svn commit: r274856 - head/contrib/binutils/gas/config

[Dimitry Andric]

Author: dim
Date: Sat Nov 22 16:30:31 2014
New Revision: 274856
URL: https://svnweb.freebsd.org/changeset/base/274856

Log:
  Avoid undefined behaviour in gas's rotate_left() macro for n == 0.
  Otherwise, clang can effectively remove the first iteration of the for
  loops where this macro is invoked, and as a result, "cmp r0, #99" fails
  to assemble.
  
  Obtained from:	joerg at netbsd
  MFC after:	3 days

Modified:
  head/contrib/binutils/gas/config/tc-arm.c

Modified: head/contrib/binutils/gas/config/tc-arm.c
==============================================================================
--- head/contrib/binutils/gas/config/tc-arm.c	Sat Nov 22 16:27:51 2014	(r274855)
+++ head/contrib/binutils/gas/config/tc-arm.c	Sat Nov 22 16:30:31 2014	(r274856)
@@ -6079,7 +6079,7 @@ parse_operands (char *str, const unsigne
 
 /* Functions for operand encoding.  ARM, then Thumb.  */
 
-#define rotate_left(v, n) (v << n | v >> (32 - n))
+#define rotate_left(v, n) (v << (n % 32) | v >> ((32 - n) % 32))
 
 /* If VAL can be encoded in the immediate field of an ARM instruction,
    return the encoded form.  Otherwise, return FAIL.  */