https://gcc.gnu.org/bugzilla/show_bug.cgi?id=122219
--- Comment #19 from Pengfei Li <pfustc at gcc dot gnu.org> ---
A further simplified case from Andrew's original one:
union u {
long l;
int i[2];
};
inline long convert(int i) {
u t;
t.i[0] = i;
return t.l;
}
long foo(int x, unsigned int n) {
long y = -1;
for (int i = 0; i < n; i++) {
x = x * 2;
y = convert(x);
}
return y;
}
GCC emits below code for the loop in foo():
.L3:
lsl w2, w2, 1
add w3, w3, 1
bfi x4, x2, 0, 32
mov x0, x4
cmp w1, w3
bne .L3
While LLVM emits:
.LBB0_1:
lsl w0, w0, #1
subs w1, w1, #1
b.ne .LBB0_1
Are you still working on fixing this, @Andrew?
