From 1bb1c03d618a9636563cf4dcf067876e50ba0d81 Mon Sep 17 00:00:00 2001 From: Ilia Mirkin Date: Fri, 5 Oct 2018 02:18:20 -0400 Subject: [PATCH] glsl: fix array assignments of a swizzled vector 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. There are two cases, one where i is a constant, and another where i is variable. We have to be extra-careful in both cases. Fixes the following WebGL test: https://www.khronos.org/registry/webgl/sdk/tests/conformance2/glsl3/vector-dynamic-indexing-swizzled-lvalue.html And the new piglit tests: swizzled-writemask-indexing-nonconst.shader_test swizzled-writemask-indexing.shader_test Signed-off-by: Ilia Mirkin Reviewed-by: Ian Romanick Cc: mesa-stable@lists.freedesktop.org --- src/compiler/glsl/lower_vector_derefs.cpp | 13 ++++++++++--- 1 file changed, 10 insertions(+), 3 deletions(-) diff --git a/src/compiler/glsl/lower_vector_derefs.cpp b/src/compiler/glsl/lower_vector_derefs.cpp index 7583d1fdd3e..6cd9a2d819a 100644 --- a/src/compiler/glsl/lower_vector_derefs.cpp +++ b/src/compiler/glsl/lower_vector_derefs.cpp @@ -59,8 +59,7 @@ 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 = @@ -72,8 +71,16 @@ vector_deref_visitor::visit_enter(ir_assignment *ir) ir->rhs, deref->array_index); ir->write_mask = (1 << new_lhs->type->vector_elements) - 1; + ir->set_lhs(new_lhs); + } 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 the "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); -- 2.30.2