| Message ID | Zf6LyragNz5RnK0i@tucnak |
|---|---|
| State | New |
| Headers | show |
| Series | bitint: Fix bitfield loads in handle_cast [PR114433] | expand |
> Am 23.03.2024 um 08:59 schrieb Jakub Jelinek <jakub@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 <jakub@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 >
--- 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 +}