nir/spirv: Hanle continues that use SSA values from the loop body

Instead of emitting the continue before the loop body we emit it
afterwards.  Then, once we've finished with the entire function, we run
nir_repair_ssa to add whatever phi nodes are needed.

diff --git a/src/glsl/nir/spirv/vtn_cfg.c b/src/glsl/nir/spirv/vtn_cfg.c
index b3061ce47bb7b4b7c1a06debee18d2881db0022c..a57a44363dd2fd0aba32299e2a19925e6ebe02a5 100644 (file)
--- a/src/glsl/nir/spirv/vtn_cfg.c
+++ b/src/glsl/nir/spirv/vtn_cfg.c
@@ -559,6 +559,9 @@ vtn_emit_cf_list(struct vtn_builder *b, struct list_head *cf_list,
          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
@@ -570,7 +573,7 @@ vtn_emit_cf_list(struct vtn_builder *b, struct list_head *cf_list,
             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_after_cf_list(&loop->body);
+            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);
@@ -580,10 +583,9 @@ vtn_emit_cf_list(struct vtn_builder *b, struct list_head *cf_list,
 
             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->nb.cursor = nir_after_cf_list(&loop->body);
-         vtn_emit_cf_list(b, &vtn_loop->body, NULL, NULL, handler);
+            b->has_loop_continue = true;
+         }
 
          b->nb.cursor = nir_after_cf_node(&loop->cf_node);
          break;
@@ -672,5 +674,14 @@ vtn_function_emit(struct vtn_builder *b, struct vtn_function *func,
 {
    nir_builder_init(&b->nb, func->impl);
    b->nb.cursor = nir_after_cf_list(&func->impl->body);
+   b->has_loop_continue = false;
+
    vtn_emit_cf_list(b, &func->body, NULL, NULL, instruction_handler);
+
+   /* 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);
 }

diff --git a/src/glsl/nir/spirv/vtn_private.h b/src/glsl/nir/spirv/vtn_private.h
index 129414a4001183631b58163ceeef62b29ae30217..f91330ad48666ae354c7d31f7acef52cb32be3bd 100644 (file)
--- a/src/glsl/nir/spirv/vtn_private.h
+++ b/src/glsl/nir/spirv/vtn_private.h
@@ -334,6 +334,8 @@ struct vtn_builder {
 
    /* Current function parameter index */
    unsigned func_param_idx;
+
+   bool has_loop_continue;
 };
 
 static inline struct vtn_value *