The L-unit nop entry isn't really a nop, but the field needed to go into the L slot of an MLX bundle, representing part of the 62-bit immediate, which should be zero. Built and tested on ia64-unknown-linux-gnu. Jan gas/ 2005-07-05 Jan Beulich * config/tc-ia64.c (nop): Use zero for L-unit pseudo-nop. --- /home/jbeulich/src/binutils/mainline/2005-07-05/gas/config/tc-ia64.c 2005-06-27 12:04:26.000000000 +0200 +++ 2005-07-05/gas/config/tc-ia64.c 2005-07-05 13:53:32.029990405 +0200 @@ -593,7 +593,7 @@ static const bfd_vma nop[IA64_NUM_UNITS] 0x0008000000LL, /* M-unit nop */ 0x4000000000LL, /* B-unit nop */ 0x0008000000LL, /* F-unit nop */ - 0x0008000000LL, /* L-"unit" nop */ + 0x0000000000LL, /* L-"unit" nop immediate */ 0x0008000000LL, /* X-unit nop */ };