nir: Remove predication

We stopped generating predicates in glsl_to_nir some time ago.  Right now,
it's all dead untested code that I'm not convinced always worked in the
first place.  If we decide we want them back, we can revert this patch.

Reviewed-by: Connor Abbott <[email protected]>

9 files changed, 7 insertions, 259 deletions

diff --git a/src/glsl/nir/nir.c b/src/glsl/nir/nir.c
index cb788d47259..bbf1a865706 100644
--- a/src/glsl/nir/nir.c
+++ b/src/glsl/nir/nir.c
@@ -381,9 +381,6 @@ nir_alu_instr_create(void *mem_ctx, nir_op op)
    for (unsigned i = 0; i < num_srcs; i++)
       alu_src_init(&instr->src[i]);
 
-   instr->has_predicate = false;
-   src_init(&instr->predicate);
-
    return instr;
 }
 
@@ -406,9 +403,6 @@ nir_load_const_instr_create(void *mem_ctx)
    instr->num_components = 0;
    instr->array_elems = 0;
 
-   instr->has_predicate = false;
-   src_init(&instr->predicate);
-
    return instr;
 }
 
@@ -429,9 +423,6 @@ nir_intrinsic_instr_create(void *mem_ctx, nir_intrinsic_op op)
    for (unsigned i = 0; i < num_srcs; i++)
       src_init(&instr->src[i]);
 
-   instr->has_predicate = false;
-   src_init(&instr->predicate);
-
    return instr;
 }
 
@@ -446,9 +437,6 @@ nir_call_instr_create(void *mem_ctx, nir_function_overload *callee)
    instr->params = ralloc_array(mem_ctx, nir_deref_var *, instr->num_params);
    instr->return_deref = NULL;
 
-   instr->has_predicate = false;
-   src_init(&instr->predicate);
-
    return instr;
 }
 
@@ -464,9 +452,6 @@ nir_tex_instr_create(void *mem_ctx, unsigned num_srcs)
    for (unsigned i = 0; i < 4; i++)
       src_init(&instr->src[i]);
 
-   instr->has_predicate = false;
-   src_init(&instr->predicate);
-
    instr->sampler_index = 0;
    instr->sampler_array_size = 0;
    instr->sampler = NULL;
@@ -1521,10 +1506,6 @@ visit_alu_src(nir_alu_instr *instr, nir_foreach_src_cb cb, void *state)
       if (!visit_src(&instr->src[i].src, cb, state))
          return false;
 
-   if (instr->has_predicate)
-      if (!visit_src(&instr->predicate, cb, state))
-         return false;
-
    return true;
 }
 
@@ -1535,10 +1516,6 @@ visit_tex_src(nir_tex_instr *instr, nir_foreach_src_cb cb, void *state)
       if (!visit_src(&instr->src[i], cb, state))
          return false;
 
-   if (instr->has_predicate)
-      if (!visit_src(&instr->predicate, cb, state))
-         return false;
-
    if (instr->sampler != NULL)
       if (!visit_deref_src(instr->sampler, cb, state))
          return false;
@@ -1561,20 +1538,12 @@ visit_intrinsic_src(nir_intrinsic_instr *instr, nir_foreach_src_cb cb,
       if (!visit_deref_src(instr->variables[i], cb, state))
          return false;
 
-   if (instr->has_predicate)
-      if (!visit_src(&instr->predicate, cb, state))
-         return false;
-
    return true;
 }
 
 static bool
 visit_call_src(nir_call_instr *instr, nir_foreach_src_cb cb, void *state)
 {
-   if (instr->has_predicate)
-      if (!visit_src(&instr->predicate, cb, state))
-         return false;
-
    return true;
 }
 
@@ -1582,10 +1551,6 @@ static bool
 visit_load_const_src(nir_load_const_instr *instr, nir_foreach_src_cb cb,
                      void *state)
 {
-   if (instr->has_predicate)
-      if (!visit_src(&instr->predicate, cb, state))
-         return false;
-
    return true;
 }
 
diff --git a/src/glsl/nir/nir.h b/src/glsl/nir/nir.h
index 822e2ae414c..8887c5815e7 100644
--- a/src/glsl/nir/nir.h
+++ b/src/glsl/nir/nir.h
@@ -606,8 +606,6 @@ extern const nir_op_info nir_op_infos[nir_num_opcodes];
 typedef struct nir_alu_instr {
    nir_instr instr;
    nir_op op;
-   bool has_predicate;
-   nir_src predicate;
    nir_alu_dest dest;
    nir_alu_src src[];
 } nir_alu_instr;
@@ -679,9 +677,6 @@ typedef struct {
    nir_deref_var **params;
    nir_deref_var *return_deref;
 
-   bool has_predicate;
-   nir_src predicate;
-
    struct nir_function_overload *callee;
 } nir_call_instr;
 
@@ -713,9 +708,6 @@ typedef struct {
 
    nir_deref_var *variables[2];
 
-   bool has_predicate;
-   nir_src predicate;
-
    nir_src src[];
 } nir_intrinsic_instr;
 
@@ -813,9 +805,6 @@ typedef enum {
 typedef struct {
    nir_instr instr;
 
-   bool has_predicate;
-   nir_src predicate;
-
    enum glsl_sampler_dim sampler_dim;
    nir_alu_type dest_type;
 
@@ -944,9 +933,6 @@ typedef struct {
     */
    unsigned array_elems;
 
-   bool has_predicate;
-   nir_src predicate;
-
    nir_dest dest;
 } nir_load_const_instr;
 
diff --git a/src/glsl/nir/nir_lower_variables.c b/src/glsl/nir/nir_lower_variables.c
index 64682056ddc..4fa421a4d65 100644
--- a/src/glsl/nir/nir_lower_variables.c
+++ b/src/glsl/nir/nir_lower_variables.c
@@ -548,11 +548,6 @@ emit_copy_load_store(nir_intrinsic_instr *copy_instr,
       store->src[0].is_ssa = true;
       store->src[0].ssa = &load->dest.ssa;
 
-      if (copy_instr->has_predicate) {
-         store->has_predicate = true;
-         store->predicate = nir_src_copy(copy_instr->predicate, state->mem_ctx);
-      }
-
       nir_instr_insert_before(&copy_instr->instr, &store->instr);
       register_store_instr(store, false, state);
    }
@@ -831,32 +826,12 @@ lower_deref_to_ssa_block(nir_block *block, void *void_state)
 
             assert(intrin->src[0].is_ssa);
 
-            nir_alu_instr *mov;
-            if (intrin->has_predicate) {
-               mov = nir_alu_instr_create(state->mem_ctx, nir_op_bcsel);
-               mov->src[0].src = nir_src_copy(intrin->predicate,
-                                              state->mem_ctx);
-               /* Splat the condition to all channels */
-               memset(mov->src[0].swizzle, 0, sizeof mov->src[0].swizzle);
-
-               mov->src[1].src.is_ssa = true;
-               mov->src[1].src.ssa = intrin->src[0].ssa;
-               for (unsigned i = intrin->num_components; i < 4; i++)
-                  mov->src[1].swizzle[i] = 0;
-
-               mov->src[2].src.is_ssa = true;
-               mov->src[2].src.ssa = get_ssa_def_for_block(node, block, state);
-               for (unsigned i = intrin->num_components; i < 4; i++)
-                  mov->src[2].swizzle[i] = 0;
-
-            } else {
-               mov = nir_alu_instr_create(state->mem_ctx, nir_op_imov);
-
-               mov->src[0].src.is_ssa = true;
-               mov->src[0].src.ssa = intrin->src[0].ssa;
-               for (unsigned i = intrin->num_components; i < 4; i++)
-                  mov->src[0].swizzle[i] = 0;
-            }
+            nir_alu_instr *mov = nir_alu_instr_create(state->mem_ctx,
+                                                      nir_op_imov);
+            mov->src[0].src.is_ssa = true;
+            mov->src[0].src.ssa = intrin->src[0].ssa;
+            for (unsigned i = intrin->num_components; i < 4; i++)
+               mov->src[0].swizzle[i] = 0;
 
             mov->dest.write_mask = (1 << intrin->num_components) - 1;
             mov->dest.dest.is_ssa = true;
diff --git a/src/glsl/nir/nir_opt_copy_propagate.c b/src/glsl/nir/nir_opt_copy_propagate.c
index 2feebe42c00..aa2df1be857 100644
--- a/src/glsl/nir/nir_opt_copy_propagate.c
+++ b/src/glsl/nir/nir_opt_copy_propagate.c
@@ -256,10 +256,6 @@ copy_prop_instr(nir_instr *instr)
          while (copy_prop_alu_src(alu_instr, i))
             progress = true;
 
-      if (alu_instr->has_predicate)
-         while (copy_prop_src(&alu_instr->predicate, instr, NULL))
-            progress = true;
-
       if (!alu_instr->dest.dest.is_ssa && alu_instr->dest.dest.reg.indirect)
          while (copy_prop_src(alu_instr->dest.dest.reg.indirect, instr, NULL))
             progress = true;
diff --git a/src/glsl/nir/nir_opt_cse.c b/src/glsl/nir/nir_opt_cse.c
index 14bd6bf50e6..0ad575c19c1 100644
--- a/src/glsl/nir/nir_opt_cse.c
+++ b/src/glsl/nir/nir_opt_cse.c
@@ -67,13 +67,6 @@ nir_instrs_equal(nir_instr *instr1, nir_instr *instr2)
       if (alu1->op != alu2->op)
          return false;
 
-      if (alu1->has_predicate != alu2->has_predicate)
-         return false;
-
-      if (alu1->has_predicate &&
-          !nir_srcs_equal(alu1->predicate, alu2->predicate))
-         return false;
-
       /* TODO: We can probably acutally do something more inteligent such
        * as allowing different numbers and taking a maximum or something
        * here */
diff --git a/src/glsl/nir/nir_print.c b/src/glsl/nir/nir_print.c
index 22a2a1d6557..7d60eb11ee8 100644
--- a/src/glsl/nir/nir_print.c
+++ b/src/glsl/nir/nir_print.c
@@ -178,12 +178,6 @@ print_alu_dest(nir_alu_dest *dest, FILE *fp)
 static void
 print_alu_instr(nir_alu_instr *instr, FILE *fp)
 {
-   if (instr->has_predicate) {
-      fprintf(fp, "(");
-      print_src(&instr->predicate, fp);
-      fprintf(fp, ") ");
-   }
-
    print_alu_dest(&instr->dest, fp);
 
    fprintf(fp, " = %s", nir_op_infos[instr->op].name);
@@ -327,12 +321,6 @@ print_intrinsic_instr(nir_intrinsic_instr *instr, print_var_state *state,
 {
    unsigned num_srcs = nir_intrinsic_infos[instr->intrinsic].num_srcs;
 
-   if (instr->has_predicate) {
-      fprintf(fp, "(");
-      print_src(&instr->predicate, fp);
-      fprintf(fp, ") ");
-   }
-
    if (nir_intrinsic_infos[instr->intrinsic].has_dest) {
       print_dest(&instr->dest, fp);
       fprintf(fp, " = ");
@@ -384,12 +372,6 @@ print_intrinsic_instr(nir_intrinsic_instr *instr, print_var_state *state,
 static void
 print_tex_instr(nir_tex_instr *instr, print_var_state *state, FILE *fp)
 {
-   if (instr->has_predicate) {
-      fprintf(fp, "(");
-      print_src(&instr->predicate, fp);
-      fprintf(fp, ") ");
-   }
-
    print_dest(&instr->dest, fp);
 
    fprintf(fp, " = ");
@@ -505,12 +487,6 @@ print_tex_instr(nir_tex_instr *instr, print_var_state *state, FILE *fp)
 static void
 print_call_instr(nir_call_instr *instr, print_var_state *state, FILE *fp)
 {
-   if (instr->has_predicate) {
-      fprintf(fp, "(");
-      print_src(&instr->predicate, fp);
-      fprintf(fp, ") ");
-   }
-
    fprintf(fp, "call %s ", instr->callee->function->name);
 
    for (unsigned i = 0; i < instr->num_params; i++) {
@@ -555,12 +531,6 @@ print_const_value(nir_const_value value, unsigned num_components, FILE *fp)
 static void
 print_load_const_instr(nir_load_const_instr *instr, unsigned tabs, FILE *fp)
 {
-   if (instr->has_predicate) {
-      fprintf(fp, "(");
-      print_src(&instr->predicate, fp);
-      fprintf(fp, ") ");
-   }
-
    print_dest(&instr->dest, fp);
 
    fprintf(fp, " = load_const ");
diff --git a/src/glsl/nir/nir_split_var_copies.c b/src/glsl/nir/nir_split_var_copies.c
index edabfb7e5c3..4d663b51bed 100644
--- a/src/glsl/nir/nir_split_var_copies.c
+++ b/src/glsl/nir/nir_split_var_copies.c
@@ -184,12 +184,6 @@ split_var_copy_instr(nir_intrinsic_instr *old_copy,
          nir_intrinsic_instr *new_copy =
             nir_intrinsic_instr_create(state->mem_ctx, nir_intrinsic_copy_var);
 
-         if (old_copy->has_predicate) {
-            new_copy->has_predicate = true;
-            new_copy->predicate = nir_src_copy(old_copy->predicate,
-                                               state->mem_ctx);
-         }
-
          /* We need to make copies because a) this deref chain actually
           * belongs to the copy instruction and b) the deref chains may
           * have some of the same links due to the way we constructed them
diff --git a/src/glsl/nir/nir_to_ssa.c b/src/glsl/nir/nir_to_ssa.c
index 6b6a0779a6d..3725ddbe226 100644
--- a/src/glsl/nir/nir_to_ssa.c
+++ b/src/glsl/nir/nir_to_ssa.c
@@ -148,9 +148,6 @@ typedef struct {
 
    /* map from SSA value -> original register */
    struct hash_table *ssa_map;
-
-   /* predicate for this instruction */
-   nir_src *predicate;
 } rewrite_state;
 
 static nir_ssa_def *get_ssa_src(nir_register *reg, rewrite_state *state)
@@ -220,27 +217,6 @@ rewrite_def_forwards(nir_dest *dest, void *_state)
    if (state->states[index].stack == NULL)
       return true;
 
-   nir_alu_instr *csel = NULL;
-   if (state->predicate) {
-         /*
-          * To capture the information that we may or may not overwrite this
-          * register due to the predicate, we need to emit a conditional select
-          * that takes the old version of the register and the new version.
-          * This is basically a watered-down version of the Psi-SSA
-          * representation, without any of the optimizations.
-          *
-          * TODO: do we actually need full-blown Psi-SSA?
-          */
-      csel = nir_alu_instr_create(state->mem_ctx, nir_op_bcsel);
-      csel->dest.dest.reg.reg = dest->reg.reg;
-      csel->dest.write_mask = (1 << dest->reg.reg->num_components) - 1;
-      csel->src[0].src = nir_src_copy(*state->predicate, state->mem_ctx);
-      /* Splat the condition to all channels */
-      memset(csel->src[0].swizzle, 0, sizeof csel->src[0].swizzle);
-      csel->src[2].src.is_ssa = true;
-      csel->src[2].src.ssa = get_ssa_src(dest->reg.reg, state);
-   }
-
    dest->is_ssa = true;
 
    char *name = NULL;
@@ -259,21 +235,6 @@ rewrite_def_forwards(nir_dest *dest, void *_state)
 
    _mesa_hash_table_insert(state->ssa_map, &dest->ssa, reg);
 
-   if (state->predicate) {
-      csel->src[1].src.is_ssa = true;
-      csel->src[1].src.ssa = &dest->ssa;
-
-      nir_instr *old_parent_instr = state->parent_instr;
-      nir_src *old_predicate = state->predicate;
-      state->parent_instr = &csel->instr;
-      state->predicate = NULL;
-      rewrite_def_forwards(&csel->dest.dest, state);
-      state->parent_instr = old_parent_instr;
-      state->predicate = old_predicate;
-
-      nir_instr_insert_after(state->parent_instr, &csel->instr);
-   }
-
    return true;
 }
 
@@ -281,7 +242,6 @@ static void
 rewrite_alu_instr_forward(nir_alu_instr *instr, rewrite_state *state)
 {
    state->parent_instr = &instr->instr;
-   state->predicate = instr->has_predicate ? &instr->predicate : NULL;
 
    nir_foreach_src(&instr->instr, rewrite_use, state);
 
@@ -383,14 +343,9 @@ rewrite_alu_instr_forward(nir_alu_instr *instr, rewrite_state *state)
          }
       }
 
-      vec->has_predicate = instr->has_predicate;
-      if (instr->has_predicate)
-         vec->predicate = nir_src_copy(instr->predicate, state->mem_ctx);
-
       nir_instr_insert_after(&instr->instr, &vec->instr);
 
       state->parent_instr = &vec->instr;
-      state->predicate = vec->has_predicate ? &vec->predicate : NULL;
       rewrite_def_forwards(&vec->dest.dest, state);
    } else {
       rewrite_def_forwards(&instr->dest.dest, state);
@@ -401,54 +356,9 @@ static void
 rewrite_phi_instr(nir_phi_instr *instr, rewrite_state *state)
 {
    state->parent_instr = &instr->instr;
-   state->predicate = NULL;
    rewrite_def_forwards(&instr->dest, state);
 }
 
-static nir_src *
-get_instr_predicate(nir_instr *instr)
-{
-   nir_alu_instr *alu_instr;
-   nir_load_const_instr *load_const_instr;
-   nir_intrinsic_instr *intrinsic_instr;
-   nir_tex_instr *tex_instr;
-
-   switch (instr->type) {
-   case nir_instr_type_alu:
-      alu_instr = nir_instr_as_alu(instr);
-      if (alu_instr->has_predicate)
-         return &alu_instr->predicate;
-      else
-         return NULL;
-
-   case nir_instr_type_load_const:
-      load_const_instr = nir_instr_as_load_const(instr);
-      if (load_const_instr->has_predicate)
-         return &load_const_instr->predicate;
-      else
-         return NULL;
-
-   case nir_instr_type_intrinsic:
-      intrinsic_instr = nir_instr_as_intrinsic(instr);
-      if (intrinsic_instr->has_predicate)
-         return &intrinsic_instr->predicate;
-      else
-         return NULL;
-
-   case nir_instr_type_tex:
-      tex_instr = nir_instr_as_tex(instr);
-      if (tex_instr->has_predicate)
-         return &tex_instr->predicate;
-      else
-         return NULL;
-
-   default:
-      break;
-   }
-
-   return NULL;
-}
-
 static void
 rewrite_instr_forward(nir_instr *instr, rewrite_state *state)
 {
@@ -463,7 +373,6 @@ rewrite_instr_forward(nir_instr *instr, rewrite_state *state)
    }
 
    state->parent_instr = instr;
-   state->predicate = get_instr_predicate(instr);
 
    nir_foreach_src(instr, rewrite_use, state);
    nir_foreach_dest(instr, rewrite_def_forwards, state);
@@ -580,35 +489,7 @@ init_rewrite_state(nir_function_impl *impl, rewrite_state *state)
           * called after phi nodes are inserted so we can count phi node
           * definitions too.
           */
-         unsigned stack_size = 0;
-         struct set_entry *entry;
-         set_foreach(reg->defs, entry) {
-            nir_instr *def = (nir_instr *) entry->key;
-
-            stack_size++;
-
-            /*
-             * predicates generate an additional predicate destination that
-             * gets pushed on the stack
-             *
-             * Note: ALU instructions generate an additional instruction too,
-             * but as of now only the additional instruction is pushed onto
-             * the stack, and not the original instruction because it doesn't
-             * need to be (actually, we could do the same with predicates,
-             * but it was easier to just use the existing codepath).
-             */
-
-            if (def->type == nir_instr_type_intrinsic) {
-               nir_intrinsic_instr *intrinsic_instr =
-                  nir_instr_as_intrinsic(def);
-               if (nir_intrinsic_infos[intrinsic_instr->intrinsic].has_dest &&
-                   intrinsic_instr->has_predicate)
-                  stack_size++;
-            } else {
-               if (get_instr_predicate(def) != NULL)
-                  stack_size++;
-            }
-         }
+         unsigned stack_size = reg->defs->entries;
 
          state->states[reg->index].stack = ralloc_array(state->states,
                                                         nir_ssa_def *,
diff --git a/src/glsl/nir/nir_validate.c b/src/glsl/nir/nir_validate.c
index 937cbb9bf6e..f0eb87fd393 100644
--- a/src/glsl/nir/nir_validate.c
+++ b/src/glsl/nir/nir_validate.c
@@ -254,9 +254,6 @@ validate_alu_instr(nir_alu_instr *instr, validate_state *state)
    for (unsigned i = 0; i < nir_op_infos[instr->op].num_inputs; i++) {
       validate_alu_src(instr, i, state);
    }
-
-   if (instr->has_predicate)
-      validate_src(&instr->predicate, state);
 }
 
 static void
@@ -372,9 +369,6 @@ validate_intrinsic_instr(nir_intrinsic_instr *instr, validate_state *state)
    default:
       break;
    }
-
-   if (instr->has_predicate)
-      validate_src(&instr->predicate, state);
 }
 
 static void
@@ -412,9 +406,6 @@ validate_call_instr(nir_call_instr *instr, validate_state *state)
    }
 
    validate_deref_var(instr->return_deref, state);
-
-   if (instr->has_predicate)
-      validate_src(&instr->predicate, state);
 }
 
 static void
@@ -427,9 +418,6 @@ validate_load_const_instr(nir_load_const_instr *instr, validate_state *state)
       assert(instr->dest.reg.base_offset + instr->array_elems <=
              instr->dest.reg.reg->num_array_elems);
    }
-
-   if (instr->has_predicate)
-      validate_src(&instr->predicate, state);
 }
 
 static void