https://gcc.gnu.org/bugzilla/show_bug.cgi?id=103192
--- Comment #15 from Andrew Macleod <amacleod at redhat dot com> ---
I added a series of vrp passes to see when things go amok.
immediately before DOM3, we see:
<bb 1416> [local count: 22683134]:
if (outer_ctx_1389 != 0B)
goto <bb 1417>; [70.00%]
else
goto <bb 1420>; [30.00%]
<bb 1417> [local count: 37567381]:
_784 = omp_clause_range_check (c_3171, 5, 7,
"/home/aldyh/src/gcc/gcc/gimplify.c", 10070, "gimplify_scan_omp_clauses");
_785 = omp_clause_elt_check (_784, 3, "/home/aldyh/src/gcc/gcc/gimplify.c",
10070, "gimplify_scan_omp_clauses");
_786 = *_785;
omp_add_variable (iftmp.2373_1515, _786, 129);
and outer_ctx_1389 is varying, so we cannot fold anything,and we know:
iftmp.2373_1515 : struct gimplify_omp_ctx * [1B, +INF]
then DOM3 runs, and transforms this into:
<bb 1415> [local count: 22683134]:
if (iftmp.2373_1515 != 0B)
goto <bb 1416>; [70.00%]
else
goto <bb 1419>; [30.00%]
<bb 1416> [local count: 37567381]:
_784 = omp_clause_range_check (c_3171, 5, 7,
"/home/aldyh/src/gcc/gcc/gimplify.c", 10070, "gimplify_scan_omp_clauses");
_785 = omp_clause_elt_check (_784, 3, "/home/aldyh/src/gcc/gcc/gimplify.c",
10070, "gimplify_scan_omp_clauses");
_786 = *_785;
omp_add_variable (iftmp.2373_1515, _786, 129);
which is going to clearly cause problems when VRP knows that iftmp.2373_151 is
non-null...
So it looks like this transformation is the problematic one for sure.
