On 01/09/2012 01:36 PM, Eric Anholt wrote:
We were doing the kill of the updated channels, then adding our copy to the list of available stuff to copy. But if the copy was updating its own source channels, we didn't notice, breaking this code:R0.xyzw = arg0 + arg1; R0.xyzw = R0.wwwx; gl_FragColor.xyzw = clamp(R0.xyzw, 0.0, 1.0); Fixes piglit glsl-copy-propagation-self-2. --- 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 be446bc..ebfd4fd 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); }
Whoops. Yeah, that's definitely necessary. Reviewed-by: Kenneth Graunke <kenn...@whitecape.org> _______________________________________________ mesa-dev mailing list mesa-dev@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/mesa-dev
