glsl: Basic support for built-in intrinsics.

Fix the linker to deal with intrinsic functions which are undefined
all the way down to the driver back-end, and introduce intrinsic
definition helpers in the built-in generator.

We still need to figure out what kind of interface we want for drivers
to communicate to the GLSL front-end which of the supported intrinsics
should use a default GLSL implementation and which should use a
hardware-specific override.  As there's no default GLSL implementation
for atomic ops, this seems like something we can worry about later on.

Reviewed-by: Ian Romanick <[email protected]>

v2: Define local helper function to generate ir_call nodes in the
    builtin generator.

1 files changed, 6 insertions, 0 deletions

diff --git a/src/glsl/ir.h b/src/glsl/ir.h
index 85b4d057f5e..49de9e358bd 100644
--- a/src/glsl/ir.h
+++ b/src/glsl/ir.h
@@ -787,6 +787,12 @@ public:
    /** Whether or not this function signature is a built-in. */
    bool is_builtin() const;
 
+   /**
+    * Whether or not this function is an intrinsic to be implemented
+    * by the driver.
+    */
+   bool is_intrinsic;
+
    /** Whether or not a built-in is available for this shader. */
    bool is_builtin_available(const _mesa_glsl_parse_state *state) const;