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Generate %shiftl instructions for shift.

This commit is contained in:
steve 2001-06-23 18:40:34 +00:00
parent a2d465804f
commit c4bd8b1463
1 changed files with 26 additions and 24 deletions
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50
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 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
*/ */
#if !defined(WINNT) #if !defined(WINNT)
#ident "$Id: eval_expr.c,v 1.32 2001/06/21 04:53:59 steve Exp $" #ident "$Id: eval_expr.c,v 1.33 2001/06/23 18:40:34 steve Exp $"
#endif #endif
# include "vvp_priv.h" # include "vvp_priv.h"
@ -381,19 +381,24 @@ static struct vector_info draw_binary_expr_logic(ivl_expr_t exp,
return lv; return lv;
} }
/*
* Draw code to evaluate the << expression. Use the %shiftl/i0
* instruction to do the real work of shifting.
*/
static struct vector_info draw_binary_expr_ls(ivl_expr_t exp, unsigned wid) static struct vector_info draw_binary_expr_ls(ivl_expr_t exp, unsigned wid)
{ {
ivl_expr_t le = ivl_expr_oper1(exp); ivl_expr_t le = ivl_expr_oper1(exp);
ivl_expr_t re = ivl_expr_oper2(exp); ivl_expr_t re = ivl_expr_oper2(exp);
unsigned shift = 0;
struct vector_info lv; struct vector_info lv;
struct vector_info rs;
/* XXXX support only constant right expressions. */ /* Figure out the shift amount and load that into the index
register. The value may be a constant, or may need to be
evaluated at run time. */
switch (ivl_expr_type(re)) { switch (ivl_expr_type(re)) {
case IVL_EX_NUMBER: { case IVL_EX_NUMBER: {
unsigned shift = 0;
unsigned idx, nbits = ivl_expr_width(re); unsigned idx, nbits = ivl_expr_width(re);
const char*bits = ivl_expr_bits(re); const char*bits = ivl_expr_bits(re);
@ -408,35 +413,29 @@ static struct vector_info draw_binary_expr_ls(ivl_expr_t exp, unsigned wid)
default: default:
assert(0); assert(0);
} }
fprintf(vvp_out, " %%ix/load 0, %u;\n", shift);
break; break;
} }
case IVL_EX_ULONG: case IVL_EX_ULONG:
shift = ivl_expr_uvalue(re); fprintf(vvp_out, " %%ix/load 0, %lu;\n", ivl_expr_uvalue(re));
break; break;
default:
assert(0);
break;
}
if (shift >= wid) { default: {
rs.base = 0; struct vector_info rv;
rs.wid = wid; rv = draw_eval_expr(re);
return rs; fprintf(vvp_out, " %%ix/get 0, %u, %u;\n",
rv.base, rv.wid);
clr_vector(rv);
break;
}
} }
lv = draw_eval_expr_wid(le, wid); lv = draw_eval_expr_wid(le, wid);
assert(lv.wid >= (wid - shift)); fprintf(vvp_out, " %%shiftl/i0 %u, %u;\n", lv.base, lv.wid);
rs.base = allocate_vector(wid); return lv;
rs.wid = wid;
fprintf(vvp_out, " %%mov %u, %u, %u;\n", rs.base+shift,
lv.base, wid-shift);
fprintf(vvp_out, " %%mov %u, 0, %u;\n", rs.base, shift);
clr_vector(lv);
return rs;
} }
static struct vector_info draw_binary_expr_rs(ivl_expr_t exp, unsigned wid) static struct vector_info draw_binary_expr_rs(ivl_expr_t exp, unsigned wid)
@ -1067,6 +1066,9 @@ struct vector_info draw_eval_expr(ivl_expr_t exp)
/* /*
* $Log: eval_expr.c,v $ * $Log: eval_expr.c,v $
* Revision 1.33 2001/06/23 18:40:34 steve
* Generate %shiftl instructions for shift.
*
* Revision 1.32 2001/06/21 04:53:59 steve * Revision 1.32 2001/06/21 04:53:59 steve
* Escaped identifiers in behavioral expressions. (Stephan Boettcher) * Escaped identifiers in behavioral expressions. (Stephan Boettcher)
* *