[Mesa-dev] [PATCH 3/9] nir/opt_peephole_select: Don't peephole_select expensive math instructions
Ian Romanick
idr at freedesktop.org
Thu Aug 30 05:35:42 UTC 2018
From: Ian Romanick <ian.d.romanick at intel.com>
On some GPUs, especially older Intel GPUs, some math instructions are
very expensive. On those architectures, don't reduce flow control to a
csel if one of the branches contains one of these expensive math
instructions.
This prevents a bunch of cycle count regressions on pre-Gen6 platforms
with a later patch (intel/compiler: More peephole select for pre-Gen6).
Signed-off-by: Ian Romanick <ian.d.romanick at intel.com>
---
src/amd/vulkan/radv_shader.c | 2 +-
src/broadcom/compiler/nir_to_vir.c | 2 +-
src/compiler/nir/nir.h | 2 +-
src/compiler/nir/nir_opt_peephole_select.c | 46 +++++++++++++++++++++++-----
src/gallium/drivers/freedreno/ir3/ir3_nir.c | 2 +-
src/gallium/drivers/radeonsi/si_shader_nir.c | 2 +-
src/gallium/drivers/vc4/vc4_program.c | 2 +-
src/intel/compiler/brw_nir.c | 4 +--
src/mesa/state_tracker/st_glsl_to_nir.cpp | 2 +-
9 files changed, 47 insertions(+), 17 deletions(-)
diff --git a/src/amd/vulkan/radv_shader.c b/src/amd/vulkan/radv_shader.c
index 632512db09b..c8d502a9e3a 100644
--- a/src/amd/vulkan/radv_shader.c
+++ b/src/amd/vulkan/radv_shader.c
@@ -143,7 +143,7 @@ radv_optimize_nir(struct nir_shader *shader, bool optimize_conservatively)
NIR_PASS(progress, shader, nir_opt_if);
NIR_PASS(progress, shader, nir_opt_dead_cf);
NIR_PASS(progress, shader, nir_opt_cse);
- NIR_PASS(progress, shader, nir_opt_peephole_select, 8, true);
+ NIR_PASS(progress, shader, nir_opt_peephole_select, 8, true, true);
NIR_PASS(progress, shader, nir_opt_algebraic);
NIR_PASS(progress, shader, nir_opt_constant_folding);
NIR_PASS(progress, shader, nir_opt_undef);
diff --git a/src/broadcom/compiler/nir_to_vir.c b/src/broadcom/compiler/nir_to_vir.c
index 0d23cea4d5b..ec0ff4b907a 100644
--- a/src/broadcom/compiler/nir_to_vir.c
+++ b/src/broadcom/compiler/nir_to_vir.c
@@ -1210,7 +1210,7 @@ v3d_optimize_nir(struct nir_shader *s)
NIR_PASS(progress, s, nir_opt_dce);
NIR_PASS(progress, s, nir_opt_dead_cf);
NIR_PASS(progress, s, nir_opt_cse);
- NIR_PASS(progress, s, nir_opt_peephole_select, 8, true);
+ NIR_PASS(progress, s, nir_opt_peephole_select, 8, true, true);
NIR_PASS(progress, s, nir_opt_algebraic);
NIR_PASS(progress, s, nir_opt_constant_folding);
NIR_PASS(progress, s, nir_opt_undef);
diff --git a/src/compiler/nir/nir.h b/src/compiler/nir/nir.h
index 67fa46d5557..feb69be6b59 100644
--- a/src/compiler/nir/nir.h
+++ b/src/compiler/nir/nir.h
@@ -3003,7 +3003,7 @@ bool nir_opt_move_comparisons(nir_shader *shader);
bool nir_opt_move_load_ubo(nir_shader *shader);
bool nir_opt_peephole_select(nir_shader *shader, unsigned limit,
- bool indirect_load_ok);
+ bool indirect_load_ok, bool expensive_alu_ok);
bool nir_opt_remove_phis_impl(nir_function_impl *impl);
bool nir_opt_remove_phis(nir_shader *shader);
diff --git a/src/compiler/nir/nir_opt_peephole_select.c b/src/compiler/nir/nir_opt_peephole_select.c
index 6808d3eda6c..09b55f3739e 100644
--- a/src/compiler/nir/nir_opt_peephole_select.c
+++ b/src/compiler/nir/nir_opt_peephole_select.c
@@ -59,7 +59,8 @@
static bool
block_check_for_allowed_instrs(nir_block *block, unsigned *count,
- bool alu_ok, bool indirect_load_ok)
+ bool alu_ok, bool indirect_load_ok,
+ bool expensive_alu_ok)
{
nir_foreach_instr(instr, block) {
switch (instr->type) {
@@ -117,6 +118,25 @@ block_check_for_allowed_instrs(nir_block *block, unsigned *count,
case nir_op_vec3:
case nir_op_vec4:
break;
+
+ case nir_op_fcos:
+ case nir_op_fdiv:
+ case nir_op_fexp2:
+ case nir_op_flog2:
+ case nir_op_fmod:
+ case nir_op_fpow:
+ case nir_op_frcp:
+ case nir_op_frem:
+ case nir_op_frsq:
+ case nir_op_fsin:
+ case nir_op_idiv:
+ case nir_op_irem:
+ case nir_op_udiv:
+ if (!alu_ok || !expensive_alu_ok)
+ return false;
+
+ break;
+
default:
if (!alu_ok) {
/* It must be a move-like operation. */
@@ -160,7 +180,8 @@ block_check_for_allowed_instrs(nir_block *block, unsigned *count,
static bool
nir_opt_peephole_select_block(nir_block *block, nir_shader *shader,
- unsigned limit, bool indirect_load_ok)
+ unsigned limit, bool indirect_load_ok,
+ bool expensive_alu_ok)
{
if (nir_cf_node_is_first(&block->cf_node))
return false;
@@ -180,10 +201,17 @@ nir_opt_peephole_select_block(nir_block *block, nir_shader *shader,
/* ... and those blocks must only contain "allowed" instructions. */
unsigned count = 0;
+#if 1
if (!block_check_for_allowed_instrs(then_block, &count, limit != 0,
- indirect_load_ok) ||
+ indirect_load_ok, expensive_alu_ok) ||
!block_check_for_allowed_instrs(else_block, &count, limit != 0,
- indirect_load_ok))
+ indirect_load_ok, expensive_alu_ok))
+#else
+ if (!block_check_for_allowed_instrs(then_block, &count, shader->info.stage,
+ limit != 0, indirect_load_ok, expensive_alu_ok) ||
+ !block_check_for_allowed_instrs(else_block, &count, shader->info.stage,
+ limit != 0, indirect_load_ok, expensive_alu_ok))
+#endif
return false;
if (count > limit)
@@ -250,14 +278,15 @@ nir_opt_peephole_select_block(nir_block *block, nir_shader *shader,
static bool
nir_opt_peephole_select_impl(nir_function_impl *impl, unsigned limit,
- bool indirect_load_ok)
+ bool indirect_load_ok, bool expensive_alu_ok)
{
nir_shader *shader = impl->function->shader;
bool progress = false;
nir_foreach_block_safe(block, impl) {
progress |= nir_opt_peephole_select_block(block, shader, limit,
- indirect_load_ok);
+ indirect_load_ok,
+ expensive_alu_ok);
}
if (progress)
@@ -268,14 +297,15 @@ nir_opt_peephole_select_impl(nir_function_impl *impl, unsigned limit,
bool
nir_opt_peephole_select(nir_shader *shader, unsigned limit,
- bool indirect_load_ok)
+ bool indirect_load_ok, bool expensive_alu_ok)
{
bool progress = false;
nir_foreach_function(function, shader) {
if (function->impl)
progress |= nir_opt_peephole_select_impl(function->impl, limit,
- indirect_load_ok);
+ indirect_load_ok,
+ expensive_alu_ok);
}
return progress;
diff --git a/src/gallium/drivers/freedreno/ir3/ir3_nir.c b/src/gallium/drivers/freedreno/ir3/ir3_nir.c
index 5f66ef5d170..bb3bb73644a 100644
--- a/src/gallium/drivers/freedreno/ir3/ir3_nir.c
+++ b/src/gallium/drivers/freedreno/ir3/ir3_nir.c
@@ -107,7 +107,7 @@ ir3_optimize_loop(nir_shader *s)
progress |= OPT(s, nir_opt_gcm, true);
else if (gcm == 2)
progress |= OPT(s, nir_opt_gcm, false);
- progress |= OPT(s, nir_opt_peephole_select, 16, true);
+ progress |= OPT(s, nir_opt_peephole_select, 16, true, true);
progress |= OPT(s, nir_opt_intrinsics);
progress |= OPT(s, nir_opt_algebraic);
progress |= OPT(s, nir_opt_constant_folding);
diff --git a/src/gallium/drivers/radeonsi/si_shader_nir.c b/src/gallium/drivers/radeonsi/si_shader_nir.c
index 9a7a8264283..cb1e208be8f 100644
--- a/src/gallium/drivers/radeonsi/si_shader_nir.c
+++ b/src/gallium/drivers/radeonsi/si_shader_nir.c
@@ -813,7 +813,7 @@ si_lower_nir(struct si_shader_selector* sel)
NIR_PASS(progress, sel->nir, nir_opt_if);
NIR_PASS(progress, sel->nir, nir_opt_dead_cf);
NIR_PASS(progress, sel->nir, nir_opt_cse);
- NIR_PASS(progress, sel->nir, nir_opt_peephole_select, 8, true);
+ NIR_PASS(progress, sel->nir, nir_opt_peephole_select, 8, true, true);
/* Needed for algebraic lowering */
NIR_PASS(progress, sel->nir, nir_opt_algebraic);
diff --git a/src/gallium/drivers/vc4/vc4_program.c b/src/gallium/drivers/vc4/vc4_program.c
index 39f7db9148c..fa2a32922f4 100644
--- a/src/gallium/drivers/vc4/vc4_program.c
+++ b/src/gallium/drivers/vc4/vc4_program.c
@@ -1580,7 +1580,7 @@ vc4_optimize_nir(struct nir_shader *s)
NIR_PASS(progress, s, nir_opt_dce);
NIR_PASS(progress, s, nir_opt_dead_cf);
NIR_PASS(progress, s, nir_opt_cse);
- NIR_PASS(progress, s, nir_opt_peephole_select, 8, true);
+ NIR_PASS(progress, s, nir_opt_peephole_select, 8, true, true);
NIR_PASS(progress, s, nir_opt_algebraic);
NIR_PASS(progress, s, nir_opt_constant_folding);
NIR_PASS(progress, s, nir_opt_undef);
diff --git a/src/intel/compiler/brw_nir.c b/src/intel/compiler/brw_nir.c
index 1d65107a93d..04d399fd0b4 100644
--- a/src/intel/compiler/brw_nir.c
+++ b/src/intel/compiler/brw_nir.c
@@ -587,9 +587,9 @@ brw_nir_optimize(nir_shader *nir, const struct brw_compiler *compiler,
const bool is_vec4_tessellation = !is_scalar &&
(nir->info.stage == MESA_SHADER_TESS_CTRL ||
nir->info.stage == MESA_SHADER_TESS_EVAL);
- OPT(nir_opt_peephole_select, 0, is_vec4_tessellation);
+ OPT(nir_opt_peephole_select, 0, is_vec4_tessellation, false);
if (compiler->devinfo->gen >= 6)
- OPT(nir_opt_peephole_select, 1, is_vec4_tessellation);
+ OPT(nir_opt_peephole_select, 1, is_vec4_tessellation, true);
OPT(nir_opt_intrinsics);
OPT(nir_opt_algebraic);
diff --git a/src/mesa/state_tracker/st_glsl_to_nir.cpp b/src/mesa/state_tracker/st_glsl_to_nir.cpp
index bfcef3a293f..098a1e98833 100644
--- a/src/mesa/state_tracker/st_glsl_to_nir.cpp
+++ b/src/mesa/state_tracker/st_glsl_to_nir.cpp
@@ -344,7 +344,7 @@ st_nir_opts(nir_shader *nir, bool scalar)
NIR_PASS(progress, nir, nir_opt_if);
NIR_PASS(progress, nir, nir_opt_dead_cf);
NIR_PASS(progress, nir, nir_opt_cse);
- NIR_PASS(progress, nir, nir_opt_peephole_select, 8, true);
+ NIR_PASS(progress, nir, nir_opt_peephole_select, 8, true, true);
NIR_PASS(progress, nir, nir_opt_algebraic);
NIR_PASS(progress, nir, nir_opt_constant_folding);
--
2.14.4
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