http://gcc.gnu.org/bugzilla/show_bug.cgi?id=49028
Richard Guenther <rguenth at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Status|UNCONFIRMED |NEW
Last reconfirmed| |2011.05.18 09:40:28
Ever Confirmed|0 |1
--- Comment #2 from Richard Guenther <rguenth at gcc dot gnu.org> 2011-05-18
09:40:28 UTC ---
I think we are confused by the division by the element size which is of course
what the language semantic requires. Thus, we start with
(void) ((this)->m_Cursor = (void * *) &(this)->m_Data + (long unsigned int)
((long unsigned int) ((((long int) ((this)->m_Cursor + 8) - (long int)
&(this)->m_Data) /[ex] 8) % 16) * 8))
and because of the modulus we can't fold it. In the IL we end up with
<bb 2>:
D.2101_3 = this_1(D)->m_Cursor;
D.2102_4 = D.2101_3 + 8;
D.2103_5 = (long int) D.2102_4;
D.2100_6 = &this_1(D)->m_Data;
D.2104_7 = (long int) D.2100_6;
D.2105_8 = D.2103_5 - D.2104_7;
D.2106_9 = D.2105_8 /[ex] 8;
D.2107_10 = D.2106_9 % 16;
D.2108_11 = (long unsigned int) D.2107_10;
D.2110_13 = &this_1(D)->m_Data[D.2108_11]{lb: 0 sz: 8};
this_1(D)->m_Cursor = D.2110_13;
MEM[(void * *)this_1(D)].m_Data[D.2108_11]{lb: 0 sz: 8} = p_15(D);
return;
where it requires quite some elaboration to combine the D.2108_11 index
computation with the address generation via the array-reference.
Maybe we can do some generic clever tricks to (A /[ex] CST1) % CST2?
We'd like to re-associate it somehow.
