Hi! Debug stmts are allowed by the verifier before the returns_twice calls. More importantly, they don't have a lhs, so the current handling of arg_stmts statements to force them on the edges ICEs.
The following patch just keeps them where they were before. Bootstrapped/regtested on x86_64-linux and i686-linux, ok for trunk? 2024-04-09 Jakub Jelinek <ja...@redhat.com> PR middle-end/114628 * gimple-lower-bitint.cc (gimple_lower_bitint): Keep debug stmts before returns_twice calls as is, don't push them into arg_stmts vector/move to edges. * gcc.dg/bitint-105.c: New test. --- gcc/gimple-lower-bitint.cc.jj 2024-04-04 10:46:52.698026863 +0200 +++ gcc/gimple-lower-bitint.cc 2024-04-08 15:42:19.719892644 +0200 @@ -7172,8 +7172,13 @@ gimple_lower_bitint (void) gimple_stmt_iterator gsi = gsi_after_labels (gimple_bb (stmt)); while (gsi_stmt (gsi) != stmt) { - arg_stmts.safe_push (gsi_stmt (gsi)); - gsi_remove (&gsi, false); + if (is_gimple_debug (gsi_stmt (gsi))) + gsi_next (&gsi); + else + { + arg_stmts.safe_push (gsi_stmt (gsi)); + gsi_remove (&gsi, false); + } } gimple *g; basic_block bb = NULL; --- gcc/testsuite/gcc.dg/bitint-105.c.jj 2024-04-08 16:00:07.843630530 +0200 +++ gcc/testsuite/gcc.dg/bitint-105.c 2024-04-08 15:49:28.687175492 +0200 @@ -0,0 +1,29 @@ +/* PR middle-end/114628 */ +/* { dg-do compile { target bitint } } */ +/* { dg-options "-O2 -g" } */ + +int foo (int); +#if __BITINT_MAXWIDTH__ >= 129 +__attribute__((returns_twice)) int bar (_BitInt(129) x); + +void +baz (int x, _BitInt(129) y) +{ + void *q[] = { &&l1, &&l2 }; +l2: + x = foo (foo (3)); + bar (y); + goto *q[x & 1]; +l1:; +} + +void +qux (int x, _BitInt(129) y) +{ + void *q[] = { &&l1, &&l2 }; +l2: + x = foo (foo (3)); + bar (y); +l1:; +} +#endif Jakub