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/*
* 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@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;
unsigned bit_size;
} nir_search_value;
typedef struct {
nir_search_value value;
/** The variable index; Must be less than NIR_SEARCH_MAX_VARIABLES */
unsigned variable;
/** Indicates that the given variable must be a constant
*
* This is only allowed in search expressions and indicates that the
* given variable is only allowed to match constant values.
*/
bool is_constant;
/** Indicates that the given variable must have a certain type
*
* This is only allowed in search expressions and indicates that the
* given variable is only allowed to match values that come from an ALU
* instruction with the given output type. A type of nir_type_void
* means it can match any type.
*
* Note: A variable that is both constant and has a non-void type will
* never match anything.
*/
nir_alu_type type;
/** Optional condition fxn ptr
*
* This allows additional constraints to be placed on the match. Typically
* used for 'is_constant' variables to require, for example, power-of-two
* in order for the search to match.
*/
bool (*cond)(nir_alu_instr *instr, unsigned src,
unsigned num_components, const uint8_t *swizzle);
} nir_search_variable;
typedef struct {
nir_search_value value;
nir_alu_type type;
union {
uint64_t u;
int64_t i;
double d;
} data;
} nir_search_constant;
typedef struct {
nir_search_value value;
/* When set on a search expression, the expression will only match an SSA
* value that does *not* have the exact bit set. If unset, the exact bit
* on the SSA value is ignored.
*/
bool inexact;
nir_op opcode;
const nir_search_value *srcs[4];
/** Optional condition fxn ptr
*
* This allows additional constraints on expression matching, it is
* typically used to match an expressions uses such as the number of times
* the expression is used, and whether its used by an if.
*/
bool (*cond)(nir_alu_instr *instr);
} nir_search_expression;
NIR_DEFINE_CAST(nir_search_value_as_variable, nir_search_value,
nir_search_variable, value,
type, nir_search_value_variable)
NIR_DEFINE_CAST(nir_search_value_as_constant, nir_search_value,
nir_search_constant, value,
type, nir_search_value_constant)
NIR_DEFINE_CAST(nir_search_value_as_expression, nir_search_value,
nir_search_expression, value,
type, nir_search_value_expression)
struct nir_search_ctx;
typedef struct nir_search_ctx nir_search_ctx;
/* Initialize a search context. The context is used internally for storing
* equivalence classes of instructions. nir_replace_instr() will not actually
* replace one pattern with the other -- it merely records that the patterns
* are equivalent. Actually choosing whether to apply a pattern or not is
* deferred until the context is destroyed, which is why we need a context in
* the first place. For more details on this, see: "Equality Saturation: A New
* Approach to Optimization" by Tate et. al.
*/
nir_search_ctx *
nir_search_ctx_init(nir_function_impl *impl);
/* Destroy the context, finalizing the choice of which patterns to actually
* apply. Returns true if progress is made, i.e. some of the patterns were
* actually applied.
*/
void
nir_search_ctx_fini(nir_search_ctx *ctx);
/* Tell the replacement engine that two patterns are equal. If must_perform is
* true, then patterns with the form of the lhs are disallowed in the final
* result, and the engine will always replace them.
*
* This function should be called in dominance order, i.e. if a dominates b
* then nir_replace_instr() should be called on a before b. It may generate
* instructions after a, and those instructions should also be considered.
*/
nir_alu_instr *
nir_replace_instr(nir_alu_instr *instr, const nir_search_expression *lhs,
const nir_search_value *rhs, nir_search_ctx *ctx,
bool must_replace_lhs);
#endif /* _NIR_SEARCH_ */
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