From 2a66ee6fc1fa1e64f2d9a22271187d4462d9e042 Mon Sep 17 00:00:00 2001 From: Iago Toral Quiroga Date: Fri, 24 Apr 2015 11:17:15 +0200 Subject: [PATCH] glsl: Don't do copy propagation on buffer variables Since the backing storage for these is shared we cannot ensure that the value won't change by writes from other threads. Normally SSBO accesses are not guaranteed to be syncronized with other threads, except when memoryBarrier is used. So, we might be able to optimize some SSBO accesses, but for now we always take the safe path and emit the SSBO access. Reviewed-by: Jordan Justen --- src/glsl/opt_copy_propagation.cpp | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/src/glsl/opt_copy_propagation.cpp b/src/glsl/opt_copy_propagation.cpp index 806027b280e..f20699563fd 100644 --- a/src/glsl/opt_copy_propagation.cpp +++ b/src/glsl/opt_copy_propagation.cpp @@ -330,7 +330,7 @@ ir_copy_propagation_visitor::add_copy(ir_assignment *ir) */ ir->condition = new(ralloc_parent(ir)) ir_constant(false); this->progress = true; - } else { + } else if (lhs_var->data.mode != ir_var_shader_storage) { entry = new(this->acp) acp_entry(lhs_var, rhs_var); this->acp->push_tail(entry); } -- 2.30.2