glsl: Fix lack of i2u in lower_ubo_reference.

ir_binop_ubo_load takes unsigned integer operands.  However, the array
index used to compute these offsets may be a signed integer.  (For
example, see Piglit's spec/glsl-1.40/uniform_buffer/fs-bvec-array).

For some reason, we were missing an ir_binop_i2u cast, and ir_validator
was failing to catch that.

Without this change, ir_builder's type inference code broke for me when
writing a new optimization pass.

Cc: [email protected]
Signed-off-by: Kenneth Graunke <[email protected]>
Reviewed-by: Ian Romanick <[email protected]>
Reviewed-by: Matt Turner <[email protected]>

1 files changed, 7 insertions, 3 deletions

diff --git a/src/glsl/lower_ubo_reference.cpp b/src/glsl/lower_ubo_reference.cpp
index c73b148b00f..90e65bd0ea0 100644
--- a/src/glsl/lower_ubo_reference.cpp
+++ b/src/glsl/lower_ubo_reference.cpp
@@ -194,12 +194,16 @@ lower_ubo_reference_visitor::handle_rvalue(ir_rvalue **rvalue)
 	    array_stride = glsl_align(array_stride, 16);
 	 }
 
-	 ir_constant *const_index = deref_array->array_index->as_constant();
+         ir_rvalue *array_index = deref_array->array_index;
+         if (array_index->type->base_type == GLSL_TYPE_INT)
+            array_index = i2u(array_index);
+
+	 ir_constant *const_index = array_index->as_constant();
 	 if (const_index) {
-	    const_offset += array_stride * const_index->value.i[0];
+	    const_offset += array_stride * const_index->value.u[0];
 	 } else {
 	    offset = add(offset,
-			 mul(deref_array->array_index,
+			 mul(array_index,
 			     new(mem_ctx) ir_constant(array_stride)));
 	 }
 	 deref = deref_array->array->as_dereference();