From e568b00562cf38afd779560c7431a94672531e95 Mon Sep 17 00:00:00 2001 From: Kenneth Graunke Date: Wed, 8 Feb 2012 16:59:39 -0800 Subject: [PATCH] i965: Fix swizzles for system values such as gl_InstanceID. visit(ir_variable *) sets dst_reg::writemask to the appropriate channel for system values. Unfortunately, visit(ir_dereference_variable *) then calls swizzle_for_size, which for a float, sets the swizzle to .x. This works for gl_VertexID, since we store it in the .x component (see brw_draw_upload.c:732 - VID), but fails for gl_InstanceID (IID) since we store it in the .y channel. To fix this, avoid calling swizzle_for_size on ir_var_system_values. Signed-off-by: Kenneth Graunke Reviewed-by: Eric Anholt --- src/mesa/drivers/dri/i965/brw_vec4_visitor.cpp | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/src/mesa/drivers/dri/i965/brw_vec4_visitor.cpp b/src/mesa/drivers/dri/i965/brw_vec4_visitor.cpp index f9a08a011f2..cb4cb877b66 100644 --- a/src/mesa/drivers/dri/i965/brw_vec4_visitor.cpp +++ b/src/mesa/drivers/dri/i965/brw_vec4_visitor.cpp @@ -1402,6 +1402,10 @@ vec4_visitor::visit(ir_dereference_variable *ir) this->result = src_reg(*reg); + /* System values get their swizzle from the dst_reg writemask */ + if (ir->var->mode == ir_var_system_value) + return; + if (type->is_scalar() || type->is_vector() || type->is_matrix()) this->result.swizzle = swizzle_for_size(type->vector_elements); } -- 2.30.2