diff options
| -rw-r--r-- | src/glsl/Makefile.sources | 1 | ||||
| -rw-r--r-- | src/glsl/nir/nir.h | 1 | ||||
| -rw-r--r-- | src/glsl/nir/nir_opcodes.h | 1 | ||||
| -rw-r--r-- | src/glsl/nir/nir_opt_peephole_ffma.c | 191 | ||||
| -rw-r--r-- | src/mesa/drivers/dri/i965/brw_fs_nir.cpp | 2 |
5 files changed, 196 insertions, 0 deletions
diff --git a/src/glsl/Makefile.sources b/src/glsl/Makefile.sources index 38ffb850807..31608dcb31e 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 5c0a1e50ff1..6a4b0fe511c 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 988f691f8d4..35d4634ec9a 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 00000000000..2c9b8e570d4 --- /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 ([email protected]) + * + */ + +#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->dest.dest.ssa.name); + + 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 22c8c0a39f5..9141dc68196 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); |