<div dir="ltr"> <div class="gmail_extra"> <div class="gmail_quote">On Wed, Dec 17, 2014 at 5:13 PM, Connor Abbott <<a href="mailto:cwabbott0@gmail.com" target="_blank">cwabbott0@gmail.com</a>> wrote:<blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">Would it be possible to drop this patch since this all gets deleted later? </blockquote><div> </div><div>We could, but I'd rather leave it in the history. </div><div>--Jason </div><div> </div><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"> <div><div class="h5"> On Tue, Dec 16, 2014 at 1:05 AM, Jason Ekstrand <<a href="mailto:jason@jlekstrand.net">jason@jlekstrand.net</a>> wrote: > --- > src/glsl/Makefile.sources | 1 + > src/glsl/nir/nir.h | 1 + > src/glsl/nir/nir_opcodes.h | 1 + > src/glsl/nir/nir_opt_peephole_ffma.c | 191 +++++++++++++++++++++++++++++++ > src/mesa/drivers/dri/i965/brw_fs_nir.cpp | 2 + > 5 files changed, 196 insertions(+) > create mode 100644 src/glsl/nir/nir_opt_peephole_ffma.c > > diff --git a/src/glsl/Makefile.sources b/src/glsl/Makefile.sources > index 38ffb85..31608dc 100644 > --- a/src/glsl/Makefile.sources > +++ b/src/glsl/Makefile.sources > @@ -32,6 +32,7 @@ NIR_FILES = \ > $(GLSL_SRCDIR)/nir/nir_opt_copy_propagate.c \ > $(GLSL_SRCDIR)/nir/nir_opt_dce.c \ > $(GLSL_SRCDIR)/nir/nir_opt_global_to_local.c \ > + $(GLSL_SRCDIR)/nir/nir_opt_peephole_ffma.c \ > $(GLSL_SRCDIR)/nir/nir_opt_peephole_select.c \ > $(GLSL_SRCDIR)/nir/nir_print.c \ > $(GLSL_SRCDIR)/nir/nir_remove_dead_variables.c \ > diff --git a/src/glsl/nir/nir.h b/src/glsl/nir/nir.h > index bc2280b..e20eb7c 100644 > --- a/src/glsl/nir/nir.h > +++ b/src/glsl/nir/nir.h > @@ -1374,6 +1374,7 @@ bool nir_opt_dce_impl(nir_function_impl *impl); > bool nir_opt_dce(nir_shader *shader); > > bool nir_opt_peephole_select(nir_shader *shader); > +bool nir_opt_peephole_ffma(nir_shader *shader); > > #ifdef __cplusplus > } /* extern "C" */ > diff --git a/src/glsl/nir/nir_opcodes.h b/src/glsl/nir/nir_opcodes.h > index 988f691..35d4634 100644 > --- a/src/glsl/nir/nir_opcodes.h > +++ b/src/glsl/nir/nir_opcodes.h > @@ -307,6 +307,7 @@ BINOP_HORIZ(vec2, 2, nir_type_unsigned, 1, nir_type_unsigned, 1, nir_type_unsign > ARR(src1_size, src2_size, src3_size), \ > ARR(nir_type_unsigned, nir_type_unsigned, nir_type_unsigned)) > > +/* fma(a, b, c) = (a * b) + c */ > TRIOP(ffma, nir_type_float) > > TRIOP(flrp, nir_type_float) > diff --git a/src/glsl/nir/nir_opt_peephole_ffma.c b/src/glsl/nir/nir_opt_peephole_ffma.c > new file mode 100644 > index 0000000..2c9b8e5 > --- /dev/null > +++ b/src/glsl/nir/nir_opt_peephole_ffma.c > @@ -0,0 +1,191 @@ > +/* > + * Copyright © 2014 Intel Corporation > + * > + * Permission is hereby granted, free of charge, to any person obtaining a > + * copy of this software and associated documentation files (the "Software"), > + * to deal in the Software without restriction, including without limitation > + * the rights to use, copy, modify, merge, publish, distribute, sublicense, > + * and/or sell copies of the Software, and to permit persons to whom the > + * Software is furnished to do so, subject to the following conditions: > + * > + * The above copyright notice and this permission notice (including the next > + * paragraph) shall be included in all copies or substantial portions of the > + * Software. > + * > + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR > + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, > + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL > + * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER > + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING > + * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS > + * IN THE SOFTWARE. > + * > + * Authors: > + * Jason Ekstrand (<a href="mailto:jason@jlekstrand.net">jason@jlekstrand.net</a>) > + * > + */ > + > +#include "nir.h" > + > +/* > + * Implements a small peephole optimization that looks for a multiply that > + * is only ever used in an add and replaces both with an fma. > + */ > + > +struct peephole_ffma_state { > + void *mem_ctx; > + nir_function_impl *impl; > + bool progress; > +}; > + > +static inline nir_alu_instr * > +get_mul_for_src(nir_alu_instr *add, unsigned idx) > +{ > + if (!add->src[idx].src.is_ssa) > + return NULL; > + > + /* We can't handle these in between the operations */ > + if (add->src[idx].negate || add->src[idx].abs) > + return NULL; > + > + nir_instr *instr = add->src[idx].src.ssa->parent_instr; > + if (instr->type != nir_instr_type_alu) > + return NULL; > + > + nir_alu_instr *mul = nir_instr_as_alu(instr); > + if (mul->op != nir_op_fmul) > + return NULL; > + > + /* Can't handle a saturate in between */ > + if (mul->dest.saturate) > + return NULL; > + > + /* We already know that the same source is not used twice in the add and > + * we will assume valid use-def information, so this check is sufficient > + */ > + if (mul->dest.dest.ssa.uses->entries > 1) > + return NULL; /* Not the only use */ > + > + return mul; > +} > + > +/* Copies (and maybe swizzles) the given ALU source */ > +static inline void > +copy_alu_src(void *mem_ctx, nir_alu_src *new_src, nir_alu_src old_src, > + uint8_t *swizzle) > +{ > + new_src->src = nir_src_copy(old_src.src, mem_ctx); > + new_src->abs = old_src.abs; > + new_src->negate = old_src.negate; > + > + if (swizzle == NULL) { > + memcpy(new_src->swizzle, old_src.swizzle, sizeof old_src.swizzle); > + } else { > + for (int i = 0; i < 4; ++i) { > + if (swizzle[i] < 4) > + new_src->swizzle[i] = old_src.swizzle[swizzle[i]]; > + } > + } > +} > + > +static bool > +nir_opt_peephole_ffma_block(nir_block *block, void *void_state) > +{ > + struct peephole_ffma_state *state = void_state; > + > + nir_foreach_instr_safe(block, instr) { > + if (instr->type != nir_instr_type_alu) > + continue; > + > + nir_alu_instr *add = nir_instr_as_alu(instr); > + if (add->op != nir_op_fadd) > + continue; > + > + /* TODO: Maybe bail if this expression is considered "precise"? */ > + > + /* This, is the case a + a. We would rather handle this with an > + * algebraic reduction than fuse it. Also, we want to only fuse > + * things where the multiply is used only once and, in this case, > + * it would be used twice by the same instruction. > + */ > + if (add->src[0].src.is_ssa && add->src[1].src.is_ssa && > + add->src[0].src.ssa == add->src[1].src.ssa) > + continue; > + > + nir_alu_instr *mul = get_mul_for_src(add, 0); > + unsigned mul_src = 0; > + > + if (mul == NULL) { > + mul = get_mul_for_src(add, 1); > + mul_src = 1; > + } > + > + if (mul == NULL) > + continue; > + > + nir_alu_instr *ffma = nir_alu_instr_create(state->mem_ctx, nir_op_ffma); > + ffma->dest.saturate = add->dest.saturate; > + ffma->dest.write_mask = add->dest.write_mask; > + > + copy_alu_src(state->mem_ctx, &ffma->src[0], mul->src[0], > + add->src[mul_src].swizzle); > + copy_alu_src(state->mem_ctx, &ffma->src[1], mul->src[1], > + add->src[mul_src].swizzle); > + copy_alu_src(state->mem_ctx, &ffma->src[2], add->src[1 - mul_src], NULL); > + > + if (add->dest.dest.is_ssa) { > + ffma->dest.dest.is_ssa = true; > + nir_ssa_def_init(state->impl, &ffma->instr, &ffma->dest.dest.ssa, > + add->dest.dest.ssa.num_components, > + add-><a href="http://dest.dest.ssa.name" target="_blank">dest.dest.ssa.name</a>); > + > + nir_src ffma_dest_src = { > + .is_ssa = true, > + .ssa = &ffma->dest.dest.ssa, > + }; > + nir_ssa_def_rewrite_uses(&add->dest.dest.ssa, ffma_dest_src, > + state->mem_ctx); > + } else { > + ffma->dest.dest = nir_dest_copy(add->dest.dest, state->mem_ctx); > + } > + > + nir_instr_insert_before(&add->instr, &ffma->instr); > + nir_instr_remove(&add->instr); > + nir_instr_remove(&mul->instr); > + > + state->progress = true; > + } > + > + return true; > +} > + > +static bool > +nir_opt_peephole_ffma_impl(nir_function_impl *impl) > +{ > + struct peephole_ffma_state state; > + > + state.mem_ctx = ralloc_parent(impl); > + state.impl = impl; > + state.progress = false; > + > + nir_foreach_block(impl, nir_opt_peephole_ffma_block, &state); > + > + if (state.progress) > + nir_metadata_dirty(impl, nir_metadata_block_index | > + nir_metadata_dominance); > + > + return state.progress; > +} > + > +bool > +nir_opt_peephole_ffma(nir_shader *shader) > +{ > + bool progress = false; > + > + nir_foreach_overload(shader, overload) { > + if (overload->impl) > + progress |= nir_opt_peephole_ffma_impl(overload->impl); > + } > + > + return progress; > +} > diff --git a/src/mesa/drivers/dri/i965/brw_fs_nir.cpp b/src/mesa/drivers/dri/i965/brw_fs_nir.cpp > index b2c5863..b6720af 100644 > --- a/src/mesa/drivers/dri/i965/brw_fs_nir.cpp > +++ b/src/mesa/drivers/dri/i965/brw_fs_nir.cpp > @@ -63,6 +63,8 @@ fs_visitor::emit_nir_code() > nir_validate_shader(nir); > nir_opt_peephole_select(nir); > nir_validate_shader(nir); > + nir_opt_peephole_ffma(nir); > + nir_validate_shader(nir); > nir_print_shader(nir, stderr); > > nir_convert_from_ssa(nir); > -- > 2.2.0 > </div></div>> _______________________________________________ > mesa-dev mailing list > <a href="mailto:mesa-dev@lists.freedesktop.org">mesa-dev@lists.freedesktop.org</a> > <a href="http://lists.freedesktop.org/mailman/listinfo/mesa-dev" target="_blank">http://lists.freedesktop.org/mailman/listinfo/mesa-dev</a> </blockquote></div></div></div>