diff --git a/gcc/testsuite/gcc.dg/torture/pr107935.c b/gcc/testsuite/gcc.dg/torture/pr107935.c new file mode 100644 index 000000000000..78175100f80e --- /dev/null +++ b/gcc/testsuite/gcc.dg/torture/pr107935.c @@ -0,0 +1,18 @@ +/* { dg-do compile } */ + +int *a, **b; +int main() { + int d = 0, *e = &d; + L: + *e = d; + if (a) { + int *g = e = *b; + if (!e) + __builtin_abort(); + if (**b) + return 0; + *g = 1; + goto L; + } + return 0; +} diff --git a/gcc/tree-ssa-sccvn.cc b/gcc/tree-ssa-sccvn.cc index 1e7763baa38e..b9f289b6ecad 100644 --- a/gcc/tree-ssa-sccvn.cc +++ b/gcc/tree-ssa-sccvn.cc @@ -5840,7 +5840,12 @@ visit_phi (gimple *phi, bool *inserted, bool backedges_varying_p) continue; } /* There's also the possibility to use equivalences. */ - if (!FLOAT_TYPE_P (TREE_TYPE (def))) + if (!FLOAT_TYPE_P (TREE_TYPE (def)) + /* But only do this if we didn't force any of sameval or + val to VARYING because of backedge processing rules. */ + && (TREE_CODE (sameval) != SSA_NAME + || SSA_VAL (sameval) == sameval) + && (TREE_CODE (def) != SSA_NAME || SSA_VAL (def) == def)) { vn_nary_op_t vnresult; tree ops[2];