https://gcc.gnu.org/bugzilla/show_bug.cgi?id=110992
Bug ID: 110992 Summary: [14 Regression] Dead Code Elimination Regression at -O3 since r14-1654-g7ceed7e3e29 Product: gcc Version: 14.0 Status: UNCONFIRMED Severity: normal Priority: P3 Component: tree-optimization Assignee: unassigned at gcc dot gnu.org Reporter: scherrer.sv at gmail dot com Target Milestone: --- static unsigned b; static short c = 4; void foo(void); static short(a)(short d, short g) { return d * g; } void e(); static char f() { b = 0; return 0; } int main() { int h = b; if ((short)(a(c && e, 65535) & h)) { foo(); h || f(); } } gcc-bcda361daae (trunk) -O3 cannot eliminate the call to foo but gcc-releases/gcc-13.1.0 -O3 can. ----------------------------------------------------------------------- gcc-bcda361daaec8623c91d0dff3ea8e576373b5f50 -O3 case.c -S -o case.s --------- OUTPUT --------- main: .LFB2: .cfi_startproc cmpw $0, b(%rip) jne .L8 xorl %eax, %eax ret .L8: pushq %rax .cfi_def_cfa_offset 16 call foo xorl %eax, %eax popq %rdx .cfi_def_cfa_offset 8 ret ---------- END OUTPUT --------- ----------------------------------------------------------------------- gcc-2b98cc24d6af0432a74f6dad1c722ce21c1f7458 -O3 case.c -S -o case.s --------- OUTPUT --------- main: .LFB2: .cfi_startproc xorl %eax, %eax ret ---------- END OUTPUT --------- ----------------------------------------------------------------------- Bisects to r14-1654-g7ceed7e3e29