Mesa (glsl2): ir_constant_expression: Add support for ir_unop_log2.

[Ian Romanick]

Module: Mesa
Branch: glsl2
Commit: cb63929df4ce17e94e8ead0316a00d48b51944c9
URL:    http://cgit.freedesktop.org/mesa/mesa/commit/?id=cb63929df4ce17e94e8ead0316a00d48b51944c9

Author: Kenneth Graunke <kenneth at whitecape.org>
Date:   Thu Jul  8 23:18:09 2010 -0700

ir_constant_expression: Add support for ir_unop_log2.

This uses a C99 function.

---

 src/glsl/ir_constant_expression.cpp |    7 +++++++
 1 files changed, 7 insertions(+), 0 deletions(-)

diff --git a/src/glsl/ir_constant_expression.cpp b/src/glsl/ir_constant_expression.cpp
index 871bce4..292461e 100644
--- a/src/glsl/ir_constant_expression.cpp
+++ b/src/glsl/ir_constant_expression.cpp
@@ -337,6 +337,13 @@ ir_constant_visitor::visit(ir_expression *ir)
       }
       break;
 
+   case ir_unop_log2:
+      assert(op[0]->type->base_type == GLSL_TYPE_FLOAT);
+      for (unsigned c = 0; c < ir->operands[0]->type->components(); c++) {
+	 data.f[c] = log2f(op[0]->value.f[c]);
+      }
+      break;
+
    case ir_unop_dFdx:
    case ir_unop_dFdy:
       assert(op[0]->type->base_type == GLSL_TYPE_FLOAT);