This code tries to shift an integer 31 bits which triggers a werror:
gas/config/tc-microblaze.c:742:21: error: integer overflow in expression [-Werror=overflow]
   e->X_add_number |= -(1 << 31);

Cast the 1 to offsetT to match X_add_number to fix things.

2015-11-15  Mike Frysinger  <vapier@gentoo.org>

	* config/tc-microblaze.c (parse_imm): Add an offsetT cast.
---
  gas/config/tc-microblaze.c | 2 +-
  1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/gas/config/tc-microblaze.c b/gas/config/tc-microblaze.c
index ac7c828..0ec24f8 100644
--- a/gas/config/tc-microblaze.c
+++ b/gas/config/tc-microblaze.c
@@ -739,7 +739,7 @@ parse_imm (char * s, expressionS * e, offsetT min, offsetT max)
      {
        /* Special case: sign extend negative 32-bit values to 64-bits.  */
        if ((e->X_add_number >> 31) == 1)
-	e->X_add_number |= -(1 << 31);
+	e->X_add_number |= -((offsetT) 1 << 31);

        if (e->X_add_number < min || e->X_add_number > max)
  	{