On October 29, 2018 6:20:25 PM GMT+01:00, Andrew MacLeod <amacl...@redhat.com> wrote: >What is valid in a switch statement for type compatibility? > > I would have expected it to follow what appears to be the gimple >"standard" of allowing types that pass the >"useless_type_convserion_p()" test. > >I am doing some switch analysis and an triggering a failure in ADA when > >the gimple_switch_index() is a signed 64 bit value and the case labels >are only 32 bit integers. I would have expected that these needed to >be >the same precision? I don't seem to get this failure anywhere else.
They should be the same type (types_ compatible_p), the same conatraint as operands of comparisons. IIRC we have some checking somewhere - eventually it just checks whether the constants fit in the index type. >(gdb) p print_gimple_stmt (stderr, sw, 0, 0) > >switch (_22) <default: <L9> [67.00%], case 1: <L6> [33.00%]> > > >(gdb) p gimple_switch_index (sw) >$16 = (tree_node *) 0x7fffee3593f0 >(gdb) p print_generic_expr (stderr, $16, 0) >_22 >(gdb) p print_generic_expr (stderr, $16->typed.type, 0) >SIGNED_64 << signed >64 >bit index > >low is the value of CASE_LOW() > >(gdb) p print_generic_expr (stderr, low, 0) >1 >(gdb) p low->typed.type >$19 = (tree) 0x7fffefacf5e8 >(gdb) p print_generic_expr (stderr, $19, 0) >integer >(gdb) p low->typed.type->type_common.precision >$22 = 32 <<< 32 bit case label >(gdb) p type->type_common.precision >$23 = 64 > >(gdb) p useless_type_conversion_p ($16->typed.type, $19) >$24 = false >(gdb) p useless_type_conversion_p ($19, $16->typed.type) >$25 = false > > >Is this valid? If so I'll do the promotion myself but this fails >the >"is_useless_type_conversion_p ()" test.... > >Andrew
