[Mesa-dev] [PATCH 110/133] nir: Add an expression matching framework
Jason Ekstrand
jason at jlekstrand.net
Mon Jan 5 22:00:08 PST 2015
On Mon, Jan 5, 2015 at 9:12 PM, Connor Abbott <cwabbott0 at gmail.com> wrote:
> Hi,
>
> Was it your intention to not support non-per-component things like dot
> product at all? I've made a few inline comments about how to do it,
> and it doesn't seem like it's that hard.
>
No, It was just never tested on them. All your comments seem valid
enough. I'll try and incorperate them.
>
> On Tue, Dec 16, 2014 at 1:12 AM, Jason Ekstrand <jason at jlekstrand.net>
> wrote:
> >
> > This framework provides a simple way to do simple search-and-replace
> > operations on NIR code. The nir_search.h header provides four simple
> data
> > structures for representing expressions: nir_value and four subtypes:
> > nir_variable, nir_constant, and nir_expression. An expression tree can
>
> Make these be the actual names (nir_search_value, nir_search_variable,
> etc.)
>
Yeah, no problem.
>
> > then be represented by nesting these data structures as needed. The
> > nir_replace_instr function takes an instruction, an expression, and a
> > value; if the instruction matches the expression, it is replaced with a
> new
> > chain of instructions to generate the given replacement value. The
> > framework keeps track of swizzles on sources and automatically generates
> > the currect swizzles for the replacement value.
> > ---
> > src/glsl/Makefile.sources | 2 +
> > src/glsl/nir/nir_search.c | 337
> ++++++++++++++++++++++++++++++++++++++++++++++
> > src/glsl/nir/nir_search.h | 80 +++++++++++
> > 3 files changed, 419 insertions(+)
> > create mode 100644 src/glsl/nir/nir_search.c
> > create mode 100644 src/glsl/nir/nir_search.h
> >
> > diff --git a/src/glsl/Makefile.sources b/src/glsl/Makefile.sources
> > index 12c1d83..201330d 100644
> > --- a/src/glsl/Makefile.sources
> > +++ b/src/glsl/Makefile.sources
> > @@ -41,6 +41,8 @@ NIR_FILES = \
> > $(GLSL_SRCDIR)/nir/nir_opt_peephole_select.c \
> > $(GLSL_SRCDIR)/nir/nir_print.c \
> > $(GLSL_SRCDIR)/nir/nir_remove_dead_variables.c \
> > + $(GLSL_SRCDIR)/nir/nir_search.c \
> > + $(GLSL_SRCDIR)/nir/nir_search.h \
> > $(GLSL_SRCDIR)/nir/nir_split_var_copies.c \
> > $(GLSL_SRCDIR)/nir/nir_to_ssa.c \
> > $(GLSL_SRCDIR)/nir/nir_validate.c \
> > diff --git a/src/glsl/nir/nir_search.c b/src/glsl/nir/nir_search.c
> > new file mode 100644
> > index 0000000..257a53b
> > --- /dev/null
> > +++ b/src/glsl/nir/nir_search.c
> > @@ -0,0 +1,337 @@
> > +/*
> > + * 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 (jason at jlekstrand.net)
> > + *
> > + */
> > +
> > +#include "nir_search.h"
> > +
> > +struct match_state {
> > + unsigned variables_seen;
> > + nir_alu_src variables[NIR_SEARCH_MAX_VARIABLES];
> > +};
> > +
> > +static bool
> > +is_commutative_binop(nir_op op)
> > +{
> > + switch (op) {
> > + case nir_op_fadd:
> > + case nir_op_iadd:
> > + case nir_op_fmul:
> > + case nir_op_imul:
> > + case nir_op_imul_high:
> > + case nir_op_umul_high:
> > + case nir_op_feq:
> > + case nir_op_fne:
> > + case nir_op_ieq:
> > + case nir_op_ine:
> > + case nir_op_fand:
> > + case nir_op_for:
> > + case nir_op_fxor:
> > + case nir_op_iand:
> > + case nir_op_ior:
> > + case nir_op_ixor:
> > + case nir_op_fmin:
> > + case nir_op_fmax:
> > + case nir_op_imin:
> > + case nir_op_imax:
> > + case nir_op_umin:
> > + case nir_op_umax:
> > + return true;
> > + default:
> > + return false;
> > + }
> > +}
> > +
> > +static bool
> > +match_expression(const nir_search_expression *expr, nir_alu_instr
> *instr,
> > + unsigned num_components, const uint8_t *swizzle,
> > + struct match_state *state);
> > +
> > +static bool
> > +match_value(const nir_search_value *value, nir_alu_instr *instr,
> unsigned src,
> > + unsigned num_components, const uint8_t *swizzle,
> > + struct match_state *state)
> > +{
> > + uint8_t new_swizzle[4];
> > +
> > + for (int i = 0; i < num_components; ++i)
> > + new_swizzle[i] = instr->src[src].swizzle[swizzle[i]];
> > +
> > + switch (value->type) {
> > + case nir_search_value_expression:
> > + if (!instr->src[src].src.is_ssa)
> > + return false;
> > +
> > + if (instr->src[src].src.ssa->parent_instr->type !=
> nir_instr_type_alu)
> > + return false;
> > +
> > + return match_expression(nir_search_value_as_expression(value),
> > +
> nir_instr_as_alu(instr->src[src].src.ssa->parent_instr),
> > + num_components, new_swizzle, state);
> > +
> > + case nir_search_value_variable: {
> > + nir_search_variable *var = nir_search_value_as_variable(value);
> > +
> > + if (state->variables_seen & (1 << var->variable)) {
> > + if (!nir_srcs_equal(state->variables[0].src,
> instr->src[src].src))
>
> I think you meant state->variables[var->variable].src here.
>
Yes, I think you're right. Kind of curious that this worked...
>
> >
> > + return false;
> >
> > +
> > + assert(!instr->src[src].abs && !instr->src[src].negate);
> > +
> > + for (int i = 0; i < num_components; ++i) {
> > + if (state->variables[var->variable].swizzle[i] !=
> new_swizzle[i])
> > + return false;
> > + }
> > +
> > + return true;
> > + } else {
> > + state->variables_seen |= (1 << var->variable);
> > + state->variables[var->variable].src = instr->src[src].src;
> > + state->variables[var->variable].abs = false;
> > + state->variables[var->variable].negate = false;
> > +
> > + for (int i = 0; i < 4; ++i) {
> > + if (i < num_components)
> > + state->variables[var->variable].swizzle[i] =
> new_swizzle[i];
> > + else
> > + state->variables[var->variable].swizzle[i] = 0;
> > + }
> > +
> > + return true;
> > + }
> > + }
> > +
> > + case nir_search_value_constant: {
> > + nir_search_constant *const_val =
> nir_search_value_as_constant(value);
> > +
> > + if (!instr->src[src].src.is_ssa)
> > + return false;
> > +
> > + if (instr->src[src].src.ssa->parent_instr->type !=
> nir_instr_type_load_const)
> > + return false;
> > +
> > + nir_load_const_instr *load =
> > + nir_instr_as_load_const(instr->src[src].src.ssa->parent_instr);
> > +
> > + switch (nir_op_infos[instr->op].input_types[src]) {
> > + case nir_type_float:
> > + for (unsigned i = 0; i < num_components; ++i) {
> > + if (load->value.f[new_swizzle[i]] != const_val->data.f)
> > + return false;
> > + }
> > + return true;
> > + case nir_type_int:
> > + case nir_type_unsigned:
> > + case nir_type_bool:
> > + for (unsigned i = 0; i < num_components; ++i) {
> > + if (load->value.i[new_swizzle[i]] != const_val->data.i)
> > + return false;
> > + }
> > + return true;
> > + default:
> > + unreachable("Invalid alu source type");
> > + }
> > + }
> > +
> > + default:
> > + unreachable("Invalid search value type");
> > + }
> > +}
> > +
> > +static bool
> > +match_expression(const nir_search_expression *expr, nir_alu_instr
> *instr,
> > + unsigned num_components, const uint8_t *swizzle,
> > + struct match_state *state)
> > +{
> > + if (instr->op != expr->opcode)
> > + return false;
> > +
> > + assert(!instr->dest.saturate);
> > + assert(nir_op_infos[instr->op].num_inputs > 0);
>
>
> If the instruction has a sized destination, we ought to bail out if
> the swizzle isn't the identity or num_components isn't equal to the
> identity for those components. Alternately, we could assert that the
> only instructions with non-per-component destinations are at the root,
> since it doesn't seem like there are that many optimizations with a
> non-per-component instruction like "dot" or "any" that's not at the
> root of the tree.
>
Good point.
> > +
> > + bool matched = true;
> > + for (unsigned i = 0; i < nir_op_infos[instr->op].num_inputs; i++) {
> > + if (!match_value(expr->srcs[i], instr, i, num_components,
> > + swizzle, state)) {
>
>
> I think we need to pass in the correct number of components if the
> source isn't per-component, since if we don't any optimizations
> involving dot products will be totally broken. Similarly, I think we
> need to reset the swizzle to the identity here for non-per-component
> inputs.
>
Right
>
> >
> > + matched = false;
> > + break;
> > + }
> > + }
> > +
> > + if (matched)
> > + return true;
> > +
> > + if (is_commutative_binop(instr->op)) {
> > + if (!match_value(expr->srcs[0], instr, 1, num_components,
> > + swizzle, state))
> > + return false;
> > +
> > + return match_value(expr->srcs[1], instr, 0, num_components,
> > + swizzle, state);
> > + } else {
> > + return false;
> > + }
> > +}
> > +
> > +static nir_alu_src
> > +construct_value(const nir_search_value *value, nir_alu_type type,
> > + unsigned num_components, struct match_state *state,
> > + nir_instr *instr, void *mem_ctx)
> > +{
> > + switch (value->type) {
> > + case nir_search_value_expression: {
> > + const nir_search_expression *expr =
> nir_search_value_as_expression(value);
> > +
> > + nir_alu_instr *alu = nir_alu_instr_create(mem_ctx, expr->opcode);
> > + alu->dest.dest.is_ssa = true;
> > + nir_ssa_def_init(&alu->instr, &alu->dest.dest.ssa,
> num_components, NULL);
> > + alu->dest.write_mask = (1 << num_components) - 1;
> > + alu->dest.saturate = false;
> > +
> > + for (unsigned i = 0; i < nir_op_infos[expr->opcode].num_inputs;
> i++) {
> > + alu->src[i] = construct_value(expr->srcs[i],
> > +
> nir_op_infos[alu->op].input_types[i],
> > + num_components,
> > + state, instr, mem_ctx);
>
> Similarly to my earlier comment, we need to set num_components
> correctly here if the source is not per-component.
>
Yup
>
> > + }
> > +
> > + nir_instr_insert_before(instr, &alu->instr);
> > +
> > + nir_alu_src val = {
> > + .src.is_ssa = true,
> > + .src.ssa = &alu->dest.dest.ssa,
> > + .negate = false,
> > + .abs = false,
> > + .swizzle = { 0, 0, 0, 0 }
> > + };
> > +
> > + /* No swizzling, but we can't have a swizzle value higher than
> > + * num_components or the validator will get cranky.
> > + */
> > + for (unsigned i = 0; i < num_components; ++i)
> > + val.swizzle[i] = i;
>
>
> The validator only checks swizzle values that are actually being used,
> so we can just do
>
> .swizzle = {0, 1, 2, 3}
>
> here and it should be fine.
>
Yeah, that should be ok.
>
> >
> > +
> > + return val;
> > + }
> > +
> > + case nir_search_value_variable: {
> > + const nir_search_variable *var =
> nir_search_value_as_variable(value);
> > + assert(state->variables_seen & (1 << var->variable));
> > +
> > + nir_alu_src val = state->variables[var->variable];
> > + val.src = nir_src_copy(val.src, mem_ctx);
> > +
> > + return val;
> > + }
> > +
> > + case nir_search_value_constant: {
> > + const nir_search_constant *c =
> nir_search_value_as_constant(value);
> > + nir_load_const_instr *load = nir_load_const_instr_create(mem_ctx);
> > + load->dest.is_ssa = true;
> > + nir_ssa_def_init(&load->instr, &load->dest.ssa, 1, NULL);
> > +
> > + switch (type) {
> > + case nir_type_float:
> > + load->dest.ssa.name = ralloc_asprintf(mem_ctx, "%f",
> c->data.f);
> > + load->value.f[0] = c->data.f;
> > + break;
> > + case nir_type_int:
> > + load->dest.ssa.name = ralloc_asprintf(mem_ctx, "%d",
> c->data.i);
> > + load->value.i[0] = c->data.i;
> > + break;
> > + case nir_type_unsigned:
> > + case nir_type_bool:
> > + load->value.u[0] = c->data.u;
> > + break;
> > + default:
> > + unreachable("Invalid alu source type");
> > + }
> > +
> > + nir_instr_insert_before(instr, &load->instr);
> > +
> > + nir_alu_src val = {
> > + .src.is_ssa = true,
> > + .src.ssa = &load->dest.ssa,
> > + .negate = false,
> > + .abs = false,
> > + .swizzle = { 0, 0, 0, 0 } /* Splatted scalar */
> > + };
> > +
> > + return val;
> > + }
> > +
> > + default:
> > + unreachable("Invalid search value type");
> > + }
> > +}
> > +
> > +nir_alu_instr *
> > +nir_replace_instr(nir_alu_instr *instr, const nir_search_expression
> *search,
> > + const nir_search_value *replace, void *mem_ctx)
> > +{
> > + uint8_t swizzle[4] = { 0, 0, 0, 0 };
> > +
> > + for (unsigned i = 0; i < instr->dest.dest.ssa.num_components; ++i)
> > + swizzle[i] = i;
> > +
> > + assert(instr->dest.dest.is_ssa);
> > +
> > + struct match_state state;
> > + state.variables_seen = 0;
> > +
> > + if (!match_expression(search, instr,
> instr->dest.dest.ssa.num_components,
> > + swizzle, &state))
> > + return NULL;
> > +
> > + /* Inserting a mov may be unnecessary. However, it's much easier to
> > + * simply let copy propagation clean this up than to try to go
> through
> > + * and rewrite swizzles ourselves.
> > + */
> > + nir_alu_instr *mov = nir_alu_instr_create(mem_ctx, nir_op_imov);
> > + mov->dest.write_mask = instr->dest.write_mask;
> > + mov->dest.dest.is_ssa = true;
> > + nir_ssa_def_init(&mov->instr, &mov->dest.dest.ssa,
> > + instr->dest.dest.ssa.num_components, NULL);
> > +
> > + mov->src[0] = construct_value(replace,
> nir_op_infos[instr->op].output_type,
> > + instr->dest.dest.ssa.num_components,
> &state,
> > + &instr->instr, mem_ctx);
> > + nir_instr_insert_before(&instr->instr, &mov->instr);
> > +
> > + nir_src replace_src = {
> > + .is_ssa = true,
> > + .ssa = &mov->dest.dest.ssa,
> > + };
> > +
> > + nir_ssa_def_rewrite_uses(&instr->dest.dest.ssa, replace_src,
> mem_ctx);
> > +
> > + /* We know this one has no more uses because we just rewrote them
> all,
> > + * so we can remove it. The rest of the matched expression,
> however, we
> > + * don't know so much about. We'll just let dead code clean them up.
> > + */
> > + nir_instr_remove(&instr->instr);
> > +
> > + return mov;
> > +}
> > diff --git a/src/glsl/nir/nir_search.h b/src/glsl/nir/nir_search.h
> > new file mode 100644
> > index 0000000..8ec58b0
> > --- /dev/null
> > +++ b/src/glsl/nir/nir_search.h
> > @@ -0,0 +1,80 @@
> > +/*
> > + * 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 (jason at jlekstrand.net)
> > + *
> > + */
> > +
> > +#ifndef _NIR_SEARCH_
> > +#define _NIR_SEARCH_
> > +
> > +#include "nir.h"
> > +
> > +#define NIR_SEARCH_MAX_VARIABLES 16
> > +
> > +typedef enum {
> > + nir_search_value_expression,
> > + nir_search_value_variable,
> > + nir_search_value_constant,
> > +} nir_search_value_type;
> > +
> > +typedef struct {
> > + nir_search_value_type type;
> > +} nir_search_value;
> > +
> > +typedef struct {
> > + nir_search_value value;
> > +
> > + /** The variable index; Must be less than NIR_SEARCH_MAX_VARIABLES
> */
> > + unsigned variable;
> > +} nir_search_variable;
> > +
> > +typedef struct {
> > + nir_search_value value;
> > +
> > + union {
> > + uint32_t u;
> > + int32_t i;
> > + float f;
> > + } data;
> > +} nir_search_constant;
> > +
> > +typedef struct {
> > + nir_search_value value;
> > +
> > + nir_op opcode;
> > + const nir_search_value *srcs[4];
> > +} nir_search_expression;
> > +
> > +NIR_DEFINE_CAST(nir_search_value_as_variable, nir_search_value,
> > + nir_search_variable, value)
> > +NIR_DEFINE_CAST(nir_search_value_as_constant, nir_search_value,
> > + nir_search_constant, value)
> > +NIR_DEFINE_CAST(nir_search_value_as_expression, nir_search_value,
> > + nir_search_expression, value)
> > +
> > +nir_alu_instr *
> > +nir_replace_instr(nir_alu_instr *instr, const nir_search_expression
> *search,
> > + const nir_search_value *replace, void *mem_ctx);
> > +
> > +#endif /* _NIR_SEARCH_ */
> > --
> > 2.2.0
> >
> > _______________________________________________
> > mesa-dev mailing list
> > mesa-dev at lists.freedesktop.org
> > http://lists.freedesktop.org/mailman/listinfo/mesa-dev
>
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