From b87259d3efeadf05556e2daf688935a038097bba Mon Sep 17 00:00:00 2001 From: Eric Anholt Date: Mon, 12 Jul 2010 15:32:37 -0700 Subject: [PATCH] glsl2: Fix copy propagation in the presence of derefs in array indexes. We would clear the in_lhs flag early, avoiding copy propagation on the array index variable (oops) and then copy propagating on the array variable (ouch). Just avoid all copy propagation on the LHS instead. --- src/glsl/ir_copy_propagation.cpp | 25 ++++++++++++++++++++++--- 1 file changed, 22 insertions(+), 3 deletions(-) diff --git a/src/glsl/ir_copy_propagation.cpp b/src/glsl/ir_copy_propagation.cpp index f502f5e0b06..57123987322 100644 --- a/src/glsl/ir_copy_propagation.cpp +++ b/src/glsl/ir_copy_propagation.cpp @@ -96,9 +96,29 @@ ir_copy_propagation_visitor::visit_enter(ir_function_signature *ir) ir_visitor_status ir_copy_propagation_visitor::visit_enter(ir_assignment *ir) { - (void) ir; + ir_visitor_status s; + + /* Inline the rest of ir_assignment::accept(ir_hv *v), wrapping the + * LHS part with setting in_lhs so that we can avoid copy + * propagating into the LHS. + * + * Note that this means we won't copy propagate into the derefs of + * an array index. Oh well. + */ this->in_lhs = true; - return visit_continue; + s = ir->lhs->accept(this); + this->in_lhs = false; + if (s != visit_continue) + return (s == visit_continue_with_parent) ? visit_continue : s; + + s = ir->rhs->accept(this); + if (s != visit_continue) + return (s == visit_continue_with_parent) ? visit_continue : s; + + if (ir->condition) + s = ir->condition->accept(this); + + return (s == visit_stop) ? s : visit_continue_with_parent; } ir_visitor_status @@ -122,7 +142,6 @@ ir_copy_propagation_visitor::visit(ir_dereference_variable *ir) * other storage! */ if (this->in_lhs) { - this->in_lhs = false; return visit_continue; } -- 2.30.2