https://gcc.gnu.org/bugzilla/show_bug.cgi?id=79578
Richard Biener <rguenth at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Keywords| |missed-optimization
Target| |x86_64-*-*, i?86-*-*
Status|UNCONFIRMED |NEW
Last reconfirmed| |2017-02-17
CC| |law at gcc dot gnu.org
Component|c++ |tree-optimization
Ever confirmed|0 |1
--- Comment #2 from Richard Biener <rguenth at gcc dot gnu.org> ---
Note that appearantly b is allowed to be NULL.
Confirmed for the partial dead code elimination issue. tree DSE sees
<bb 2> [100.00%]:
if (b_3(D) != 0B)
goto <bb 3>; [0.00%]
else
goto <bb 4>; [0.00%]
<bb 3> [0.00%]:
MEM[(struct A *)b_3(D)] = {};
<bb 4> [0.00%]:
MEM[(struct A *)b_3(D)].a = 1;
MEM[(struct A *)b_3(D)].b = 2;
return b_3(D);
and after store-merging we have (no further DSE):
<bb 2> [100.00%]:
if (b_2(D) != 0B)
goto <bb 3>; [73.26%]
else
goto <bb 4>; [26.74%]
<bb 3> [73.26%]:
MEM[(struct A *)b_2(D)] = {};
<bb 4> [100.00%]:
MEM[(short unsigned int *)b_2(D)] = 131073;
return b_2(D);
Jeff -- wasn't your "partial DSE" supposed to help here? Ah, it was to
trim partial stores rather than full stores followed by partial ones
making it dead?
