| Message ID | 508EB0F4.2@redhat.com |
|---|---|
| State | New |
| Headers | show |
On Mon, Oct 29, 2012 at 9:38 AM, Vladimir Makarov <vmakarov@redhat.com> wrote: > On 12-10-29 12:21 PM, Richard Sandiford wrote: >> >> Vladimir Makarov <vmakarov@redhat.com> writes: >>> >>> H.J. in >>> >>> http://gcc.gnu.org/bugzilla/show_bug.cgi?id=55116 >>> >>> reported an interesting address >>> >>> (and:DI (subreg:DI (plus:SI (ashift:SI (reg:SI 96 [ glob_vol_int.22 ]) >>> (const_int 2 [0x2])) >>> (symbol_ref:SI ("glob_vol_int_arr") <var_decl >>> 0x7ffff03c2720 glob_vol_int_arr>)) 0) >>> (const_int 4294967295 [0xffffffff])) >>> >>> which can not be correctly extracted. Here `and' with `subreg' >>> behaves as an address mutation. >>> >>> The following patch fixes the problem. >>> >>> Ok to commit, Richard? >> >> Heh, I wondered if subregs might still be used like that, and was almost >> tempted to add them just in case. >> >> I think this particular case is really a failed canonicalisation and that: >> >> (and:DI (subreg:DI (foo:SI ...) 0) (const_int 0xffffffff)) >> >> ought to be: >> >> (zero_extend:DI (foo:SI ...)) > > Yes, that was my thought too. > >> But I know I've approved MIPS patches to accept >> (and:DI ... (const_int 0xffffffff)) as an alternative. >> >>> Index: rtlanal.c >>> =================================================================== >>> --- rtlanal.c (revision 192942) >>> +++ rtlanal.c (working copy) >>> @@ -5459,6 +5459,11 @@ strip_address_mutations (rtx *loc, enum >>> else if (code == AND && CONST_INT_P (XEXP (*loc, 1))) >>> /* (and ... (const_int -X)) is used to align to X bytes. */ >>> loc = &XEXP (*loc, 0); >>> + else if (code == SUBREG >>> + && ! REG_P (XEXP (*loc, 0)) && ! MEM_P (XEXP (*loc, 0))) >>> + /* (subreg (operator ...) ...) usually inside and is used for >>> + mode conversion too. */ >>> + loc = &XEXP (*loc, 0); >> >> I think the condition should be: >> >> else if (code == SUBREG >> && !OBJECT_P (SUBREG_REG (*loc)) >> && subreg_lowpart (*loc)) >> >> OK with that change, if it works. >> > Yes, it works. > I've submitted the following patch. > It doesn't work right. I will create a new testcase.
On Mon, Oct 29, 2012 at 4:41 PM, H.J. Lu <hjl.tools@gmail.com> wrote: > On Mon, Oct 29, 2012 at 9:38 AM, Vladimir Makarov <vmakarov@redhat.com> wrote: >> On 12-10-29 12:21 PM, Richard Sandiford wrote: >>> >>> Vladimir Makarov <vmakarov@redhat.com> writes: >>>> >>>> H.J. in >>>> >>>> http://gcc.gnu.org/bugzilla/show_bug.cgi?id=55116 >>>> >>>> reported an interesting address >>>> >>>> (and:DI (subreg:DI (plus:SI (ashift:SI (reg:SI 96 [ glob_vol_int.22 ]) >>>> (const_int 2 [0x2])) >>>> (symbol_ref:SI ("glob_vol_int_arr") <var_decl >>>> 0x7ffff03c2720 glob_vol_int_arr>)) 0) >>>> (const_int 4294967295 [0xffffffff])) >>>> >>>> which can not be correctly extracted. Here `and' with `subreg' >>>> behaves as an address mutation. >>>> >>>> The following patch fixes the problem. >>>> >>>> Ok to commit, Richard? >>> >>> Heh, I wondered if subregs might still be used like that, and was almost >>> tempted to add them just in case. >>> >>> I think this particular case is really a failed canonicalisation and that: >>> >>> (and:DI (subreg:DI (foo:SI ...) 0) (const_int 0xffffffff)) >>> >>> ought to be: >>> >>> (zero_extend:DI (foo:SI ...)) >> >> Yes, that was my thought too. >> >>> But I know I've approved MIPS patches to accept >>> (and:DI ... (const_int 0xffffffff)) as an alternative. >>> >>>> Index: rtlanal.c >>>> =================================================================== >>>> --- rtlanal.c (revision 192942) >>>> +++ rtlanal.c (working copy) >>>> @@ -5459,6 +5459,11 @@ strip_address_mutations (rtx *loc, enum >>>> else if (code == AND && CONST_INT_P (XEXP (*loc, 1))) >>>> /* (and ... (const_int -X)) is used to align to X bytes. */ >>>> loc = &XEXP (*loc, 0); >>>> + else if (code == SUBREG >>>> + && ! REG_P (XEXP (*loc, 0)) && ! MEM_P (XEXP (*loc, 0))) >>>> + /* (subreg (operator ...) ...) usually inside and is used for >>>> + mode conversion too. */ >>>> + loc = &XEXP (*loc, 0); >>> >>> I think the condition should be: >>> >>> else if (code == SUBREG >>> && !OBJECT_P (SUBREG_REG (*loc)) >>> && subreg_lowpart (*loc)) >>> >>> OK with that change, if it works. >>> >> Yes, it works. >> I've submitted the following patch. >> > > It doesn't work right. I will create a new testcase. > I uploaded a tectase to http://gcc.gnu.org/bugzilla/show_bug.cgi?id=55116
Index: rtlanal.c =================================================================== --- rtlanal.c (revision 192942) +++ rtlanal.c (working copy) @@ -5459,6 +5459,12 @@ strip_address_mutations (rtx *loc, enum else if (code == AND && CONST_INT_P (XEXP (*loc, 1))) /* (and ... (const_int -X)) is used to align to X bytes. */ loc = &XEXP (*loc, 0); + else if (code == SUBREG + && !OBJECT_P (SUBREG_REG (*loc)) + && subreg_lowpart_p (*loc)) + /* (subreg (operator ...) ...) inside and is used for mode + conversion too. */ + loc = &XEXP (*loc, 0); else return loc; if (outer_code)