Hi, > > > main.c:107: sprintf (str,"%x", (uint8) *sys_rstack); > > > 01B4 A9 10 708 mov r1,_sys_rstack > > > 01B6 87 07 709 mov ar7,@r1 > > > 01B8 C0 07 710 push ar7 [...]
> what difference does the cast make? the declaration is already > uint8, so isn't the cast a no-op? what am i missing? As Maarten said, the cast inhibits automatic promotion to int: > > Since you use an explicit cast to char on the parameter passed to a > > varargs function (sprintf) the value is not passed as an int as > > normal. > this sdcc behavior bites us (bytes us? :-) all the time -- i'm always > having to go back to add "(uint)foo" casts when printing byte-wide > values as %x or %d, to make the values show correctly. unless there > are new format chars for byte-wide parameters, Not sure, but does our printf() support, say, "%hx" with "h" as a size-modifier for byte-sized args? > how does this save memory? > what am i missing? Look at the code above: Pushing one argument byte costs 6 byte code space and 1 byte stack space. If we promote byte args to int, this would cost 12 byte code space and 2 byte on the stack. At every variadic call site. And for every variadic argument. We had discussed this problem when it was implemented and did not find *the* ideal solution back then. Not sure if we can find one now :-( Best regards Raphael ------------------------------------------------------------------------------ All of the data generated in your IT infrastructure is seriously valuable. Why? It contains a definitive record of application performance, security threats, fraudulent activity, and more. Splunk takes this data and makes sense of it. IT sense. And common sense. http://p.sf.net/sfu/splunk-d2dcopy2 _______________________________________________ Sdcc-user mailing list Sdcc-user@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/sdcc-user
