glsl: Create an ir_builder helper for hand-generating IR.

The C++ constructors with placement new, while functional, are
extremely verbose, leading to generation of simple GLSL IR expressions
like (a * b + c * d) expanding to many lines of code and using lots of
temporary variables.  By creating a new ir_builder.h that puts simple
generators in our namespace and taking advantage of ralloc_parent(),
we can generate much more compact code, at a minor runtime cost.

v2: Replace ir_instruction usage with just ir_rvalue.
v3: Drop remaining missed as_rvalue() in v2.

Reviewed-by: Kenneth Graunke <[email protected]>

1 files changed, 69 insertions, 0 deletions

diff --git a/src/glsl/ir_builder.cpp b/src/glsl/ir_builder.cpp
new file mode 100644
index 00000000000..a9d87145735
--- /dev/null
+++ b/src/glsl/ir_builder.cpp
@@ -0,0 +1,69 @@
+/*
+ * Copyright © 2012 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.
+ */
+
+#include "ir_builder.h"
+
+using namespace ir_builder;
+
+namespace ir_builder {
+
+ir_expression *
+expr(ir_expression_operation op,
+     ir_rvalue *a, ir_rvalue *b)
+{
+   void *mem_ctx = ralloc_parent(a);
+
+   return new(mem_ctx) ir_expression(op, a, b);
+}
+
+ir_expression *add(ir_rvalue *a, ir_rvalue *b)
+{
+   return expr(ir_binop_add, a, b);
+}
+
+ir_expression *sub(ir_rvalue *a, ir_rvalue *b)
+{
+   return expr(ir_binop_sub, a, b);
+}
+
+ir_expression *mul(ir_rvalue *a, ir_rvalue *b)
+{
+   return expr(ir_binop_mul, a, b);
+}
+
+ir_expression *dot(ir_rvalue *a, ir_rvalue *b)
+{
+   return expr(ir_binop_dot, a, b);
+}
+
+ir_expression *
+saturate(ir_rvalue *a)
+{
+   void *mem_ctx = ralloc_parent(a);
+
+   return expr(ir_binop_max,
+	       expr(ir_binop_min, a, new(mem_ctx) ir_constant(1.0f)),
+	       new(mem_ctx) ir_constant(0.0f));
+}
+
+} /* namespace ir_builder */