Re: manually inserted software breakpoints in MIPS

[Andrew Cagney]

> Hi,
>
> I tried to insert software breakpoints manually to my code in MIPS so that
> I could stop GDB every time the program takes a branch I it should not
> take.  Instructions "teq $0,$0" and "break 0" do the trick and the GDB
> breaks on the instructions as if there were true breakpoints inserted
> from the GDB interface.  However, I would like the GDB continue execution
> by the continue command.  Currently it just keeps looping in the
> breakpoint instruction until I force it to jump over.
>
> The very same feature works fine on i386 if I insert "int 3"
> instructions.

It works on the x86 through good luck rather than good management.
When the x86 stops, it leaves PC on the _next_ instruction (the one 
after the breakpoint) while for the MIPS it leaves the PC on the current 
instruction.  Consequently, when you resume on the x86 that breakpoint 
is magically skipped.

If the behavour were to be changed it would be to fix the x86.

enjoy,
        Andrew