st/glsl_to_tgsi: Use SecondaryOutputsWritten to determine dual-source fragment outputs.

Currently the mesa state tracker relies on there being two bits set
per dual-source output in the gl_program::OutputsWritten bitset, but
that only worked due to a GLSL front-end bug that caused it to set the
OutputsWritten bit for both location and location+1 even though at the
GLSL level the primary and secondary color outputs used for
dual-source blending have the same location.  Fix it by extending
outputMapping[] to 2*FRAG_RESULT_MAX elements in order to represent a
mapping from a (location, index) pair to its TGSI output, which should
also make it slightly easier to add support for dual-source blending
in combination with multiple render targets in the long run.

No Piglit regressions on llvmpipe.

Reviewed-by: Ilia Mirkin <[email protected]>

1 files changed, 12 insertions, 6 deletions

diff --git a/src/mesa/state_tracker/st_program.c b/src/mesa/state_tracker/st_program.c
index 03a685c4db6..429d0c9eb6d 100644
--- a/src/mesa/state_tracker/st_program.c
+++ b/src/mesa/state_tracker/st_program.c
@@ -586,7 +586,9 @@ bool
 st_translate_fragment_program(struct st_context *st,
                               struct st_fragment_program *stfp)
 {
-   GLuint outputMapping[FRAG_RESULT_MAX];
+   GLuint outputMapping[2 * FRAG_RESULT_MAX] =
+      { 0 /* XXX - Avoid temporary regression due to bogus OutputsWritten
+           *       bitset. */ };
    GLuint inputMapping[VARYING_SLOT_MAX];
    GLuint inputSlotToAttr[VARYING_SLOT_MAX];
    GLuint interpMode[PIPE_MAX_SHADER_INPUTS];  /* XXX size? */
@@ -810,9 +812,13 @@ st_translate_fragment_program(struct st_context *st,
       }
 
       /* handle remaining outputs (color) */
-      for (attr = 0; attr < FRAG_RESULT_MAX; attr++) {
-         if (outputsWritten & BITFIELD64_BIT(attr)) {
-            switch (attr) {
+      for (attr = 0; attr < ARRAY_SIZE(outputMapping); attr++) {
+         const GLbitfield64 written = attr < FRAG_RESULT_MAX ? outputsWritten :
+            stfp->Base.Base.SecondaryOutputsWritten;
+         const unsigned loc = attr % FRAG_RESULT_MAX;
+
+         if (written & BITFIELD64_BIT(loc)) {
+            switch (loc) {
             case FRAG_RESULT_DEPTH:
             case FRAG_RESULT_STENCIL:
             case FRAG_RESULT_SAMPLE_MASK:
@@ -822,8 +828,8 @@ st_translate_fragment_program(struct st_context *st,
             case FRAG_RESULT_COLOR:
                write_all = GL_TRUE; /* fallthrough */
             default:
-               assert(attr == FRAG_RESULT_COLOR ||
-                      (FRAG_RESULT_DATA0 <= attr && attr < FRAG_RESULT_MAX));
+               assert(loc == FRAG_RESULT_COLOR ||
+                      (FRAG_RESULT_DATA0 <= loc && loc < FRAG_RESULT_MAX));
                fs_output_semantic_name[fs_num_outputs] = TGSI_SEMANTIC_COLOR;
                fs_output_semantic_index[fs_num_outputs] = numColors;
                outputMapping[attr] = fs_num_outputs;