https://gcc.gnu.org/bugzilla/show_bug.cgi?id=96482
--- Comment #9 from Martin Liška <marxin at gcc dot gnu.org> --- Also this one shows the problem: -fdbg-cnt=ipa_cp_bits:10460-10461. If I see correctly the function body: lto-dump -dump-body=addr_to_index nir_lower_io.c.o Gimple Body of Function: addr_to_index addr_to_index (struct nir_builder * b, struct nir_ssa_def * addr, nir_address_format addr_format) { unsigned int c; <bb 2> [local count: 1073741824]: if (addr_format_3(D) == 3) goto <bb 3>; [20.24%] else goto <bb 4>; [79.76%] <bb 3> [local count: 217325344]: c = 0; _9 = nir_swizzle (b_5(D), addr_6(D), &c, 1); c ={v} {CLOBBER}; goto <bb 7>; [100.00%] <bb 4> [local count: 856416481]: if (addr_format_3(D) == 4) goto <bb 5>; [100.00%] else goto <bb 6>; [0.00%] <bb 5> [local count: 856416481]: _8 = nir_channels (b_5(D), addr_6(D), 3); goto <bb 7>; [100.00%] <bb 6> [count: 0]: __builtin_unreachable (); <bb 7> [local count: 1073741824]: # _1 = PHI <_9(3), _8(5)> return _1; } addr_format (aka param 2) is either 3 or 4. 3 = 0x011 4 = 0x100 so mask 6 = 0x110 is wrong as first bit is not constant. @Martin: Am I right?