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From: Keith Thompson <Keith.S.Thompson+u@gmail.com>
Newsgroups: comp.lang.c++
Subject: Re: How to get mantissa of long double?
Date: Tue, 05 Oct 2021 09:04:21 -0700
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David Brown <david.brown@hesbynett.no> writes:
> On 05/10/2021 07:12, Bonita Montero wrote:
>> Am 04.10.2021 um 20:04 schrieb David Brown:
>> 
>>> MSVC for ARM has 64-bit "long doubles" even on 64-bit ARM, other 64-bit
>>> ARM targets have 128-bit (I don't know off-hand if they are IEEE quad
>>> precision).  For RISC-V, even 32-bit targets have 128-bit "long double".
>> 
>> There isn't any ARM-implementation with 128 bit FP.
>
> And you know that because ... what?  Because you are confusing hardware
> floating point with floating point in general?

    $ uname -m
    aarch64
    $ cat c.c
    #include <stdio.h>
    #include <limits.h>
    #include <float.h>

    int main(void) {
        printf("sizeof (long double) = %zu (%zu bits), LDBL_DIG = %d\n",
               sizeof (long double),
               CHAR_BIT * sizeof (long double),
               LDBL_DIG);
    }
    $ gcc c.c -o c && ./c
    sizeof (long double) = 16 (128 bits), LDBL_DIG = 33
    $

-- 
Keith Thompson (The_Other_Keith) Keith.S.Thompson+u@gmail.com
Working, but not speaking, for Philips
void Void(void) { Void(); } /* The recursive call of the void */