glsl_types: add type::bit_size and glsl_base_type_bit_size helpers

Note that the nir_types glsl_get_bit_size is not a wrapper of this
one, because for bools at the nir level, we want to return size 1, but
at the glsl_types we want to return 32.

v2: reuse the new method in order to simplify is_16bit and is_32bit
    helpers (Timothy)

v3: add a comment clarifying the difference between
    glsl_base_type_bit_size and glsl_get_bit_size.

Reviewed-by: Timothy Arceri <tarceri@itsqueeze.com>

diff --git a/src/compiler/glsl_types.h b/src/compiler/glsl_types.h
index e986b51d5233128a9a5c6c1c28b443493ba3899e..1e550986e478a7bbefe76ac402800bac8b30690f 100644 (file)
--- a/src/compiler/glsl_types.h
+++ b/src/compiler/glsl_types.h
@@ -91,20 +91,55 @@ enum glsl_base_type {
    GLSL_TYPE_ERROR
 };
 
+/* Return the bit size of a type. Note that this differs from 
+ * glsl_get_bit_size in that it returns 32 bits for bools, whereas at
+ * the NIR level we would want to return 1 bit for bools.
+ */
+static unsigned glsl_base_type_bit_size(enum glsl_base_type type)
+{
+   switch (type) {
+   case GLSL_TYPE_BOOL:
+   case GLSL_TYPE_INT:
+   case GLSL_TYPE_UINT:
+   case GLSL_TYPE_FLOAT: /* TODO handle mediump */
+   case GLSL_TYPE_SUBROUTINE:
+      return 32;
+
+   case GLSL_TYPE_FLOAT16:
+   case GLSL_TYPE_UINT16:
+   case GLSL_TYPE_INT16:
+      return 16;
+
+   case GLSL_TYPE_UINT8:
+   case GLSL_TYPE_INT8:
+      return 8;
+
+   case GLSL_TYPE_DOUBLE:
+   case GLSL_TYPE_INT64:
+   case GLSL_TYPE_UINT64:
+   case GLSL_TYPE_IMAGE:
+   case GLSL_TYPE_SAMPLER:
+      return 64;
+
+   default:
+      /* For GLSL_TYPE_STRUCT etc, it should be ok to return 0. This usually
+       * happens when calling this method through is_64bit and is_16bit
+       * methods
+       */
+      return 0;
+   }
+
+   return 0;
+}
+
 static inline bool glsl_base_type_is_16bit(enum glsl_base_type type)
 {
-   return type == GLSL_TYPE_FLOAT16 ||
-          type == GLSL_TYPE_UINT16 ||
-          type == GLSL_TYPE_INT16;
+   return glsl_base_type_bit_size(type) == 16;
 }
 
 static inline bool glsl_base_type_is_64bit(enum glsl_base_type type)
 {
-   return type == GLSL_TYPE_DOUBLE ||
-          type == GLSL_TYPE_UINT64 ||
-          type == GLSL_TYPE_INT64  ||
-          type == GLSL_TYPE_IMAGE  ||
-          type == GLSL_TYPE_SAMPLER;
+   return glsl_base_type_bit_size(type) == 64;
 }
 
 static inline bool glsl_base_type_is_integer(enum glsl_base_type type)
@@ -828,6 +863,15 @@ public:
       return size;
    }
 
+   /**
+    * Return bit size for this type.
+    */
+   unsigned bit_size() const
+   {
+      return glsl_base_type_bit_size(this->base_type);
+   }
+
+
    /**
     * Query whether or not a type is an atomic_uint.
     */