ira.c update_equiv_regs patch causes gcc/testsuite/gcc.target/arm/pr43920-2.c regression
Shiva Chen
shiva0217@gmail.com
Mon Apr 20 07:09:00 GMT 2015
Hi, Jeff
Thanks for your advice.
can_replace_by.patch is the new patch to handle both cases.
pr43920-2.c.244r.jump2.ori is the original jump2 rtl dump
pr43920-2.c.244r.jump2.patch_can_replace_by is the jump2 rtl dump
after patch can_replace_by.patch
Could you help me to review the patch?
Thanks again.
Shiva
2015-04-18 0:03 GMT+08:00 Jeff Law <law@redhat.com>:
> On 04/17/2015 03:57 AM, Shiva Chen wrote:
>>
>> Hi,
>>
>> I think the rtl dump in
>> https://gcc.gnu.org/bugzilla/show_bug.cgi?id=64916
>> is not jump2 phase rtl dump.
>>
>> Because jump2 is after ira, the register number should be hardware
>> register number.
>>
>> the jump2 rtl dump should as follow
>>
>> ...
>> 31: NOTE_INSN_BASIC_BLOCK 5
>> 32: [r6:SI]=r4:SI
>> REG_DEAD r6:SI
>> REG_DEAD r4:SI
>> 33: [r5:SI]=r0:SI
>> REG_DEAD r5:SI
>> REG_DEAD r0:SI
>> 7: r0:SI=0
>> REG_EQUAL 0
>> 85: use r0:SI
>> 86:
>> {return;sp:SI=sp:SI+0x18;r3:SI=[sp:SI];r4:SI=[sp:SI+0x4];r5:SI=[sp:SI+0x8];r6:SI=[sp:SI+0xc];r7:SI=[sp:SI+0x10];pc:SI=[sp:SI+0x14];}
>> REG_UNUSED pc:SI
>> REG_UNUSED r3:SI
>> REG_CFA_RESTORE r7:SI
>> REG_CFA_RESTORE r6:SI
>> REG_CFA_RESTORE r5:SI
>> REG_CFA_RESTORE r4:SI
>> REG_CFA_RESTORE r3:SI
>> 77: barrier
>> 46: L46:
>> 45: NOTE_INSN_BASIC_BLOCK 6
>> 8: r0:SI=r4:SI
>> REG_DEAD r4:SI
>> REG_EQUAL 0xffffffffffffffff
>> 87: use r0:SI
>> 88:
>> {return;sp:SI=sp:SI+0x18;r3:SI=[sp:SI];r4:SI=[sp:SI+0x4];r5:SI=[sp:SI+0x8];r6:SI=[sp:SI+0xc];r7:SI=[sp:SI+0x10];pc:SI=[sp:SI+0x14];}
>> REG_UNUSED pc:SI
>> REG_UNUSED r3:SI
>> REG_CFA_RESTORE r7:SI
>> REG_CFA_RESTORE r6:SI
>> REG_CFA_RESTORE r5:SI
>> REG_CFA_RESTORE r4:SI
>> REG_CFA_RESTORE r3:SI
>> 79: barrier
>> 54: L54:
>> 53: NOTE_INSN_BASIC_BLOCK 7
>> 9: r0:SI=0xffffffffffffffff <== lost REG_EQUAL after patch
>> 34: L34:
>> 35: NOTE_INSN_BASIC_BLOCK 8
>> 41: use r0:SI
>> 90:
>> {return;sp:SI=sp:SI+0x18;r3:SI=[sp:SI];r4:SI=[sp:SI+0x4];r5:SI=[sp:SI+0x8];r6:SI=[sp:SI+0xc];r7:SI=[sp:SI+0x10];pc:SI=[sp:SI+0x14];}
>> REG_UNUSED pc:SI
>> REG_UNUSED r3:SI
>> REG_CFA_RESTORE r7:SI
>> REG_CFA_RESTORE r6:SI
>> REG_CFA_RESTORE r5:SI
>> REG_CFA_RESTORE r4:SI
>> REG_CFA_RESTORE r3:SI
>> 89: barrier
>
> Intead of the slim dump, can you please include the full RTL dump. I find
> those much easier to read.
>
>
>
>>
>> Possible patch for can_replace_by in cfgcleanup.c.
>>
>> - if (!note1 || !note2 || !rtx_equal_p (XEXP (note1, 0), XEXP (note2, 0))
>> - || !CONST_INT_P (XEXP (note1, 0)))
>> +
>> + if (!note1 || !CONST_INT_P (XEXP (note1, 0)))
>> return dir_none;
>>
>> + if (note2)
>> + {
>> + if (!rtx_equal_p (XEXP (note1, 0), XEXP (note2, 0)))
>> + return dir_none;
>> + }
>> + else
>> + {
>> + if (!CONST_INT_P (SET_SRC (s2))
>> + || !rtx_equal_p (XEXP (note1, 0), SET_SRC (s2)))
>> + return dir_none;
>> + }
>> +
>>
>> I'm not sure the idea is ok or it might crash something.
>> Any suggestion would be very helpful.
>
> Seems like you're on a reasonable path to me. I suggest you stick with it.
>
> Basically what it appears you're trying to do is unify insns from different
> blocks where one looks like
>
> (set x y) with an attached REG_EQUAL note
>
> And the other looks like
>
> (set x const_int)
>
> Where the REG_EQUAL note has the same value as the const_int in the second
> set.
>
> I think you'd want to handle both cases i1 has the note i2, no note and i1
> has no note and i2 has a note.
>
> Jeff
>
> jeff
-------------- next part --------------
A non-text attachment was scrubbed...
Name: can_replace_by.patch
Type: application/octet-stream
Size: 1861 bytes
Desc: not available
URL: <http://gcc.gnu.org/pipermail/gcc-patches/attachments/20150420/74392c74/attachment.obj>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: pr43920-2.c.244r.jump2.ori
Type: application/octet-stream
Size: 23006 bytes
Desc: not available
URL: <http://gcc.gnu.org/pipermail/gcc-patches/attachments/20150420/74392c74/attachment-0001.obj>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: pr43920-2.c.244r.jump2.patch_can_replace_by
Type: application/octet-stream
Size: 29539 bytes
Desc: not available
URL: <http://gcc.gnu.org/pipermail/gcc-patches/attachments/20150420/74392c74/attachment-0002.obj>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: Changelog.can_replace_by
Type: application/octet-stream
Size: 423 bytes
Desc: not available
URL: <http://gcc.gnu.org/pipermail/gcc-patches/attachments/20150420/74392c74/attachment-0003.obj>
More information about the Gcc-patches
mailing list