[Mesa-dev] [PATCH] glsl: fix lower jumps for nested non-void returns

[Timothy Arceri]

Fixes the case were a loop contains a return and the loop is
nested inside an if.

https://bugs.freedesktop.org/show_bug.cgi?id=100303
---
 src/compiler/glsl/lower_jumps.cpp                        | 6 ++++++
 src/compiler/glsl/tests/lower_jumps/create_test_cases.py | 5 ++++-
 2 files changed, 10 insertions(+), 1 deletion(-)

diff --git a/src/compiler/glsl/lower_jumps.cpp b/src/compiler/glsl/lower_jumps.cpp
index e165172..7dc3405 100644
--- a/src/compiler/glsl/lower_jumps.cpp
+++ b/src/compiler/glsl/lower_jumps.cpp
@@ -938,20 +938,26 @@ lower_continue:
              * those instructions into the else clause of the generated if
              * statement.
              */
             move_outer_block_inside(ir, &return_if->else_instructions);
 
             /* In case the loop is embedded inside an if add a new return to
              * the return flag then branch and let a future pass tidy it up.
              */
             if (this->function.signature->return_type->is_void())
                return_if->then_instructions.push_tail(new(ir) ir_return(NULL));
+            else {
+               assert(this->function.return_value);
+               ir_variable* return_value = this->function.return_value;
+               return_if->then_instructions.push_tail(
+                  new(ir) ir_return(new(ir) ir_dereference_variable(return_value)));
+            }
          }
 
          ir->insert_after(return_if);
       }
 
       this->loop = saved_loop;
       --this->function.nesting_depth;
    }
 
    virtual void visit(ir_function_signature *ir)
diff --git a/src/compiler/glsl/tests/lower_jumps/create_test_cases.py b/src/compiler/glsl/tests/lower_jumps/create_test_cases.py
index 20f5ace..623487e 100644
--- a/src/compiler/glsl/tests/lower_jumps/create_test_cases.py
+++ b/src/compiler/glsl/tests/lower_jumps/create_test_cases.py
@@ -621,21 +621,24 @@ def test_lower_return_non_void_at_end_of_loop():
             assign_x('b', const_float(3)) +
             return_(const_float(4))
             ))
     expected_sexp = make_test_case('sub', 'float', (
             declare_execute_flag() +
             declare_return_value() +
             declare_return_flag() +
             loop(assign_x('a', const_float(1)) +
                  lowered_return_simple(const_float(2)) +
                  break_()) +
-            if_not_return_flag(assign_x('b', const_float(3)) +
+            if_return_flag(assign_x('return_value', '(var_ref return_value)') +
+                           assign_x('return_flag', const_bool(1)) +
+                           assign_x('execute_flag', const_bool(0)),
+                           assign_x('b', const_float(3)) +
                                lowered_return(const_float(4))) +
             final_return()
             ))
     create_test_case(doc_string, input_sexp, input_sexp, 'return_non_void_at_end_of_loop_lower_nothing')
     create_test_case(doc_string, input_sexp, expected_sexp, 'return_non_void_at_end_of_loop_lower_return',
                      lower_sub_return=True)
     create_test_case(doc_string, input_sexp, expected_sexp, 'return_non_void_at_end_of_loop_lower_return_and_break',
                      lower_sub_return=True, lower_break=True)
 
 if __name__ == '__main__':
-- 
2.9.3