--- /dev/null
+/*
+ * Copyright © 2013 Intel Corporation
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice (including the next
+ * paragraph) shall be included in all copies or substantial portions of the
+ * Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+ * DEALINGS IN THE SOFTWARE.
+ */
+
+/**
+ * \file brw_lower_unnormalized_offset.cpp
+ *
+ * IR lower pass to convert a texture offset into an adjusted coordinate,
+ * for use with unnormalized coordinates. At least the gather4* messages
+ * on Ivybridge and Haswell make a mess with nonzero offsets.
+ *
+ * \author Chris Forbes <chrisf@ijw.co.nz>
+ */
+
+#include "glsl/glsl_types.h"
+#include "glsl/ir.h"
+#include "glsl/ir_builder.h"
+
+using namespace ir_builder;
+
+class brw_lower_unnormalized_offset_visitor : public ir_hierarchical_visitor {
+public:
+ brw_lower_unnormalized_offset_visitor()
+ {
+ progress = false;
+ }
+
+ ir_visitor_status visit_leave(ir_texture *ir);
+
+ bool progress;
+};
+
+ir_visitor_status
+brw_lower_unnormalized_offset_visitor::visit_leave(ir_texture *ir)
+{
+ if (ir->sampler->type->sampler_dimensionality != GLSL_SAMPLER_DIM_RECT ||
+ !ir->offset || ir->op != ir_tg4)
+ return visit_continue;
+
+ ir->coordinate = add(ir->coordinate, i2f(ir->offset));
+ ir->offset = NULL;
+
+ progress = true;
+ return visit_continue;
+}
+
+extern "C" {
+
+bool
+brw_do_lower_unnormalized_offset(exec_list *instructions)
+{
+ brw_lower_unnormalized_offset_visitor v;
+
+ visit_list_elements(&v, instructions);
+
+ return v.progress;
+}
+
+}