Hi! This patch fixes 2 issues. One is when we want to get address of an uninitialized large/huge bitint SSA_NAME for multiplication/division/modulo or conversion to floating point (binary or decimal), the code just creates an uninitialized limb sized variable and passes address of that, but I forgot to initialize *prec in that case, so it invoked UB at compile time rather than at runtime. As it is UB, we could use anything valid as precision there, say 2 bits for signed, 1 bit for unsigned as smallest possible set of values, or full bitint precision as full random value. Though, because we only pass address to a single limb, I think it is best to pass the bitsize of the limb.
And the other issue is that when ranger in range_to_prec finds some range is undefined_p (), it will assert {lower,upper}_bound () method isn't called on it, but we were. So, the patch adjusts range_to_proc to treat it like the !optimized case, full bitint precision. Bootstrapped/regtested on x86_64-linux and i686-linux, committed to trunk. 2023-09-30 Jakub Jelinek <ja...@redhat.com> PR middle-end/111625 PR middle-end/111637 * gimple-lower-bitint.cc (range_to_prec): Use prec or -prec if r.undefined_p (). (bitint_large_huge::handle_operand_addr): For uninitialized operands use limb_prec or -limb_prec precision. --- gcc/gimple-lower-bitint.cc.jj 2023-09-20 09:45:39.000000000 +0200 +++ gcc/gimple-lower-bitint.cc 2023-09-29 16:29:36.541473743 +0200 @@ -1932,7 +1932,8 @@ range_to_prec (tree op, gimple *stmt) unsigned int prec = TYPE_PRECISION (type); if (!optimize - || !get_range_query (cfun)->range_of_expr (r, op, stmt)) + || !get_range_query (cfun)->range_of_expr (r, op, stmt) + || r.undefined_p ()) { if (TYPE_UNSIGNED (type)) return prec; @@ -2066,6 +2067,9 @@ bitint_large_huge::handle_operand_addr ( } else if (gimple_code (g) == GIMPLE_NOP) { + *prec = TYPE_UNSIGNED (TREE_TYPE (op)) ? limb_prec : -limb_prec; + if (prec_stored) + *prec_stored = *prec; tree var = create_tmp_var (m_limb_type); TREE_ADDRESSABLE (var) = 1; ret = build_fold_addr_expr (var); Jakub