From: Jakub Jelinek <jakub@redhat.com>
Date: Thu, 10 Nov 2011 15:40:34 +0000 (+0100)
Subject: vec.h (VEC_BASE): If base is at offset 0 in the structure, use &(P)->base even if... 
X-Git-Tag: releases/gcc-4.7.0~2269
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=c8bf99b4e84b9b0783aca23ecc85425cb3569f16;p=thirdparty%2Fgcc.git

vec.h (VEC_BASE): If base is at offset 0 in the structure, use &(P)->base even if P is NULL.

	* vec.h (VEC_BASE): If base is at offset 0 in the structure,
	use &(P)->base even if P is NULL.

From-SVN: r181258
---

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index faea63af24d5..86515365d217 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,5 +1,8 @@
 2011-11-10  Jakub Jelinek  <jakub@redhat.com>
 
+	* vec.h (VEC_BASE): If base is at offset 0 in the structure,
+	use &(P)->base even if P is NULL.
+
 	PR rtl-optimization/51023
 	* combine.c (simplify_comparison) <case SIGN_EXTEND>: Don't use
 	val_signbit_known_clear_p for signed comparison narrowing
diff --git a/gcc/vec.h b/gcc/vec.h
index 789e8e2d4df6..d47795879f18 100644
--- a/gcc/vec.h
+++ b/gcc/vec.h
@@ -549,7 +549,12 @@ typedef struct VEC(T,A)							  \
 } VEC(T,A)
 
 /* Convert to base type.  */
+#if GCC_VERSION >= 4000
+#define VEC_BASE(P) \
+  ((offsetof (__typeof (*P), base) == 0 || (P)) ? &(P)->base : 0)
+#else
 #define VEC_BASE(P)  ((P) ? &(P)->base : 0)
+#endif
 
 /* Vector of integer-like object.  */
 #define DEF_VEC_I(T)							  \