glsl: Refactor is_zero/one/negative_one into an is_value() method.

This patch creates a new generic is_value() method, which checks if an
ir_constant has a particular value.  (For vectors, it must have the
single value repeated across all components.)

It then rewrites the is_zero/is_one/is_negative_one methods to use this
generic helper.  All three were basically identical except for the value
they checked for.  The other difference is that is_negative_one rejects
boolean types.  The new is_value function maintains this behavior, only
allowing boolean types when checking for 0 or 1.

Signed-off-by: Kenneth Graunke <kenneth@whitecape.org>
Reviewed-by: Matt Turner <mattst88@gmail.com>

1 files changed, 6 insertions, 0 deletions

diff --git a/src/glsl/ir.h b/src/glsl/ir.h
index 780959b..4d86385 100644
--- a/src/glsl/ir.h
+++ b/src/glsl/ir.h
@@ -2186,6 +2186,12 @@ public:
     */
    bool has_value(const ir_constant *) const;
 
+   /**
+    * Return true if this ir_constant represents the given value.
+    *
+    * For vectors, this checks that each component is the given value.
+    */
+   virtual bool is_value(float f, int i) const;
    virtual bool is_zero() const;
    virtual bool is_one() const;
    virtual bool is_negative_one() const;