Message ID | 20170918104624.14743-1-laurent@vivier.eu |
---|---|
State | New |
Headers | show |
Series | softfloat: rename make_float[x80|128]_init to const_float[x80|128] | expand |
On 09/18/2017 07:46 AM, Laurent Vivier wrote: > We already have const_float16(), const_float32() and const_float64(), > so rename make_floatx80_init() and make_float128_init() as > const_floatx80() and const_float128(). > > Redefine make_floatx80() and make_float128() as make_float16(), > make_float32() and make_float64() using a variable and not only > a cast. > > Signed-off-by: Laurent Vivier <laurent@vivier.eu> > --- > include/fpu/softfloat.h | 10 ++++++---- > target/m68k/fpu_helper.c | 44 ++++++++++++++++++++++---------------------- > 2 files changed, 28 insertions(+), 26 deletions(-) > > diff --git a/include/fpu/softfloat.h b/include/fpu/softfloat.h > index 0f96a0edd1..2e1a79ebf7 100644 > --- a/include/fpu/softfloat.h > +++ b/include/fpu/softfloat.h > @@ -146,8 +146,9 @@ typedef struct { > uint64_t low; > uint16_t high; > } floatx80; > -#define make_floatx80(exp, mant) ((floatx80) { mant, exp }) > -#define make_floatx80_init(exp, mant) { .low = mant, .high = exp } > +#define make_floatx80(exp, mant) __extension__ \ > + ({ floatx80 f80_val = { .low = mant, .high = exp }; f80_val; }) > +#define const_floatx80(exp, mant) { .low = mant, .high = exp } cleaner. Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org> > typedef struct { > #ifdef HOST_WORDS_BIGENDIAN > uint64_t high, low; > @@ -155,8 +156,9 @@ typedef struct { > uint64_t low, high; > #endif > } float128; > -#define make_float128(high_, low_) ((float128) { .high = high_, .low = low_ }) > -#define make_float128_init(high_, low_) { .high = high_, .low = low_ } > +#define make_float128(high_, low_) __extension__ \ > + ({float128 f128_val = { .high = high_, .low = low_ }; f128_val; }) > +#define const_float128(high_, low_) { .high = high_, .low = low_ } > > /*---------------------------------------------------------------------------- > | Software IEC/IEEE floating-point underflow tininess-detection mode. > diff --git a/target/m68k/fpu_helper.c b/target/m68k/fpu_helper.c > index 665e7609af..bf62cf8003 100644 > --- a/target/m68k/fpu_helper.c > +++ b/target/m68k/fpu_helper.c > @@ -29,28 +29,28 @@ > */ > > static const floatx80 fpu_rom[128] = { > - [0x00] = make_floatx80_init(0x4000, 0xc90fdaa22168c235ULL), /* Pi */ > - [0x0b] = make_floatx80_init(0x3ffd, 0x9a209a84fbcff798ULL), /* Log10(2) */ > - [0x0c] = make_floatx80_init(0x4000, 0xadf85458a2bb4a9aULL), /* e */ > - [0x0d] = make_floatx80_init(0x3fff, 0xb8aa3b295c17f0bcULL), /* Log2(e) */ > - [0x0e] = make_floatx80_init(0x3ffd, 0xde5bd8a937287195ULL), /* Log10(e) */ > - [0x0f] = make_floatx80_init(0x0000, 0x0000000000000000ULL), /* Zero */ > - [0x30] = make_floatx80_init(0x3ffe, 0xb17217f7d1cf79acULL), /* ln(2) */ > - [0x31] = make_floatx80_init(0x4000, 0x935d8dddaaa8ac17ULL), /* ln(10) */ > - [0x32] = make_floatx80_init(0x3fff, 0x8000000000000000ULL), /* 10^0 */ > - [0x33] = make_floatx80_init(0x4002, 0xa000000000000000ULL), /* 10^1 */ > - [0x34] = make_floatx80_init(0x4005, 0xc800000000000000ULL), /* 10^2 */ > - [0x35] = make_floatx80_init(0x400c, 0x9c40000000000000ULL), /* 10^4 */ > - [0x36] = make_floatx80_init(0x4019, 0xbebc200000000000ULL), /* 10^8 */ > - [0x37] = make_floatx80_init(0x4034, 0x8e1bc9bf04000000ULL), /* 10^16 */ > - [0x38] = make_floatx80_init(0x4069, 0x9dc5ada82b70b59eULL), /* 10^32 */ > - [0x39] = make_floatx80_init(0x40d3, 0xc2781f49ffcfa6d5ULL), /* 10^64 */ > - [0x3a] = make_floatx80_init(0x41a8, 0x93ba47c980e98ce0ULL), /* 10^128 */ > - [0x3b] = make_floatx80_init(0x4351, 0xaa7eebfb9df9de8eULL), /* 10^256 */ > - [0x3c] = make_floatx80_init(0x46a3, 0xe319a0aea60e91c7ULL), /* 10^512 */ > - [0x3d] = make_floatx80_init(0x4d48, 0xc976758681750c17ULL), /* 10^1024 */ > - [0x3e] = make_floatx80_init(0x5a92, 0x9e8b3b5dc53d5de5ULL), /* 10^2048 */ > - [0x3f] = make_floatx80_init(0x7525, 0xc46052028a20979bULL), /* 10^4096 */ > + [0x00] = const_floatx80(0x4000, 0xc90fdaa22168c235ULL), /* Pi */ > + [0x0b] = const_floatx80(0x3ffd, 0x9a209a84fbcff798ULL), /* Log10(2) */ > + [0x0c] = const_floatx80(0x4000, 0xadf85458a2bb4a9aULL), /* e */ > + [0x0d] = const_floatx80(0x3fff, 0xb8aa3b295c17f0bcULL), /* Log2(e) */ > + [0x0e] = const_floatx80(0x3ffd, 0xde5bd8a937287195ULL), /* Log10(e) */ > + [0x0f] = const_floatx80(0x0000, 0x0000000000000000ULL), /* Zero */ > + [0x30] = const_floatx80(0x3ffe, 0xb17217f7d1cf79acULL), /* ln(2) */ > + [0x31] = const_floatx80(0x4000, 0x935d8dddaaa8ac17ULL), /* ln(10) */ > + [0x32] = const_floatx80(0x3fff, 0x8000000000000000ULL), /* 10^0 */ > + [0x33] = const_floatx80(0x4002, 0xa000000000000000ULL), /* 10^1 */ > + [0x34] = const_floatx80(0x4005, 0xc800000000000000ULL), /* 10^2 */ > + [0x35] = const_floatx80(0x400c, 0x9c40000000000000ULL), /* 10^4 */ > + [0x36] = const_floatx80(0x4019, 0xbebc200000000000ULL), /* 10^8 */ > + [0x37] = const_floatx80(0x4034, 0x8e1bc9bf04000000ULL), /* 10^16 */ > + [0x38] = const_floatx80(0x4069, 0x9dc5ada82b70b59eULL), /* 10^32 */ > + [0x39] = const_floatx80(0x40d3, 0xc2781f49ffcfa6d5ULL), /* 10^64 */ > + [0x3a] = const_floatx80(0x41a8, 0x93ba47c980e98ce0ULL), /* 10^128 */ > + [0x3b] = const_floatx80(0x4351, 0xaa7eebfb9df9de8eULL), /* 10^256 */ > + [0x3c] = const_floatx80(0x46a3, 0xe319a0aea60e91c7ULL), /* 10^512 */ > + [0x3d] = const_floatx80(0x4d48, 0xc976758681750c17ULL), /* 10^1024 */ > + [0x3e] = const_floatx80(0x5a92, 0x9e8b3b5dc53d5de5ULL), /* 10^2048 */ > + [0x3f] = const_floatx80(0x7525, 0xc46052028a20979bULL), /* 10^4096 */ > }; > > int32_t HELPER(reds32)(CPUM68KState *env, FPReg *val) >
On 09/18/2017 05:46 AM, Laurent Vivier wrote: > Redefine make_floatx80() and make_float128() as make_float16(), > make_float32() and make_float64() using a variable and not only > a cast. I don't like this part -- (type){ init } is a standard C99 compound literal. There's no point using a gcc extension instead. r~
On 09/19/2017 11:30 AM, Richard Henderson wrote: > On 09/18/2017 05:46 AM, Laurent Vivier wrote: >> Redefine make_floatx80() and make_float128() as make_float16(), >> make_float32() and make_float64() using a variable and not only >> a cast. >> -#define make_floatx80(exp, mant) ((floatx80) { mant, exp }) >> -#define make_floatx80_init(exp, mant) { .low = mant, .high = exp } >> +#define make_floatx80(exp, mant) __extension__ \ >> + ({ floatx80 f80_val = { .low = mant, .high = exp }; f80_val; }) >> +#define const_floatx80(exp, mant) { .low = mant, .high = exp } > > I don't like this part -- (type){ init } is a standard C99 compound literal. > There's no point using a gcc extension instead. The C99 compound literal is not a const initializer in all situations, though :( Here's another thread where we had a similar discussion, but there, the solution was to just make the macro behave as an initializer (which is C99 compliant, but loses some type safety) instead of relying on a gcc extension: https://lists.gnu.org/archive/html/qemu-devel/2017-08/msg06566.html I suspect you're running into the same issues that Laszlo already helped us understand regarding QLit.
On 09/19/17 19:39, Eric Blake wrote: > On 09/19/2017 11:30 AM, Richard Henderson wrote: >> On 09/18/2017 05:46 AM, Laurent Vivier wrote: >>> Redefine make_floatx80() and make_float128() as make_float16(), >>> make_float32() and make_float64() using a variable and not only >>> a cast. > >>> -#define make_floatx80(exp, mant) ((floatx80) { mant, exp }) >>> -#define make_floatx80_init(exp, mant) { .low = mant, .high = exp } >>> +#define make_floatx80(exp, mant) __extension__ \ >>> + ({ floatx80 f80_val = { .low = mant, .high = exp }; f80_val; }) >>> +#define const_floatx80(exp, mant) { .low = mant, .high = exp } > >> >> I don't like this part -- (type){ init } is a standard C99 compound literal. >> There's no point using a gcc extension instead. > > The C99 compound literal is not a const initializer in all situations, > though :( Here's another thread where we had a similar discussion, but > there, the solution was to just make the macro behave as an initializer > (which is C99 compliant, but loses some type safety) instead of relying > on a gcc extension: > > https://lists.gnu.org/archive/html/qemu-devel/2017-08/msg06566.html > > I suspect you're running into the same issues that Laszlo already helped > us understand regarding QLit. > Thanks for the CC! I don't have much context, but the patch looks quite isolated. I think I agree with Richard here -- I don't think there's any reason to change the replacement text of make_floatx80. The patch names make_float64() as an earlier example (already using __extension__), but I don't understand why make_float64() was written that way. ... It seems to go back to ancient commit f090c9d4ad58 ("Add strict checking mode for softfp code.", 2007-11-18). Was C99 support (esp. compound literals) spotty in gcc back then? Not having much background, I'd suggest the opposite change -- replace the statement-expression in make_float64() with a compound literal. Thanks Laszlo
On 09/19/2017 12:39 PM, Eric Blake wrote: > On 09/19/2017 11:30 AM, Richard Henderson wrote: >> On 09/18/2017 05:46 AM, Laurent Vivier wrote: >>> Redefine make_floatx80() and make_float128() as make_float16(), >>> make_float32() and make_float64() using a variable and not only >>> a cast. > >>> -#define make_floatx80(exp, mant) ((floatx80) { mant, exp }) >>> -#define make_floatx80_init(exp, mant) { .low = mant, .high = exp } >>> +#define make_floatx80(exp, mant) __extension__ \ >>> + ({ floatx80 f80_val = { .low = mant, .high = exp }; f80_val; }) >>> +#define const_floatx80(exp, mant) { .low = mant, .high = exp } > >> >> I don't like this part -- (type){ init } is a standard C99 compound literal. >> There's no point using a gcc extension instead. > > The C99 compound literal is not a const initializer in all situations, > though :( A compound literal not officially a const initializer in any situation. That it is accepted by gcc as a const initializer is an extension. I don't dispute const_floatx80, but the change to make_floatx80. r~
Le 19/09/2017 à 20:45, Laszlo Ersek a écrit : > On 09/19/17 19:39, Eric Blake wrote: >> On 09/19/2017 11:30 AM, Richard Henderson wrote: >>> On 09/18/2017 05:46 AM, Laurent Vivier wrote: >>>> Redefine make_floatx80() and make_float128() as make_float16(), >>>> make_float32() and make_float64() using a variable and not only >>>> a cast. >> >>>> -#define make_floatx80(exp, mant) ((floatx80) { mant, exp }) >>>> -#define make_floatx80_init(exp, mant) { .low = mant, .high = exp } >>>> +#define make_floatx80(exp, mant) __extension__ \ >>>> + ({ floatx80 f80_val = { .low = mant, .high = exp }; f80_val; }) >>>> +#define const_floatx80(exp, mant) { .low = mant, .high = exp } >> >>> >>> I don't like this part -- (type){ init } is a standard C99 compound literal. >>> There's no point using a gcc extension instead. >> >> The C99 compound literal is not a const initializer in all situations, >> though :( Here's another thread where we had a similar discussion, but >> there, the solution was to just make the macro behave as an initializer >> (which is C99 compliant, but loses some type safety) instead of relying >> on a gcc extension: >> >> https://lists.gnu.org/archive/html/qemu-devel/2017-08/msg06566.html >> >> I suspect you're running into the same issues that Laszlo already helped >> us understand regarding QLit. >> > > Thanks for the CC! I don't have much context, but the patch looks quite > isolated. > > I think I agree with Richard here -- I don't think there's any reason to > change the replacement text of make_floatx80. > > The patch names make_float64() as an earlier example (already using > __extension__), but I don't understand why make_float64() was written > that way. ... It seems to go back to ancient commit f090c9d4ad58 ("Add > strict checking mode for softfp code.", 2007-11-18). Was C99 support > (esp. compound literals) spotty in gcc back then? > > Not having much background, I'd suggest the opposite change -- replace > the statement-expression in make_float64() with a compound literal. Okay, I'll do this way. Thank you all for your comments. Laurent
diff --git a/include/fpu/softfloat.h b/include/fpu/softfloat.h index 0f96a0edd1..2e1a79ebf7 100644 --- a/include/fpu/softfloat.h +++ b/include/fpu/softfloat.h @@ -146,8 +146,9 @@ typedef struct { uint64_t low; uint16_t high; } floatx80; -#define make_floatx80(exp, mant) ((floatx80) { mant, exp }) -#define make_floatx80_init(exp, mant) { .low = mant, .high = exp } +#define make_floatx80(exp, mant) __extension__ \ + ({ floatx80 f80_val = { .low = mant, .high = exp }; f80_val; }) +#define const_floatx80(exp, mant) { .low = mant, .high = exp } typedef struct { #ifdef HOST_WORDS_BIGENDIAN uint64_t high, low; @@ -155,8 +156,9 @@ typedef struct { uint64_t low, high; #endif } float128; -#define make_float128(high_, low_) ((float128) { .high = high_, .low = low_ }) -#define make_float128_init(high_, low_) { .high = high_, .low = low_ } +#define make_float128(high_, low_) __extension__ \ + ({float128 f128_val = { .high = high_, .low = low_ }; f128_val; }) +#define const_float128(high_, low_) { .high = high_, .low = low_ } /*---------------------------------------------------------------------------- | Software IEC/IEEE floating-point underflow tininess-detection mode. diff --git a/target/m68k/fpu_helper.c b/target/m68k/fpu_helper.c index 665e7609af..bf62cf8003 100644 --- a/target/m68k/fpu_helper.c +++ b/target/m68k/fpu_helper.c @@ -29,28 +29,28 @@ */ static const floatx80 fpu_rom[128] = { - [0x00] = make_floatx80_init(0x4000, 0xc90fdaa22168c235ULL), /* Pi */ - [0x0b] = make_floatx80_init(0x3ffd, 0x9a209a84fbcff798ULL), /* Log10(2) */ - [0x0c] = make_floatx80_init(0x4000, 0xadf85458a2bb4a9aULL), /* e */ - [0x0d] = make_floatx80_init(0x3fff, 0xb8aa3b295c17f0bcULL), /* Log2(e) */ - [0x0e] = make_floatx80_init(0x3ffd, 0xde5bd8a937287195ULL), /* Log10(e) */ - [0x0f] = make_floatx80_init(0x0000, 0x0000000000000000ULL), /* Zero */ - [0x30] = make_floatx80_init(0x3ffe, 0xb17217f7d1cf79acULL), /* ln(2) */ - [0x31] = make_floatx80_init(0x4000, 0x935d8dddaaa8ac17ULL), /* ln(10) */ - [0x32] = make_floatx80_init(0x3fff, 0x8000000000000000ULL), /* 10^0 */ - [0x33] = make_floatx80_init(0x4002, 0xa000000000000000ULL), /* 10^1 */ - [0x34] = make_floatx80_init(0x4005, 0xc800000000000000ULL), /* 10^2 */ - [0x35] = make_floatx80_init(0x400c, 0x9c40000000000000ULL), /* 10^4 */ - [0x36] = make_floatx80_init(0x4019, 0xbebc200000000000ULL), /* 10^8 */ - [0x37] = make_floatx80_init(0x4034, 0x8e1bc9bf04000000ULL), /* 10^16 */ - [0x38] = make_floatx80_init(0x4069, 0x9dc5ada82b70b59eULL), /* 10^32 */ - [0x39] = make_floatx80_init(0x40d3, 0xc2781f49ffcfa6d5ULL), /* 10^64 */ - [0x3a] = make_floatx80_init(0x41a8, 0x93ba47c980e98ce0ULL), /* 10^128 */ - [0x3b] = make_floatx80_init(0x4351, 0xaa7eebfb9df9de8eULL), /* 10^256 */ - [0x3c] = make_floatx80_init(0x46a3, 0xe319a0aea60e91c7ULL), /* 10^512 */ - [0x3d] = make_floatx80_init(0x4d48, 0xc976758681750c17ULL), /* 10^1024 */ - [0x3e] = make_floatx80_init(0x5a92, 0x9e8b3b5dc53d5de5ULL), /* 10^2048 */ - [0x3f] = make_floatx80_init(0x7525, 0xc46052028a20979bULL), /* 10^4096 */ + [0x00] = const_floatx80(0x4000, 0xc90fdaa22168c235ULL), /* Pi */ + [0x0b] = const_floatx80(0x3ffd, 0x9a209a84fbcff798ULL), /* Log10(2) */ + [0x0c] = const_floatx80(0x4000, 0xadf85458a2bb4a9aULL), /* e */ + [0x0d] = const_floatx80(0x3fff, 0xb8aa3b295c17f0bcULL), /* Log2(e) */ + [0x0e] = const_floatx80(0x3ffd, 0xde5bd8a937287195ULL), /* Log10(e) */ + [0x0f] = const_floatx80(0x0000, 0x0000000000000000ULL), /* Zero */ + [0x30] = const_floatx80(0x3ffe, 0xb17217f7d1cf79acULL), /* ln(2) */ + [0x31] = const_floatx80(0x4000, 0x935d8dddaaa8ac17ULL), /* ln(10) */ + [0x32] = const_floatx80(0x3fff, 0x8000000000000000ULL), /* 10^0 */ + [0x33] = const_floatx80(0x4002, 0xa000000000000000ULL), /* 10^1 */ + [0x34] = const_floatx80(0x4005, 0xc800000000000000ULL), /* 10^2 */ + [0x35] = const_floatx80(0x400c, 0x9c40000000000000ULL), /* 10^4 */ + [0x36] = const_floatx80(0x4019, 0xbebc200000000000ULL), /* 10^8 */ + [0x37] = const_floatx80(0x4034, 0x8e1bc9bf04000000ULL), /* 10^16 */ + [0x38] = const_floatx80(0x4069, 0x9dc5ada82b70b59eULL), /* 10^32 */ + [0x39] = const_floatx80(0x40d3, 0xc2781f49ffcfa6d5ULL), /* 10^64 */ + [0x3a] = const_floatx80(0x41a8, 0x93ba47c980e98ce0ULL), /* 10^128 */ + [0x3b] = const_floatx80(0x4351, 0xaa7eebfb9df9de8eULL), /* 10^256 */ + [0x3c] = const_floatx80(0x46a3, 0xe319a0aea60e91c7ULL), /* 10^512 */ + [0x3d] = const_floatx80(0x4d48, 0xc976758681750c17ULL), /* 10^1024 */ + [0x3e] = const_floatx80(0x5a92, 0x9e8b3b5dc53d5de5ULL), /* 10^2048 */ + [0x3f] = const_floatx80(0x7525, 0xc46052028a20979bULL), /* 10^4096 */ }; int32_t HELPER(reds32)(CPUM68KState *env, FPReg *val)
We already have const_float16(), const_float32() and const_float64(), so rename make_floatx80_init() and make_float128_init() as const_floatx80() and const_float128(). Redefine make_floatx80() and make_float128() as make_float16(), make_float32() and make_float64() using a variable and not only a cast. Signed-off-by: Laurent Vivier <laurent@vivier.eu> --- include/fpu/softfloat.h | 10 ++++++---- target/m68k/fpu_helper.c | 44 ++++++++++++++++++++++---------------------- 2 files changed, 28 insertions(+), 26 deletions(-)