Re: [sdcc-devel] comparison of int and uint

[Maarten B. <sou...@ds...>]

Hi Vaclav,

A warning could be given for comparison of signed and unsigned int. Other
compilers do. But they cannot be cast to a larger type as that is not
allowed by the C standard.

Maarten

> Hello,
>
> I am currently playing with comparison. I found that if I compare char and
> uchar, both operands are promoted to int and then compared. This is in
> iCode, as well and I am getting message "warning 185: comparison of
> 'signed char' with 'unsigned char' requires promotion to int".
>
> But when I compare int with uint, no warning is printed and int is
> silently casted to uint:
> sign_compare.c(l23:s12:k15:d0:s0)        iTemp8 [k14 lr12:13 so:0]{
> ia0 a2p0
> re0 rm0 nos0 ru0 dp0}{volatile-unsigned-int xdata} := iTemp6 [k12 lr10:12
> so:0]{ ia0 a2p0 re0 rm0 nos0 ru0 dp0}{volatile-int xdata}
> sign_compare.c(l23:s13:k16:d0:s0)        iTemp9 [k15 lr13:14 so:0]{
> ia0 a2p0
> re0 rm0 nos0 ru0 dp0}{char fixed} = iTemp8 [k14 lr12:13 so:0]{ ia0 a2p0
> re0
> rm0 nos0 ru0 dp0}{volatile-unsigned-int xdata} > iTemp7 [k13 lr11:13
> so:0]{
> ia0 a2p0 re0 rm0 nos0 ru0 dp0}{volatile-unsigned-int xdata}
>
> Is there any possibility to extend icode generator to cast such operands
> to signed 3 bytes and then signed comparison ? And some warning message ?
> The same probably applies to long and ulong.
>
> Shall I create bug report for this issue ?
>
> Vaclav