* [PATCH v2] fpu/softfloat: Silent 'bitwise negation of a boolean expression' warning
@ 2020-05-28 8:48 Philippe Mathieu-Daudé
2020-05-28 8:57 ` Thomas Huth
0 siblings, 1 reply; 5+ messages in thread
From: Philippe Mathieu-Daudé @ 2020-05-28 8:48 UTC (permalink / raw)
To: qemu-devel
Cc: Peter Maydell, Thomas Huth, Alex Bennée, Richard Henderson,
Philippe Mathieu-Daudé, Aurelien Jarno
When building with clang version 10.0.0-4ubuntu1, we get:
CC lm32-softmmu/fpu/softfloat.o
fpu/softfloat.c:3365:13: error: bitwise negation of a boolean expression; did you mean logical negation? [-Werror,-Wbool-operation]
absZ &= ~ ( ( ( roundBits ^ 0x40 ) == 0 ) & roundNearestEven );
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
fpu/softfloat.c:3423:18: error: bitwise negation of a boolean expression; did you mean logical negation? [-Werror,-Wbool-operation]
absZ0 &= ~ ( ( (uint64_t) ( absZ1<<1 ) == 0 ) & roundNearestEven );
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
fpu/softfloat.c:3483:18: error: bitwise negation of a boolean expression; did you mean logical negation? [-Werror,-Wbool-operation]
absZ0 &= ~(((uint64_t)(absZ1<<1) == 0) & roundNearestEven);
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
fpu/softfloat.c:3606:13: error: bitwise negation of a boolean expression; did you mean logical negation? [-Werror,-Wbool-operation]
zSig &= ~ ( ( ( roundBits ^ 0x40 ) == 0 ) & roundNearestEven );
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
fpu/softfloat.c:3760:13: error: bitwise negation of a boolean expression; did you mean logical negation? [-Werror,-Wbool-operation]
zSig &= ~ ( ( ( roundBits ^ 0x200 ) == 0 ) & roundNearestEven );
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
fpu/softfloat.c:3987:21: error: bitwise negation of a boolean expression; did you mean logical negation? [-Werror,-Wbool-operation]
~ ( ( (uint64_t) ( zSig1<<1 ) == 0 ) & roundNearestEven );
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
fpu/softfloat.c:4003:22: error: bitwise negation of a boolean expression; did you mean logical negation? [-Werror,-Wbool-operation]
zSig0 &= ~ ( ( (uint64_t) ( zSig1<<1 ) == 0 ) & roundNearestEven );
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
fpu/softfloat.c:4273:18: error: bitwise negation of a boolean expression; did you mean logical negation? [-Werror,-Wbool-operation]
zSig1 &= ~ ( ( zSig2 + zSig2 == 0 ) & roundNearestEven );
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Fix by rewriting the fishy bitwise AND of two bools as an int.
Suggested-by: Eric Blake <eblake@redhat.com>
Buglink: https://bugs.launchpad.net/bugs/1881004
Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
---
v2: Resend without the Cc: "Toni Wilen <twilen@winuae.net>" tag
---
fpu/softfloat.c | 33 ++++++++++++++++++++++++---------
1 file changed, 24 insertions(+), 9 deletions(-)
diff --git a/fpu/softfloat.c b/fpu/softfloat.c
index 6c8f2d597a..0dd57eddd7 100644
--- a/fpu/softfloat.c
+++ b/fpu/softfloat.c
@@ -3362,7 +3362,9 @@ static int32_t roundAndPackInt32(bool zSign, uint64_t absZ,
}
roundBits = absZ & 0x7F;
absZ = ( absZ + roundIncrement )>>7;
- absZ &= ~ ( ( ( roundBits ^ 0x40 ) == 0 ) & roundNearestEven );
+ if (((roundBits ^ 0x40) == 0) && roundNearestEven) {
+ absZ &= ~1;
+ }
z = absZ;
if ( zSign ) z = - z;
if ( ( absZ>>32 ) || ( z && ( ( z < 0 ) ^ zSign ) ) ) {
@@ -3420,7 +3422,9 @@ static int64_t roundAndPackInt64(bool zSign, uint64_t absZ0, uint64_t absZ1,
if ( increment ) {
++absZ0;
if ( absZ0 == 0 ) goto overflow;
- absZ0 &= ~ ( ( (uint64_t) ( absZ1<<1 ) == 0 ) & roundNearestEven );
+ if (((absZ1 << 1) == 0) && roundNearestEven) {
+ absZ0 &= ~1;
+ }
}
z = absZ0;
if ( zSign ) z = - z;
@@ -3480,7 +3484,9 @@ static int64_t roundAndPackUint64(bool zSign, uint64_t absZ0,
float_raise(float_flag_invalid, status);
return UINT64_MAX;
}
- absZ0 &= ~(((uint64_t)(absZ1<<1) == 0) & roundNearestEven);
+ if (((absZ1 << 1) == 0) && roundNearestEven) {
+ absZ0 &= ~1;
+ }
}
if (zSign && absZ0) {
@@ -3603,7 +3609,9 @@ static float32 roundAndPackFloat32(bool zSign, int zExp, uint32_t zSig,
status->float_exception_flags |= float_flag_inexact;
}
zSig = ( zSig + roundIncrement )>>7;
- zSig &= ~ ( ( ( roundBits ^ 0x40 ) == 0 ) & roundNearestEven );
+ if (((roundBits ^ 0x40) == 0) && roundNearestEven) {
+ zSig &= ~1;
+ }
if ( zSig == 0 ) zExp = 0;
return packFloat32( zSign, zExp, zSig );
@@ -3757,7 +3765,9 @@ static float64 roundAndPackFloat64(bool zSign, int zExp, uint64_t zSig,
status->float_exception_flags |= float_flag_inexact;
}
zSig = ( zSig + roundIncrement )>>10;
- zSig &= ~ ( ( ( roundBits ^ 0x200 ) == 0 ) & roundNearestEven );
+ if (((roundBits ^ 0x200) == 0) && roundNearestEven) {
+ zSig &= ~1;
+ }
if ( zSig == 0 ) zExp = 0;
return packFloat64( zSign, zExp, zSig );
@@ -3983,8 +3993,9 @@ floatx80 roundAndPackFloatx80(int8_t roundingPrecision, bool zSign,
}
if ( increment ) {
++zSig0;
- zSig0 &=
- ~ ( ( (uint64_t) ( zSig1<<1 ) == 0 ) & roundNearestEven );
+ if (((zSig1 << 1) == 0) && roundNearestEven) {
+ zSig0 &= ~1;
+ }
if ( (int64_t) zSig0 < 0 ) zExp = 1;
}
return packFloatx80( zSign, zExp, zSig0 );
@@ -4000,7 +4011,9 @@ floatx80 roundAndPackFloatx80(int8_t roundingPrecision, bool zSign,
zSig0 = UINT64_C(0x8000000000000000);
}
else {
- zSig0 &= ~ ( ( (uint64_t) ( zSig1<<1 ) == 0 ) & roundNearestEven );
+ if (((zSig1 << 1) == 0) && roundNearestEven) {
+ zSig0 &= ~1;
+ }
}
}
else {
@@ -4270,7 +4283,9 @@ static float128 roundAndPackFloat128(bool zSign, int32_t zExp,
}
if ( increment ) {
add128( zSig0, zSig1, 0, 1, &zSig0, &zSig1 );
- zSig1 &= ~ ( ( zSig2 + zSig2 == 0 ) & roundNearestEven );
+ if ((zSig2 + zSig2 == 0) && roundNearestEven) {
+ zSig1 &= ~1;
+ }
}
else {
if ( ( zSig0 | zSig1 ) == 0 ) zExp = 0;
--
2.21.3
^ permalink raw reply related [flat|nested] 5+ messages in thread* Re: [PATCH v2] fpu/softfloat: Silent 'bitwise negation of a boolean expression' warning
2020-05-28 8:48 [PATCH v2] fpu/softfloat: Silent 'bitwise negation of a boolean expression' warning Philippe Mathieu-Daudé
@ 2020-05-28 8:57 ` Thomas Huth
2020-05-28 9:00 ` Philippe Mathieu-Daudé
0 siblings, 1 reply; 5+ messages in thread
From: Thomas Huth @ 2020-05-28 8:57 UTC (permalink / raw)
To: Philippe Mathieu-Daudé, qemu-devel
Cc: Richard Henderson, Alex Bennée, Aurelien Jarno,
Peter Maydell
On 28/05/2020 10.48, Philippe Mathieu-Daudé wrote:
> When building with clang version 10.0.0-4ubuntu1, we get:
>
> CC lm32-softmmu/fpu/softfloat.o
> fpu/softfloat.c:3365:13: error: bitwise negation of a boolean expression; did you mean logical negation? [-Werror,-Wbool-operation]
> absZ &= ~ ( ( ( roundBits ^ 0x40 ) == 0 ) & roundNearestEven );
> ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>
> fpu/softfloat.c:3423:18: error: bitwise negation of a boolean expression; did you mean logical negation? [-Werror,-Wbool-operation]
> absZ0 &= ~ ( ( (uint64_t) ( absZ1<<1 ) == 0 ) & roundNearestEven );
> ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>
> fpu/softfloat.c:3483:18: error: bitwise negation of a boolean expression; did you mean logical negation? [-Werror,-Wbool-operation]
> absZ0 &= ~(((uint64_t)(absZ1<<1) == 0) & roundNearestEven);
> ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>
> fpu/softfloat.c:3606:13: error: bitwise negation of a boolean expression; did you mean logical negation? [-Werror,-Wbool-operation]
> zSig &= ~ ( ( ( roundBits ^ 0x40 ) == 0 ) & roundNearestEven );
> ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>
> fpu/softfloat.c:3760:13: error: bitwise negation of a boolean expression; did you mean logical negation? [-Werror,-Wbool-operation]
> zSig &= ~ ( ( ( roundBits ^ 0x200 ) == 0 ) & roundNearestEven );
> ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>
> fpu/softfloat.c:3987:21: error: bitwise negation of a boolean expression; did you mean logical negation? [-Werror,-Wbool-operation]
> ~ ( ( (uint64_t) ( zSig1<<1 ) == 0 ) & roundNearestEven );
> ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>
> fpu/softfloat.c:4003:22: error: bitwise negation of a boolean expression; did you mean logical negation? [-Werror,-Wbool-operation]
> zSig0 &= ~ ( ( (uint64_t) ( zSig1<<1 ) == 0 ) & roundNearestEven );
> ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>
> fpu/softfloat.c:4273:18: error: bitwise negation of a boolean expression; did you mean logical negation? [-Werror,-Wbool-operation]
> zSig1 &= ~ ( ( zSig2 + zSig2 == 0 ) & roundNearestEven );
> ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>
> Fix by rewriting the fishy bitwise AND of two bools as an int.
>
> Suggested-by: Eric Blake <eblake@redhat.com>
> Buglink: https://bugs.launchpad.net/bugs/1881004
> Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
> ---
> v2: Resend without the Cc: "Toni Wilen <twilen@winuae.net>" tag
> ---
> fpu/softfloat.c | 33 ++++++++++++++++++++++++---------
> 1 file changed, 24 insertions(+), 9 deletions(-)
>
> diff --git a/fpu/softfloat.c b/fpu/softfloat.c
> index 6c8f2d597a..0dd57eddd7 100644
> --- a/fpu/softfloat.c
> +++ b/fpu/softfloat.c
> @@ -3362,7 +3362,9 @@ static int32_t roundAndPackInt32(bool zSign, uint64_t absZ,
> }
> roundBits = absZ & 0x7F;
> absZ = ( absZ + roundIncrement )>>7;
> - absZ &= ~ ( ( ( roundBits ^ 0x40 ) == 0 ) & roundNearestEven );
> + if (((roundBits ^ 0x40) == 0) && roundNearestEven) {
> + absZ &= ~1;
> + }
You could get rid of some more parentheses now:
if ((roundBits ^ 0x40) == 0 && roundNearestEven)
... also in the other hunks.
Anyway:
Reviewed-by: Thomas Huth <thuth@redhat.com>
^ permalink raw reply [flat|nested] 5+ messages in thread* Re: [PATCH v2] fpu/softfloat: Silent 'bitwise negation of a boolean expression' warning
2020-05-28 8:57 ` Thomas Huth
@ 2020-05-28 9:00 ` Philippe Mathieu-Daudé
2020-05-28 13:37 ` Eric Blake
0 siblings, 1 reply; 5+ messages in thread
From: Philippe Mathieu-Daudé @ 2020-05-28 9:00 UTC (permalink / raw)
To: Thomas Huth, qemu-devel
Cc: Richard Henderson, Alex Bennée, Aurelien Jarno,
Peter Maydell
On 5/28/20 10:57 AM, Thomas Huth wrote:
> On 28/05/2020 10.48, Philippe Mathieu-Daudé wrote:
>> When building with clang version 10.0.0-4ubuntu1, we get:
>>
>> CC lm32-softmmu/fpu/softfloat.o
>> fpu/softfloat.c:3365:13: error: bitwise negation of a boolean expression; did you mean logical negation? [-Werror,-Wbool-operation]
>> absZ &= ~ ( ( ( roundBits ^ 0x40 ) == 0 ) & roundNearestEven );
>> ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>>
>> fpu/softfloat.c:3423:18: error: bitwise negation of a boolean expression; did you mean logical negation? [-Werror,-Wbool-operation]
>> absZ0 &= ~ ( ( (uint64_t) ( absZ1<<1 ) == 0 ) & roundNearestEven );
>> ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>>
>> fpu/softfloat.c:3483:18: error: bitwise negation of a boolean expression; did you mean logical negation? [-Werror,-Wbool-operation]
>> absZ0 &= ~(((uint64_t)(absZ1<<1) == 0) & roundNearestEven);
>> ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>>
>> fpu/softfloat.c:3606:13: error: bitwise negation of a boolean expression; did you mean logical negation? [-Werror,-Wbool-operation]
>> zSig &= ~ ( ( ( roundBits ^ 0x40 ) == 0 ) & roundNearestEven );
>> ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>>
>> fpu/softfloat.c:3760:13: error: bitwise negation of a boolean expression; did you mean logical negation? [-Werror,-Wbool-operation]
>> zSig &= ~ ( ( ( roundBits ^ 0x200 ) == 0 ) & roundNearestEven );
>> ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>>
>> fpu/softfloat.c:3987:21: error: bitwise negation of a boolean expression; did you mean logical negation? [-Werror,-Wbool-operation]
>> ~ ( ( (uint64_t) ( zSig1<<1 ) == 0 ) & roundNearestEven );
>> ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>>
>> fpu/softfloat.c:4003:22: error: bitwise negation of a boolean expression; did you mean logical negation? [-Werror,-Wbool-operation]
>> zSig0 &= ~ ( ( (uint64_t) ( zSig1<<1 ) == 0 ) & roundNearestEven );
>> ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>>
>> fpu/softfloat.c:4273:18: error: bitwise negation of a boolean expression; did you mean logical negation? [-Werror,-Wbool-operation]
>> zSig1 &= ~ ( ( zSig2 + zSig2 == 0 ) & roundNearestEven );
>> ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>>
>> Fix by rewriting the fishy bitwise AND of two bools as an int.
>>
>> Suggested-by: Eric Blake <eblake@redhat.com>
>> Buglink: https://bugs.launchpad.net/bugs/1881004
>> Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
>> ---
>> v2: Resend without the Cc: "Toni Wilen <twilen@winuae.net>" tag
>> ---
>> fpu/softfloat.c | 33 ++++++++++++++++++++++++---------
>> 1 file changed, 24 insertions(+), 9 deletions(-)
>>
>> diff --git a/fpu/softfloat.c b/fpu/softfloat.c
>> index 6c8f2d597a..0dd57eddd7 100644
>> --- a/fpu/softfloat.c
>> +++ b/fpu/softfloat.c
>> @@ -3362,7 +3362,9 @@ static int32_t roundAndPackInt32(bool zSign, uint64_t absZ,
>> }
>> roundBits = absZ & 0x7F;
>> absZ = ( absZ + roundIncrement )>>7;
>> - absZ &= ~ ( ( ( roundBits ^ 0x40 ) == 0 ) & roundNearestEven );
>> + if (((roundBits ^ 0x40) == 0) && roundNearestEven) {
>> + absZ &= ~1;
>> + }
>
> You could get rid of some more parentheses now:
>
> if ((roundBits ^ 0x40) == 0 && roundNearestEven)
>
> ... also in the other hunks.
I first wrote
if (!(roundBits ^ 0x40) && roundNearestEven)
But then thought this would diverge from Eric suggestion, so I kept what
he wrote (which is a bit closer to the style of rest of this file).
>
> Anyway:
> Reviewed-by: Thomas Huth <thuth@redhat.com>
>
Thanks!
^ permalink raw reply [flat|nested] 5+ messages in thread* Re: [PATCH v2] fpu/softfloat: Silent 'bitwise negation of a boolean expression' warning
2020-05-28 9:00 ` Philippe Mathieu-Daudé
@ 2020-05-28 13:37 ` Eric Blake
2020-05-28 13:41 ` Philippe Mathieu-Daudé
0 siblings, 1 reply; 5+ messages in thread
From: Eric Blake @ 2020-05-28 13:37 UTC (permalink / raw)
To: Philippe Mathieu-Daudé, Thomas Huth, qemu-devel
Cc: Richard Henderson, Alex Bennée, Aurelien Jarno,
Peter Maydell
On 5/28/20 4:00 AM, Philippe Mathieu-Daudé wrote:
> On 5/28/20 10:57 AM, Thomas Huth wrote:
>> On 28/05/2020 10.48, Philippe Mathieu-Daudé wrote:
>>> When building with clang version 10.0.0-4ubuntu1, we get:
In the subject, I'd suggest s/Silent/Silence/
>>>
>>> CC lm32-softmmu/fpu/softfloat.o
>>> fpu/softfloat.c:3365:13: error: bitwise negation of a boolean expression; did you mean logical negation? [-Werror,-Wbool-operation]
>>> absZ &= ~ ( ( ( roundBits ^ 0x40 ) == 0 ) & roundNearestEven );
>>> ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>>>
>>> fpu/softfloat.c:3423:18: error: bitwise negation of a boolean expression; did you mean logical negation? [-Werror,-Wbool-operation]
>>> absZ0 &= ~ ( ( (uint64_t) ( absZ1<<1 ) == 0 ) & roundNearestEven );
>>> ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>>>
Also, do you need to list all errors, or will just one or two
representative errors be sufficient?
>>>
>>> Fix by rewriting the fishy bitwise AND of two bools as an int.
>>>
>>> Suggested-by: Eric Blake <eblake@redhat.com>
>>> Buglink: https://bugs.launchpad.net/bugs/1881004
>>> Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
>>> ---
>>> +++ b/fpu/softfloat.c
>>> @@ -3362,7 +3362,9 @@ static int32_t roundAndPackInt32(bool zSign, uint64_t absZ,
>>> }
>>> roundBits = absZ & 0x7F;
>>> absZ = ( absZ + roundIncrement )>>7;
>>> - absZ &= ~ ( ( ( roundBits ^ 0x40 ) == 0 ) & roundNearestEven );
>>> + if (((roundBits ^ 0x40) == 0) && roundNearestEven) {
>>> + absZ &= ~1;
>>> + }
>>
>> You could get rid of some more parentheses now:
>>
>> if ((roundBits ^ 0x40) == 0 && roundNearestEven)
>>
>> ... also in the other hunks.
>
> I first wrote
>
> if (!(roundBits ^ 0x40) && roundNearestEven)
>
> But then thought this would diverge from Eric suggestion, so I kept what
> he wrote (which is a bit closer to the style of rest of this file).
I don't mind the patch as-is for minimizing churn and matching existing
style, but I also would not be opposed if you wanted to elide
unnecessary ().
>
>>
>> Anyway:
>> Reviewed-by: Thomas Huth <thuth@redhat.com>
>>
>
> Thanks!
>
Reviewed-by: Eric Blake <eblake@redhat.com>
--
Eric Blake, Principal Software Engineer
Red Hat, Inc. +1-919-301-3226
Virtualization: qemu.org | libvirt.org
^ permalink raw reply [flat|nested] 5+ messages in thread* Re: [PATCH v2] fpu/softfloat: Silent 'bitwise negation of a boolean expression' warning
2020-05-28 13:37 ` Eric Blake
@ 2020-05-28 13:41 ` Philippe Mathieu-Daudé
0 siblings, 0 replies; 5+ messages in thread
From: Philippe Mathieu-Daudé @ 2020-05-28 13:41 UTC (permalink / raw)
To: Eric Blake, Thomas Huth, qemu-devel
Cc: Richard Henderson, Alex Bennée, Aurelien Jarno,
Peter Maydell
On 5/28/20 3:37 PM, Eric Blake wrote:
> On 5/28/20 4:00 AM, Philippe Mathieu-Daudé wrote:
>> On 5/28/20 10:57 AM, Thomas Huth wrote:
>>> On 28/05/2020 10.48, Philippe Mathieu-Daudé wrote:
>>>> When building with clang version 10.0.0-4ubuntu1, we get:
>
> In the subject, I'd suggest s/Silent/Silence/
Don't fit... 73 chars :S I'll use 'Avoid' (or 'Remove'?) instead.
>
>>>>
>>>> CC lm32-softmmu/fpu/softfloat.o
>>>> fpu/softfloat.c:3365:13: error: bitwise negation of a boolean
>>>> expression; did you mean logical negation? [-Werror,-Wbool-operation]
>>>> absZ &= ~ ( ( ( roundBits ^ 0x40 ) == 0 ) & roundNearestEven );
>>>> ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>>>>
>>>> fpu/softfloat.c:3423:18: error: bitwise negation of a boolean
>>>> expression; did you mean logical negation? [-Werror,-Wbool-operation]
>>>> absZ0 &= ~ ( ( (uint64_t) ( absZ1<<1 ) == 0 ) &
>>>> roundNearestEven );
>>>>
>>>> ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>>>>
>
> Also, do you need to list all errors, or will just one or two
> representative errors be sufficient?
Fair :)
>
>>>>
>>>> Fix by rewriting the fishy bitwise AND of two bools as an int.
>>>>
>>>> Suggested-by: Eric Blake <eblake@redhat.com>
>>>> Buglink: https://bugs.launchpad.net/bugs/1881004
>>>> Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
>>>> ---
>
>>>> +++ b/fpu/softfloat.c
>>>> @@ -3362,7 +3362,9 @@ static int32_t roundAndPackInt32(bool zSign,
>>>> uint64_t absZ,
>>>> }
>>>> roundBits = absZ & 0x7F;
>>>> absZ = ( absZ + roundIncrement )>>7;
>>>> - absZ &= ~ ( ( ( roundBits ^ 0x40 ) == 0 ) & roundNearestEven );
>>>> + if (((roundBits ^ 0x40) == 0) && roundNearestEven) {
>>>> + absZ &= ~1;
>>>> + }
>>>
>>> You could get rid of some more parentheses now:
>>>
>>> if ((roundBits ^ 0x40) == 0 && roundNearestEven)
>>>
>>> ... also in the other hunks.
>>
>> I first wrote
>>
>> if (!(roundBits ^ 0x40) && roundNearestEven)
>>
>> But then thought this would diverge from Eric suggestion, so I kept what
>> he wrote (which is a bit closer to the style of rest of this file).
>
> I don't mind the patch as-is for minimizing churn and matching existing
> style, but I also would not be opposed if you wanted to elide
> unnecessary ().
OK, thanks for the review!
>
>>
>>>
>>> Anyway:
>>> Reviewed-by: Thomas Huth <thuth@redhat.com>
>>>
>>
>> Thanks!
>>
>
> Reviewed-by: Eric Blake <eblake@redhat.com>
>
^ permalink raw reply [flat|nested] 5+ messages in thread
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2020-05-28 8:48 [PATCH v2] fpu/softfloat: Silent 'bitwise negation of a boolean expression' warning Philippe Mathieu-Daudé
2020-05-28 8:57 ` Thomas Huth
2020-05-28 9:00 ` Philippe Mathieu-Daudé
2020-05-28 13:37 ` Eric Blake
2020-05-28 13:41 ` Philippe Mathieu-Daudé
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