https://gcc.gnu.org/bugzilla/show_bug.cgi?id=80180
--- Comment #2 from uros at gcc dot gnu.org --- Author: uros Date: Sat Mar 25 18:10:37 2017 New Revision: 246477 URL: https://gcc.gnu.org/viewcvs?rev=246477&root=gcc&view=rev Log: PR target/80180 * config/i386/i386.c (ix86_expand_builtin) <IX86_BUILTIN_RDSEED{16,32,64}_STEP>: Do not expand arg0 between flags reg setting and flags reg using instructions. <IX86_BUILTIN_RDRAND{16,32,64}_STEP>: Ditto. Use non-flags reg clobbering instructions to zero extend op2. Modified: branches/gcc-6-branch/gcc/ChangeLog branches/gcc-6-branch/gcc/config/i386/i386.c