From cbfe469fc41cdb10d9d5dc06c381531d0e5e9dba Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Nicolai=20H=C3=A4hnle?= Date: Mon, 25 Apr 2016 18:20:50 -0500 Subject: [PATCH] st/glsl_to_tgsi: reduce stack explosion in recursive expression visitor In optimized builds, visit(ir_expression *) experiences inlining with gcc that leads the function to have a roughly 32KB stack frame. This is a problem given that the function is called recursively. In non-optimized builds, the stack frame is much smaller, hence one gets crashes that happen only in optimized builds. Arguably there is a compiler bug or at least severe misfeature here. In any case, the easy thing to do for now seems to be moving the bulk of the non-recursive code into a separate function. This is sufficient to convince my version of gcc not to blow up the stack frame of the recursive part. Just to be sure, add the gcc-specific noinline attribute to prevent this bug from reoccuring if inliner heuristics change. Cc: "11.1 11.2" Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=95133 Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=95026 --- src/mesa/state_tracker/st_glsl_to_tgsi.cpp | 24 ++++++++++++++++++++---- 1 file changed, 20 insertions(+), 4 deletions(-) diff --git a/src/mesa/state_tracker/st_glsl_to_tgsi.cpp b/src/mesa/state_tracker/st_glsl_to_tgsi.cpp index ad818a8..958b2c0 100644 --- a/src/mesa/state_tracker/st_glsl_to_tgsi.cpp +++ b/src/mesa/state_tracker/st_glsl_to_tgsi.cpp @@ -450,6 +450,12 @@ public: virtual void visit(ir_barrier *); /*@}*/ + void visit_expression(ir_expression *, st_src_reg *) +#if defined(__GNUC__) + __attribute__((noinline)) +#endif + ; + void visit_atomic_counter_intrinsic(ir_call *); void visit_ssbo_intrinsic(ir_call *); void visit_membar_intrinsic(ir_call *); @@ -1535,10 +1541,7 @@ 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 +1564,7 @@ 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 +1581,19 @@ 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, -- 2.5.0