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* [Qemu-devel] [Bug 1843651] [NEW] m68k fpu bug
@ 2019-09-11 22:09 Pierre Muller
  2019-09-12 18:32 ` [Qemu-devel] [Bug 1843651] " Alex Bennée
                   ` (2 more replies)
  0 siblings, 3 replies; 4+ messages in thread
From: Pierre Muller @ 2019-09-11 22:09 UTC (permalink / raw)
  To: qemu-devel

Public bug reported:

On gcc123 cfarm machine,
I was testing m68k executables generated by Free Pascal Compiler.

muller@gcc123:~/pas/check$ cat inf.pp
function get_double(x : double):double;
  begin
    get_double:=x;
  end;


var
  y : double;
  py : pbyte;
  i : byte;
begin
  y:=1.0/0.0;
  py:=@y;
{$ifdef ENDIAN_LITTLE}
  write('little endian y=');
  for i:=7 downto 0 do
{$else not ENDIAN_LITTLE}
  write('big endian y=');
  for i:=0 to 7 do
{$endif}
    write(hexstr(py[i],2));
  writeln;
  y:=get_double(y)+1;
{$ifdef ENDIAN_LITTLE}
  write('little endian y=');
  for i:=7 downto 0 do
{$else not ENDIAN_LITTLE}
  write('big endian y=');
  for i:=0 to 7 do
{$endif}
    write(hexstr(py[i],2));
  writeln;
end.
muller@gcc123:~/pas/check$ ppc68k inf
Free Pascal Compiler version 3.3.1-r20:42973M [2019/09/11] for m68k
Copyright (c) 1993-2019 by Florian Klaempfl and others
Target OS: Linux for m68k
Compiling inf.pp
Assembling program
Linking inf
33 lines compiled, 0.1 sec
muller@gcc123:~/pas/check$ ./inf
big endian y=7FF0000000000000
big endian y=7FFFFFFFFFFFFFFF
muller@gcc123:~/pas/check$ qemu-m68k ./inf
big endian y=7FF0000000000000
big endian y=7FFFFFFFFFFFFFFF
muller@gcc123:~/pas/check$ ~/sys-root/bin/qemu-m68k ./inf
qemu-m68k        qemu-m68k-fixed
muller@gcc123:~/pas/check$ ~/sys-root/bin/qemu-m68k-fixed ./inf
big endian y=7FF0000000000000
big endian y=7FF0000000000000

~/sys-root/bin/qemu-m68k  is 4.1.0 release,
~/sys-root/bin/qemu-m68k-fixed is the same source with a unique change:

gnu/qemu/qemu-4.1.0/fpu/softfloat-specialize.h:214:#if defined(TARGET_M68K)
gnu/qemu/qemu-4.1.0/fpu/softfloat-specialize.h-215-#define floatx80_infinity_low  LIT64(0x0000000000000000)
gnu/qemu/qemu-4.1.0/fpu/softfloat-specialize.h-216-#else
gnu/qemu/qemu-4.1.0/fpu/softfloat-specialize.h-217-#define floatx80_infinity_low  LIT64(0x8000000000000000)
gnu/qemu/qemu-4.1.0/fpu/softfloat-specialize.h-218-#endif

the M68K branch value is set to the same value as the other branch.

The problem of the M68K specific floatx86_infinity_low values
is that is enters in conflict with
muller@gcc123:~/pas/check$ grep -nA6 invalid_enc  /home/muller/gnu/qemu/qemu-4.1.0/include/fpu/softfloat.h
752:static inline bool floatx80_invalid_encoding(floatx80 a)
753-{
754-    return (a.low & (1ULL << 63)) == 0 && (a.high & 0x7FFF) != 0;
755-}

And thus the m68k variant of floatx80 representing +Infinity is
considered as an invalid encoding, and thus converted into a NaN 7FFFFFFFFFFFFFFF

** Affects: qemu
     Importance: Undecided
         Status: New

-- 
You received this bug notification because you are a member of qemu-
devel-ml, which is subscribed to QEMU.
https://bugs.launchpad.net/bugs/1843651

Title:
  m68k fpu bug

Status in QEMU:
  New

Bug description:
  On gcc123 cfarm machine,
  I was testing m68k executables generated by Free Pascal Compiler.

  muller@gcc123:~/pas/check$ cat inf.pp
  function get_double(x : double):double;
    begin
      get_double:=x;
    end;

  
  var
    y : double;
    py : pbyte;
    i : byte;
  begin
    y:=1.0/0.0;
    py:=@y;
  {$ifdef ENDIAN_LITTLE}
    write('little endian y=');
    for i:=7 downto 0 do
  {$else not ENDIAN_LITTLE}
    write('big endian y=');
    for i:=0 to 7 do
  {$endif}
      write(hexstr(py[i],2));
    writeln;
    y:=get_double(y)+1;
  {$ifdef ENDIAN_LITTLE}
    write('little endian y=');
    for i:=7 downto 0 do
  {$else not ENDIAN_LITTLE}
    write('big endian y=');
    for i:=0 to 7 do
  {$endif}
      write(hexstr(py[i],2));
    writeln;
  end.
  muller@gcc123:~/pas/check$ ppc68k inf
  Free Pascal Compiler version 3.3.1-r20:42973M [2019/09/11] for m68k
  Copyright (c) 1993-2019 by Florian Klaempfl and others
  Target OS: Linux for m68k
  Compiling inf.pp
  Assembling program
  Linking inf
  33 lines compiled, 0.1 sec
  muller@gcc123:~/pas/check$ ./inf
  big endian y=7FF0000000000000
  big endian y=7FFFFFFFFFFFFFFF
  muller@gcc123:~/pas/check$ qemu-m68k ./inf
  big endian y=7FF0000000000000
  big endian y=7FFFFFFFFFFFFFFF
  muller@gcc123:~/pas/check$ ~/sys-root/bin/qemu-m68k ./inf
  qemu-m68k        qemu-m68k-fixed
  muller@gcc123:~/pas/check$ ~/sys-root/bin/qemu-m68k-fixed ./inf
  big endian y=7FF0000000000000
  big endian y=7FF0000000000000

  ~/sys-root/bin/qemu-m68k  is 4.1.0 release,
  ~/sys-root/bin/qemu-m68k-fixed is the same source with a unique change:

  gnu/qemu/qemu-4.1.0/fpu/softfloat-specialize.h:214:#if defined(TARGET_M68K)
  gnu/qemu/qemu-4.1.0/fpu/softfloat-specialize.h-215-#define floatx80_infinity_low  LIT64(0x0000000000000000)
  gnu/qemu/qemu-4.1.0/fpu/softfloat-specialize.h-216-#else
  gnu/qemu/qemu-4.1.0/fpu/softfloat-specialize.h-217-#define floatx80_infinity_low  LIT64(0x8000000000000000)
  gnu/qemu/qemu-4.1.0/fpu/softfloat-specialize.h-218-#endif

  the M68K branch value is set to the same value as the other branch.

  The problem of the M68K specific floatx86_infinity_low values
  is that is enters in conflict with
  muller@gcc123:~/pas/check$ grep -nA6 invalid_enc  /home/muller/gnu/qemu/qemu-4.1.0/include/fpu/softfloat.h
  752:static inline bool floatx80_invalid_encoding(floatx80 a)
  753-{
  754-    return (a.low & (1ULL << 63)) == 0 && (a.high & 0x7FFF) != 0;
  755-}

  And thus the m68k variant of floatx80 representing +Infinity is
  considered as an invalid encoding, and thus converted into a NaN 7FFFFFFFFFFFFFFF

To manage notifications about this bug go to:
https://bugs.launchpad.net/qemu/+bug/1843651/+subscriptions


^ permalink raw reply	[flat|nested] 4+ messages in thread

* [Qemu-devel] [Bug 1843651] Re: m68k fpu bug
  2019-09-11 22:09 [Qemu-devel] [Bug 1843651] [NEW] m68k fpu bug Pierre Muller
@ 2019-09-12 18:32 ` Alex Bennée
  2021-04-22  7:32 ` Thomas Huth
  2021-04-23 14:40 ` Pierre Muller
  2 siblings, 0 replies; 4+ messages in thread
From: Alex Bennée @ 2019-09-12 18:32 UTC (permalink / raw)
  To: qemu-devel

** Tags added: fpu m68k

-- 
You received this bug notification because you are a member of qemu-
devel-ml, which is subscribed to QEMU.
https://bugs.launchpad.net/bugs/1843651

Title:
  m68k fpu bug

Status in QEMU:
  New

Bug description:
  On gcc123 cfarm machine,
  I was testing m68k executables generated by Free Pascal Compiler.

  muller@gcc123:~/pas/check$ cat inf.pp
  function get_double(x : double):double;
    begin
      get_double:=x;
    end;

  
  var
    y : double;
    py : pbyte;
    i : byte;
  begin
    y:=1.0/0.0;
    py:=@y;
  {$ifdef ENDIAN_LITTLE}
    write('little endian y=');
    for i:=7 downto 0 do
  {$else not ENDIAN_LITTLE}
    write('big endian y=');
    for i:=0 to 7 do
  {$endif}
      write(hexstr(py[i],2));
    writeln;
    y:=get_double(y)+1;
  {$ifdef ENDIAN_LITTLE}
    write('little endian y=');
    for i:=7 downto 0 do
  {$else not ENDIAN_LITTLE}
    write('big endian y=');
    for i:=0 to 7 do
  {$endif}
      write(hexstr(py[i],2));
    writeln;
  end.
  muller@gcc123:~/pas/check$ ppc68k inf
  Free Pascal Compiler version 3.3.1-r20:42973M [2019/09/11] for m68k
  Copyright (c) 1993-2019 by Florian Klaempfl and others
  Target OS: Linux for m68k
  Compiling inf.pp
  Assembling program
  Linking inf
  33 lines compiled, 0.1 sec
  muller@gcc123:~/pas/check$ ./inf
  big endian y=7FF0000000000000
  big endian y=7FFFFFFFFFFFFFFF
  muller@gcc123:~/pas/check$ qemu-m68k ./inf
  big endian y=7FF0000000000000
  big endian y=7FFFFFFFFFFFFFFF
  muller@gcc123:~/pas/check$ ~/sys-root/bin/qemu-m68k ./inf
  qemu-m68k        qemu-m68k-fixed
  muller@gcc123:~/pas/check$ ~/sys-root/bin/qemu-m68k-fixed ./inf
  big endian y=7FF0000000000000
  big endian y=7FF0000000000000

  ~/sys-root/bin/qemu-m68k  is 4.1.0 release,
  ~/sys-root/bin/qemu-m68k-fixed is the same source with a unique change:

  gnu/qemu/qemu-4.1.0/fpu/softfloat-specialize.h:214:#if defined(TARGET_M68K)
  gnu/qemu/qemu-4.1.0/fpu/softfloat-specialize.h-215-#define floatx80_infinity_low  LIT64(0x0000000000000000)
  gnu/qemu/qemu-4.1.0/fpu/softfloat-specialize.h-216-#else
  gnu/qemu/qemu-4.1.0/fpu/softfloat-specialize.h-217-#define floatx80_infinity_low  LIT64(0x8000000000000000)
  gnu/qemu/qemu-4.1.0/fpu/softfloat-specialize.h-218-#endif

  the M68K branch value is set to the same value as the other branch.

  The problem of the M68K specific floatx86_infinity_low values
  is that is enters in conflict with
  muller@gcc123:~/pas/check$ grep -nA6 invalid_enc  /home/muller/gnu/qemu/qemu-4.1.0/include/fpu/softfloat.h
  752:static inline bool floatx80_invalid_encoding(floatx80 a)
  753-{
  754-    return (a.low & (1ULL << 63)) == 0 && (a.high & 0x7FFF) != 0;
  755-}

  And thus the m68k variant of floatx80 representing +Infinity is
  considered as an invalid encoding, and thus converted into a NaN 7FFFFFFFFFFFFFFF

To manage notifications about this bug go to:
https://bugs.launchpad.net/qemu/+bug/1843651/+subscriptions


^ permalink raw reply	[flat|nested] 4+ messages in thread

* [Bug 1843651] Re: m68k fpu bug
  2019-09-11 22:09 [Qemu-devel] [Bug 1843651] [NEW] m68k fpu bug Pierre Muller
  2019-09-12 18:32 ` [Qemu-devel] [Bug 1843651] " Alex Bennée
@ 2021-04-22  7:32 ` Thomas Huth
  2021-04-23 14:40 ` Pierre Muller
  2 siblings, 0 replies; 4+ messages in thread
From: Thomas Huth @ 2021-04-22  7:32 UTC (permalink / raw)
  To: qemu-devel

The QEMU project is currently considering to move its bug tracking to
another system. For this we need to know which bugs are still valid
and which could be closed already. Thus we are setting older bugs to
"Incomplete" now.

If you still think this bug report here is valid, then please switch
the state back to "New" within the next 60 days, otherwise this report
will be marked as "Expired". Or please mark it as "Fix Released" if
the problem has been solved with a newer version of QEMU already.

Thank you and sorry for the inconvenience.


** Changed in: qemu
       Status: New => Incomplete

-- 
You received this bug notification because you are a member of qemu-
devel-ml, which is subscribed to QEMU.
https://bugs.launchpad.net/bugs/1843651

Title:
  m68k fpu bug

Status in QEMU:
  Incomplete

Bug description:
  On gcc123 cfarm machine,
  I was testing m68k executables generated by Free Pascal Compiler.

  muller@gcc123:~/pas/check$ cat inf.pp
  function get_double(x : double):double;
    begin
      get_double:=x;
    end;

  
  var
    y : double;
    py : pbyte;
    i : byte;
  begin
    y:=1.0/0.0;
    py:=@y;
  {$ifdef ENDIAN_LITTLE}
    write('little endian y=');
    for i:=7 downto 0 do
  {$else not ENDIAN_LITTLE}
    write('big endian y=');
    for i:=0 to 7 do
  {$endif}
      write(hexstr(py[i],2));
    writeln;
    y:=get_double(y)+1;
  {$ifdef ENDIAN_LITTLE}
    write('little endian y=');
    for i:=7 downto 0 do
  {$else not ENDIAN_LITTLE}
    write('big endian y=');
    for i:=0 to 7 do
  {$endif}
      write(hexstr(py[i],2));
    writeln;
  end.
  muller@gcc123:~/pas/check$ ppc68k inf
  Free Pascal Compiler version 3.3.1-r20:42973M [2019/09/11] for m68k
  Copyright (c) 1993-2019 by Florian Klaempfl and others
  Target OS: Linux for m68k
  Compiling inf.pp
  Assembling program
  Linking inf
  33 lines compiled, 0.1 sec
  muller@gcc123:~/pas/check$ ./inf
  big endian y=7FF0000000000000
  big endian y=7FFFFFFFFFFFFFFF
  muller@gcc123:~/pas/check$ qemu-m68k ./inf
  big endian y=7FF0000000000000
  big endian y=7FFFFFFFFFFFFFFF
  muller@gcc123:~/pas/check$ ~/sys-root/bin/qemu-m68k ./inf
  qemu-m68k        qemu-m68k-fixed
  muller@gcc123:~/pas/check$ ~/sys-root/bin/qemu-m68k-fixed ./inf
  big endian y=7FF0000000000000
  big endian y=7FF0000000000000

  ~/sys-root/bin/qemu-m68k  is 4.1.0 release,
  ~/sys-root/bin/qemu-m68k-fixed is the same source with a unique change:

  gnu/qemu/qemu-4.1.0/fpu/softfloat-specialize.h:214:#if defined(TARGET_M68K)
  gnu/qemu/qemu-4.1.0/fpu/softfloat-specialize.h-215-#define floatx80_infinity_low  LIT64(0x0000000000000000)
  gnu/qemu/qemu-4.1.0/fpu/softfloat-specialize.h-216-#else
  gnu/qemu/qemu-4.1.0/fpu/softfloat-specialize.h-217-#define floatx80_infinity_low  LIT64(0x8000000000000000)
  gnu/qemu/qemu-4.1.0/fpu/softfloat-specialize.h-218-#endif

  the M68K branch value is set to the same value as the other branch.

  The problem of the M68K specific floatx86_infinity_low values
  is that is enters in conflict with
  muller@gcc123:~/pas/check$ grep -nA6 invalid_enc  /home/muller/gnu/qemu/qemu-4.1.0/include/fpu/softfloat.h
  752:static inline bool floatx80_invalid_encoding(floatx80 a)
  753-{
  754-    return (a.low & (1ULL << 63)) == 0 && (a.high & 0x7FFF) != 0;
  755-}

  And thus the m68k variant of floatx80 representing +Infinity is
  considered as an invalid encoding, and thus converted into a NaN 7FFFFFFFFFFFFFFF

To manage notifications about this bug go to:
https://bugs.launchpad.net/qemu/+bug/1843651/+subscriptions


^ permalink raw reply	[flat|nested] 4+ messages in thread

* [Bug 1843651] Re: m68k fpu bug
  2019-09-11 22:09 [Qemu-devel] [Bug 1843651] [NEW] m68k fpu bug Pierre Muller
  2019-09-12 18:32 ` [Qemu-devel] [Bug 1843651] " Alex Bennée
  2021-04-22  7:32 ` Thomas Huth
@ 2021-04-23 14:40 ` Pierre Muller
  2 siblings, 0 replies; 4+ messages in thread
From: Pierre Muller @ 2021-04-23 14:40 UTC (permalink / raw)
  To: qemu-devel

I tested, in release 5.2.0, this issue is fixed.

Thanks

** Changed in: qemu
       Status: Incomplete => Fix Released

-- 
You received this bug notification because you are a member of qemu-
devel-ml, which is subscribed to QEMU.
https://bugs.launchpad.net/bugs/1843651

Title:
  m68k fpu bug

Status in QEMU:
  Fix Released

Bug description:
  On gcc123 cfarm machine,
  I was testing m68k executables generated by Free Pascal Compiler.

  muller@gcc123:~/pas/check$ cat inf.pp
  function get_double(x : double):double;
    begin
      get_double:=x;
    end;

  
  var
    y : double;
    py : pbyte;
    i : byte;
  begin
    y:=1.0/0.0;
    py:=@y;
  {$ifdef ENDIAN_LITTLE}
    write('little endian y=');
    for i:=7 downto 0 do
  {$else not ENDIAN_LITTLE}
    write('big endian y=');
    for i:=0 to 7 do
  {$endif}
      write(hexstr(py[i],2));
    writeln;
    y:=get_double(y)+1;
  {$ifdef ENDIAN_LITTLE}
    write('little endian y=');
    for i:=7 downto 0 do
  {$else not ENDIAN_LITTLE}
    write('big endian y=');
    for i:=0 to 7 do
  {$endif}
      write(hexstr(py[i],2));
    writeln;
  end.
  muller@gcc123:~/pas/check$ ppc68k inf
  Free Pascal Compiler version 3.3.1-r20:42973M [2019/09/11] for m68k
  Copyright (c) 1993-2019 by Florian Klaempfl and others
  Target OS: Linux for m68k
  Compiling inf.pp
  Assembling program
  Linking inf
  33 lines compiled, 0.1 sec
  muller@gcc123:~/pas/check$ ./inf
  big endian y=7FF0000000000000
  big endian y=7FFFFFFFFFFFFFFF
  muller@gcc123:~/pas/check$ qemu-m68k ./inf
  big endian y=7FF0000000000000
  big endian y=7FFFFFFFFFFFFFFF
  muller@gcc123:~/pas/check$ ~/sys-root/bin/qemu-m68k ./inf
  qemu-m68k        qemu-m68k-fixed
  muller@gcc123:~/pas/check$ ~/sys-root/bin/qemu-m68k-fixed ./inf
  big endian y=7FF0000000000000
  big endian y=7FF0000000000000

  ~/sys-root/bin/qemu-m68k  is 4.1.0 release,
  ~/sys-root/bin/qemu-m68k-fixed is the same source with a unique change:

  gnu/qemu/qemu-4.1.0/fpu/softfloat-specialize.h:214:#if defined(TARGET_M68K)
  gnu/qemu/qemu-4.1.0/fpu/softfloat-specialize.h-215-#define floatx80_infinity_low  LIT64(0x0000000000000000)
  gnu/qemu/qemu-4.1.0/fpu/softfloat-specialize.h-216-#else
  gnu/qemu/qemu-4.1.0/fpu/softfloat-specialize.h-217-#define floatx80_infinity_low  LIT64(0x8000000000000000)
  gnu/qemu/qemu-4.1.0/fpu/softfloat-specialize.h-218-#endif

  the M68K branch value is set to the same value as the other branch.

  The problem of the M68K specific floatx86_infinity_low values
  is that is enters in conflict with
  muller@gcc123:~/pas/check$ grep -nA6 invalid_enc  /home/muller/gnu/qemu/qemu-4.1.0/include/fpu/softfloat.h
  752:static inline bool floatx80_invalid_encoding(floatx80 a)
  753-{
  754-    return (a.low & (1ULL << 63)) == 0 && (a.high & 0x7FFF) != 0;
  755-}

  And thus the m68k variant of floatx80 representing +Infinity is
  considered as an invalid encoding, and thus converted into a NaN 7FFFFFFFFFFFFFFF

To manage notifications about this bug go to:
https://bugs.launchpad.net/qemu/+bug/1843651/+subscriptions


^ permalink raw reply	[flat|nested] 4+ messages in thread

end of thread, other threads:[~2021-04-23 14:47 UTC | newest]

Thread overview: 4+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2019-09-11 22:09 [Qemu-devel] [Bug 1843651] [NEW] m68k fpu bug Pierre Muller
2019-09-12 18:32 ` [Qemu-devel] [Bug 1843651] " Alex Bennée
2021-04-22  7:32 ` Thomas Huth
2021-04-23 14:40 ` Pierre Muller

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