Mesa (master): i965: Use arrays in Gen7+ URB code.

Kenneth Graunke kwg at kemper.freedesktop.org
Sat Nov 19 19:40:07 UTC 2016


Module: Mesa
Branch: master
Commit: 6d416bcd846a49414f210cd761789156c37a7b3e
URL:    http://cgit.freedesktop.org/mesa/mesa/commit/?id=6d416bcd846a49414f210cd761789156c37a7b3e

Author: Kenneth Graunke <kenneth at whitecape.org>
Date:   Tue Nov 15 01:03:13 2016 -0800

i965: Use arrays in Gen7+ URB code.

So much of this code was cut and pasted per stage.  We can accomplish
much of it by looping over shader stages.

Improves performance of OglBatch7 (version 6) by 1.50783% +/- 0.287049%
(n = 71) at 1024x768 on Cherryview.

Signed-off-by: Kenneth Graunke <kenneth at whitecape.org>
Reviewed-by: Topi Pohjolainen <topi.pohjolainen at intel.com>

---

 src/mesa/drivers/dri/i965/gen7_urb.c | 336 ++++++++++++++---------------------
 1 file changed, 134 insertions(+), 202 deletions(-)

diff --git a/src/mesa/drivers/dri/i965/gen7_urb.c b/src/mesa/drivers/dri/i965/gen7_urb.c
index 61fd774..72b409c 100644
--- a/src/mesa/drivers/dri/i965/gen7_urb.c
+++ b/src/mesa/drivers/dri/i965/gen7_urb.c
@@ -152,40 +152,6 @@ const struct brw_tracked_state gen7_push_constant_space = {
 };
 
 static void
-gen7_emit_urb_state(struct brw_context *brw,
-                    unsigned nr_vs_entries,
-                    unsigned vs_size, unsigned vs_start,
-                    unsigned nr_hs_entries,
-                    unsigned hs_size, unsigned hs_start,
-                    unsigned nr_ds_entries,
-                    unsigned ds_size, unsigned ds_start,
-                    unsigned nr_gs_entries,
-                    unsigned gs_size, unsigned gs_start)
-{
-   BEGIN_BATCH(8);
-   OUT_BATCH(_3DSTATE_URB_VS << 16 | (2 - 2));
-   OUT_BATCH(nr_vs_entries |
-             ((vs_size - 1) << GEN7_URB_ENTRY_SIZE_SHIFT) |
-             (vs_start << GEN7_URB_STARTING_ADDRESS_SHIFT));
-
-   OUT_BATCH(_3DSTATE_URB_GS << 16 | (2 - 2));
-   OUT_BATCH(nr_gs_entries |
-             ((gs_size - 1) << GEN7_URB_ENTRY_SIZE_SHIFT) |
-             (gs_start << GEN7_URB_STARTING_ADDRESS_SHIFT));
-
-   OUT_BATCH(_3DSTATE_URB_HS << 16 | (2 - 2));
-   OUT_BATCH(nr_hs_entries |
-             ((hs_size - 1) << GEN7_URB_ENTRY_SIZE_SHIFT) |
-             (hs_start << GEN7_URB_STARTING_ADDRESS_SHIFT));
-
-   OUT_BATCH(_3DSTATE_URB_DS << 16 | (2 - 2));
-   OUT_BATCH(nr_ds_entries |
-             ((ds_size - 1) << GEN7_URB_ENTRY_SIZE_SHIFT) |
-             (ds_start << GEN7_URB_STARTING_ADDRESS_SHIFT));
-   ADVANCE_BATCH();
-}
-
-static void
 upload_urb(struct brw_context *brw)
 {
    /* BRW_NEW_VS_PROG_DATA */
@@ -208,56 +174,45 @@ gen7_upload_urb(struct brw_context *brw, unsigned vs_size,
    const int push_size_kB =
       (brw->gen >= 8 || (brw->is_haswell && brw->gt == 3)) ? 32 : 16;
 
-   /* BRW_NEW_VS_PROG_DATA */
-   unsigned vs_entry_size_bytes = vs_size * 64;
-   /* BRW_NEW_GEOMETRY_PROGRAM, BRW_NEW_GS_PROG_DATA */
-   const struct brw_vue_prog_data *gs_vue_prog_data =
-      brw_vue_prog_data(brw->gs.base.prog_data);
-   unsigned gs_size = gs_present ? gs_vue_prog_data->urb_entry_size : 1;
-   unsigned gs_entry_size_bytes = gs_size * 64;
-
-   /* BRW_NEW_TCS_PROG_DATA */
-   const struct brw_vue_prog_data *tcs_vue_prog_data =
-      brw_vue_prog_data(brw->tcs.base.prog_data);
-   unsigned hs_size = tess_present ? tcs_vue_prog_data->urb_entry_size : 1;
-   unsigned hs_entry_size_bytes = hs_size * 64;
-   /* BRW_NEW_TES_PROG_DATA */
-   const struct brw_vue_prog_data *tes_vue_prog_data =
-      brw_vue_prog_data(brw->tes.base.prog_data);
-   unsigned ds_size = tess_present ? tes_vue_prog_data->urb_entry_size : 1;
-   unsigned ds_entry_size_bytes = ds_size * 64;
+   const bool active[4] = { true, tess_present, tess_present, gs_present };
+
+   /* BRW_NEW_{VS,TCS,TES,GS}_PROG_DATA */
+   struct brw_vue_prog_data *prog_data[4] = {
+      [MESA_SHADER_VERTEX] =
+         brw_vue_prog_data(brw->vs.base.prog_data),
+      [MESA_SHADER_TESS_CTRL] =
+         tess_present ? brw_vue_prog_data(brw->tcs.base.prog_data) : NULL,
+      [MESA_SHADER_TESS_EVAL] =
+         tess_present ? brw_vue_prog_data(brw->tes.base.prog_data) : NULL,
+      [MESA_SHADER_GEOMETRY] =
+         gs_present ? brw_vue_prog_data(brw->gs.base.prog_data) : NULL,
+   };
+
+   unsigned entry_size[4];
+   entry_size[MESA_SHADER_VERTEX] = vs_size;
+   for (int i = MESA_SHADER_TESS_CTRL; i <= MESA_SHADER_GEOMETRY; i++) {
+      entry_size[i] = prog_data[i] ? prog_data[i]->urb_entry_size : 1;
+   }
 
    /* If we're just switching between programs with the same URB requirements,
     * skip the rest of the logic.
     */
    if (!(brw->ctx.NewDriverState & BRW_NEW_CONTEXT) &&
        !(brw->ctx.NewDriverState & BRW_NEW_URB_SIZE) &&
-       brw->urb.vsize == vs_size &&
+       brw->urb.vsize == entry_size[MESA_SHADER_VERTEX] &&
        brw->urb.gs_present == gs_present &&
-       brw->urb.gsize == gs_size &&
+       brw->urb.gsize == entry_size[MESA_SHADER_GEOMETRY] &&
        brw->urb.tess_present == tess_present &&
-       brw->urb.hsize == hs_size &&
-       brw->urb.dsize == ds_size) {
+       brw->urb.hsize == entry_size[MESA_SHADER_TESS_CTRL] &&
+       brw->urb.dsize == entry_size[MESA_SHADER_TESS_EVAL]) {
       return;
    }
-   brw->urb.vsize = vs_size;
+   brw->urb.vsize = entry_size[MESA_SHADER_VERTEX];
    brw->urb.gs_present = gs_present;
-   brw->urb.gsize = gs_size;
+   brw->urb.gsize = entry_size[MESA_SHADER_GEOMETRY];
    brw->urb.tess_present = tess_present;
-   brw->urb.hsize = hs_size;
-   brw->urb.dsize = ds_size;
-
-   /* From p35 of the Ivy Bridge PRM (section 1.7.1: 3DSTATE_URB_GS):
-    *
-    *     VS Number of URB Entries must be divisible by 8 if the VS URB Entry
-    *     Allocation Size is less than 9 512-bit URB entries.
-    *
-    * Similar text exists for HS, DS and GS.
-    */
-   unsigned vs_granularity = (vs_size < 9) ? 8 : 1;
-   unsigned hs_granularity = (hs_size < 9) ? 8 : 1;
-   unsigned ds_granularity = (ds_size < 9) ? 8 : 1;
-   unsigned gs_granularity = (gs_size < 9) ? 8 : 1;
+   brw->urb.hsize = entry_size[MESA_SHADER_TESS_CTRL];
+   brw->urb.dsize = entry_size[MESA_SHADER_TESS_EVAL];
 
    /* URB allocations must be done in 8k chunks. */
    unsigned chunk_size_bytes = 8192;
@@ -269,36 +224,30 @@ gen7_upload_urb(struct brw_context *brw, unsigned vs_size,
 
    /* Reserve space for push constants */
    unsigned push_constant_bytes = 1024 * push_size_kB;
-   unsigned push_constant_chunks =
-      push_constant_bytes / chunk_size_bytes;
-
-   /* Initially, assign each stage the minimum amount of URB space it needs,
-    * and make a note of how much additional space it "wants" (the amount of
-    * additional space it could actually make use of).
-    */
+   unsigned push_constant_chunks = push_constant_bytes / chunk_size_bytes;
 
-   /* VS has a lower limit on the number of URB entries.
+   /* From p35 of the Ivy Bridge PRM (section 1.7.1: 3DSTATE_URB_GS):
     *
-    * From the Broadwell PRM, 3DSTATE_URB_VS instruction:
-    * "When tessellation is enabled, the VS Number of URB Entries must be
-    *  greater than or equal to 192."
+    *     VS Number of URB Entries must be divisible by 8 if the VS URB Entry
+    *     Allocation Size is less than 9 512-bit URB entries.
+    *
+    * Similar text exists for HS, DS and GS.
     */
-   unsigned vs_min_entries =
-      tess_present && brw->gen == 8 ?
-         192 : devinfo->urb.min_entries[MESA_SHADER_VERTEX];
-   /* Min VS Entries isn't a multiple of 8 on Cherryview/Broxton; round up */
-   vs_min_entries = ALIGN(vs_min_entries, vs_granularity);
-
-   unsigned vs_chunks =
-      DIV_ROUND_UP(vs_min_entries * vs_entry_size_bytes, chunk_size_bytes);
-   unsigned vs_wants =
-      DIV_ROUND_UP(devinfo->urb.max_entries[MESA_SHADER_VERTEX] *
-                   vs_entry_size_bytes,
-                   chunk_size_bytes) - vs_chunks;
-
-   unsigned gs_chunks = 0;
-   unsigned gs_wants = 0;
-   if (gs_present) {
+   unsigned granularity[4];
+   for (int i = MESA_SHADER_VERTEX; i <= MESA_SHADER_GEOMETRY; i++) {
+      granularity[i] = (entry_size[i] < 9) ? 8 : 1;
+   }
+
+   unsigned min_entries[4] = {
+      /* VS has a lower limit on the number of URB entries.
+       *
+       * From the Broadwell PRM, 3DSTATE_URB_VS instruction:
+       * "When tessellation is enabled, the VS Number of URB Entries must be
+       *  greater than or equal to 192."
+       */
+      [MESA_SHADER_VERTEX] = tess_present && brw->gen == 8 ?
+         192 : devinfo->urb.min_entries[MESA_SHADER_VERTEX],
+
       /* There are two constraints on the minimum amount of URB space we can
        * allocate:
        *
@@ -307,133 +256,116 @@ gen7_upload_urb(struct brw_context *brw, unsigned vs_size,
        *
        * (2) We can't allocate less than nr_gs_entries_granularity.
        */
-      gs_chunks = DIV_ROUND_UP(MAX2(gs_granularity, 2) * gs_entry_size_bytes,
-                               chunk_size_bytes);
-      gs_wants = DIV_ROUND_UP(devinfo->urb.max_entries[MESA_SHADER_GEOMETRY] *
-                              gs_entry_size_bytes,
-                              chunk_size_bytes) - gs_chunks;
+      [MESA_SHADER_GEOMETRY] = gs_present ? 2 : 0,
+
+      [MESA_SHADER_TESS_CTRL] = tess_present ? 1 : 0,
+
+      [MESA_SHADER_TESS_EVAL] = tess_present ?
+         devinfo->urb.min_entries[MESA_SHADER_TESS_EVAL] : 0,
+   };
+
+   /* Min VS Entries isn't a multiple of 8 on Cherryview/Broxton; round up.
+    * Round them all up.
+    */
+   for (int i = MESA_SHADER_VERTEX; i <= MESA_SHADER_GEOMETRY; i++) {
+      min_entries[i] = ALIGN(min_entries[i], granularity[i]);
    }
 
-   unsigned hs_chunks = 0;
-   unsigned hs_wants = 0;
-   unsigned ds_chunks = 0;
-   unsigned ds_wants = 0;
-
-   if (tess_present) {
-      hs_chunks =
-         DIV_ROUND_UP(hs_granularity * hs_entry_size_bytes,
-                      chunk_size_bytes);
-      hs_wants =
-         DIV_ROUND_UP(devinfo->urb.max_entries[MESA_SHADER_TESS_CTRL] *
-                      hs_entry_size_bytes, chunk_size_bytes) - hs_chunks;
-
-      ds_chunks =
-         DIV_ROUND_UP(devinfo->urb.min_entries[MESA_SHADER_TESS_EVAL] *
-                      ds_entry_size_bytes, chunk_size_bytes);
-      ds_wants =
-         DIV_ROUND_UP(devinfo->urb.max_entries[MESA_SHADER_TESS_EVAL] *
-                      ds_entry_size_bytes, chunk_size_bytes) - ds_chunks;
+   unsigned entry_size_bytes[4];
+   for (int i = MESA_SHADER_VERTEX; i <= MESA_SHADER_GEOMETRY; i++) {
+      entry_size_bytes[i] = 64 * entry_size[i];
    }
 
-   /* There should always be enough URB space to satisfy the minimum
-    * requirements of each stage.
+   /* Initially, assign each stage the minimum amount of URB space it needs,
+    * and make a note of how much additional space it "wants" (the amount of
+    * additional space it could actually make use of).
     */
-   unsigned total_needs = push_constant_chunks +
-                          vs_chunks + hs_chunks + ds_chunks + gs_chunks;
+   unsigned chunks[4];
+   unsigned wants[4];
+   unsigned total_needs = push_constant_chunks;
+   unsigned total_wants = 0;
+
+   for (int i = MESA_SHADER_VERTEX; i <= MESA_SHADER_GEOMETRY; i++) {
+      if (active[i]) {
+         chunks[i] = DIV_ROUND_UP(min_entries[i] * entry_size_bytes[i],
+                                  chunk_size_bytes);
+
+         wants[i] =
+            DIV_ROUND_UP(devinfo->urb.max_entries[i] * entry_size_bytes[i],
+                         chunk_size_bytes) - chunks[i];
+      } else {
+         chunks[i] = 0;
+         wants[i] = 0;
+      }
+
+      total_needs += chunks[i];
+      total_wants += wants[i];
+   }
+
    assert(total_needs <= urb_chunks);
 
    /* Mete out remaining space (if any) in proportion to "wants". */
-   unsigned total_wants = vs_wants + hs_wants + ds_wants + gs_wants;
-   unsigned remaining_space = urb_chunks - total_needs;
-   if (remaining_space > total_wants)
-      remaining_space = total_wants;
-   if (remaining_space > 0) {
-      unsigned vs_additional = (unsigned)
-         roundf(vs_wants * (((float) remaining_space) / total_wants));
-      vs_chunks += vs_additional;
-      remaining_space -= vs_additional;
-      total_wants -= vs_wants;
-
-      if (total_wants > 0) {
-         unsigned hs_additional = (unsigned)
-            roundf(hs_wants * (((float) remaining_space) / total_wants));
-         hs_chunks += hs_additional;
-         remaining_space -= hs_additional;
-         total_wants -= hs_wants;
-      }
+   unsigned remaining_space = MIN2(urb_chunks - total_needs, total_wants);
 
-      if (total_wants > 0) {
-         unsigned ds_additional = (unsigned)
-            roundf(ds_wants * (((float) remaining_space) / total_wants));
-         ds_chunks += ds_additional;
-         remaining_space -= ds_additional;
-         total_wants -= ds_wants;
+   if (remaining_space > 0) {
+      for (int i = MESA_SHADER_VERTEX;
+           total_wants > 0 && i <= MESA_SHADER_TESS_EVAL; i++) {
+         unsigned additional = (unsigned)
+            roundf(wants[i] * (((float) remaining_space) / total_wants));
+         chunks[i] += additional;
+         remaining_space -= additional;
+         total_wants -= additional;
       }
 
-      gs_chunks += remaining_space;
+      chunks[MESA_SHADER_GEOMETRY] += remaining_space;
    }
 
    /* Sanity check that we haven't over-allocated. */
-   assert(push_constant_chunks +
-          vs_chunks + hs_chunks + ds_chunks + gs_chunks <= urb_chunks);
+   unsigned total_chunks = push_constant_chunks;
+   for (int i = MESA_SHADER_VERTEX; i <= MESA_SHADER_GEOMETRY; i++) {
+      total_chunks += chunks[i];
+   }
+   assert(total_chunks <= urb_chunks);
 
    /* Finally, compute the number of entries that can fit in the space
     * allocated to each stage.
     */
-   unsigned nr_vs_entries = vs_chunks * chunk_size_bytes / vs_entry_size_bytes;
-   unsigned nr_hs_entries = hs_chunks * chunk_size_bytes / hs_entry_size_bytes;
-   unsigned nr_ds_entries = ds_chunks * chunk_size_bytes / ds_entry_size_bytes;
-   unsigned nr_gs_entries = gs_chunks * chunk_size_bytes / gs_entry_size_bytes;
+   unsigned entries[4];
+   for (int i = MESA_SHADER_VERTEX; i <= MESA_SHADER_GEOMETRY; i++) {
+      entries[i] = chunks[i] * chunk_size_bytes / entry_size_bytes[i];
 
-   /* Since we rounded up when computing *_wants, this may be slightly more
-    * than the maximum allowed amount, so correct for that.
-    */
-   nr_vs_entries =
-      MIN2(nr_vs_entries, devinfo->urb.max_entries[MESA_SHADER_VERTEX]);
-   nr_hs_entries =
-      MIN2(nr_hs_entries, devinfo->urb.max_entries[MESA_SHADER_TESS_CTRL]);
-   nr_ds_entries =
-      MIN2(nr_ds_entries, devinfo->urb.max_entries[MESA_SHADER_TESS_EVAL]);
-   nr_gs_entries =
-      MIN2(nr_gs_entries, devinfo->urb.max_entries[MESA_SHADER_GEOMETRY]);
-
-   /* Ensure that we program a multiple of the granularity. */
-   nr_vs_entries = ROUND_DOWN_TO(nr_vs_entries, vs_granularity);
-   nr_hs_entries = ROUND_DOWN_TO(nr_hs_entries, hs_granularity);
-   nr_ds_entries = ROUND_DOWN_TO(nr_ds_entries, ds_granularity);
-   nr_gs_entries = ROUND_DOWN_TO(nr_gs_entries, gs_granularity);
-
-   /* Finally, sanity check to make sure we have at least the minimum number
-    * of entries needed for each stage.
-    */
-   assert(nr_vs_entries >= vs_min_entries);
-   if (gs_present)
-      assert(nr_gs_entries >= 2);
-   if (tess_present) {
-      assert(nr_hs_entries >= 1);
-      assert(nr_ds_entries >= devinfo->urb.min_entries[MESA_SHADER_TESS_EVAL]);
+      /* Since we rounded up when computing wants[], this may be slightly
+       * more than the maximum allowed amount, so correct for that.
+       */
+      entries[i] = MIN2(entries[i], devinfo->urb.max_entries[i]);
+
+      /* Ensure that we program a multiple of the granularity. */
+      entries[i] = ROUND_DOWN_TO(entries[i], granularity[i]);
+
+      /* Finally, sanity check to make sure we have at least the minimum
+       * number of entries needed for each stage.
+       */
+      assert(entries[i] >= min_entries[i]);
    }
 
-   /* Lay out the URB in the following order:
-    * - push constants
-    * - VS
-    * - HS
-    * - DS
-    * - GS
-    */
-   unsigned vs_start = push_constant_chunks;
-   unsigned hs_start = push_constant_chunks + vs_chunks;
-   unsigned ds_start = push_constant_chunks + vs_chunks + hs_chunks;
-   unsigned gs_start = push_constant_chunks + vs_chunks + hs_chunks +
-                       ds_chunks;
+   /* Lay out the URB in pipeline order: push constants, VS, HS, DS, GS. */
+   unsigned start[4];
+   start[0] = push_constant_chunks;
+   for (int i = MESA_SHADER_TESS_CTRL; i <= MESA_SHADER_GEOMETRY; i++) {
+      start[i] = start[i - 1] + chunks[i - 1];
+   }
 
    if (brw->gen == 7 && !brw->is_haswell && !brw->is_baytrail)
       gen7_emit_vs_workaround_flush(brw);
-   gen7_emit_urb_state(brw,
-                       nr_vs_entries, vs_size, vs_start,
-                       nr_hs_entries, hs_size, hs_start,
-                       nr_ds_entries, ds_size, ds_start,
-                       nr_gs_entries, gs_size, gs_start);
+
+   BEGIN_BATCH(8);
+   for (int i = MESA_SHADER_VERTEX; i <= MESA_SHADER_GEOMETRY; i++) {
+      OUT_BATCH((_3DSTATE_URB_VS + i) << 16 | (2 - 2));
+      OUT_BATCH(entries[i] |
+                ((entry_size[i] - 1) << GEN7_URB_ENTRY_SIZE_SHIFT) |
+                (start[i] << GEN7_URB_STARTING_ADDRESS_SHIFT));
+   }
+   ADVANCE_BATCH();
 }
 
 const struct brw_tracked_state gen7_urb = {




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