The following patch fixes https://gcc.gnu.org/bugzilla/show_bug.cgi?id=84014
The patch was tested on powerpc64 and bootstrapped on x86-64. Committed as rev. 257029.
Index: ChangeLog =================================================================== --- ChangeLog (revision 257028) +++ ChangeLog (working copy) @@ -1,3 +1,9 @@ +2018-01-24 Vladimir Makarov <vmaka...@redhat.com> + + PR target/84014 + * ira-build.c (setup_min_max_allocno_live_range_point): Set up + min/max for never referenced object. + 2018-01-24 Jakub Jelinek <ja...@redhat.com> PR middle-end/83977 Index: testsuite/ChangeLog =================================================================== --- testsuite/ChangeLog (revision 257028) +++ testsuite/ChangeLog (working copy) @@ -1,3 +1,8 @@ +2018-01-24 Vladimir Makarov <vmaka...@redhat.com> + + PR target/84014 + * gcc.target/powerpc/pr84014.c: New. + 2018-01-24 Jakub Jelinek <ja...@redhat.com> PR middle-end/83977 Index: ira-build.c =================================================================== --- ira-build.c (revision 256891) +++ ira-build.c (working copy) @@ -2728,7 +2728,13 @@ setup_min_max_allocno_live_range_point ( ira_object_t parent_obj; if (OBJECT_MAX (obj) < 0) - continue; + { + /* The object is not used and hence does not live. */ + ira_assert (OBJECT_LIVE_RANGES (obj) == NULL); + OBJECT_MAX (obj) = 0; + OBJECT_MIN (obj) = 1; + continue; + } ira_assert (ALLOCNO_CAP_MEMBER (a) == NULL); /* Accumulation of range info. */ if (ALLOCNO_CAP (a) != NULL) Index: testsuite/gcc.target/powerpc/pr84014.c =================================================================== --- testsuite/gcc.target/powerpc/pr84014.c (nonexistent) +++ testsuite/gcc.target/powerpc/pr84014.c (working copy) @@ -0,0 +1,20 @@ +/* { dg-do compile { target powerpc*-*-* } }*/ +/* { dg-options "-O1 -fno-split-wide-types -m32 -mcpu=e300c3" } */ + +int +nh (void) +{ +} + +long long int +si (void) +{ +} + +int +xf (int fg) +{ + int y5 = nh (); + fg += !!y5 ? y5 : si (); + return fg; +}