[Bug c++/100322] Switching from std=c++17 to std=c++20 causes performance regression in relationals

[barry.revzin at gmail dot com via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100322

--- Comment #5 from Barry Revzin <barry.revzin at gmail dot com> ---
Sorry meant to actually copy the reduction:

#include <compare> 

bool compare_count(int a, int b)
{
    return a > b;
}

bool compare(int a, int b)
{
    return (a <=> b) > 0;
}

which generates:

compare_count(int, int):
        cmp     r0, r1
        ite     le
        movle   r0, #0
        movgt   r0, #1
        bx      lr
compare(int, int):
        cmp     r0, r1
        beq     .L4
        blt     .L5
        movs    r0, #1
.L3:
        cmp     r0, #0
        ite     le
        movle   r0, #0
        movgt   r0, #1
        bx      lr
.L4:
        movs    r0, #0
        b       .L3
.L5:
        mov     r0, #-1
        b       .L3