diff options
Diffstat (limited to 'src/mesa')
| -rw-r--r-- | src/mesa/state_tracker/st_glsl_to_tgsi.cpp | 29 |
1 files changed, 28 insertions, 1 deletions
diff --git a/src/mesa/state_tracker/st_glsl_to_tgsi.cpp b/src/mesa/state_tracker/st_glsl_to_tgsi.cpp index fd2485de892..a7ea19fb239 100644 --- a/src/mesa/state_tracker/st_glsl_to_tgsi.cpp +++ b/src/mesa/state_tracker/st_glsl_to_tgsi.cpp @@ -2110,8 +2110,35 @@ glsl_to_tgsi_visitor::visit_expression(ir_expression* ir, st_src_reg *op) cbuf.index = const_offset / 16; } else { + ir_expression *offset_expr = ir->operands[1]->as_expression(); + st_src_reg offset = op[1]; + + /* The OpenGL spec is written in such a way that accesses with + * non-constant offset are almost always vec4-aligned. The only + * exception to this are members of structs in arrays of structs: + * each struct in an array of structs is at least vec4-aligned, + * but single-element and [ui]vec2 members of the struct may be at + * an offset that is not a multiple of 16 bytes. + * + * Here, we extract that offset, relying on previous passes to always + * generate offset expressions of the form (+ expr constant_offset). + * + * Note that the std430 layout, which allows more cases of alignment + * less than vec4 in arrays, is not supported for uniform blocks, so + * we do not have to deal with it here. + */ + if (offset_expr && offset_expr->operation == ir_binop_add) { + const_offset_ir = offset_expr->operands[1]->as_constant(); + if (const_offset_ir) { + const_offset = const_offset_ir->value.u[0]; + cbuf.index = const_offset / 16; + offset_expr->operands[0]->accept(this); + offset = this->result; + } + } + /* Relative/variable index into constant buffer */ - emit_asm(ir, TGSI_OPCODE_USHR, st_dst_reg(index_reg), op[1], + emit_asm(ir, TGSI_OPCODE_USHR, st_dst_reg(index_reg), offset, st_src_reg_for_int(4)); cbuf.reladdr = ralloc(mem_ctx, st_src_reg); memcpy(cbuf.reladdr, &index_reg, sizeof(index_reg)); |