global.c (global_alloc): Use xmalloc instead of alloca for CONFLICTS...

	* global.c (global_alloc): Use xmalloc instead of alloca for
	CONFLICTS, since max_allocno * allocno_row_words alone can be more
	than 2.5Mb sometimes.

From-SVN: r16223

1 files changed, 7 insertions, 2 deletions

diff --git a/gcc/global.c b/gcc/global.c
index 83b09fe431f..0480ebf3c4d 100644
--- a/gcc/global.c
+++ b/gcc/global.c
@@ -486,8 +486,11 @@ global_alloc (file)
 
   allocno_row_words = (max_allocno + INT_BITS - 1) / INT_BITS;
 
-  conflicts = (INT_TYPE *) alloca (max_allocno * allocno_row_words
-				   * sizeof (INT_TYPE));
+  /* We used to use alloca here, but the size of what it would try to
+     allocate would occasionally cause it to exceed the stack limit and
+     cause unpredictable core dumps.  Some examples were > 2Mb in size.  */
+  conflicts = (INT_TYPE *) xmalloc (max_allocno * allocno_row_words
+				    * sizeof (INT_TYPE));
   bzero ((char *) conflicts,
 	 max_allocno * allocno_row_words * sizeof (INT_TYPE));
 
@@ -570,6 +573,8 @@ global_alloc (file)
 	  }
     }
 
+  free (conflicts);
+
   /* Do the reloads now while the allocno data still exist, so that we can
      try to assign new hard regs to any pseudo regs that are spilled.  */