https://gcc.gnu.org/bugzilla/show_bug.cgi?id=111942
Alexandre Oliva <aoliva at gcc dot gnu.org> changed: What |Removed |Added ---------------------------------------------------------------------------- Status|UNCONFIRMED |NEW Last reconfirmed| |2023-10-26 Ever confirmed|0 |1 --- Comment #1 from Alexandre Oliva <aoliva at gcc dot gnu.org> --- Thanks for the report. This latent bug is independent from -fharden-control-flow-redundancy. The issue is that volatile asm stmts are considered throw points when -fnon-call-exceptions is enabled. I'm not sure where C++ wires non-call exceptions to enclosing handlers, but it appears that it doesn't: even with a handler added around f's body, no EH edges are added. However, inlining f() into another function with a handler for the call will wire all escaping exceptions to that handler, creating the same arrangement of 3 outgoing edges (fallthrough, asm jmp, and EH) that the rtl splitter barfs at. /* compile with -fnon-call-exceptions */ int i, j; int f(void) { asm goto ("# %0 %2" : "+r" (i) ::: jmp); i += 2; asm goto ("# %0 %1 %l[jmp]" : "+r" (i), "+r" (j) ::: jmp); jmp: return i; } int inline __attribute__ ((__always_inline__)) f(void); int g(void) { try { return f(); } catch (...) { i++; throw; } } ./xgcc -B./ pr98096.cc -fno-harden-control-flow-redundancy -fnon-call-exceptions during RTL pass: expand pr98096.cc: In function ‘int g()’: pr98096.cc:19:1: internal compiler error: in rtl_split_edge, at cfgrtl.cc:1943 19 | }