i386: Fix ICE caused by ix86_emit_i387_log1p [PR105214]
authorJakub Jelinek <jakub@redhat.com>
Tue, 12 Apr 2022 07:19:11 +0000 (09:19 +0200)
committerJakub Jelinek <jakub@redhat.com>
Tue, 12 Apr 2022 07:19:11 +0000 (09:19 +0200)
commitd481d13786cb84f6294833538133dbd6f39d2e55
treeb511366a18b9349f529bf70969be3795e1cec7d9
parent91a38e8a848c61b2e23ee277306dc8cd194d135b
i386: Fix ICE caused by ix86_emit_i387_log1p [PR105214]

The following testcase ICEs, because ix86_emit_i387_log1p attempts to
emit something like
  if (cond)
    some_code1;
  else
    some_code2;
and emits a conditional jump using emit_jump_insn (standard way in
the file) and an unconditional jump using emit_jump.
The problem with that is that if there is pending stack adjustment,
it isn't emitted before the conditional jump, but is before the
unconditional jump and therefore stack is adjusted only conditionally
(at the end of some_code1 above), which makes dwarf2 pass unhappy about it
but is a serious wrong-code even if it doesn't ICE.

This can be fixed either by emitting pending stack adjust before the
conditional jump as the following patch does, or by not using
  emit_jump (label2);
and instead hand inlining what that function does except for the
pending stack adjustment, like:
  emit_jump_insn (targetm.gen_jump (label2));
  emit_barrier ();
In that case there will be no stack adjustment in the sequence and
it will be done later on somewhere else.

2022-04-12  Jakub Jelinek  <jakub@redhat.com>

PR target/105214
* config/i386/i386-expand.cc (ix86_emit_i387_log1p): Call
do_pending_stack_adjust.

* gcc.dg/asan/pr105214.c: New test.
gcc/config/i386/i386-expand.cc
gcc/testsuite/gcc.dg/asan/pr105214.c [new file with mode: 0644]