[Mesa-dev] [PATCH 06/10] glsl: copy function out to temp if we don't directly ref a variable

[Timothy Arceri]

Otherwise we can end up with IR that looks like this:

    (
      (declare (temporary ) vec4 f at 8)
      (assign  (xyzw) (var_ref f at 8)  (var_ref f) )
      (call f16  ((swiz y (var_ref f at 8) )))

      (assign  (xyzw) (var_ref f)  (var_ref f at 8) )
    ))

When we really need:

      (declare (temporary ) float inout_tmp)
      (assign  (x) (var_ref inout_tmp)  (swiz y (var_ref f) ))
      (call f16  ((var_ref inout_tmp) ))

      (assign  (y) (var_ref f)  (swiz y (swiz xxxx (var_ref inout_tmp) )))
      (declare (temporary ) void void_var)

The GLSL IR function inlining code seemed to produce correct code
even without this but we need the correct IR for GLSL IR -> NIR to
be able to understand whats going on.
---
 src/compiler/glsl/ast_function.cpp | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/src/compiler/glsl/ast_function.cpp b/src/compiler/glsl/ast_function.cpp
index eab18446ef8..fff911e76d0 100644
--- a/src/compiler/glsl/ast_function.cpp
+++ b/src/compiler/glsl/ast_function.cpp
@@ -446,7 +446,8 @@ fix_parameter(void *mem_ctx, ir_rvalue *actual, const glsl_type *formal_type,
     * nothing needs to be done to fix the parameter.
     */
    if (formal_type == actual->type
-       && (expr == NULL || expr->operation != ir_binop_vector_extract))
+       && (expr == NULL || expr->operation != ir_binop_vector_extract) &&
+       actual->as_dereference_variable())
       return;
 
    /* An array index could also be an out variable so we need to make a copy
@@ -496,7 +497,7 @@ fix_parameter(void *mem_ctx, ir_rvalue *actual, const glsl_type *formal_type,
       ir_dereference_variable *const deref_tmp_1 =
          new(mem_ctx) ir_dereference_variable(tmp);
       ir_assignment *const assignment =
-         new(mem_ctx) ir_assignment(deref_tmp_1, actual);
+         new(mem_ctx) ir_assignment(deref_tmp_1, actual->clone(mem_ctx, NULL));
       before_instructions->push_tail(assignment);
    }
 
-- 
2.17.0