diff options
| -rw-r--r-- | src/glsl/nir/nir_instr_set.c | 314 | ||||
| -rw-r--r-- | src/glsl/nir/nir_instr_set.h | 35 |
2 files changed, 349 insertions, 0 deletions
diff --git a/src/glsl/nir/nir_instr_set.c b/src/glsl/nir/nir_instr_set.c index 72ab04895f6..7460fccba10 100644 --- a/src/glsl/nir/nir_instr_set.c +++ b/src/glsl/nir/nir_instr_set.c @@ -22,6 +22,181 @@ */ #include "nir_instr_set.h" +#include "nir_vla.h" + +#define HASH(hash, data) _mesa_fnv32_1a_accumulate((hash), (data)) + +static uint32_t +hash_src(uint32_t hash, const nir_src *src) +{ + assert(src->is_ssa); + hash = HASH(hash, src->ssa); + return hash; +} + +static uint32_t +hash_alu_src(uint32_t hash, const nir_alu_src *src, unsigned num_components) +{ + hash = HASH(hash, src->abs); + hash = HASH(hash, src->negate); + + for (unsigned i = 0; i < num_components; i++) + hash = HASH(hash, src->swizzle[i]); + + hash = hash_src(hash, &src->src); + return hash; +} + +static uint32_t +hash_alu(uint32_t hash, const nir_alu_instr *instr) +{ + hash = HASH(hash, instr->op); + hash = HASH(hash, instr->dest.dest.ssa.num_components); + + if (nir_op_infos[instr->op].algebraic_properties & NIR_OP_IS_COMMUTATIVE) { + assert(nir_op_infos[instr->op].num_inputs == 2); + uint32_t hash0 = hash_alu_src(hash, &instr->src[0], + nir_ssa_alu_instr_src_components(instr, 0)); + uint32_t hash1 = hash_alu_src(hash, &instr->src[1], + nir_ssa_alu_instr_src_components(instr, 1)); + /* For commutative operations, we need some commutative way of + * combining the hashes. One option would be to XOR them but that + * means that anything with two identical sources will hash to 0 and + * that's common enough we probably don't want the guaranteed + * collision. Either addition or multiplication will also work. + */ + hash = hash0 * hash1; + } else { + for (unsigned i = 0; i < nir_op_infos[instr->op].num_inputs; i++) { + hash = hash_alu_src(hash, &instr->src[i], + nir_ssa_alu_instr_src_components(instr, i)); + } + } + + return hash; +} + +static uint32_t +hash_load_const(uint32_t hash, const nir_load_const_instr *instr) +{ + hash = HASH(hash, instr->def.num_components); + + hash = _mesa_fnv32_1a_accumulate_block(hash, instr->value.f, + instr->def.num_components + * sizeof(instr->value.f[0])); + + return hash; +} + +static int +cmp_phi_src(const void *data1, const void *data2) +{ + nir_phi_src *src1 = *(nir_phi_src **)data1; + nir_phi_src *src2 = *(nir_phi_src **)data2; + return src1->pred - src2->pred; +} + +static uint32_t +hash_phi(uint32_t hash, const nir_phi_instr *instr) +{ + hash = HASH(hash, instr->instr.block); + + /* sort sources by predecessor, since the order shouldn't matter */ + unsigned num_preds = instr->instr.block->predecessors->entries; + NIR_VLA(nir_phi_src *, srcs, num_preds); + unsigned i = 0; + nir_foreach_phi_src(instr, src) { + srcs[i++] = src; + } + + qsort(srcs, num_preds, sizeof(nir_phi_src *), cmp_phi_src); + + for (i = 0; i < num_preds; i++) { + hash = hash_src(hash, &srcs[i]->src); + hash = HASH(hash, srcs[i]->pred); + } + + return hash; +} + +static uint32_t +hash_intrinsic(uint32_t hash, const nir_intrinsic_instr *instr) +{ + const nir_intrinsic_info *info = &nir_intrinsic_infos[instr->intrinsic]; + hash = HASH(hash, instr->intrinsic); + + if (info->has_dest) + hash = HASH(hash, instr->dest.ssa.num_components); + + assert(info->num_variables == 0); + + hash = _mesa_fnv32_1a_accumulate_block(hash, instr->const_index, + info->num_indices + * sizeof(instr->const_index[0])); + return hash; +} + +static uint32_t +hash_tex(uint32_t hash, const nir_tex_instr *instr) +{ + hash = HASH(hash, instr->op); + hash = HASH(hash, instr->num_srcs); + + for (unsigned i = 0; i < instr->num_srcs; i++) { + hash = HASH(hash, instr->src[i].src_type); + hash = hash_src(hash, &instr->src[i].src); + } + + hash = HASH(hash, instr->coord_components); + hash = HASH(hash, instr->sampler_dim); + hash = HASH(hash, instr->is_array); + hash = HASH(hash, instr->is_shadow); + hash = HASH(hash, instr->is_new_style_shadow); + hash = HASH(hash, instr->const_offset); + unsigned component = instr->component; + hash = HASH(hash, component); + hash = HASH(hash, instr->sampler_index); + hash = HASH(hash, instr->sampler_array_size); + + assert(!instr->sampler); + + return hash; +} + +/* Computes a hash of an instruction for use in a hash table. Note that this + * will only work for instructions where instr_can_rewrite() returns true, and + * it should return identical hashes for two instructions that are the same + * according nir_instrs_equal(). + */ + +static uint32_t +hash_instr(const void *data) +{ + const nir_instr *instr = data; + uint32_t hash = _mesa_fnv32_1a_offset_bias; + + switch (instr->type) { + case nir_instr_type_alu: + hash = hash_alu(hash, nir_instr_as_alu(instr)); + break; + case nir_instr_type_load_const: + hash = hash_load_const(hash, nir_instr_as_load_const(instr)); + break; + case nir_instr_type_phi: + hash = hash_phi(hash, nir_instr_as_phi(instr)); + break; + case nir_instr_type_intrinsic: + hash = hash_intrinsic(hash, nir_instr_as_intrinsic(instr)); + break; + case nir_instr_type_tex: + hash = hash_tex(hash, nir_instr_as_tex(instr)); + break; + default: + unreachable("Invalid instruction type"); + } + + return hash; +} bool nir_srcs_equal(nir_src src1, nir_src src2) @@ -66,6 +241,12 @@ nir_alu_srcs_equal(const nir_alu_instr *alu1, const nir_alu_instr *alu2, return nir_srcs_equal(alu1->src[src1].src, alu2->src[src2].src); } +/* Returns "true" if two instructions are equal. Note that this will only + * work for the subset of instructions defined by instr_can_rewrite(). Also, + * it should only return "true" for instructions that hash_instr() will return + * the same hash for (ignoring collisions, of course). + */ + bool nir_instrs_equal(const nir_instr *instr1, const nir_instr *instr2) { @@ -204,3 +385,136 @@ nir_instrs_equal(const nir_instr *instr1, const nir_instr *instr2) return false; } +static bool +src_is_ssa(nir_src *src, void *data) +{ + (void) data; + return src->is_ssa; +} + +static bool +dest_is_ssa(nir_dest *dest, void *data) +{ + (void) data; + return dest->is_ssa; +} + +/* This function determines if uses of an instruction can safely be rewritten + * to use another identical instruction instead. Note that this function must + * be kept in sync with hash_instr() and nir_instrs_equal() -- only + * instructions that pass this test will be handed on to those functions, and + * conversely they must handle everything that this function returns true for. + */ + +static bool +instr_can_rewrite(nir_instr *instr) +{ + /* We only handle SSA. */ + if (!nir_foreach_dest(instr, dest_is_ssa, NULL) || + !nir_foreach_src(instr, src_is_ssa, NULL)) + return false; + + switch (instr->type) { + case nir_instr_type_alu: + case nir_instr_type_load_const: + case nir_instr_type_phi: + return true; + case nir_instr_type_tex: { + nir_tex_instr *tex = nir_instr_as_tex(instr); + + /* Don't support un-lowered sampler derefs currently. */ + if (tex->sampler) + return false; + + return true; + } + case nir_instr_type_intrinsic: { + const nir_intrinsic_info *info = + &nir_intrinsic_infos[nir_instr_as_intrinsic(instr)->intrinsic]; + return (info->flags & NIR_INTRINSIC_CAN_ELIMINATE) && + (info->flags & NIR_INTRINSIC_CAN_REORDER) && + info->num_variables == 0; /* not implemented yet */ + } + case nir_instr_type_call: + case nir_instr_type_jump: + case nir_instr_type_ssa_undef: + return false; + case nir_instr_type_parallel_copy: + default: + unreachable("Invalid instruction type"); + } + + return false; +} + +static nir_ssa_def * +nir_instr_get_dest_ssa_def(nir_instr *instr) +{ + switch (instr->type) { + case nir_instr_type_alu: + assert(nir_instr_as_alu(instr)->dest.dest.is_ssa); + return &nir_instr_as_alu(instr)->dest.dest.ssa; + case nir_instr_type_load_const: + return &nir_instr_as_load_const(instr)->def; + case nir_instr_type_phi: + assert(nir_instr_as_phi(instr)->dest.is_ssa); + return &nir_instr_as_phi(instr)->dest.ssa; + case nir_instr_type_intrinsic: + assert(nir_instr_as_intrinsic(instr)->dest.is_ssa); + return &nir_instr_as_intrinsic(instr)->dest.ssa; + case nir_instr_type_tex: + assert(nir_instr_as_tex(instr)->dest.is_ssa); + return &nir_instr_as_tex(instr)->dest.ssa; + default: + unreachable("We never ask for any of these"); + } +} + +static bool +cmp_func(const void *data1, const void *data2) +{ + return nir_instrs_equal(data1, data2); +} + +struct set * +nir_instr_set_create(void *mem_ctx) +{ + return _mesa_set_create(mem_ctx, hash_instr, cmp_func); +} + +void +nir_instr_set_destroy(struct set *instr_set) +{ + _mesa_set_destroy(instr_set, NULL); +} + +bool +nir_instr_set_add_or_rewrite(struct set *instr_set, nir_instr *instr) +{ + if (!instr_can_rewrite(instr)) + return false; + + struct set_entry *entry = _mesa_set_search(instr_set, instr); + if (entry) { + nir_ssa_def *def = nir_instr_get_dest_ssa_def(instr); + nir_ssa_def *new_def = + nir_instr_get_dest_ssa_def((nir_instr *) entry->key); + nir_ssa_def_rewrite_uses(def, nir_src_for_ssa(new_def)); + return true; + } + + _mesa_set_add(instr_set, instr); + return false; +} + +void +nir_instr_set_remove(struct set *instr_set, nir_instr *instr) +{ + if (!instr_can_rewrite(instr)) + return; + + struct set_entry *entry = _mesa_set_search(instr_set, instr); + if (entry) + _mesa_set_remove(instr_set, entry); +} + diff --git a/src/glsl/nir/nir_instr_set.h b/src/glsl/nir/nir_instr_set.h index f5baffacb0e..a7f6c9dd1eb 100644 --- a/src/glsl/nir/nir_instr_set.h +++ b/src/glsl/nir/nir_instr_set.h @@ -27,3 +27,38 @@ bool nir_instrs_equal(const nir_instr *instr1, const nir_instr *instr2); +/** + * This file defines functions for creating, destroying, and manipulating an + * "instruction set," which is an abstraction for finding duplicate + * instructions using a hash set. Note that the question of whether an + * instruction is actually a duplicate (e.g. whether it has any side effects) + * is handled transparently. The user can pass any instruction to + * nir_instr_set_add_or_rewrite() and nir_instr_set_remove(), and if the + * instruction isn't safe to rewrite or isn't supported, it's silently + * removed. + */ + +/*@{*/ + +/** Creates an instruction set, using a given ralloc mem_ctx */ +struct set *nir_instr_set_create(void *mem_ctx); + +/** Destroys an instruction set. */ +void nir_instr_set_destroy(struct set *instr_set); + +/** + * Adds an instruction to an instruction set if it doesn't exist, or if it + * does already exist, rewrites all uses of it to point to the other + * already-inserted instruction. Returns 'true' if the uses of the instruction + * were rewritten. + */ +bool nir_instr_set_add_or_rewrite(struct set *instr_set, nir_instr *instr); + +/** + * Removes an instruction from an instruction set, so that other instructions + * won't be merged with it. + */ +void nir_instr_set_remove(struct set *instr_set, nir_instr *instr); + +/*@}*/ + |