spirv: Move to compiler/

While it does rely on NIR, it's not really part of the NIR core.  At the
moment, it still builds as part of libnir but that can be changed later if
desired.

1 files changed, 778 insertions, 0 deletions

diff --git a/src/compiler/spirv/vtn_cfg.c b/src/compiler/spirv/vtn_cfg.c
new file mode 100644
index 00000000000..6a43ef8b2dd
--- /dev/null
+++ b/src/compiler/spirv/vtn_cfg.c
@@ -0,0 +1,778 @@
+/*
+ * Copyright © 2015 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.
+ */
+
+#include "vtn_private.h"
+#include "nir/nir_vla.h"
+
+static bool
+vtn_cfg_handle_prepass_instruction(struct vtn_builder *b, SpvOp opcode,
+                                   const uint32_t *w, unsigned count)
+{
+   switch (opcode) {
+   case SpvOpFunction: {
+      assert(b->func == NULL);
+      b->func = rzalloc(b, struct vtn_function);
+
+      list_inithead(&b->func->body);
+      b->func->control = w[3];
+
+      const struct glsl_type *result_type =
+         vtn_value(b, w[1], vtn_value_type_type)->type->type;
+      struct vtn_value *val = vtn_push_value(b, w[2], vtn_value_type_function);
+      val->func = b->func;
+
+      const struct glsl_type *func_type =
+         vtn_value(b, w[4], vtn_value_type_type)->type->type;
+
+      assert(glsl_get_function_return_type(func_type) == result_type);
+
+      nir_function *func =
+         nir_function_create(b->shader, ralloc_strdup(b->shader, val->name));
+
+      func->num_params = glsl_get_length(func_type);
+      func->params = ralloc_array(b->shader, nir_parameter, func->num_params);
+      for (unsigned i = 0; i < func->num_params; i++) {
+         const struct glsl_function_param *param =
+            glsl_get_function_param(func_type, i);
+         func->params[i].type = param->type;
+         if (param->in) {
+            if (param->out) {
+               func->params[i].param_type = nir_parameter_inout;
+            } else {
+               func->params[i].param_type = nir_parameter_in;
+            }
+         } else {
+            if (param->out) {
+               func->params[i].param_type = nir_parameter_out;
+            } else {
+               assert(!"Parameter is neither in nor out");
+            }
+         }
+      }
+
+      func->return_type = glsl_get_function_return_type(func_type);
+
+      b->func->impl = nir_function_impl_create(func);
+
+      b->func_param_idx = 0;
+      break;
+   }
+
+   case SpvOpFunctionEnd:
+      b->func->end = w;
+      b->func = NULL;
+      break;
+
+   case SpvOpFunctionParameter: {
+      struct vtn_value *val =
+         vtn_push_value(b, w[2], vtn_value_type_access_chain);
+
+      struct vtn_type *type = vtn_value(b, w[1], vtn_value_type_type)->type;
+
+      assert(b->func_param_idx < b->func->impl->num_params);
+      nir_variable *param = b->func->impl->params[b->func_param_idx++];
+
+      assert(param->type == type->type);
+
+      /* Name the parameter so it shows up nicely in NIR */
+      param->name = ralloc_strdup(param, val->name);
+
+      struct vtn_variable *vtn_var = rzalloc(b, struct vtn_variable);
+      vtn_var->type = type;
+      vtn_var->var = param;
+      vtn_var->chain.var = vtn_var;
+      vtn_var->chain.length = 0;
+
+      struct vtn_type *without_array = type;
+      while(glsl_type_is_array(without_array->type))
+         without_array = without_array->array_element;
+
+      if (glsl_type_is_image(without_array->type)) {
+         vtn_var->mode = vtn_variable_mode_image;
+         param->interface_type = without_array->type;
+      } else if (glsl_type_is_sampler(without_array->type)) {
+         vtn_var->mode = vtn_variable_mode_sampler;
+         param->interface_type = without_array->type;
+      } else {
+         vtn_var->mode = vtn_variable_mode_param;
+      }
+
+      val->access_chain = &vtn_var->chain;
+      break;
+   }
+
+   case SpvOpLabel: {
+      assert(b->block == NULL);
+      b->block = rzalloc(b, struct vtn_block);
+      b->block->node.type = vtn_cf_node_type_block;
+      b->block->label = w;
+      vtn_push_value(b, w[1], vtn_value_type_block)->block = b->block;
+
+      if (b->func->start_block == NULL) {
+         /* This is the first block encountered for this function.  In this
+          * case, we set the start block and add it to the list of
+          * implemented functions that we'll walk later.
+          */
+         b->func->start_block = b->block;
+         exec_list_push_tail(&b->functions, &b->func->node);
+      }
+      break;
+   }
+
+   case SpvOpSelectionMerge:
+   case SpvOpLoopMerge:
+      assert(b->block && b->block->merge == NULL);
+      b->block->merge = w;
+      break;
+
+   case SpvOpBranch:
+   case SpvOpBranchConditional:
+   case SpvOpSwitch:
+   case SpvOpKill:
+   case SpvOpReturn:
+   case SpvOpReturnValue:
+   case SpvOpUnreachable:
+      assert(b->block && b->block->branch == NULL);
+      b->block->branch = w;
+      b->block = NULL;
+      break;
+
+   default:
+      /* Continue on as per normal */
+      return true;
+   }
+
+   return true;
+}
+
+static void
+vtn_add_case(struct vtn_builder *b, struct vtn_switch *swtch,
+             struct vtn_block *break_block,
+             uint32_t block_id, uint32_t val, bool is_default)
+{
+   struct vtn_block *case_block =
+      vtn_value(b, block_id, vtn_value_type_block)->block;
+
+   /* Don't create dummy cases that just break */
+   if (case_block == break_block)
+      return;
+
+   if (case_block->switch_case == NULL) {
+      struct vtn_case *c = ralloc(b, struct vtn_case);
+
+      list_inithead(&c->body);
+      c->start_block = case_block;
+      c->fallthrough = NULL;
+      nir_array_init(&c->values, b);
+      c->is_default = false;
+      c->visited = false;
+
+      list_addtail(&c->link, &swtch->cases);
+
+      case_block->switch_case = c;
+   }
+
+   if (is_default) {
+      case_block->switch_case->is_default = true;
+   } else {
+      nir_array_add(&case_block->switch_case->values, uint32_t, val);
+   }
+}
+
+/* This function performs a depth-first search of the cases and puts them
+ * in fall-through order.
+ */
+static void
+vtn_order_case(struct vtn_switch *swtch, struct vtn_case *cse)
+{
+   if (cse->visited)
+      return;
+
+   cse->visited = true;
+
+   list_del(&cse->link);
+
+   if (cse->fallthrough) {
+      vtn_order_case(swtch, cse->fallthrough);
+
+      /* If we have a fall-through, place this case right before the case it
+       * falls through to.  This ensures that fallthroughs come one after
+       * the other.  These two can never get separated because that would
+       * imply something else falling through to the same case.  Also, this
+       * can't break ordering because the DFS ensures that this case is
+       * visited before anything that falls through to it.
+       */
+      list_addtail(&cse->link, &cse->fallthrough->link);
+   } else {
+      list_add(&cse->link, &swtch->cases);
+   }
+}
+
+static enum vtn_branch_type
+vtn_get_branch_type(struct vtn_block *block,
+                    struct vtn_case *swcase, struct vtn_block *switch_break,
+                    struct vtn_block *loop_break, struct vtn_block *loop_cont)
+{
+   if (block->switch_case) {
+      /* This branch is actually a fallthrough */
+      assert(swcase->fallthrough == NULL ||
+             swcase->fallthrough == block->switch_case);
+      swcase->fallthrough = block->switch_case;
+      return vtn_branch_type_switch_fallthrough;
+   } else if (block == switch_break) {
+      return vtn_branch_type_switch_break;
+   } else if (block == loop_break) {
+      return vtn_branch_type_loop_break;
+   } else if (block == loop_cont) {
+      return vtn_branch_type_loop_continue;
+   } else {
+      return vtn_branch_type_none;
+   }
+}
+
+static void
+vtn_cfg_walk_blocks(struct vtn_builder *b, struct list_head *cf_list,
+                    struct vtn_block *start, struct vtn_case *switch_case,
+                    struct vtn_block *switch_break,
+                    struct vtn_block *loop_break, struct vtn_block *loop_cont,
+                    struct vtn_block *end)
+{
+   struct vtn_block *block = start;
+   while (block != end) {
+      if (block->merge && (*block->merge & SpvOpCodeMask) == SpvOpLoopMerge &&
+          !block->loop) {
+         struct vtn_loop *loop = ralloc(b, struct vtn_loop);
+
+         loop->node.type = vtn_cf_node_type_loop;
+         list_inithead(&loop->body);
+         list_inithead(&loop->cont_body);
+         loop->control = block->merge[3];
+
+         list_addtail(&loop->node.link, cf_list);
+         block->loop = loop;
+
+         struct vtn_block *new_loop_break =
+            vtn_value(b, block->merge[1], vtn_value_type_block)->block;
+         struct vtn_block *new_loop_cont =
+            vtn_value(b, block->merge[2], vtn_value_type_block)->block;
+
+         /* Note: This recursive call will start with the current block as
+          * its start block.  If we weren't careful, we would get here
+          * again and end up in infinite recursion.  This is why we set
+          * block->loop above and check for it before creating one.  This
+          * way, we only create the loop once and the second call that
+          * tries to handle this loop goes to the cases below and gets
+          * handled as a regular block.
+          *
+          * Note: When we make the recursive walk calls, we pass NULL for
+          * the switch break since you have to break out of the loop first.
+          * We do, however, still pass the current switch case because it's
+          * possible that the merge block for the loop is the start of
+          * another case.
+          */
+         vtn_cfg_walk_blocks(b, &loop->body, block, switch_case, NULL,
+                             new_loop_break, new_loop_cont, NULL );
+         vtn_cfg_walk_blocks(b, &loop->cont_body, new_loop_cont, NULL, NULL,
+                             new_loop_break, NULL, block);
+
+         block = new_loop_break;
+         continue;
+      }
+
+      assert(block->node.link.next == NULL);
+      list_addtail(&block->node.link, cf_list);
+
+      switch (*block->branch & SpvOpCodeMask) {
+      case SpvOpBranch: {
+         struct vtn_block *branch_block =
+            vtn_value(b, block->branch[1], vtn_value_type_block)->block;
+
+         block->branch_type = vtn_get_branch_type(branch_block,
+                                                  switch_case, switch_break,
+                                                  loop_break, loop_cont);
+
+         if (block->branch_type != vtn_branch_type_none)
+            return;
+
+         block = branch_block;
+         continue;
+      }
+
+      case SpvOpReturn:
+      case SpvOpReturnValue:
+         block->branch_type = vtn_branch_type_return;
+         return;
+
+      case SpvOpKill:
+         block->branch_type = vtn_branch_type_discard;
+         return;
+
+      case SpvOpBranchConditional: {
+         struct vtn_block *then_block =
+            vtn_value(b, block->branch[2], vtn_value_type_block)->block;
+         struct vtn_block *else_block =
+            vtn_value(b, block->branch[3], vtn_value_type_block)->block;
+
+         struct vtn_if *if_stmt = ralloc(b, struct vtn_if);
+
+         if_stmt->node.type = vtn_cf_node_type_if;
+         if_stmt->condition = block->branch[1];
+         list_inithead(&if_stmt->then_body);
+         list_inithead(&if_stmt->else_body);
+
+         list_addtail(&if_stmt->node.link, cf_list);
+
+         if (block->merge &&
+             (*block->merge & SpvOpCodeMask) == SpvOpSelectionMerge) {
+            if_stmt->control = block->merge[2];
+         }
+
+         if_stmt->then_type = vtn_get_branch_type(then_block,
+                                                  switch_case, switch_break,
+                                                  loop_break, loop_cont);
+         if_stmt->else_type = vtn_get_branch_type(else_block,
+                                                  switch_case, switch_break,
+                                                  loop_break, loop_cont);
+
+         if (if_stmt->then_type == vtn_branch_type_none &&
+             if_stmt->else_type == vtn_branch_type_none) {
+            /* Neither side of the if is something we can short-circuit. */
+            assert((*block->merge & SpvOpCodeMask) == SpvOpSelectionMerge);
+            struct vtn_block *merge_block =
+               vtn_value(b, block->merge[1], vtn_value_type_block)->block;
+
+            vtn_cfg_walk_blocks(b, &if_stmt->then_body, then_block,
+                                switch_case, switch_break,
+                                loop_break, loop_cont, merge_block);
+            vtn_cfg_walk_blocks(b, &if_stmt->else_body, else_block,
+                                switch_case, switch_break,
+                                loop_break, loop_cont, merge_block);
+
+            enum vtn_branch_type merge_type =
+               vtn_get_branch_type(merge_block, switch_case, switch_break,
+                                   loop_break, loop_cont);
+            if (merge_type == vtn_branch_type_none) {
+               block = merge_block;
+               continue;
+            } else {
+               return;
+            }
+         } else if (if_stmt->then_type != vtn_branch_type_none &&
+                    if_stmt->else_type != vtn_branch_type_none) {
+            /* Both sides were short-circuited.  We're done here. */
+            return;
+         } else {
+            /* Exeactly one side of the branch could be short-circuited.
+             * We set the branch up as a predicated break/continue and we
+             * continue on with the other side as if it were what comes
+             * after the if.
+             */
+            if (if_stmt->then_type == vtn_branch_type_none) {
+               block = then_block;
+            } else {
+               block = else_block;
+            }
+            continue;
+         }
+         unreachable("Should have returned or continued");
+      }
+
+      case SpvOpSwitch: {
+         assert((*block->merge & SpvOpCodeMask) == SpvOpSelectionMerge);
+         struct vtn_block *break_block =
+            vtn_value(b, block->merge[1], vtn_value_type_block)->block;
+
+         struct vtn_switch *swtch = ralloc(b, struct vtn_switch);
+
+         swtch->node.type = vtn_cf_node_type_switch;
+         swtch->selector = block->branch[1];
+         list_inithead(&swtch->cases);
+
+         list_addtail(&swtch->node.link, cf_list);
+
+         /* First, we go through and record all of the cases. */
+         const uint32_t *branch_end =
+            block->branch + (block->branch[0] >> SpvWordCountShift);
+
+         vtn_add_case(b, swtch, break_block, block->branch[2], 0, true);
+         for (const uint32_t *w = block->branch + 3; w < branch_end; w += 2)
+            vtn_add_case(b, swtch, break_block, w[1], w[0], false);
+
+         /* Now, we go through and walk the blocks.  While we walk through
+          * the blocks, we also gather the much-needed fall-through
+          * information.
+          */
+         list_for_each_entry(struct vtn_case, cse, &swtch->cases, link) {
+            assert(cse->start_block != break_block);
+            vtn_cfg_walk_blocks(b, &cse->body, cse->start_block, cse,
+                                break_block, NULL, loop_cont, NULL);
+         }
+
+         /* Finally, we walk over all of the cases one more time and put
+          * them in fall-through order.
+          */
+         for (const uint32_t *w = block->branch + 2; w < branch_end; w += 2) {
+            struct vtn_block *case_block =
+               vtn_value(b, *w, vtn_value_type_block)->block;
+
+            if (case_block == break_block)
+               continue;
+
+            assert(case_block->switch_case);
+
+            vtn_order_case(swtch, case_block->switch_case);
+         }
+
+         block = break_block;
+         continue;
+      }
+
+      case SpvOpUnreachable:
+         return;
+
+      default:
+         unreachable("Unhandled opcode");
+      }
+   }
+}
+
+void
+vtn_build_cfg(struct vtn_builder *b, const uint32_t *words, const uint32_t *end)
+{
+   vtn_foreach_instruction(b, words, end,
+                           vtn_cfg_handle_prepass_instruction);
+
+   foreach_list_typed(struct vtn_function, func, node, &b->functions) {
+      vtn_cfg_walk_blocks(b, &func->body, func->start_block,
+                          NULL, NULL, NULL, NULL, NULL);
+   }
+}
+
+static bool
+vtn_handle_phis_first_pass(struct vtn_builder *b, SpvOp opcode,
+                           const uint32_t *w, unsigned count)
+{
+   if (opcode == SpvOpLabel)
+      return true; /* Nothing to do */
+
+   /* If this isn't a phi node, stop. */
+   if (opcode != SpvOpPhi)
+      return false;
+
+   /* For handling phi nodes, we do a poor-man's out-of-ssa on the spot.
+    * For each phi, we create a variable with the appropreate type and
+    * do a load from that variable.  Then, in a second pass, we add
+    * stores to that variable to each of the predecessor blocks.
+    *
+    * We could do something more intelligent here.  However, in order to
+    * handle loops and things properly, we really need dominance
+    * information.  It would end up basically being the into-SSA
+    * algorithm all over again.  It's easier if we just let
+    * lower_vars_to_ssa do that for us instead of repeating it here.
+    */
+   struct vtn_value *val = vtn_push_value(b, w[2], vtn_value_type_ssa);
+
+   struct vtn_type *type = vtn_value(b, w[1], vtn_value_type_type)->type;
+   nir_variable *phi_var =
+      nir_local_variable_create(b->nb.impl, type->type, "phi");
+   _mesa_hash_table_insert(b->phi_table, w, phi_var);
+
+   val->ssa = vtn_local_load(b, nir_deref_var_create(b, phi_var));
+
+   return true;
+}
+
+static bool
+vtn_handle_phi_second_pass(struct vtn_builder *b, SpvOp opcode,
+                           const uint32_t *w, unsigned count)
+{
+   if (opcode != SpvOpPhi)
+      return true;
+
+   struct hash_entry *phi_entry = _mesa_hash_table_search(b->phi_table, w);
+   assert(phi_entry);
+   nir_variable *phi_var = phi_entry->data;
+
+   for (unsigned i = 3; i < count; i += 2) {
+      struct vtn_ssa_value *src = vtn_ssa_value(b, w[i]);
+      struct vtn_block *pred =
+         vtn_value(b, w[i + 1], vtn_value_type_block)->block;
+
+      b->nb.cursor = nir_after_block_before_jump(pred->end_block);
+
+      vtn_local_store(b, src, nir_deref_var_create(b, phi_var));
+   }
+
+   return true;
+}
+
+static void
+vtn_emit_branch(struct vtn_builder *b, enum vtn_branch_type branch_type,
+                nir_variable *switch_fall_var, bool *has_switch_break)
+{
+   switch (branch_type) {
+   case vtn_branch_type_switch_break:
+      nir_store_var(&b->nb, switch_fall_var, nir_imm_int(&b->nb, NIR_FALSE), 1);
+      *has_switch_break = true;
+      break;
+   case vtn_branch_type_switch_fallthrough:
+      break; /* Nothing to do */
+   case vtn_branch_type_loop_break:
+      nir_jump(&b->nb, nir_jump_break);
+      break;
+   case vtn_branch_type_loop_continue:
+      nir_jump(&b->nb, nir_jump_continue);
+      break;
+   case vtn_branch_type_return:
+      nir_jump(&b->nb, nir_jump_return);
+      break;
+   case vtn_branch_type_discard: {
+      nir_intrinsic_instr *discard =
+         nir_intrinsic_instr_create(b->nb.shader, nir_intrinsic_discard);
+      nir_builder_instr_insert(&b->nb, &discard->instr);
+      break;
+   }
+   default:
+      unreachable("Invalid branch type");
+   }
+}
+
+static void
+vtn_emit_cf_list(struct vtn_builder *b, struct list_head *cf_list,
+                 nir_variable *switch_fall_var, bool *has_switch_break,
+                 vtn_instruction_handler handler)
+{
+   list_for_each_entry(struct vtn_cf_node, node, cf_list, link) {
+      switch (node->type) {
+      case vtn_cf_node_type_block: {
+         struct vtn_block *block = (struct vtn_block *)node;
+
+         const uint32_t *block_start = block->label;
+         const uint32_t *block_end = block->merge ? block->merge :
+                                                    block->branch;
+
+         block_start = vtn_foreach_instruction(b, block_start, block_end,
+                                               vtn_handle_phis_first_pass);
+
+         vtn_foreach_instruction(b, block_start, block_end, handler);
+
+         block->end_block = nir_cursor_current_block(b->nb.cursor);
+
+         if ((*block->branch & SpvOpCodeMask) == SpvOpReturnValue) {
+            struct vtn_ssa_value *src = vtn_ssa_value(b, block->branch[1]);
+            vtn_local_store(b, src,
+                            nir_deref_var_create(b, b->impl->return_var));
+         }
+
+         if (block->branch_type != vtn_branch_type_none) {
+            vtn_emit_branch(b, block->branch_type,
+                            switch_fall_var, has_switch_break);
+         }
+
+         break;
+      }
+
+      case vtn_cf_node_type_if: {
+         struct vtn_if *vtn_if = (struct vtn_if *)node;
+
+         nir_if *if_stmt = nir_if_create(b->shader);
+         if_stmt->condition =
+            nir_src_for_ssa(vtn_ssa_value(b, vtn_if->condition)->def);
+         nir_cf_node_insert(b->nb.cursor, &if_stmt->cf_node);
+
+         bool sw_break = false;
+
+         b->nb.cursor = nir_after_cf_list(&if_stmt->then_list);
+         if (vtn_if->then_type == vtn_branch_type_none) {
+            vtn_emit_cf_list(b, &vtn_if->then_body,
+                             switch_fall_var, &sw_break, handler);
+         } else {
+            vtn_emit_branch(b, vtn_if->then_type, switch_fall_var, &sw_break);
+         }
+
+         b->nb.cursor = nir_after_cf_list(&if_stmt->else_list);
+         if (vtn_if->else_type == vtn_branch_type_none) {
+            vtn_emit_cf_list(b, &vtn_if->else_body,
+                             switch_fall_var, &sw_break, handler);
+         } else {
+            vtn_emit_branch(b, vtn_if->else_type, switch_fall_var, &sw_break);
+         }
+
+         b->nb.cursor = nir_after_cf_node(&if_stmt->cf_node);
+
+         /* If we encountered a switch break somewhere inside of the if,
+          * then it would have been handled correctly by calling
+          * emit_cf_list or emit_branch for the interrior.  However, we
+          * need to predicate everything following on wether or not we're
+          * still going.
+          */
+         if (sw_break) {
+            *has_switch_break = true;
+
+            nir_if *switch_if = nir_if_create(b->shader);
+            switch_if->condition =
+               nir_src_for_ssa(nir_load_var(&b->nb, switch_fall_var));
+            nir_cf_node_insert(b->nb.cursor, &switch_if->cf_node);
+
+            b->nb.cursor = nir_after_cf_list(&if_stmt->then_list);
+         }
+         break;
+      }
+
+      case vtn_cf_node_type_loop: {
+         struct vtn_loop *vtn_loop = (struct vtn_loop *)node;
+
+         nir_loop *loop = nir_loop_create(b->shader);
+         nir_cf_node_insert(b->nb.cursor, &loop->cf_node);
+
+         b->nb.cursor = nir_after_cf_list(&loop->body);
+         vtn_emit_cf_list(b, &vtn_loop->body, NULL, NULL, handler);
+
+         if (!list_empty(&vtn_loop->cont_body)) {
+            /* If we have a non-trivial continue body then we need to put
+             * it at the beginning of the loop with a flag to ensure that
+             * it doesn't get executed in the first iteration.
+             */
+            nir_variable *do_cont =
+               nir_local_variable_create(b->nb.impl, glsl_bool_type(), "cont");
+
+            b->nb.cursor = nir_before_cf_node(&loop->cf_node);
+            nir_store_var(&b->nb, do_cont, nir_imm_int(&b->nb, NIR_FALSE), 1);
+
+            b->nb.cursor = nir_before_cf_list(&loop->body);
+            nir_if *cont_if = nir_if_create(b->shader);
+            cont_if->condition = nir_src_for_ssa(nir_load_var(&b->nb, do_cont));
+            nir_cf_node_insert(b->nb.cursor, &cont_if->cf_node);
+
+            b->nb.cursor = nir_after_cf_list(&cont_if->then_list);
+            vtn_emit_cf_list(b, &vtn_loop->cont_body, NULL, NULL, handler);
+
+            b->nb.cursor = nir_after_cf_node(&cont_if->cf_node);
+            nir_store_var(&b->nb, do_cont, nir_imm_int(&b->nb, NIR_TRUE), 1);
+
+            b->has_loop_continue = true;
+         }
+
+         b->nb.cursor = nir_after_cf_node(&loop->cf_node);
+         break;
+      }
+
+      case vtn_cf_node_type_switch: {
+         struct vtn_switch *vtn_switch = (struct vtn_switch *)node;
+
+         /* First, we create a variable to keep track of whether or not the
+          * switch is still going at any given point.  Any switch breaks
+          * will set this variable to false.
+          */
+         nir_variable *fall_var =
+            nir_local_variable_create(b->nb.impl, glsl_bool_type(), "fall");
+         nir_store_var(&b->nb, fall_var, nir_imm_int(&b->nb, NIR_FALSE), 1);
+
+         /* Next, we gather up all of the conditions.  We have to do this
+          * up-front because we also need to build an "any" condition so
+          * that we can use !any for default.
+          */
+         const int num_cases = list_length(&vtn_switch->cases);
+         NIR_VLA(nir_ssa_def *, conditions, num_cases);
+
+         nir_ssa_def *sel = vtn_ssa_value(b, vtn_switch->selector)->def;
+         /* An accumulation of all conditions.  Used for the default */
+         nir_ssa_def *any = NULL;
+
+         int i = 0;
+         list_for_each_entry(struct vtn_case, cse, &vtn_switch->cases, link) {
+            if (cse->is_default) {
+               conditions[i++] = NULL;
+               continue;
+            }
+
+            nir_ssa_def *cond = NULL;
+            nir_array_foreach(&cse->values, uint32_t, val) {
+               nir_ssa_def *is_val =
+                  nir_ieq(&b->nb, sel, nir_imm_int(&b->nb, *val));
+
+               cond = cond ? nir_ior(&b->nb, cond, is_val) : is_val;
+            }
+
+            any = any ? nir_ior(&b->nb, any, cond) : cond;
+            conditions[i++] = cond;
+         }
+         assert(i == num_cases);
+
+         /* Now we can walk the list of cases and actually emit code */
+         i = 0;
+         list_for_each_entry(struct vtn_case, cse, &vtn_switch->cases, link) {
+            /* Figure out the condition */
+            nir_ssa_def *cond = conditions[i++];
+            if (cse->is_default) {
+               assert(cond == NULL);
+               cond = nir_inot(&b->nb, any);
+            }
+            /* Take fallthrough into account */
+            cond = nir_ior(&b->nb, cond, nir_load_var(&b->nb, fall_var));
+
+            nir_if *case_if = nir_if_create(b->nb.shader);
+            case_if->condition = nir_src_for_ssa(cond);
+            nir_cf_node_insert(b->nb.cursor, &case_if->cf_node);
+
+            bool has_break = false;
+            b->nb.cursor = nir_after_cf_list(&case_if->then_list);
+            nir_store_var(&b->nb, fall_var, nir_imm_int(&b->nb, NIR_TRUE), 1);
+            vtn_emit_cf_list(b, &cse->body, fall_var, &has_break, handler);
+            (void)has_break; /* We don't care */
+
+            b->nb.cursor = nir_after_cf_node(&case_if->cf_node);
+         }
+         assert(i == num_cases);
+
+         break;
+      }
+
+      default:
+         unreachable("Invalid CF node type");
+      }
+   }
+}
+
+void
+vtn_function_emit(struct vtn_builder *b, struct vtn_function *func,
+                  vtn_instruction_handler instruction_handler)
+{
+   nir_builder_init(&b->nb, func->impl);
+   b->nb.cursor = nir_after_cf_list(&func->impl->body);
+   b->has_loop_continue = false;
+   b->phi_table = _mesa_hash_table_create(b, _mesa_hash_pointer,
+                                          _mesa_key_pointer_equal);
+
+   vtn_emit_cf_list(b, &func->body, NULL, NULL, instruction_handler);
+
+   vtn_foreach_instruction(b, func->start_block->label, func->end,
+                           vtn_handle_phi_second_pass);
+
+   /* Continue blocks for loops get inserted before the body of the loop
+    * but instructions in the continue may use SSA defs in the loop body.
+    * Therefore, we need to repair SSA to insert the needed phi nodes.
+    */
+   if (b->has_loop_continue)
+      nir_repair_ssa_impl(func->impl);
+}