Bug#948490: gcc-9: -std=c11 prevents the use of decimal FP

[Vincent Lefevre]

Control: tags -1 upstream
Control: forwarded -1 https://gcc.gnu.org/bugzilla/show_bug.cgi?id=93410

On 2020-01-23 14:04:59 +0100, Matthias Klose wrote:
> please could you recheck with trunk,

This is still OK with the trunk (e9ee848dcdc).

> and report that upstream?

Done.

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Processed: Re: Bug#948490: gcc-9: -std=c11 prevents the use of decimal FP

[Debian Bug Tracking System]

Processing control commands:

> tags -1 upstream
Bug #948490 [gcc-9] gcc-9: -std=c11 prevents the use of decimal FP
Added tag(s) upstream.
> forwarded -1 https://gcc.gnu.org/bugzilla/show_bug.cgi?id=93410
Bug #948490 [gcc-9] gcc-9: -std=c11 prevents the use of decimal FP
Set Bug forwarded-to-address to 
'https://gcc.gnu.org/bugzilla/show_bug.cgi?id=93410'.

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Bug#948490: gcc-9: -std=c11 prevents the use of decimal FP

[Matthias Klose]

On 09.01.20 14:24, Vincent Lefevre wrote:
> Package: gcc-9
> Version: 9.2.1-22
> Severity: normal
> 
> The -std=c11 option (or other versions of the C standard) prevents
> the use of decimal FP:
> 
> $ cat tst.c
> int main (void)
> {
>   _Decimal64 x = 1;
>   return x != 1;
> }
> $ gcc-9 tst.c -o tst
> $ gcc-9 -std=c11 tst.c -o tst
> tst.c: In function ‘main’:
> tst.c:3:3: error: unknown type name ‘_Decimal64’
> 3 |   _Decimal64 x = 1;
>   |   ^~
> 
> There is no such issue with gcc-snapshot (_Decimal64 is not a
> forbidden extension):
> 
> $ gcc-snapshot -std=c11 tst.c -o tst
> $ gcc-snapshot -std=c11 -pedantic tst.c -o tst
> tst.c: In function 'main':
> tst.c:3:3: warning: ISO C does not support decimal floating-point before C2X 
> [-Wpedantic]
> 3 |   _Decimal64 x = 1;
>   |   ^~
> 
> The GCC 9.2.0 manual does not mention a possible limitation.

please could you recheck with trunk, and report that upstream?

Bug#948490: gcc-9: -std=c11 prevents the use of decimal FP

[Vincent Lefevre]

Package: gcc-9
Version: 9.2.1-22
Severity: normal

The -std=c11 option (or other versions of the C standard) prevents
the use of decimal FP:

$ cat tst.c
int main (void)
{
  _Decimal64 x = 1;
  return x != 1;
}
$ gcc-9 tst.c -o tst
$ gcc-9 -std=c11 tst.c -o tst
tst.c: In function ‘main’:
tst.c:3:3: error: unknown type name ‘_Decimal64’
3 |   _Decimal64 x = 1;
  |   ^~

There is no such issue with gcc-snapshot (_Decimal64 is not a
forbidden extension):

$ gcc-snapshot -std=c11 tst.c -o tst
$ gcc-snapshot -std=c11 -pedantic tst.c -o tst
tst.c: In function 'main':
tst.c:3:3: warning: ISO C does not support decimal floating-point before C2X 
[-Wpedantic]
3 |   _Decimal64 x = 1;
  |   ^~

The GCC 9.2.0 manual does not mention a possible limitation.

-- System Information:
Debian Release: bullseye/sid
  APT prefers unstable-debug
  APT policy: (500, 'unstable-debug'), (500, 'stable-updates'), (500, 
'unstable'), (500, 'testing'), (500, 'stable'), (1, 'experimental')
Architecture: amd64 (x86_64)
Foreign Architectures: i386

Kernel: Linux 5.4.0-2-amd64 (SMP w/12 CPU cores)
Kernel taint flags: TAINT_PROPRIETARY_MODULE, TAINT_OOT_MODULE, 
TAINT_UNSIGNED_MODULE
Locale: LANG=POSIX, LC_CTYPE=en_US.UTF-8 (charmap=UTF-8), LANGUAGE=POSIX 
(charmap=UTF-8)
Shell: /bin/sh linked to /bin/dash
Init: systemd (via /run/systemd/system)
LSM: AppArmor: enabled

Versions of packages gcc-9 depends on:
ii  binutils  2.33.50.20200107-1
ii  cpp-9 9.2.1-22
ii  gcc-9-base9.2.1-22
ii  libc6 2.29-8
ii  libcc1-0  9.2.1-22
ii  libgcc-9-dev  9.2.1-22
ii  libgcc1   1:9.2.1-22
ii  libgmp10  2:6.1.2+dfsg-4
ii  libisl22  0.22-2
ii  libmpc3   1.1.0-1
ii  libmpfr6  4.0.2-1
ii  libstdc++69.2.1-22
ii  zlib1g1:1.2.11.dfsg-1+b1

Versions of packages gcc-9 recommends:
ii  libc6-dev  2.29-8

Versions of packages gcc-9 suggests:
ii  gcc-9-doc   9.2.0-2
ii  gcc-9-locales   9.2.1-22
ii  gcc-9-multilib  9.2.1-22

-- no debconf information