diff options
| -rw-r--r-- | src/glsl/opt_copy_propagation_elements.cpp | 10 |
1 files changed, 10 insertions, 0 deletions
diff --git a/src/glsl/opt_copy_propagation_elements.cpp b/src/glsl/opt_copy_propagation_elements.cpp index f131894608d..a67f5070cb0 100644 --- a/src/glsl/opt_copy_propagation_elements.cpp +++ b/src/glsl/opt_copy_propagation_elements.cpp @@ -209,6 +209,7 @@ ir_copy_propagation_elements_visitor::handle_rvalue(ir_rvalue **ir) ir_variable *source[4] = {NULL, NULL, NULL, NULL}; int source_chan[4] = {0, 0, 0, 0}; int chans; + bool noop_swizzle = true; if (!*ir) return; @@ -250,6 +251,9 @@ ir_copy_propagation_elements_visitor::handle_rvalue(ir_rvalue **ir) if (entry->write_mask & (1 << swizzle_chan[c])) { source[c] = entry->rhs; source_chan[c] = entry->swizzle[swizzle_chan[c]]; + + if (source_chan[c] != swizzle_chan[c]) + noop_swizzle = false; } } } @@ -266,6 +270,12 @@ ir_copy_propagation_elements_visitor::handle_rvalue(ir_rvalue **ir) if (!shader_mem_ctx) shader_mem_ctx = ralloc_parent(deref_var); + /* Don't pointlessly replace the rvalue with itself (or a noop swizzle + * of itself, which would just be deleted by opt_noop_swizzle). + */ + if (source[0] == var && noop_swizzle) + return; + if (debug) { printf("Copy propagation from:\n"); (*ir)->print(); |