1 files changed, 519 insertions, 0 deletions

diff --git a/src/compiler/nir/nir_instr_set.c b/src/compiler/nir/nir_instr_set.c
new file mode 100644
index 00000000000..d3f939fe805
--- /dev/null
+++ b/src/compiler/nir/nir_instr_set.c
@@ -0,0 +1,519 @@
+/*
+ * Copyright © 2014 Connor Abbott
+ *
+ * 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.
+ */
+
+#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)
+{
+   if (src1.is_ssa) {
+      if (src2.is_ssa) {
+         return src1.ssa == src2.ssa;
+      } else {
+         return false;
+      }
+   } else {
+      if (src2.is_ssa) {
+         return false;
+      } else {
+         if ((src1.reg.indirect == NULL) != (src2.reg.indirect == NULL))
+            return false;
+
+         if (src1.reg.indirect) {
+            if (!nir_srcs_equal(*src1.reg.indirect, *src2.reg.indirect))
+               return false;
+         }
+
+         return src1.reg.reg == src2.reg.reg &&
+                src1.reg.base_offset == src2.reg.base_offset;
+      }
+   }
+}
+
+static bool
+nir_alu_srcs_equal(const nir_alu_instr *alu1, const nir_alu_instr *alu2,
+                   unsigned src1, unsigned src2)
+{
+   if (alu1->src[src1].abs != alu2->src[src2].abs ||
+       alu1->src[src1].negate != alu2->src[src2].negate)
+      return false;
+
+   for (unsigned i = 0; i < nir_ssa_alu_instr_src_components(alu1, src1); i++) {
+      if (alu1->src[src1].swizzle[i] != alu2->src[src2].swizzle[i])
+         return false;
+   }
+
+   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).
+ */
+
+static bool
+nir_instrs_equal(const nir_instr *instr1, const nir_instr *instr2)
+{
+   if (instr1->type != instr2->type)
+      return false;
+
+   switch (instr1->type) {
+   case nir_instr_type_alu: {
+      nir_alu_instr *alu1 = nir_instr_as_alu(instr1);
+      nir_alu_instr *alu2 = nir_instr_as_alu(instr2);
+
+      if (alu1->op != alu2->op)
+         return false;
+
+      /* TODO: We can probably acutally do something more inteligent such
+       * as allowing different numbers and taking a maximum or something
+       * here */
+      if (alu1->dest.dest.ssa.num_components != alu2->dest.dest.ssa.num_components)
+         return false;
+
+      if (nir_op_infos[alu1->op].algebraic_properties & NIR_OP_IS_COMMUTATIVE) {
+         assert(nir_op_infos[alu1->op].num_inputs == 2);
+         return (nir_alu_srcs_equal(alu1, alu2, 0, 0) &&
+                 nir_alu_srcs_equal(alu1, alu2, 1, 1)) ||
+                (nir_alu_srcs_equal(alu1, alu2, 0, 1) &&
+                 nir_alu_srcs_equal(alu1, alu2, 1, 0));
+      } else {
+         for (unsigned i = 0; i < nir_op_infos[alu1->op].num_inputs; i++) {
+            if (!nir_alu_srcs_equal(alu1, alu2, i, i))
+               return false;
+         }
+      }
+      return true;
+   }
+   case nir_instr_type_tex: {
+      nir_tex_instr *tex1 = nir_instr_as_tex(instr1);
+      nir_tex_instr *tex2 = nir_instr_as_tex(instr2);
+
+      if (tex1->op != tex2->op)
+         return false;
+
+      if (tex1->num_srcs != tex2->num_srcs)
+         return false;
+      for (unsigned i = 0; i < tex1->num_srcs; i++) {
+         if (tex1->src[i].src_type != tex2->src[i].src_type ||
+             !nir_srcs_equal(tex1->src[i].src, tex2->src[i].src)) {
+            return false;
+         }
+      }
+
+      if (tex1->coord_components != tex2->coord_components ||
+          tex1->sampler_dim != tex2->sampler_dim ||
+          tex1->is_array != tex2->is_array ||
+          tex1->is_shadow != tex2->is_shadow ||
+          tex1->is_new_style_shadow != tex2->is_new_style_shadow ||
+          memcmp(tex1->const_offset, tex2->const_offset,
+                 sizeof(tex1->const_offset)) != 0 ||
+          tex1->component != tex2->component ||
+         tex1->sampler_index != tex2->sampler_index ||
+         tex1->sampler_array_size != tex2->sampler_array_size) {
+         return false;
+      }
+
+      /* Don't support un-lowered sampler derefs currently. */
+      assert(!tex1->sampler && !tex2->sampler);
+
+      return true;
+   }
+   case nir_instr_type_load_const: {
+      nir_load_const_instr *load1 = nir_instr_as_load_const(instr1);
+      nir_load_const_instr *load2 = nir_instr_as_load_const(instr2);
+
+      if (load1->def.num_components != load2->def.num_components)
+         return false;
+
+      return memcmp(load1->value.f, load2->value.f,
+                    load1->def.num_components * sizeof(*load2->value.f)) == 0;
+   }
+   case nir_instr_type_phi: {
+      nir_phi_instr *phi1 = nir_instr_as_phi(instr1);
+      nir_phi_instr *phi2 = nir_instr_as_phi(instr2);
+
+      if (phi1->instr.block != phi2->instr.block)
+         return false;
+
+      nir_foreach_phi_src(phi1, src1) {
+         nir_foreach_phi_src(phi2, src2) {
+            if (src1->pred == src2->pred) {
+               if (!nir_srcs_equal(src1->src, src2->src))
+                  return false;
+
+               break;
+            }
+         }
+      }
+
+      return true;
+   }
+   case nir_instr_type_intrinsic: {
+      nir_intrinsic_instr *intrinsic1 = nir_instr_as_intrinsic(instr1);
+      nir_intrinsic_instr *intrinsic2 = nir_instr_as_intrinsic(instr2);
+      const nir_intrinsic_info *info =
+         &nir_intrinsic_infos[intrinsic1->intrinsic];
+
+      if (intrinsic1->intrinsic != intrinsic2->intrinsic ||
+          intrinsic1->num_components != intrinsic2->num_components)
+         return false;
+
+      if (info->has_dest && intrinsic1->dest.ssa.num_components !=
+                            intrinsic2->dest.ssa.num_components)
+         return false;
+
+      for (unsigned i = 0; i < info->num_srcs; i++) {
+         if (!nir_srcs_equal(intrinsic1->src[i], intrinsic2->src[i]))
+            return false;
+      }
+
+      assert(info->num_variables == 0);
+
+      for (unsigned i = 0; i < info->num_indices; i++) {
+         if (intrinsic1->const_index[i] != intrinsic2->const_index[i])
+            return false;
+      }
+
+      return true;
+   }
+   case nir_instr_type_call:
+   case nir_instr_type_jump:
+   case nir_instr_type_ssa_undef:
+   case nir_instr_type_parallel_copy:
+   default:
+      unreachable("Invalid instruction type");
+   }
+
+   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);
+}
+