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Evaluate string expressions (Philip Blundell)

This commit is contained in:
steve 2001-10-18 16:41:49 +00:00
parent 84b70be7ee
commit ce7d64f427
1 changed files with 52 additions and 5 deletions
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57
tgt-vvp/eval_expr.c
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@ -17,7 +17,7 @@
* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
*/
#if !defined(WINNT)
#ident "$Id: eval_expr.c,v 1.50 2001/10/16 01:27:17 steve Exp $"
#ident "$Id: eval_expr.c,v 1.51 2001/10/18 16:41:49 steve Exp $"
#endif
# include "vvp_priv.h"
@ -767,6 +767,53 @@ static struct vector_info draw_number_expr(ivl_expr_t exp, unsigned wid)
return res;
}
/*
* A string in an expression is made up by copying constant bits into
* the allocated vector.
*/
static struct vector_info draw_string_expr(ivl_expr_t exp, unsigned wid)
{
struct vector_info res;
const char *p = ivl_expr_string(exp);
unsigned ewid, nwid;
unsigned bit = 0, idx;
res.wid = wid;
nwid = wid;
ewid = ivl_expr_width(exp);
if (ewid < nwid)
nwid = ewid;
p += (ewid / 8) - 1;
/* The string needs to be represented as an allocated
vector. Allocate the vector and use %mov instructions to
load the constant bit values. */
res.base = allocate_vector(wid);
idx = 0;
while (idx < nwid) {
unsigned this_bit = ((*p) & (1 << bit)) ? 1 : 0;
fprintf(vvp_out, " %%mov %u, %d, 1;\n",
res.base+idx, this_bit);
bit++;
if (bit == 8) {
bit = 0;
p--;
}
idx++;
}
/* Pad the number up to the expression width. */
if (idx < wid)
fprintf(vvp_out, " %%mov %u, 0, %u;\n", res.base+idx, wid-idx);
return res;
}
/*
* Evaluating a signal expression means loading the bits of the signal
* into the thread bits. Remember to account for the part select by
@ -1232,10 +1279,7 @@ struct vector_info draw_eval_expr_wid(ivl_expr_t exp, unsigned wid)
break;
case IVL_EX_STRING:
fprintf(stderr, "vvp error: unhandled expr type STRING\n");
assert(0);
res.base = 0;
res.wid = 0;
res = draw_string_expr(exp, wid);
break;
case IVL_EX_BINARY:
@ -1289,6 +1333,9 @@ struct vector_info draw_eval_expr(ivl_expr_t exp)
/*
* $Log: eval_expr.c,v $
* Revision 1.51 2001/10/18 16:41:49 steve
* Evaluate string expressions (Philip Blundell)
*
* Revision 1.50 2001/10/16 01:27:17 steve
* Generate %div instructions for binary /.
*