Previously, UBOs were implemented using global memory loads for compute on
Kepler+ because it only supported 8 constant buffers on compute. This
required bounds checking and expensive load instructions.
However 6 of the constant buffer bindings were left unused, this uses them
instead of loading from global memory in the shader for the first 6
non-user constant buffers when possible.
total instructions in shared programs : 5787979 -> 5748677 (-0.68%)
total gprs used in shared programs : 669901 -> 669373 (-0.08%)
total shared used in shared programs : 548832 -> 548832 (0.00%)
total local used in shared programs : 21068 -> 21064 (-0.02%)
local shared gpr inst bytes
helped 1 0 152 274 274
hurt 0 0 0 0 0
Signed-off-by: Rhys Perry <pendingchao...@gmail.com>
---
.../nouveau/codegen/nv50_ir_lowering_nvc0.cpp | 18 +++++++-------
src/gallium/drivers/nouveau/nvc0/nve4_compute.c | 28 ++++++++++++++++++++++
2 files changed, 36 insertions(+), 10 deletions(-)
diff --git a/src/gallium/drivers/nouveau/codegen/nv50_ir_lowering_nvc0.cpp
b/src/gallium/drivers/nouveau/codegen/nv50_ir_lowering_nvc0.cpp
index 1410cf26c8..0fba96f261 100644
--- a/src/gallium/drivers/nouveau/codegen/nv50_ir_lowering_nvc0.cpp
+++ b/src/gallium/drivers/nouveau/codegen/nv50_ir_lowering_nvc0.cpp
@@ -2437,18 +2437,16 @@ NVC0LoweringPass::handleLDST(Instruction *i)
assert(prog->getType() != Program::TYPE_FRAGMENT); // INTERP
}
} else if (i->src(0).getFile() == FILE_MEMORY_CONST) {
+ int8_t fileIndex = i->getSrc(0)->reg.fileIndex - 1;
+ Value *ind = i->getIndirect(0, 1);
+
if (targ->getChipset() >= NVISA_GK104_CHIPSET &&
- prog->getType() == Program::TYPE_COMPUTE) {
+ prog->getType() == Program::TYPE_COMPUTE &&
+ (fileIndex >= 6 || ind)) {
// The launch descriptor only allows to set up 8 CBs, but OpenGL
- // requires at least 12 UBOs. To bypass this limitation, we store the
- // addrs into the driver constbuf and we directly load from the global
- // memory.
- int8_t fileIndex = i->getSrc(0)->reg.fileIndex - 1;
- Value *ind = i->getIndirect(0, 1);
-
- if (!ind && fileIndex == -1)
- return;
-
+ // requires at least 12 UBOs. To bypass this limitation, for constant
+ // buffers 7+, we store the addrs into the driver constbuf and we
+ // directly load from the global memory.
if (ind) {
// Clamp the UBO index when an indirect access is used to avoid
// loading information from the wrong place in the driver cb.
diff --git a/src/gallium/drivers/nouveau/nvc0/nve4_compute.c
b/src/gallium/drivers/nouveau/nvc0/nve4_compute.c
index 28460f8cbe..8aa8d4936f 100644
--- a/src/gallium/drivers/nouveau/nvc0/nve4_compute.c
+++ b/src/gallium/drivers/nouveau/nvc0/nve4_compute.c
@@ -551,6 +551,30 @@ nve4_compute_derive_cache_split(struct nvc0_context *nvc0,
uint32_t shared_size)
return NVC1_3D_CACHE_SPLIT_16K_SHARED_48K_L1;
}
+static void
+nve4_compute_setup_buf_cb(struct nvc0_context *nvc0, bool gp100, void *desc)
+{
+ // only user constant buffers 1-6 can be put in the descriptor, the rest are
+ // loaded through global memory
+ for (int i = 1; i <= 6; i++) {
+ if (nvc0->constbuf[5][i].user || !nvc0->constbuf[5][i].u.buf)
+ continue;
+
+ struct nv04_resource *res =
+ nv04_resource(nvc0->constbuf[5][i].u.buf);
+
+ uint32_t base = res->offset + nvc0->constbuf[5][i].offset;
+ uint32_t size = nvc0->constbuf[5][i].size;
+ if (gp100)
+ gp100_cp_launch_desc_set_cb(desc, i, res->bo, base, size);
+ else
+ nve4_cp_launch_desc_set_cb(desc, i, res->bo, base, size);
+ }
+
+ // there is no need to do FLUSH(NVE4_COMPUTE_FLUSH_CB) because
+ // nve4_compute_upload_input() does it later
+}
+
static void
nve4_compute_setup_launch_desc(struct nvc0_context *nvc0,
struct nve4_cp_launch_desc *desc,
@@ -588,6 +612,8 @@ nve4_compute_setup_launch_desc(struct nvc0_context *nvc0,
}
nve4_cp_launch_desc_set_cb(desc, 7, screen->uniform_bo,
NVC0_CB_AUX_INFO(5), 1 << 11);
+
+ nve4_compute_setup_buf_cb(nvc0, false, desc);
}
static void
@@ -626,6 +652,8 @@ gp100_compute_setup_launch_desc(struct nvc0_context *nvc0,
}
gp100_cp_launch_desc_set_cb(desc, 7, screen->uniform_bo,
NVC0_CB_AUX_INFO(5), 1 << 11);
+
+ nve4_compute_setup_buf_cb(nvc0, true, desc);
}
static inline void *
--
2.14.4
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