Tool/software: Code Composer Studio
Hello, guys.
I tested MULS instructions. However, in some cases, it did not update Z, N flags.
I tried all instructions by myself and below is the result.
Case 1 for updating Z, N flags
MULS r1, r1, r2
MULS r1, r2
MULS r1, r2, r1
Case 2 for no updating Z, N flags
MULS r1, r2, r3
MULS r1, r2, r2
In document name "DUI0553A_cortex_m4_dgug_(instruction)" or "Cortex -M4 Devices - Generic User Guide",
it show me that S suffix with the MUL instruction has restrictions in 123 page.
like this.
According to this document, "MULS r1, r1, r2", "MULS r1, r2" should not update the Z, N flags. But CCS update them.
Also, example in document show "MULS R0, R2, R2" updates flags. But CCS does not update them.
(And it should not update because of restrictions.There is a contradiction.)
I wonder the reason of this situations.
I tried to search for reason but I can not find it.
Thanks for your reading.
