st/glsl_to_tgsi: reduce stack explosion in recursive expression visitor

[mesa.git] / src / mesa / state_tracker / st_glsl_to_tgsi.cpp

diff --git a/src/mesa/state_tracker/st_glsl_to_tgsi.cpp b/src/mesa/state_tracker/st_glsl_to_tgsi.cpp
index ad818a8240beef8979c477a4a762885f16214715..3c4c91b0e2f7835eb0e02597cf4c636e631b0b15 100644 (file)
--- a/src/mesa/state_tracker/st_glsl_to_tgsi.cpp
+++ b/src/mesa/state_tracker/st_glsl_to_tgsi.cpp
@@ -450,6 +450,8 @@ public:
    virtual void visit(ir_barrier *);
    /*@}*/
 
+   void visit_expression(ir_expression *, st_src_reg *) ATTRIBUTE_NOINLINE;
+
    void visit_atomic_counter_intrinsic(ir_call *);
    void visit_ssbo_intrinsic(ir_call *);
    void visit_membar_intrinsic(ir_call *);
@@ -1535,10 +1537,7 @@ glsl_to_tgsi_visitor::reladdr_to_temp(ir_instruction *ir,
 void
 glsl_to_tgsi_visitor::visit(ir_expression *ir)
 {
-   unsigned int operand;
    st_src_reg op[ARRAY_SIZE(ir->operands)];
-   st_src_reg result_src;
-   st_dst_reg result_dst;
 
    /* Quick peephole: Emit MAD(a, b, c) instead of ADD(MUL(a, b), c)
     */
@@ -1561,7 +1560,7 @@ glsl_to_tgsi_visitor::visit(ir_expression *ir)
    if (ir->operation == ir_quadop_vector)
       assert(!"ir_quadop_vector should have been lowered");
 
-   for (operand = 0; operand < ir->get_num_operands(); operand++) {
+   for (unsigned int operand = 0; operand < ir->get_num_operands(); operand++) {
       this->result.file = PROGRAM_UNDEFINED;
       ir->operands[operand]->accept(this);
       if (this->result.file == PROGRAM_UNDEFINED) {
@@ -1578,6 +1577,19 @@ glsl_to_tgsi_visitor::visit(ir_expression *ir)
       assert(!ir->operands[operand]->type->is_matrix());
    }
 
+   visit_expression(ir, op);
+}
+
+/* The non-recursive part of the expression visitor lives in a separate
+ * function and should be prevented from being inlined, to avoid a stack
+ * explosion when deeply nested expressions are visited.
+ */
+void
+glsl_to_tgsi_visitor::visit_expression(ir_expression* ir, st_src_reg *op)
+{
+   st_src_reg result_src;
+   st_dst_reg result_dst;
+
    int vector_elements = ir->operands[0]->type->vector_elements;
    if (ir->operands[1]) {
       vector_elements = MAX2(vector_elements,