Description
| Bugzilla Link | 50766 |
| Version | 12.0 |
| OS | Linux |
| Reporter | LLVM Bugzilla Contributor |
| CC | @DougGregor,@zygoloid |
Extended Description
In C double and _Float64 are destinct types always.
In C float and _Float32 are destinct types always.
In _Float32 must NOT promote to double.
I have the definitive response from the sc22wg14 mailing list confirming
above statements.
Since the mailing list is not public I cannot sent the answer here.
x86-64 clang 12.0.0, icc 19.01 and tcc (unknown version) fail to compile
following program, but gcc 9.2.1 succeeds:
#include <stdio.h>
#include <math.h>
#define PGFN(name) _Generic((name),
float: printf("%s():" #name "=%f\n",func,name),
double: printf("%s():" #name "=%f\n",func,name),
default: printf("%s():" #name "=[unknown type]\n",func),
_Float32:printf("%s():" #name "=%f\n",func,((double)name)),
_Float64:printf("%s():" #name "=%f\n",func,name)
)
int main(int argc,char *argv[]){
float f=4.0;
double d=8.0;
_Float32 f32=32.0;
_Float64 f64=64.0;
(void)argc,(void)argv;
PGFN(f);
PGFN(d);
PGFN(f32);
PGFN(f64);
return 0;
}