http://gcc.gnu.org/bugzilla/show_bug.cgi?id=55142
--- Comment #21 from H.J. Lu <hjl.tools at gmail dot com> 2012-11-07 22:11:46 UTC --- (In reply to comment #20) > If you compile the testcase with the unmodified compiler but without -fPIC, > you > get in the assembly file: > > movl %edx, _dl_rtld_map-1073742800(,%eax,4) > > I presume that's wrong, correct? Yet the RTL instruction is: That is not wrong. > (insn:TI 43 38 44 4 (set (mem/f:SI (zero_extend:DI (plus:SI (ashift:SI (reg:SI > 0 ax [87]) > (const_int 2 [0x2])) > (const:SI (plus:SI (symbol_ref:SI ("_dl_rtld_map") [flags > 0x42] <var_decl 0x7ffff6d2b7b8 _dl_rtld_map>) > (const_int -1073742800 [0xffffffffbffffc30]))))) > [3 > *_8+0 S4 A32]) > (reg:SI 1 dx [orig:82 dyn ] [82])) pr55142.c:32 65 {*movsi_internal} > (expr_list:REG_DEAD (reg:SI 0 ax [87]) > (nil))) > > and there is a zero_extend. (,%eax,4) generates a 0x67 address-size prefix, which zero-extends 32-bit address to 64-bit.