> Am 23.03.2024 um 08:59 schrieb Jakub Jelinek <ja...@redhat.com>:
>
> Hi!
>
> We ICE on the following testcase, because handle_cast was incorrectly
> testing !m_first to see whether it should use m_data[m_bitfld_load + 1]
> or fresh SSA_NAME for a PHI result.
> Now, m_first is in the routine sometimes temporarily cleared in between
> doing prepare_data_in_out and the !m_first check and only before returning
> restored from the save_first copy.
> Without this patch, we try to use the same SSA_NAME (_12 here) in 2
> different PHI results which is obviously invalid IL and ICEs very quickly.
>
> Bootstrapped/regtested on x86_64-linux and i686-linux, ok for trunk?
Ok
Richard
> 2024-03-23 Jakub Jelinek <ja...@redhat.com>
>
> PR tree-optimization/114433
> * gimple-lower-bitint.cc (bitint_large_huge::handle_cast): For
> m_bitfld_load check save_first rather than m_first.
>
> * gcc.dg/torture/bitint-68.c: New test.
>
> --- gcc/gimple-lower-bitint.cc.jj 2024-03-22 14:54:41.767972684 +0100
> +++ gcc/gimple-lower-bitint.cc 2024-03-22 17:13:43.702249666 +0100
> @@ -1506,7 +1506,7 @@ bitint_large_huge::handle_cast (tree lhs
> if (m_bitfld_load)
> {
> tree t4;
> - if (!m_first)
> + if (!save_first)
> t4 = m_data[m_bitfld_load + 1];
> else
> t4 = make_ssa_name (m_limb_type);
> --- gcc/testsuite/gcc.dg/torture/bitint-68.c.jj 2024-03-22
> 17:26:29.841713520 +0100
> +++ gcc/testsuite/gcc.dg/torture/bitint-68.c 2024-03-22 17:26:51.941409603
> +0100
> @@ -0,0 +1,28 @@
> +/* PR tree-optimization/114433 */
> +/* { dg-do run { target bitint } } */
> +/* { dg-options "-std=c23" } */
> +/* { dg-skip-if "" { ! run_expensive_tests } { "*" } { "-O0" "-O2" } } */
> +/* { dg-skip-if "" { ! run_expensive_tests } { "-flto" } { "" } } */
> +
> +#if __BITINT_MAXWIDTH__ >= 511
> +struct S { int : 31; _BitInt(511) b : 300; } s;
> +
> +__attribute__((noipa)) _BitInt(511)
> +foo (void)
> +{
> + return s.b << 1;
> +}
> +#endif
> +
> +int
> +main ()
> +{
> +#if __BITINT_MAXWIDTH__ >= 511
> + s.b =
> 642460398785925402356009598661384732715767737595497615767135001949421105426024498988100867wb;
> + if (foo () != ((_BitInt(511))
> 642460398785925402356009598661384732715767737595497615767135001949421105426024498988100867wb)
> << 1)
> + __builtin_abort ();
> + s.b =
> 2655156766298562299560755420298083843774074962786295887660222690220887wb;
> + if (foo () != ((_BitInt(511))
> 2655156766298562299560755420298083843774074962786295887660222690220887wb) <<
> 1)
> + __builtin_abort ();
> +#endif
> +}
>
> Jakub
>
