This can be used for both CSE and value numbering.
Signed-off-by: Connor Abbott <cwabbo...@gmail.com>
---
src/glsl/Makefile.sources | 2 +
src/glsl/nir/nir_instr_hash.c | 255 ++++++++++++++++++++++++++++++++++++++++++
src/glsl/nir/nir_instr_hash.h | 36 ++++++
3 files changed, 293 insertions(+)
create mode 100644 src/glsl/nir/nir_instr_hash.c
create mode 100644 src/glsl/nir/nir_instr_hash.h
diff --git a/src/glsl/Makefile.sources b/src/glsl/Makefile.sources
index 75e5377..fd10cdd 100644
--- a/src/glsl/Makefile.sources
+++ b/src/glsl/Makefile.sources
@@ -28,6 +28,8 @@ NIR_FILES = \
nir/nir_dominance.c \
nir/nir_from_ssa.c \
nir/nir_instr_compare.c \
+ nir/nir_instr_hash.c \
+ nir/nir_instr_hash.h \
nir/nir_intrinsics.c \
nir/nir_intrinsics.h \
nir/nir_live_variables.c \
diff --git a/src/glsl/nir/nir_instr_hash.c b/src/glsl/nir/nir_instr_hash.c
new file mode 100644
index 0000000..d900b66
--- /dev/null
+++ b/src/glsl/nir/nir_instr_hash.c
@@ -0,0 +1,255 @@
+#include "nir_instr_hash.h"
+
+#define HASH(data) hash = _mesa_fnv32_1a_accumulate(hash, (data))
+
+static uint32_t
+hash_src(uint32_t hash, const nir_src *src)
+{
+ assert(src->is_ssa);
+ HASH(src->ssa);
+ return hash;
+}
+
+static uint32_t
+hash_alu_src(uint32_t hash, const nir_alu_src *src, unsigned num_components)
+{
+ HASH(src->abs);
+ HASH(src->negate);
+
+ for (unsigned i = 0; i < num_components; i++)
+ 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(instr->op);
+ 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(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)
+{
+ const nir_phi_src *src1 = data1, *src2 = data2;
+ return src1->pred->index - src2->pred->index;
+}
+
+static uint32_t
+hash_phi(uint32_t hash, const nir_phi_instr *instr)
+{
+ HASH(instr->instr.block);
+
+ /* sort sources by predecessor index, since the order shouldn't matter */
+ unsigned num_preds = instr->instr.block->predecessors->entries;
+ nir_phi_src *srcs = malloc(num_preds * sizeof(nir_phi_src));
+ 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(srcs[i].pred);
+ }
+ free(srcs);
+
+ 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(instr->intrinsic);
+
+ if (info->has_dest)
+ 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_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;
+ default:
+ unreachable("Invalid instruction type");
+ }
+
+ return hash;
+}
+
+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;
+}
+
+static bool
+instr_can_hash(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:
+ return false; /* TODO */
+ 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;
+ 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(struct set *instr_set, nir_instr *instr)
+{
+ void *mem_ctx = ralloc_parent(instr);
+
+ if (!instr_can_hash(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), mem_ctx);
+ 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_hash(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_hash.h b/src/glsl/nir/nir_instr_hash.h
new file mode 100644
index 0000000..2ff053f
--- /dev/null
+++ b/src/glsl/nir/nir_instr_hash.h
@@ -0,0 +1,36 @@
+#ifndef _NIR_INSTR_HASH_H
+#define _NIR_INSTR_HASH_H
+
+#include "nir.h"
+
+/**
+ * This file defines functions for creating, destroying, and manipulating an
+ * "instruction set," which is an abstraction for finding duplicate
+ * instructions using a hash set.
+ */
+
+/*@{*/
+
+/** 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(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);
+
+/*@}*/
+
+#endif
--
2.1.0
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