[M3devel] IR init_int with out of range values?

[Jay K]

Is this reasonable?


m3-libs/m3core/src/float/IEEE-be/LongRealRep.i3

INTERFACE LongRealRep;

(* This interface describes the layout of IEEE double precision reals
   on big endian machines *)

TYPE
  T = RECORD 
    sign         : BITS  1 FOR [0..1]                          := 0;
    exponent     : BITS 11 FOR [0..16_7FF]                     := 0;
    significand0 : BITS 20 FOR [0..16_FFFFF]                   := 0;
    significand1 : BITS 32 FOR [-16_7fffffff-1 .. 16_7fffffff] := 0;
  END;

CONST
  NegInf = T { sign := 1, exponent := 16_7FF };
  PosInf = T { sign := 0, exponent := 16_7FF };
  Nan    = T { sign := 0, exponent := 16_7FF, significand0 := 1 };

END LongRealRep.


	begin_init	 v.1
	# constant NegInf
	# constant PosInf
	init_int	 0 18442240474082181120 Int.64
	# constant Nan
	init_int	 8 9218868437227405312 Int.64



My C backend doesn't like 18442240474082181120 Int.64, since
18442240474082181120 does not fit in a signed 64bit integer.


Should the frontend be obligated to make it Word.64?

I guess I can make it work.


jair:python jay$ cat 1.c



#include <stdio.h>

int main()
{
long long a = 18442240474082181120ll;

printf("%llu %llx %lld %llx\n", a, a, a, a);
return 0;
}
jair:python jay$ edit 1.c
jair:python jay$ cat 1.c
#include <stdio.h>

int main()
{
long long a = 18442240474082181120ll;

printf("%llu %llx %lld %llx\n", a, a, a, a);
return 0;
}
jair:python jay$ cc 1.c
1.c:5:15: warning: integer literal is too large to be represented in a signed integer type, interpreting as unsigned
      [-Wimplicitly-unsigned-literal]
long long a = 18442240474082181120ll;
              ^
1 warning generated.
jair:python jay$ ./a.out
18442240474082181120 fff0000000000000 -4503599627370496 fff0000000000000

Thank you,
 - Jay