uptime wraps too soon about cm_mcu HOT 2 CLOSED

Looking at the assembly output it looks like the compiler does not reduce this to 1/6000.

        bl      xTaskGetTickCount
        mov     r2, r0
        mov     r3, #1000
        mul     r3, r3, r2
        .loc 1 1116 14
        ldr     r2, .L354
        umull   r2, r3, r2, r3
        lsrs    r3, r3, #19

So we have an explicit multiplication by 1000 and then a division by a constant. The value stored at L354 is 375299969, so the umul followed by the shift corresponds to a multiplication of 1/5999999.999161332198245, i.e., 1/6e6.

from cm_mcu.

If I change the code in question to the following instead

  TickType_t now = xTaskGetTickCount()/(configTICK_RATE_HZ*60); // time in minutes

the generated assembly is now

        bl      xTaskGetTickCount
        mov     r2, r0
        .loc 1 1115 14
        ldr     r3, .L354
        umull   r2, r3, r3, r2
        lsrs    r3, r3, #7

where the value at 354 is now 91625969, which with the shift corresponds to multiplication by 1/6000.

from cm_mcu.