On Mon, Mar 5, 2012 at 9:01 AM, Uros Bizjak <ubiz...@gmail.com> wrote:
>>> @@ -11388,6 +11400,11 @@ ix86_decompose_address (rtx addr, struct >>> ix86_address *out) >>> else >>> disp = addr; /* displacement */ >>> >>> + /* Since address override works only on the (reg) part in fs:(reg), >>> + we can't use it as memory operand. */ >>> + if (Pmode != word_mode && seg == SEG_FS && (base || index)) >>> + return 0; >>> >>> Can you explain the above some more? IMO, if the override works on >>> (reg) part, this is just what we want. >> >> When Pmode == SImode, we have >> >> fs segment register == 0x1001 >> >> and >> >> base register (SImode) == -1 (0xffffffff). >> >> We are expecting address to be 0x1001 - 1 == 0x1000. But, what we get >> is 0x1000 + 0xffffffff, not 0x1000 since 0x67 address prefix only applies to >> base register to zero-extend 0xffffffff to 64bit. > > I would call this a bug in the specification - I guess that > 0x1001(%eax) works correctly. > > We will treat this issue as a bug. Nice, we have TARGET_TLS_DIRECT_SEG_REFS option. We can just clear it somewhere appropriate when Pmode != word_mode. Uros.
