When spliting edge with self loop, the split edge should be placed just next to the edge_in->src, otherwise it may generate different position latch bbs for two consecutive self loops. For details, please refer to: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=93680#c4
Regression tested pass on x86_64-linux-gnu and aarch64-linux-gnu, OK for master? gcc/ChangeLog: PR gcov/93680 * tree-cfg.cc (split_edge_bb_loc): Return edge_in->src for self loop. gcc/testsuite/ChangeLog: PR gcov/93680 * gcc.misc-tests/gcov-pr93680.c: New test. Signed-off-by: Xionghu Luo <xionghu...@tencent.com> --- gcc/testsuite/gcc.misc-tests/gcov-pr93680.c | 24 +++++++++++++++++++++ gcc/tree-cfg.cc | 2 +- 2 files changed, 25 insertions(+), 1 deletion(-) create mode 100644 gcc/testsuite/gcc.misc-tests/gcov-pr93680.c diff --git a/gcc/testsuite/gcc.misc-tests/gcov-pr93680.c b/gcc/testsuite/gcc.misc-tests/gcov-pr93680.c new file mode 100644 index 00000000000..b2bf9e626fc --- /dev/null +++ b/gcc/testsuite/gcc.misc-tests/gcov-pr93680.c @@ -0,0 +1,24 @@ +/* { dg-options "-fprofile-arcs -ftest-coverage" } */ +/* { dg-do run { target native } } */ + +int f(int s, int n) +{ + int p = 0; + + switch (s) + { + case 0: /* count(5) */ + do { p++; } while (--n); /* count(5) */ + return p; /* count(1) */ + + case 1: /* count(5) */ + do { p++; } while (--n); /* count(5) */ + return p; /* count(1) */ + } + + return 0; +} + +int main() { f(0, 5); f(1, 5); return 0; } + +/* { dg-final { run-gcov gcov-pr93680.c } } */ diff --git a/gcc/tree-cfg.cc b/gcc/tree-cfg.cc index a9fcc7fd050..6fa1d83d366 100644 --- a/gcc/tree-cfg.cc +++ b/gcc/tree-cfg.cc @@ -3009,7 +3009,7 @@ split_edge_bb_loc (edge edge_in) if (dest_prev) { edge e = find_edge (dest_prev, dest); - if (e && !(e->flags & EDGE_COMPLEX)) + if ((e && !(e->flags & EDGE_COMPLEX)) || edge_in->src == edge_in->dest) return edge_in->src; } return dest_prev; -- 2.27.0