https://gcc.gnu.org/bugzilla/show_bug.cgi?id=83477
--- Comment #2 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
This goes wrong during dom2. Before that we have still correct:
<bb 2> [local count: 1073741825]:
if (q5_4(D) != 0)
goto <bb 3>; [50.00%]
else
goto <bb 4>; [50.00%]
<bb 3> [local count: 536870912]:
<bb 4> [local count: 1073741825]:
# iftmp.0_2 = PHI <1(3), q5_4(D)(2)>
_1 = nd_5(D) <= 1 ? iftmp.0_2 : 0;
if (_1 != 0)
goto <bb 6>; [50.00%]
else
goto <bb 5>; [50.00%]
<bb 5> [local count: 536870912]:
<bb 6> [local count: 1073741825]:
# iftmp.2_3 = PHI <nd_5(D)(4), 0(5)>
yf = iftmp.2_3;
in pl, and dom2 changes it as:
<bb 4> [local count: 1073741825]:
- # iftmp.0_2 = PHI <1(3), q5_4(D)(2)>
- _1 = nd_5(D) <= 1 ? iftmp.0_2 : 0;
- if (_1 != 0)
- goto <bb 6>; [50.00%]
- else
- goto <bb 5>; [50.00%]
-
- <bb 5> [local count: 536870912]:
-
- <bb 6> [local count: 1073741825]:
- # iftmp.2_3 = PHI <nd_5(D)(4), 0(5)>
- yf = iftmp.2_3;
+ # RANGE [0, 1] NONZERO 1
+ # iftmp.0_8 = PHI <0(2), 1(3)>
+ # RANGE [0, 1] NONZERO 1
+ _9 = nd_5(D) <= 1 ? iftmp.0_8 : 0;
+ yf = 0;
Now, the iftmp.0_2 to iftmp.0_8 and _1 to _9 changes look reasonable, but it
doesn't imply yf is 0. Jeff, will leave this to you if you don't mind.
