Hi!
The following testcase ICEs on ppc64le. The problem is that
copy_reg_eh_region_note_* functions accept either some instruction, or
REG_EH_REGION note directly. To differentiate between those it uses INSN_P
test (and returns early if the insn doesn't contain any REG_EH_REGION
notes). If the function is called on a rtx_insn * that isn't INSN_P, like
on the testcase on a NOTE, it assumes it must be REG_EH_REGION note, uses
XEXP (note, 0) on it, which is actually PREV_INSN in this case and stores
an instruction (JUMP_INSN in this case) into REG_EH_REGION notes it creates.
I believe we should treat rtx_insn * that aren't INSN_P like instructions
that don't have any REG_EH_REGION notes.
Bootstrapped/regtested on x86_64-linux and i686-linux, ok for trunk?
2019-02-07 Jakub Jelinek
PR rtl-optimization/89234
* except.c (copy_reg_eh_region_note_forward): Return if note_or_insn
is a NOTE, CODE_LABEL etc. - rtx_insn * other than INSN_P.
(copy_reg_eh_region_note_backward): Likewise.
* g++.dg/ubsan/pr89234.C: New test.
--- gcc/except.c.jj 2019-01-10 11:43:14.387377695 +0100
+++ gcc/except.c2019-02-07 15:11:27.756869475 +0100
@@ -1756,6 +1756,8 @@ copy_reg_eh_region_note_forward (rtx not
if (note == NULL)
return;
}
+ else if (is_a (note_or_insn))
+return;
note = XEXP (note, 0);
for (insn = first; insn != last ; insn = NEXT_INSN (insn))
@@ -1778,6 +1780,8 @@ copy_reg_eh_region_note_backward (rtx no
if (note == NULL)
return;
}
+ else if (is_a (note_or_insn))
+return;
note = XEXP (note, 0);
for (insn = last; insn != first; insn = PREV_INSN (insn))
--- gcc/testsuite/g++.dg/ubsan/pr89234.C.jj 2019-02-07 17:12:02.081024666
+0100
+++ gcc/testsuite/g++.dg/ubsan/pr89234.C2019-02-07 17:08:55.026097949
+0100
@@ -0,0 +1,11 @@
+// PR rtl-optimization/89234
+// { dg-do compile { target dfp } }
+// { dg-options "-O2 -fnon-call-exceptions -fsanitize=null" }
+
+typedef float __attribute__((mode (SD))) _Decimal32;
+
+void
+foo (_Decimal32 *b, _Decimal32 c)
+{
+ *b = c + 1.5;
+}
Jakub