diff options
| -rw-r--r-- | src/glsl/loop_analysis.cpp | 28 | ||||
| -rw-r--r-- | src/glsl/loop_analysis.h | 6 |
2 files changed, 34 insertions, 0 deletions
diff --git a/src/glsl/loop_analysis.cpp b/src/glsl/loop_analysis.cpp index 9bba6a97c48..6a0e4da5100 100644 --- a/src/glsl/loop_analysis.cpp +++ b/src/glsl/loop_analysis.cpp @@ -110,6 +110,8 @@ public: virtual ir_visitor_status visit(ir_loop_jump *); virtual ir_visitor_status visit(ir_dereference_variable *); + virtual ir_visitor_status visit_enter(ir_call *); + virtual ir_visitor_status visit_enter(ir_loop *); virtual ir_visitor_status visit_leave(ir_loop *); virtual ir_visitor_status visit_enter(ir_assignment *); @@ -153,6 +155,21 @@ loop_analysis::visit(ir_loop_jump *ir) ir_visitor_status +loop_analysis::visit_enter(ir_call *ir) +{ + /* If we're not somewhere inside a loop, there's nothing to do. */ + if (this->state.is_empty()) + return visit_continue; + + loop_variable_state *const ls = + (loop_variable_state *) this->state.get_head(); + + ls->contains_calls = true; + return visit_continue_with_parent; +} + + +ir_visitor_status loop_analysis::visit(ir_dereference_variable *ir) { /* If we're not somewhere inside a loop, there's nothing to do. @@ -209,6 +226,17 @@ loop_analysis::visit_leave(ir_loop *ir) loop_variable_state *const ls = (loop_variable_state *) this->state.pop_head(); + /* Function calls may contain side effects. These could alter any of our + * variables in ways that cannot be known, and may even terminate shader + * execution (say, calling discard in the fragment shader). So we can't + * rely on any of our analysis about assignments to variables. + * + * We could perform some conservative analysis (prove there's no statically + * possible assignment, etc.) but it isn't worth it for now; function + * inlining will allow us to unroll loops anyway. + */ + if (ls->contains_calls) + return visit_continue; foreach_list(node, &ir->body_instructions) { /* Skip over declarations at the start of a loop. diff --git a/src/glsl/loop_analysis.h b/src/glsl/loop_analysis.h index 229730836a8..8bed1db0210 100644 --- a/src/glsl/loop_analysis.h +++ b/src/glsl/loop_analysis.h @@ -122,10 +122,16 @@ public: */ unsigned num_loop_jumps; + /** + * Whether this loop contains any function calls. + */ + bool contains_calls; + loop_variable_state() { this->max_iterations = -1; this->num_loop_jumps = 0; + this->contains_calls = false; this->var_hash = hash_table_ctor(0, hash_table_pointer_hash, hash_table_pointer_compare); } |