https://gcc.gnu.org/bugzilla/show_bug.cgi?id=111799
--- Comment #4 from Theodoros Theodoridis <theodort at inf dot ethz.ch> --- Oops, there was a bug in my reduction, here's the fixed code: https://godbolt.org/z/shxffzs8E void foo(void); typedef unsigned short uint16_t; static int b; static int ****c; static int *f = &b; static int *****ad; static char(a)(char g, char h) { return g + h; } static char(d)(char g, char h) { return g * h; } static void(e)(uint16_t g) { if (!(((g) >= 1) && ((g) <= 65459))) { __builtin_unreachable(); } } int main() { b = 0; for (;; b = 1) { char i = d(126 | 1, 205); e(i); short j; int k = *f; j = -21; for (; j; j = a(j, 7)) e((j ^ k && *f) <= *f); if (b) break; ad = &c; } if (ad) ; else foo(); ; } trunk -O2: main: movl $0, b(%rip) movl $2, %esi xorl %ecx, %ecx xorl %r8d, %r8d .L7: movl $-21, %eax .L2: testl %ecx, %ecx je .L26 leal 7(%rax), %edx movsbw %dl, %di testb %dl, %dl je .L6 .L5: movl $8, %eax cmpb $1, %dl je .L2 movl %edi, %eax leal 7(%rax), %edx movsbw %dl, %di testb %dl, %dl jne .L5 .L6: cmpl $1, %esi je .L27 .L12: movl $1, %esi movl $1, %ecx movl $1, %r8d jmp .L7 .L26: testb $1, %al je .L4 leal 7(%rax), %edx movsbw %dl, %ax testb %dl, %dl je .L6 .L4: leal 14(%rax), %edx movsbw %dl, %ax testb %dl, %dl jne .L4 cmpl $1, %esi jne .L12 .L27: testb %r8b, %r8b je .L28 movq $c, ad(%rip) movl %ecx, b(%rip) .L23: xorl %eax, %eax ret .L28: cmpq $0, ad(%rip) jne .L23 pushq %rax call foo xorl %eax, %eax popq %rdx ret 13.2 -O2: main: movq $c, ad(%rip) xorl %eax, %eax movl $1, b(%rip) ret the bisection remains the same: r14-2365-g2e406f0753e
