[sdcc-devel] implicit cast of bit types

[Scott D. <sc...@da...>]

In the pic port, I noticed SDCC implicitly casts bit types when bits are in
expressions involving other types that are larger than chars. For example,

Declare this:

int aint0 = 0;
char achar0 =0;
bit bit0 = 0;

And then try this:


  achar0 += bit0;  //t.c 45
  aint0 += bit0;   //t.c 46

For the char, there is no implicit cast but for the int there is.

Here's the raw dump:

t.c(45:0:53:0:0)		iTemp35 [k47 lr0:0 so:0]{ ia0 re0 rm0}{char } = _achar0 [k5
lr0:0 so:0]{ ia0 re0 rm0}{char } + _bit0 [k3 lr0:0 so:0]{ ia0 re0 rm0}{bit
{0,1}}
t.c(45:0:54:0:0)		iTemp36 [k48 lr0:0 so:0]{ ia0 re0 rm0}{char } := iTemp35 [k47
lr0:0 so:0]{ ia0 re0 rm0}{char }
t.c(45:0:55:0:0)		_achar0 [k5 lr0:0 so:0]{ ia1 re0 rm0}{char } := iTemp36 [k48
lr0:0 so:0]{ ia0 re0 rm0}{char }

t.c(46:0:56:0:0)		iTemp37 [k49 lr0:0 so:0]{ ia0 re0 rm0}{int } = (int )_bit0 [k3
lr0:0 so:0]{ ia0 re0 rm0}{bit {0,1}}
t.c(46:0:57:0:0)		iTemp38 [k50 lr0:0 so:0]{ ia0 re0 rm0}{int } = _aint0 [k25
lr0:0 so:0]{ ia0 re0 rm0}{int } + iTemp37 [k49 lr0:0 so:0]{ ia0 re0 rm0}{int }
t.c(46:0:58:0:0)		iTemp39 [k51 lr0:0 so:0]{ ia0 re0 rm0}{int } := iTemp38 [k50
lr0:0 so:0]{ ia0 re0 rm0}{int }
t.c(46:0:59:0:0)		_aint0 [k25 lr0:0 so:0]{ ia1 re0 rm0}{int } := iTemp39 [k51
lr0:0 so:0]{ ia0 re0 rm0}{int }

The first raw line for t.c,46 has the iCode Cast. Why? At what point does the
compiler introduce this?

The reason I want to know is because the cast is unnecessary for the Pic
port and causes a whole bunch of code to be generated.

Thanks,
Scott