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authorEric Anholt <[email protected]>2010-08-13 07:16:38 -0700
committerEric Anholt <[email protected]>2010-08-13 17:54:47 -0700
commit8f8cdbfba43550d0b8985fb087961864e4cd92b6 (patch)
tree3f8fb030267b1c128268e6beb84d4ab98523d81d /src/glsl/ir_noop_swizzle.cpp
parent42cab131dac469475c67ab38a2c29f2f66e6ff49 (diff)
glsl2: Add a pass to strip out noop swizzles.
With the glsl2-965 branch, the optimization of glsl-algebraic-rcp-rcp regressed due to noop swizzles hiding information from ir_algebraic. This cleans up those noop swizzles for us.
Diffstat (limited to 'src/glsl/ir_noop_swizzle.cpp')
-rw-r--r--src/glsl/ir_noop_swizzle.cpp80
1 files changed, 80 insertions, 0 deletions
diff --git a/src/glsl/ir_noop_swizzle.cpp b/src/glsl/ir_noop_swizzle.cpp
new file mode 100644
index 00000000000..b78c87b47f3
--- /dev/null
+++ b/src/glsl/ir_noop_swizzle.cpp
@@ -0,0 +1,80 @@
+/*
+ * Copyright © 2010 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 ir_noop_swizzle.cpp
+ *
+ * If a swizzle doesn't change the order or count of components, then
+ * remove the swizzle so that other optimization passes see the value
+ * behind it.
+ */
+
+#include "ir.h"
+#include "ir_visitor.h"
+#include "ir_rvalue_visitor.h"
+#include "ir_print_visitor.h"
+#include "glsl_types.h"
+
+class ir_noop_swizzle_visitor : public ir_rvalue_visitor {
+public:
+ ir_noop_swizzle_visitor()
+ {
+ this->progress = false;
+ }
+
+ void handle_rvalue(ir_rvalue **rvalue);
+ bool progress;
+};
+
+void
+ir_noop_swizzle_visitor::handle_rvalue(ir_rvalue **rvalue)
+{
+ if (!*rvalue)
+ return;
+
+ ir_swizzle *swiz = (*rvalue)->as_swizzle();
+ if (!swiz || swiz->type != swiz->val->type)
+ return;
+
+ int elems = swiz->val->type->vector_elements;
+ if (swiz->mask.x != 0)
+ return;
+ if (elems >= 2 && swiz->mask.y != 1)
+ return;
+ if (elems >= 3 && swiz->mask.z != 1)
+ return;
+ if (elems >= 4 && swiz->mask.w != 1)
+ return;
+
+ this->progress = true;
+ *rvalue = swiz->val;
+}
+
+bool
+do_noop_swizzle(exec_list *instructions)
+{
+ ir_noop_swizzle_visitor v;
+ visit_list_elements(&v, instructions);
+
+ return v.progress;
+}