https://gcc.gnu.org/bugzilla/show_bug.cgi?id=110177
--- Comment #3 from Theodoros Theodoridis <theodort at inf dot ethz.ch> ---
I think the correct bisection is: r11-3063-gfcae5121154 (or its parent
r11-3062-g90e88fd376b)
I can't build its parent but with its grandparent r11-3061-g1644d7f4c1c the
call to foo is eliminated:
gcc-1644d7f4c1c4f99231d7de5e35fa7ce2d2e2c4c6 -Os test.c -S -o /dev/stdout
main:
movq g(%rip), %rax
movl $0, c(%rip)
movq (%rax), %rdx
movq %rdx, f(%rip)
testq %rdx, %rdx
je .L2
movq (%rax), %rax
movq %rax, f(%rip)
testq %rax, %rax
jne .L8
movl $9, c(%rip)
.L2:
pushq %rax
xorl %eax, %eax
call __assert_fail
.L8:
movl $27, c(%rip)
xorl %eax, %eax
movl $0, e(%rip)
ret
r11-3063-gfcae5121154 with ranger disabled generates the same code
gcc-fcae5121154d1c3382b056bcc2c563cedac28e74 -Os test.c -S -o /dev/stdout:
main:
movq g(%rip), %rax
movl $0, c(%rip)
movq (%rax), %rdx
movq %rdx, f(%rip)
testq %rdx, %rdx
je .L2
movq (%rax), %rax
movq %rax, f(%rip)
testq %rax, %rax
jne .L8
movl $9, c(%rip)
.L2:
pushq %rax
xorl %eax, %eax
call __assert_fail
.L8:
movl $27, c(%rip)
xorl %eax, %eax
movl $0, e(%rip)
ret
with ranger enabled it doesn't eliminate the call and generates mode code:
gcc-fcae5121154d1c3382b056bcc2c563cedac28e74 -Os -fevrp-mode=ranger test.c -S
-o /dev/stdout:
main:
pushq %rcx
movl e(%rip), %edi
xorl %eax, %eax
xorl %edx, %edx
movl $0, c(%rip)
movq g(%rip), %r8
.L2:
movl %eax, %esi
cmpl $27, %eax
je .L20
testl %eax, %eax
je .L3
movl %edi, %ecx
movl %eax, %r9d
movl %eax, %r10d
sall %cl, %r9d
movl %r9d, %ecx
sarl %cl, %r10d
testw %r10w, %r10w
je .L3
movl %eax, c(%rip)
.L3:
movq (%r8), %rcx
addl $9, %eax
movq %rcx, f(%rip)
testq %rcx, %rcx
jne .L8
testb %dl, %dl
je .L4
movl %esi, c(%rip)
.L4:
xorl %eax, %eax
call __assert_fail
.L8:
movb $1, %dl
jmp .L2
.L20:
testb %dl, %dl
je .L6
movl $27, c(%rip)
.L6:
cmpq $0, f(%rip)
movl $0, e(%rip)
jne .L7
call foo
.L7:
xorl %eax, %eax
popq %rdx
ret
