This happens in situations where we might do vec.wzyx[i] = ...
The swizzle would get effectively ignored because of the interaction between how ir_assignment->set_lhs works and overwriting the write_mask. Fixes the following WebGL test: https://www.khronos.org/registry/webgl/sdk/tests/conformance2/glsl3/vector-dynamic-indexing-swizzled-lvalue.html Signed-off-by: Ilia Mirkin <imir...@alum.mit.edu> Cc: mesa-sta...@lists.freedesktop.org --- src/compiler/glsl/lower_vector_derefs.cpp | 12 +++++++++--- 1 file changed, 9 insertions(+), 3 deletions(-) diff --git a/src/compiler/glsl/lower_vector_derefs.cpp b/src/compiler/glsl/lower_vector_derefs.cpp index 7583d1fdd3e..af046966491 100644 --- a/src/compiler/glsl/lower_vector_derefs.cpp +++ b/src/compiler/glsl/lower_vector_derefs.cpp @@ -59,21 +59,27 @@ vector_deref_visitor::visit_enter(ir_assignment *ir) if (!deref->array->type->is_vector()) return ir_rvalue_enter_visitor::visit_enter(ir); - ir_dereference *const new_lhs = (ir_dereference *) deref->array; - ir->set_lhs(new_lhs); + ir_rvalue *const new_lhs = deref->array; void *mem_ctx = ralloc_parent(ir); ir_constant *old_index_constant = deref->array_index->constant_expression_value(mem_ctx); if (!old_index_constant) { + ir->set_lhs(new_lhs); ir->rhs = new(mem_ctx) ir_expression(ir_triop_vector_insert, new_lhs->type, new_lhs->clone(mem_ctx, NULL), ir->rhs, deref->array_index); ir->write_mask = (1 << new_lhs->type->vector_elements) - 1; + } else if (new_lhs->ir_type != ir_type_swizzle) { + ir->set_lhs(new_lhs); + ir->write_mask = 1 << old_index_constant->get_uint_component(0); } else { - ir->write_mask = 1 << old_index_constant->get_int_component(0); + // If there "new" lhs is a swizzle, use the set_lhs helper to instead + // swizzle the rhs. + unsigned component[1] = { old_index_constant->get_uint_component(0) }; + ir->set_lhs(new(mem_ctx) ir_swizzle(new_lhs, component, 1)); } return ir_rvalue_enter_visitor::visit_enter(ir); -- 2.16.4 _______________________________________________ mesa-dev mailing list mesa-dev@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/mesa-dev
