Mesa (master): glsl: Return ir_variable from compare_index_block

[Ian Romanick]

Module: Mesa
Branch: master
Commit: 1f4fcdb2cabcc2cc8cdce87b5d233f3639cf378e
URL:    http://cgit.freedesktop.org/mesa/mesa/commit/?id=1f4fcdb2cabcc2cc8cdce87b5d233f3639cf378e

Author: Ian Romanick <ian.d.romanick at intel.com>
Date:   Thu Sep 14 18:20:14 2017 -0700

glsl: Return ir_variable from compare_index_block

This is basically a wash now, but it simplifies later patches that
convert to using ir_builder.

Signed-off-by: Ian Romanick <ian.d.romanick at intel.com>
Reviewed-by: Alejandro Piñeiro <apinheiro at igalia.com>
Reviewed-by: Thomas Helland <thomashelland90 at gmail.com>

---

 src/compiler/glsl/ir_optimization.h                |  6 ++---
 .../glsl/lower_variable_index_to_cond_assign.cpp   | 26 +++++++++++++---------
 .../glsl/lower_vec_index_to_cond_assign.cpp        |  4 ++--
 3 files changed, 20 insertions(+), 16 deletions(-)

diff --git a/src/compiler/glsl/ir_optimization.h b/src/compiler/glsl/ir_optimization.h
index 573ddb4a8d..0fbbf34595 100644
--- a/src/compiler/glsl/ir_optimization.h
+++ b/src/compiler/glsl/ir_optimization.h
@@ -170,9 +170,9 @@ bool lower_blend_equation_advanced(gl_linked_shader *shader);
 bool lower_subroutine(exec_list *instructions, struct _mesa_glsl_parse_state *state);
 void propagate_invariance(exec_list *instructions);
 
-ir_rvalue *
-compare_index_block(exec_list *instructions, ir_variable *index,
-		    unsigned base, unsigned components, void *mem_ctx);
+ir_variable *compare_index_block(exec_list *instructions, ir_variable *index,
+                                 unsigned base, unsigned components,
+                                 void *mem_ctx);
 
 bool lower_64bit_integer_instructions(exec_list *instructions,
                                       unsigned what_to_lower);
diff --git a/src/compiler/glsl/lower_variable_index_to_cond_assign.cpp b/src/compiler/glsl/lower_variable_index_to_cond_assign.cpp
index fcb12d1b77..dd49272abb 100644
--- a/src/compiler/glsl/lower_variable_index_to_cond_assign.cpp
+++ b/src/compiler/glsl/lower_variable_index_to_cond_assign.cpp
@@ -66,10 +66,10 @@
  * \param mem_ctx       ralloc memory context to be used for all allocations.
  *
  * \returns
- * An \c ir_rvalue that \b must be cloned for each use in conditional
- * assignments, etc.
+ * An \c ir_variable containing the per-component comparison results.  This
+ * must be dereferenced per use.
  */
-ir_rvalue *
+ir_variable *
 compare_index_block(exec_list *instructions, ir_variable *index,
 		    unsigned base, unsigned components, void *mem_ctx)
 {
@@ -113,7 +113,7 @@ compare_index_block(exec_list *instructions, ir_variable *index,
       new(mem_ctx) ir_dereference_variable(condition);
    instructions->push_tail(new(mem_ctx) ir_assignment(cond_deref, condition_val, 0));
 
-   return cond_deref;
+   return condition;
 }
 
 static inline bool
@@ -275,17 +275,21 @@ struct switch_generator
       for (unsigned i = first; i < end; i += 4) {
          const unsigned comps = MIN2(condition_components, end - i);
 
-	 ir_rvalue *const cond_deref =
-	    compare_index_block(list, index, i, comps, this->mem_ctx);
+         ir_variable *const cond =
+            compare_index_block(list, index, i, comps, this->mem_ctx);
 
          if (comps == 1) {
-            this->generator.generate(i, cond_deref->clone(this->mem_ctx, NULL),
-				     list);
+            ir_rvalue *const cond_deref =
+               new(mem_ctx) ir_dereference_variable(cond);
+
+            this->generator.generate(i, cond_deref, list);
          } else {
             for (unsigned j = 0; j < comps; j++) {
-	       ir_rvalue *const cond_swiz =
-		  new(this->mem_ctx) ir_swizzle(cond_deref->clone(this->mem_ctx, NULL),
-						j, 0, 0, 0, 1);
+               ir_rvalue *const cond_deref =
+                  new(mem_ctx) ir_dereference_variable(cond);
+               ir_rvalue *const cond_swiz =
+                  new(this->mem_ctx) ir_swizzle(cond_deref,
+                                                j, 0, 0, 0, 1);
 
                this->generator.generate(i + j, cond_swiz, list);
             }
diff --git a/src/compiler/glsl/lower_vec_index_to_cond_assign.cpp b/src/compiler/glsl/lower_vec_index_to_cond_assign.cpp
index 597d852c76..f60ff7b77f 100644
--- a/src/compiler/glsl/lower_vec_index_to_cond_assign.cpp
+++ b/src/compiler/glsl/lower_vec_index_to_cond_assign.cpp
@@ -115,7 +115,7 @@ ir_vec_index_to_cond_assign_visitor::convert_vec_index_to_cond_assign(void *mem_
    /* Generate a single comparison condition "mask" for all of the components
     * in the vector.
     */
-   ir_rvalue *const cond_deref =
+   ir_variable *const cond =
       compare_index_block(&list, index, 0,
                           orig_vector->type->vector_elements,
                           mem_ctx);
@@ -123,7 +123,7 @@ ir_vec_index_to_cond_assign_visitor::convert_vec_index_to_cond_assign(void *mem_
    /* Generate a conditional move of each vector element to the temp. */
    for (i = 0; i < orig_vector->type->vector_elements; i++) {
       ir_rvalue *condition_swizzle =
-         new(base_ir) ir_swizzle(cond_deref->clone(mem_ctx, NULL),
+         new(base_ir) ir_swizzle(new(mem_ctx) ir_dereference_variable(cond),
                                  i, 0, 0, 0, 1);
 
       /* Just clone the rest of the deref chain when trying to get at the