ack/lang/cem/cemcom.ansi/conversion.c
George Koehler 15950f9c95 Add long long literals like 123LL to ACK C.
For now, a long long literal must have the 'LL' or 'll' suffix.  A
literal without 'LL' or 'll' acts as before: it may become unsigned
long but not long long.  (For targets where int and long have the same
size, some literals change from unsigned int to unsigned long.)

Type `arith` may be too narrow for long long values.  Add a second
type `writh` for wide arithmetic, and change some variables from arith
to writh.  This may cause bugs if I forget to use writh, or if a
conversion from writh to arith overflows.  I mark some conversions
with (arith) or (writh) casts.

 - BigPars, SmallPars: Remove SPECIAL_ARITHMETICS.  This feature
   would change arith to a different type, but can't work, because it
   would conflict with definitions of arith in both <em_arith.h> and
   <flt_arith.h>.
 - LLlex.c: Understand 'LL' or 'll' suffix.  Cut size of constant when
   it overflows writh, not only when it overflows the target machine's
   types.  (This cut might not be necessary, because we might cut it
   again later.)  When picking signed long or unsigned long, check the
   target's long type, not the compiler's arith type; the old check
   for `val >= 0` was broken where sizeof(arith) > 4.
 - LLlex.h: Change struct token's tok_ival to writh, so it can hold a
   long long literal.
 - arith.c: Adjust to VL_VALUE being writh.  Don't convert between
   float and integer at compile-time if the integer might be too wide
   for <flt_arith.h>.  Add writh2str(), because writh might be too
   wide for long2str().
 - arith.h: Remove SPECIAL_ARITHMETICS.  Declare full_mask[] here,
   not in several *.c files.  Declare writh2str().
 - ch3.c, ch3bin.c, ch3mon.c, declarator.c, statement.g: Remove
   obsolete casts.  Adjust to VL_VALUE being writh.
 - conversion.c, stab.c: Don't declare full_mask[].
 - cstoper.c: Use writh for constant operations on VL_VALUE, and for
   full_mask[].
 - declar., field.c, ival.g: Add casts.
 - dumpidf.c: Need to #include "parameters.h" before checking DEBUG.
   Use writh2str, because "%ld" might not work.
 - eval.c, eval.h: Add casts.  Use writh when writing a wide constant
   in EM.
 - expr.c: Add and remove casts.  In fill_int_expr(), make expression
   from long long literal.  In chk_cst_expr(), allow long long as
   constant expression, so the compiler may accept `case 123LL:` in a
   switch statement.
 - expr.str: Change struct value's vl_value and struct expr's VL_VALUE
   to writh, so an expression may have a long long value at compile
   time.
 - statement.g: Remove obsolete casts.
 - switch.c, switch.str: Use writh in case entries for switch
   statements, so `switch (ll) {...}` with long long ll works.
 - tokenname.c: Add ULNGLNG so LLlex.c can use it for literals.
2019-09-04 22:14:38 -04:00

153 lines
3.1 KiB
C

/*
* (c) copyright 1987 by the Vrije Universiteit, Amsterdam, The Netherlands.
* See the copyright notice in the ACK home directory, in the file "Copyright".
*/
/* $Id$ */
/* C O N V E R S I O N - C O D E G E N E R A T O R */
#include "parameters.h"
#ifndef LINT
#include "conversion.h"
#include <em.h>
#include "interface.h"
#include "arith.h"
#include "type.h"
#include "sizes.h"
#include "Lpars.h"
#include "error.h"
#define T_SIGNED 1
#define T_UNSIGNED 2
#define T_FLOATING 3
/* conversion() generates the EM code for a conversion between
the types char, short, int, long, float, double and pointer.
There are three conversion types: signed, unsigned and floating.
The EM code to obtain this conversion looks like:
LOC sizeof(from_type)
LOC sizeof(to_type)
C??
*/
static int convtype(register struct type *);
void conversion(register struct type *from_type, register struct type *to_type)
{
register arith from_size = from_type->tp_size;
register arith to_size = to_type->tp_size;
int from_cnvtype = convtype(from_type);
int to_cnvtype = convtype(to_type);
if ((int)to_size < (int)word_size) to_size = word_size;
if ((int)from_size != (int)to_size || from_cnvtype != to_cnvtype) {
switch (from_cnvtype) {
case T_SIGNED:
switch (to_cnvtype) {
case T_SIGNED:
C_loc(from_size);
C_loc(to_size);
C_cii();
break;
case T_UNSIGNED:
case T_FLOATING:
if ((int)from_size < (int)word_size) {
C_loc(from_size);
C_loc(word_size);
C_cii();
from_size = word_size;
}
/* 3.2.1.2 */
if (to_cnvtype == T_UNSIGNED
&& (int)from_size < (int)to_size) {
C_loc(from_size);
C_loc(to_size);
C_cii();
from_size = to_size;
}
C_loc(from_size);
C_loc(to_size);
if (to_cnvtype == T_UNSIGNED) C_ciu();
else C_cif();
break;
}
break;
case T_UNSIGNED:
if ((int)from_size < (int)word_size) from_size = word_size;
C_loc(from_size);
C_loc(to_size);
switch (to_cnvtype) {
case T_SIGNED:
C_cui();
break;
case T_UNSIGNED:
C_cuu();
break;
case T_FLOATING:
C_cuf();
break;
}
break;
case T_FLOATING:
C_loc(from_size);
C_loc(to_size);
switch (to_cnvtype) {
case T_SIGNED:
C_cfi();
break;
case T_UNSIGNED:
C_cfu();
break;
case T_FLOATING:
C_cff();
break;
}
break;
default:
crash("(conversion) illegal type conversion");
/*NOTREACHED*/
}
}
if ((int)(to_type->tp_size) < (int)word_size
&& to_cnvtype != T_FLOATING
) {
if (to_cnvtype == T_SIGNED) {
C_loc(to_type->tp_size);
C_loc(word_size);
C_cii();
}
else {
C_loc((arith) full_mask[(int)(to_type->tp_size)]);
C_and(word_size);
}
}
}
/* convtype() returns in which category a given type falls:
signed, unsigned or floating
*/
static int convtype(register struct type *tp)
{
switch (tp->tp_fund) {
case CHAR:
case SHORT:
case INT:
case ERRONEOUS:
case LONG:
case LNGLNG:
case ENUM:
return tp->tp_unsigned ? T_UNSIGNED : T_SIGNED;
case FLOAT:
case DOUBLE:
case LNGDBL:
return T_FLOATING;
case POINTER:
return T_UNSIGNED;
}
return 0;
}
#endif /* LINT */