diff options
| -rw-r--r-- | src/glsl/opt_copy_propagation_elements.cpp | 15 |
1 files changed, 14 insertions, 1 deletions
diff --git a/src/glsl/opt_copy_propagation_elements.cpp b/src/glsl/opt_copy_propagation_elements.cpp index be446bc08ba..ebfd4fd3fe1 100644 --- a/src/glsl/opt_copy_propagation_elements.cpp +++ b/src/glsl/opt_copy_propagation_elements.cpp @@ -461,7 +461,20 @@ ir_copy_propagation_elements_visitor::add_copy(ir_assignment *ir) swizzle[i] = orig_swizzle[j++]; } - entry = new(this->mem_ctx) acp_entry(lhs->var, rhs->var, ir->write_mask, + int write_mask = ir->write_mask; + if (lhs->var == rhs->var) { + /* If this is a copy from the variable to itself, then we need + * to be sure not to include the updated channels from this + * instruction in the set of new source channels to be + * copy-propagated from. + */ + for (int i = 0; i < 4; i++) { + if (ir->write_mask & (1 << orig_swizzle[i])) + write_mask &= ~(1 << i); + } + } + + entry = new(this->mem_ctx) acp_entry(lhs->var, rhs->var, write_mask, swizzle); this->acp->push_tail(entry); } |