summaryrefslogtreecommitdiff
path: root/src/glsl
diff options
context:
space:
mode:
authorIan Romanick <ian.d.romanick@intel.com>2013-03-22 17:45:52 -0700
committerIan Romanick <ian.d.romanick@intel.com>2013-05-13 12:05:19 -0700
commit1e773626eee2076e791737f86ba78c410a60aa19 (patch)
treef9be9bfbf3c59279ea3c3910db62719ef3f2dd98 /src/glsl
parentc3bb07f875075b08a0b13f47be95e0c49edb6555 (diff)
glsl: Generate correct ir_binop_vector_extract code for out and inout parameters
Like with type conversions on out parameters, some extra copies need to occur to handle these cases. The fundamental problem is that ir_binop_vector_extract is not an lvalue, but out and inout parameters must be lvalues. A previous patch delt with a similar problem in the LHS of ir_assignment. v2: Convert tabs to spaces. Suggested by Eric. Signed-off-by: Ian Romanick <ian.d.romanick@intel.com> Reviewed-by: Eric Anholt <eric@anholt.net> Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>
Diffstat (limited to 'src/glsl')
-rw-r--r--src/glsl/ast_function.cpp149
1 files changed, 102 insertions, 47 deletions
diff --git a/src/glsl/ast_function.cpp b/src/glsl/ast_function.cpp
index 26f72cf8e9..00e0c05ddd 100644
--- a/src/glsl/ast_function.cpp
+++ b/src/glsl/ast_function.cpp
@@ -165,10 +165,18 @@ verify_parameter_modes(_mesa_glsl_parse_state *state,
actual->variable_referenced()->name);
return false;
} else if (!actual->is_lvalue()) {
- _mesa_glsl_error(&loc, state,
- "function parameter '%s %s' is not an lvalue",
- mode, formal->name);
- return false;
+ /* Even though ir_binop_vector_extract is not an l-value, let it
+ * slop through. generate_call will handle it correctly.
+ */
+ ir_expression *const expr = ((ir_rvalue *) actual)->as_expression();
+ if (expr == NULL
+ || expr->operation != ir_binop_vector_extract
+ || !expr->operands[0]->is_lvalue()) {
+ _mesa_glsl_error(&loc, state,
+ "function parameter '%s %s' is not an lvalue",
+ mode, formal->name);
+ return false;
+ }
}
}
@@ -178,6 +186,93 @@ verify_parameter_modes(_mesa_glsl_parse_state *state,
return true;
}
+static void
+fix_parameter(void *mem_ctx, ir_rvalue *actual, const glsl_type *formal_type,
+ exec_list *before_instructions, exec_list *after_instructions,
+ bool parameter_is_inout)
+{
+ ir_expression *const expr = actual->as_expression();
+
+ /* If the types match exactly and the parameter is not a vector-extract,
+ * nothing needs to be done to fix the parameter.
+ */
+ if (formal_type == actual->type
+ && (expr == NULL || expr->operation != ir_binop_vector_extract))
+ return;
+
+ /* To convert an out parameter, we need to create a temporary variable to
+ * hold the value before conversion, and then perform the conversion after
+ * the function call returns.
+ *
+ * This has the effect of transforming code like this:
+ *
+ * void f(out int x);
+ * float value;
+ * f(value);
+ *
+ * Into IR that's equivalent to this:
+ *
+ * void f(out int x);
+ * float value;
+ * int out_parameter_conversion;
+ * f(out_parameter_conversion);
+ * value = float(out_parameter_conversion);
+ *
+ * If the parameter is an ir_expression of ir_binop_vector_extract,
+ * additional conversion is needed in the post-call re-write.
+ */
+ ir_variable *tmp =
+ new(mem_ctx) ir_variable(formal_type, "inout_tmp", ir_var_temporary);
+
+ before_instructions->push_tail(tmp);
+
+ /* If the parameter is an inout parameter, copy the value of the actual
+ * parameter to the new temporary. Note that no type conversion is allowed
+ * here because inout parameters must match types exactly.
+ */
+ if (parameter_is_inout) {
+ /* Inout parameters should never require conversion, since that would
+ * require an implicit conversion to exist both to and from the formal
+ * parameter type, and there are no bidirectional implicit conversions.
+ */
+ assert (actual->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);
+ before_instructions->push_tail(assignment);
+ }
+
+ /* Replace the parameter in the call with a dereference of the new
+ * temporary.
+ */
+ ir_dereference_variable *const deref_tmp_2 =
+ new(mem_ctx) ir_dereference_variable(tmp);
+ actual->replace_with(deref_tmp_2);
+
+
+ /* Copy the temporary variable to the actual parameter with optional
+ * type conversion applied.
+ */
+ ir_rvalue *rhs = new(mem_ctx) ir_dereference_variable(tmp);
+ if (actual->type != formal_type)
+ rhs = convert_component(rhs, actual->type);
+
+ ir_rvalue *lhs = actual;
+ if (expr != NULL && expr->operation == ir_binop_vector_extract) {
+ rhs = new(mem_ctx) ir_expression(ir_triop_vector_insert,
+ expr->operands[0]->type,
+ expr->operands[0]->clone(mem_ctx, NULL),
+ rhs,
+ expr->operands[1]->clone(mem_ctx, NULL));
+ lhs = expr->operands[0]->clone(mem_ctx, NULL);
+ }
+
+ ir_assignment *const assignment_2 = new(mem_ctx) ir_assignment(lhs, rhs);
+ after_instructions->push_tail(assignment_2);
+}
+
/**
* If a function call is generated, \c call_ir will point to it on exit.
* Otherwise \c call_ir will be set to \c NULL.
@@ -218,50 +313,10 @@ generate_call(exec_list *instructions, ir_function_signature *sig,
break;
}
case ir_var_function_out:
- if (actual->type != formal->type) {
- /* To convert an out parameter, we need to create a
- * temporary variable to hold the value before conversion,
- * and then perform the conversion after the function call
- * returns.
- *
- * This has the effect of transforming code like this:
- *
- * void f(out int x);
- * float value;
- * f(value);
- *
- * Into IR that's equivalent to this:
- *
- * void f(out int x);
- * float value;
- * int out_parameter_conversion;
- * f(out_parameter_conversion);
- * value = float(out_parameter_conversion);
- */
- ir_variable *tmp =
- new(ctx) ir_variable(formal->type,
- "out_parameter_conversion",
- ir_var_temporary);
- instructions->push_tail(tmp);
- ir_dereference_variable *deref_tmp_1
- = new(ctx) ir_dereference_variable(tmp);
- ir_dereference_variable *deref_tmp_2
- = new(ctx) ir_dereference_variable(tmp);
- ir_rvalue *converted_tmp
- = convert_component(deref_tmp_1, actual->type);
- ir_assignment *assignment
- = new(ctx) ir_assignment(actual, converted_tmp);
- post_call_conversions.push_tail(assignment);
- actual->replace_with(deref_tmp_2);
- }
- break;
case ir_var_function_inout:
- /* Inout parameters should never require conversion, since that
- * would require an implicit conversion to exist both to and
- * from the formal parameter type, and there are no
- * bidirectional implicit conversions.
- */
- assert (actual->type == formal->type);
+ fix_parameter(ctx, actual, formal->type,
+ instructions, &post_call_conversions,
+ formal->mode == ir_var_function_inout);
break;
default:
assert (!"Illegal formal parameter mode");