Mesa (master): nir: Mark nir_start_block()/nir_impl_last_block() with returns_nonnull.

[Matt Turner]

Module: Mesa
Branch: master
Commit: 41915512624b26f10ebc2e7c41e9b982fb9208bb
URL:    http://cgit.freedesktop.org/mesa/mesa/commit/?id=41915512624b26f10ebc2e7c41e9b982fb9208bb

Author: Matt Turner <mattst88 at gmail.com>
Date:   Fri May 13 13:17:34 2016 -0700

nir: Mark nir_start_block()/nir_impl_last_block() with returns_nonnull.

Reviewed-by: Kenneth Graunke <kenneth at whitecape.org>

---

 src/compiler/nir/nir.h | 9 +++++----
 1 file changed, 5 insertions(+), 4 deletions(-)

diff --git a/src/compiler/nir/nir.h b/src/compiler/nir/nir.h
index cb9d44a..2cfca3e 100644
--- a/src/compiler/nir/nir.h
+++ b/src/compiler/nir/nir.h
@@ -34,6 +34,7 @@
 #include "util/ralloc.h"
 #include "util/set.h"
 #include "util/bitset.h"
+#include "util/macros.h"
 #include "compiler/nir_types.h"
 #include "compiler/shader_enums.h"
 #include <stdio.h>
@@ -1550,16 +1551,16 @@ typedef struct {
    nir_metadata valid_metadata;
 } nir_function_impl;
 
-static inline nir_block *
+ATTRIBUTE_RETURNS_NONNULL static inline nir_block *
 nir_start_block(nir_function_impl *impl)
 {
-   return (nir_block *) exec_list_get_head(&impl->body);
+   return (nir_block *) impl->body.head;
 }
 
-static inline nir_block *
+ATTRIBUTE_RETURNS_NONNULL static inline nir_block *
 nir_impl_last_block(nir_function_impl *impl)
 {
-   return (nir_block *) exec_list_get_tail(&impl->body);
+   return (nir_block *) impl->body.tail_pred;
 }
 
 static inline nir_cf_node *