_output(llvm->draw, 0);
-   cd[1] = draw_current_shader_clipdistance_output(llvm->draw, 1);
+   cd[0] = llvm->draw->vs.clipdistance_output[0];
+   cd[1] = llvm->draw->vs.clipdistance_output[1];
 
    if (cd[0] != pos || cd[1] != pos)
       have_cd = true;
@@ -1551,8 +1551,8 @@ draw_llvm_generate(struct draw_llvm *llvm, struct draw_llvm_variant *variant,
                                            key->clip_z  ||
                                            key->clip_user);
    LLVMValueRef variant_func;
-   const unsigned pos = draw_current_shader_position_output(llvm->draw);
-   const unsigned cv = draw_current_shader_clipvertex_output(llvm->draw);
+   const unsigned pos = llvm->draw->vs.position_output;
+   const unsigned cv = llvm->draw->vs.clipvertex_output;
    boolean have_clipdist = FALSE;
    struct lp_bld_tgsi_system_values system_values;