From b39e6f33b60ef9bbaf81f320aaca6a440d8a6a8f Mon Sep 17 00:00:00 2001 From: Eric Anholt Date: Wed, 22 Sep 2010 11:47:03 -0700 Subject: glsl: Rework assignments with write_masks to have LHS chan count match RHS. It turns out that most people new to this IR are surprised when an assignment to (say) 3 components on the LHS takes 4 components on the RHS. It also makes for quite strange IR output: (assign (constant bool (1)) (x) (var_ref color) (swiz x (var_ref v) )) (assign (constant bool (1)) (y) (var_ref color) (swiz yy (var_ref v) )) (assign (constant bool (1)) (z) (var_ref color) (swiz zzz (var_ref v) )) But even worse, even we get it wrong, as shown by this line of our current step(float, vec4): (assign (constant bool (1)) (w) (var_ref t) (expression float b2f (expression bool >= (swiz w (var_ref x))(var_ref edge)))) where we try to assign a float to the writemasked-out x channel and don't supply anything for the actual w channel we're writing. Drivers right now just get lucky since ir_to_mesa spams the float value across all the source channels of a vec4. Instead, the RHS will now have a number of components equal to the number of components actually being written. Hopefully this confuses everyone less, and it also makes codegen for a scalar target simpler. Reviewed-by: Kenneth Graunke Reviewed-by: Ian Romanick --- src/glsl/ir_validate.cpp | 16 +++++++++------- 1 file changed, 9 insertions(+), 7 deletions(-) (limited to 'src/glsl/ir_validate.cpp') diff --git a/src/glsl/ir_validate.cpp b/src/glsl/ir_validate.cpp index 912d1c0d70..e35514aa6f 100644 --- a/src/glsl/ir_validate.cpp +++ b/src/glsl/ir_validate.cpp @@ -391,14 +391,16 @@ ir_validate::visit_enter(ir_assignment *ir) abort(); } - /* Mask of fields that do not exist in the destination. These should - * not be written by the assignment. - */ - const unsigned invalid_mask = ~((1U << lhs->type->components()) - 1); + int lhs_components = 0; + for (int i = 0; i < 4; i++) { + if (ir->write_mask & (1 << i)) + lhs_components++; + } - if ((invalid_mask & ir->write_mask) != 0) { - printf("Assignment write mask enables invalid components for " - "type %s:\n", lhs->type->name); + if (lhs_components != ir->rhs->type->vector_elements) { + printf("Assignment count of LHS write mask channels enabled not\n" + "matching RHS vector size (%d LHS, %d RHS).\n", + lhs_components, ir->rhs->type->vector_elements); ir->print(); abort(); } -- cgit v1.2.3