Reorder the uniforms to load first the dvec4-aligned variables
in the push constant buffer and then push the vec4-aligned ones.
This fixes a bug were the dvec3/4 might be loaded one part on a GRF and
the rest in next GRF, so the region parameters to read that could break
the HW rules.
v2:
- Fix broken logic.
- Add a comment to explain what should be needed to optimise the usage
of the push constant buffer slots, as this patch does not pack the
uniforms.
Signed-off-by: Samuel Iglesias Gonsálvez <sigles...@igalia.com>
Cc: "17.1" <mesa-sta...@lists.freedesktop.org>
---
src/intel/compiler/brw_vec4.cpp | 97 +++++++++++++++++++++++++++++++----------
1 file changed, 74 insertions(+), 23 deletions(-)
diff --git a/src/intel/compiler/brw_vec4.cpp b/src/intel/compiler/brw_vec4.cpp
index 0909ddb586..18bfd48fa1 100644
--- a/src/intel/compiler/brw_vec4.cpp
+++ b/src/intel/compiler/brw_vec4.cpp
@@ -583,16 +583,44 @@ vec4_visitor::split_uniform_registers()
}
}
+/* This function returns the register number where we placed the uniform */
+static int
+set_push_constant_loc(const int nr_uniforms, int *new_uniform_count,
+ const int src, const int size,
+ int *new_loc, int *new_chan,
+ int *new_chans_used)
+{
+ int dst;
+ /* Find the lowest place we can slot this uniform in. */
+ for (dst = 0; dst < nr_uniforms; dst++) {
+ if (new_chans_used[dst] + size <= 4)
+ break;
+ }
+
+ assert(dst < nr_uniforms);
+
+ new_loc[src] = dst;
+ new_chan[src] = new_chans_used[dst];
+ new_chans_used[dst] += size;
+
+ *new_uniform_count = MAX2(*new_uniform_count, dst + 1);
+ return dst;
+}
+
void
vec4_visitor::pack_uniform_registers()
{
uint8_t chans_used[this->uniforms];
int new_loc[this->uniforms];
int new_chan[this->uniforms];
+ bool is_aligned_to_dvec4[this->uniforms];
+ int new_chans_used[this->uniforms];
memset(chans_used, 0, sizeof(chans_used));
memset(new_loc, 0, sizeof(new_loc));
memset(new_chan, 0, sizeof(new_chan));
+ memset(new_chans_used, 0, sizeof(new_chans_used));
+ memset(is_aligned_to_dvec4, 0, sizeof(is_aligned_to_dvec4));
/* Find which uniform vectors are actually used by the program. We
* expect unused vector elements when we've moved array access out
@@ -631,10 +659,19 @@ vec4_visitor::pack_uniform_registers()
unsigned channel = BRW_GET_SWZ(inst->src[i].swizzle, c) + 1;
unsigned used = MAX2(chans_used[reg], channel * channel_size);
- if (used <= 4)
- chans_used[reg] = used;
- else
- chans_used[reg + 1] = used - 4;
+ /* FIXME: Marked all channels as used, so each uniform will
+ * fully use one or two vec4s. If we want to pack them, we need
+ * to, among other changes, set chans_used[reg] = used;
+ * chans_used[reg+1] = used - 4; and fix the swizzle at the
+ * end in order to set the proper location.
+ */
+ if (used <= 4) {
+ chans_used[reg] = 4;
+ } else {
+ is_aligned_to_dvec4[reg] = true;
+ is_aligned_to_dvec4[reg + 1] = true;
+ chans_used[reg + 1] = 4;
+ }
}
}
@@ -659,42 +696,56 @@ vec4_visitor::pack_uniform_registers()
int new_uniform_count = 0;
+ /* As the uniforms are going to be reordered, take the data from a temporary
+ * copy of the original param[].
+ */
+ gl_constant_value **param = ralloc_array(NULL, gl_constant_value*,
+ stage_prog_data->nr_params);
+ memcpy(param, stage_prog_data->param,
+ sizeof(gl_constant_value*) * stage_prog_data->nr_params);
+
/* Now, figure out a packing of the live uniform vectors into our
- * push constants.
+ * push constants. Start with dvec{3,4} because they are aligned to
+ * dvec4 size (2 vec4).
*/
for (int src = 0; src < uniforms; src++) {
int size = chans_used[src];
- if (size == 0)
+ if (size == 0 || !is_aligned_to_dvec4[src])
continue;
- int dst;
- /* Find the lowest place we can slot this uniform in. */
- for (dst = 0; dst < src; dst++) {
- if (chans_used[dst] + size <= 4)
- break;
+ int dst = set_push_constant_loc(uniforms, &new_uniform_count,
+ src, size, new_loc, new_chan,
+ new_chans_used);
+ if (dst != src) {
+ /* Move the references to the data */
+ for (int j = 0; j < size; j++) {
+ stage_prog_data->param[dst * 4 + new_chan[src] + j] =
+ param[src * 4 + j];
+ }
}
+ }
- if (src == dst) {
- new_loc[src] = dst;
- new_chan[src] = 0;
- } else {
- new_loc[src] = dst;
- new_chan[src] = chans_used[dst];
+ /* Continue with the rest of data, which is aligned to vec4. */
+ for (int src = 0; src < uniforms; src++) {
+ int size = chans_used[src];
+
+ if (size == 0 || is_aligned_to_dvec4[src])
+ continue;
+ int dst = set_push_constant_loc(uniforms, &new_uniform_count,
+ src, size, new_loc, new_chan,
+ new_chans_used);
+ if (dst != src) {
/* Move the references to the data */
for (int j = 0; j < size; j++) {
stage_prog_data->param[dst * 4 + new_chan[src] + j] =
- stage_prog_data->param[src * 4 + j];
+ param[src * 4 + j];
}
-
- chans_used[dst] += size;
- chans_used[src] = 0;
}
-
- new_uniform_count = MAX2(new_uniform_count, dst + 1);
}
+ ralloc_free(param);
this->uniforms = new_uniform_count;
/* Now, update the instructions for our repacked uniforms. */
--
2.11.0
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