compiler: Move double_inputs to gl_program::DualSlotInputs

Previously, we had two field in shader_info: double_inputs_read and
double_inputs.  Presumably, the one was for all double inputs that are
read and the other is all that exist.  However, because nir_gather_info
regenerates these two values, there is a possibility, if a variable gets
deleted, that the value of double_inputs could change over time.  This
is a problem because double_inputs is used to remap the input locations
to a two-slot-per-dvec3/4 scheme for i965.  If that mapping were to
change between glsl_to_nir and back-end state setup, we would fall over
when trying to map the NIR outputs back onto the GL location space.

This commit changes the way slot re-mapping works.  Instead of the
double_inputs field in shader_info, it adds a DualSlotInputs bitfield to
gl_program.  By having it in gl_program, we more easily guarantee that
NIR passes won't touch it after it's been set.  It also makes more sense
to put it in a GL data structure since it's really a mapping from GL
slots to back-end and/or NIR slots and not really a NIR shader thing.

Tested-by: Alejandro Piñeiro <[email protected]> (ARB_gl_spirv tests)
Reviewed-by: Alejandro Piñeiro <[email protected]>
Reviewed-by: Timothy Arceri <[email protected]>

2 files changed, 12 insertions, 10 deletions

diff --git a/src/mesa/drivers/dri/i965/brw_draw_upload.c b/src/mesa/drivers/dri/i965/brw_draw_upload.c
index bc9b2566deb..dc3022bc417 100644
--- a/src/mesa/drivers/dri/i965/brw_draw_upload.c
+++ b/src/mesa/drivers/dri/i965/brw_draw_upload.c
@@ -29,6 +29,7 @@
 #include "main/enums.h"
 #include "main/macros.h"
 #include "main/glformats.h"
+#include "nir.h"
 
 #include "brw_draw.h"
 #include "brw_defines.h"
@@ -454,10 +455,14 @@ brw_prepare_vertices(struct brw_context *brw)
 {
    const struct gen_device_info *devinfo = &brw->screen->devinfo;
    struct gl_context *ctx = &brw->ctx;
+   /* BRW_NEW_VERTEX_PROGRAM */
+   const struct gl_program *vp = brw->programs[MESA_SHADER_VERTEX];
    /* BRW_NEW_VS_PROG_DATA */
    const struct brw_vs_prog_data *vs_prog_data =
       brw_vs_prog_data(brw->vs.base.prog_data);
-   GLbitfield64 vs_inputs = vs_prog_data->inputs_read;
+   GLbitfield64 vs_inputs =
+      nir_get_single_slot_attribs_mask(vs_prog_data->inputs_read,
+                                       vp->DualSlotInputs);
    const unsigned char *ptr = NULL;
    GLuint interleaved = 0;
    unsigned int min_index = brw->vb.min_index + brw->basevertex;
@@ -486,16 +491,12 @@ brw_prepare_vertices(struct brw_context *brw)
    /* Accumulate the list of enabled arrays. */
    brw->vb.nr_enabled = 0;
    while (vs_inputs) {
-      GLuint first = ffsll(vs_inputs) - 1;
-      assert (first < 64);
-      GLuint index =
-         first - DIV_ROUND_UP(_mesa_bitcount_64(vs_prog_data->double_inputs_read &
-                                                BITFIELD64_MASK(first)), 2);
+      const unsigned index = ffsll(vs_inputs) - 1;
+      assert(index < 64);
+
       struct brw_vertex_element *input = &brw->vb.inputs[index];
-      input->is_dual_slot = (vs_prog_data->double_inputs_read & BITFIELD64_BIT(first)) != 0;
-      vs_inputs &= ~BITFIELD64_BIT(first);
-      if (input->is_dual_slot)
-         vs_inputs &= ~BITFIELD64_BIT(first + 1);
+      input->is_dual_slot = (vp->DualSlotInputs & BITFIELD64_BIT(index)) != 0;
+      vs_inputs &= ~BITFIELD64_BIT(index);
       brw->vb.enabled[brw->vb.nr_enabled++] = input;
    }
 
diff --git a/src/mesa/drivers/dri/i965/genX_state_upload.c b/src/mesa/drivers/dri/i965/genX_state_upload.c
index 09a42e44b08..740cb0c4d2e 100644
--- a/src/mesa/drivers/dri/i965/genX_state_upload.c
+++ b/src/mesa/drivers/dri/i965/genX_state_upload.c
@@ -933,6 +933,7 @@ static const struct brw_tracked_state genX(vertices) = {
       .mesa = _NEW_POLYGON,
       .brw = BRW_NEW_BATCH |
              BRW_NEW_BLORP |
+             BRW_NEW_VERTEX_PROGRAM |
              BRW_NEW_VERTICES |
              BRW_NEW_VS_PROG_DATA,
    },