https://gcc.gnu.org/bugzilla/show_bug.cgi?id=30354
--- Comment #18 from Denis Vlasenko <vda.linux at googlemail dot com> --- Created attachment 38297 --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=38297&action=edit Comparison of generated code with 7.0.0.svn on i86 With div cost of 3: 00000000 <ud_x_100>: - 0: 8b 44 24 04 mov 0x4(%esp),%eax - 4: b9 64 00 00 00 mov $0x64,%ecx - 9: 31 d2 xor %edx,%edx - b: f7 f1 div %ecx - d: c3 ret With div cost of 13: + 0: b9 1f 85 eb 51 mov $0x51eb851f,%ecx + 5: 89 c8 mov %ecx,%eax + 7: f7 64 24 04 mull 0x4(%esp) + b: 89 d1 mov %edx,%ecx + d: 89 c8 mov %ecx,%eax + f: c1 e8 05 shr $0x5,%eax + 12: c3 ret