https://gcc.gnu.org/bugzilla/show_bug.cgi?id=87485
Bug ID: 87485
Summary: [9 Regression] Compile time hog w/ -O2
-fschedule-insns -fno-guess-branch-probability
-fno-isolate-erroneous-paths-dereference
-fno-omit-frame-pointer -fno-split-wide-types
-fno-tree-ccp -fno-tree-sra
Product: gcc
Version: 9.0
Status: UNCONFIRMED
Keywords: compile-time-hog
Severity: normal
Priority: P3
Component: rtl-optimization
Assignee: unassigned at gcc dot gnu.org
Reporter: asolokha at gmx dot com
Target Milestone: ---
Target: x86_64-pc-linux-gnu
gcc-9.0.0-alpha20180930 snapshot (r264727) takes indefinite time when compiling
the following snippet w/ -O2 -fschedule-insns -fno-guess-branch-probability
-fno-isolate-erroneous-paths-dereference -fno-omit-frame-pointer
-fno-split-wide-types -fno-tree-ccp -fno-tree-sra:
int *xh;
int
c8 (__int128 n8, int dx, int b7)
{
__int128 fl;
*xh = ((!!dx ? dx : n8) * dx | n8) * 2;
if (b7 == 0)
{
unsigned int e4 = 1;
__int128 *lj = &fl;
for (*xh = 0; *xh < 1; *xh += dx)
{
}
*xh += fl < (e4 / 0);
goto f0;
c7:
while (fl < 1)
{
}
++*xh;
}
goto c7;
f0:
return 0;
}
Previously weekly snapshot of the trunk has been ICEing on the same snippet w/
"internal compiler error: Maximum number of LRA assignment passes is achieved
(30)". I believe it stopped ICEing after r264726.
