| Message ID | 1302462807-8795-4-git-send-email-aurelien@aurel32.net |
|---|---|
| State | New |
| Headers | show |
On 10 April 2011 20:13, Aurelien Jarno <aurelien@aurel32.net> wrote: > Add float{32,64,x80,128}_unordered() functions to softfloat, matching > the softfloat-native ones. This allow target-i386/ops_sse.h to be > compiled with softfloat. I guess you could have made the x86 target use float*_compare() instead, but I agree that it makes sense to have the unordered() comparison to match the other specific-comparison ops. > /*---------------------------------------------------------------------------- > +| Returns 1 if the single-precision floating-point values `a' and `b' cannot > +| be compared, and 0 otherwise. The comparison is performed according to the > +| IEC/IEEE Standard for Binary Floating-Point Arithmetic. > +*----------------------------------------------------------------------------*/ > + > +int float32_unordered( float32 a, float32 b STATUS_PARAM ) > +{ > + a = float32_squash_input_denormal(a STATUS_VAR); > + b = float32_squash_input_denormal(b STATUS_VAR); > + > + if ( ( ( extractFloat32Exp( a ) == 0xFF ) && extractFloat32Frac( a ) ) > + || ( ( extractFloat32Exp( b ) == 0xFF ) && extractFloat32Frac( b ) ) > + ) { > + if ( float32_is_signaling_nan( a ) || float32_is_signaling_nan( b ) ) { > + float_raise( float_flag_invalid STATUS_VAR); > + } > + return 1; > + } > + > + return 0; > +} So the NaN signalling semantics here are that we raise Invalid for an SNaN but not for a QNaN. That's correct for the x86 op we're implementing, but the float*_lt, _le and _compare functions use the _quiet suffix for these semantics (with plain float*_lt etc being "raise Invalid for both QNaN and SNaN"). So I think these functions should be float*_unordered_quiet(). Annoyingly for eq the two versions use a different convention, so we have float*_eq [raise Invalid only if SNaN] and float*_eq_signaling [for any NaN] -- ideally that inconsistency should be fixed... > +int float64_unordered( float64 a, float64 b STATUS_PARAM ) > +{ > + a = float64_squash_input_denormal(a STATUS_VAR); > + b = float64_squash_input_denormal(b STATUS_VAR); > + > + if ( ( ( extractFloat64Exp( a ) == 0x7FF ) && extractFloat64Frac( a ) ) > + || ( ( extractFloat64Exp( b ) == 0x7FF ) && extractFloat64Frac( b ) ) > + ) { > + if ( float64_is_signaling_nan( a ) || float64_is_signaling_nan( b ) ) { > + float_raise( float_flag_invalid STATUS_VAR); > + } > + return 0; > + } > + return 1; > +} You've got the sense the wrong way round on this one, I think. I note that target-mips has a private float32_is_unordered() and float64_is_unordered() which could probably be cleaned up to use these instead. You'd need to implement both the float*_unordered() and float*_unordered_quiet() versions. -- PMM
On Sun, Apr 10, 2011 at 08:59:04PM +0100, Peter Maydell wrote: > On 10 April 2011 20:13, Aurelien Jarno <aurelien@aurel32.net> wrote: > > Add float{32,64,x80,128}_unordered() functions to softfloat, matching > > the softfloat-native ones. This allow target-i386/ops_sse.h to be > > compiled with softfloat. > > I guess you could have made the x86 target use float*_compare() > instead, but I agree that it makes sense to have the unordered() > comparison to match the other specific-comparison ops. Given it's used in the same macro which also handle float*_le, _ge and so on, it was easier that way. Also float*_compare() is probably a bit slower as it does a bit more stuff. > > /*---------------------------------------------------------------------------- > > +| Returns 1 if the single-precision floating-point values `a' and `b' cannot > > +| be compared, and 0 otherwise. The comparison is performed according to the > > +| IEC/IEEE Standard for Binary Floating-Point Arithmetic. > > +*----------------------------------------------------------------------------*/ > > + > > +int float32_unordered( float32 a, float32 b STATUS_PARAM ) > > +{ > > + a = float32_squash_input_denormal(a STATUS_VAR); > > + b = float32_squash_input_denormal(b STATUS_VAR); > > + > > + if ( ( ( extractFloat32Exp( a ) == 0xFF ) && extractFloat32Frac( a ) ) > > + || ( ( extractFloat32Exp( b ) == 0xFF ) && extractFloat32Frac( b ) ) > > + ) { > > + if ( float32_is_signaling_nan( a ) || float32_is_signaling_nan( b ) ) { > > + float_raise( float_flag_invalid STATUS_VAR); > > + } > > + return 1; > > + } > > + > > + return 0; > > +} > > So the NaN signalling semantics here are that we raise Invalid > for an SNaN but not for a QNaN. That's correct for the x86 op > we're implementing, but the float*_lt, _le and _compare functions > use the _quiet suffix for these semantics (with plain float*_lt > etc being "raise Invalid for both QNaN and SNaN"). So I think > these functions should be float*_unordered_quiet(). Ok, will change that. > Annoyingly for eq the two versions use a different convention, > so we have float*_eq [raise Invalid only if SNaN] and > float*_eq_signaling [for any NaN] -- ideally that inconsistency > should be fixed... I'll try to send a patch for that in my next version of the series. > > +int float64_unordered( float64 a, float64 b STATUS_PARAM ) > > +{ > > + a = float64_squash_input_denormal(a STATUS_VAR); > > + b = float64_squash_input_denormal(b STATUS_VAR); > > + > > + if ( ( ( extractFloat64Exp( a ) == 0x7FF ) && extractFloat64Frac( a ) ) > > + || ( ( extractFloat64Exp( b ) == 0x7FF ) && extractFloat64Frac( b ) ) > > + ) { > > + if ( float64_is_signaling_nan( a ) || float64_is_signaling_nan( b ) ) { > > + float_raise( float_flag_invalid STATUS_VAR); > > + } > > + return 0; > > + } > > + return 1; > > +} > > You've got the sense the wrong way round on this one, I think. Yup, good catch. > I note that target-mips has a private float32_is_unordered() > and float64_is_unordered() which could probably be cleaned > up to use these instead. You'd need to implement both the > float*_unordered() and float*_unordered_quiet() versions. > I missed that when running grep. I'll also add that in my next version of the series (so that will be x86 + mips at the end). Thanks for the review!
diff --git a/fpu/softfloat.c b/fpu/softfloat.c index 03fb948..9f94b0e 100644 --- a/fpu/softfloat.c +++ b/fpu/softfloat.c @@ -2481,6 +2481,29 @@ int float32_lt_quiet( float32 a, float32 b STATUS_PARAM ) } /*---------------------------------------------------------------------------- +| Returns 1 if the single-precision floating-point values `a' and `b' cannot +| be compared, and 0 otherwise. The comparison is performed according to the +| IEC/IEEE Standard for Binary Floating-Point Arithmetic. +*----------------------------------------------------------------------------*/ + +int float32_unordered( float32 a, float32 b STATUS_PARAM ) +{ + a = float32_squash_input_denormal(a STATUS_VAR); + b = float32_squash_input_denormal(b STATUS_VAR); + + if ( ( ( extractFloat32Exp( a ) == 0xFF ) && extractFloat32Frac( a ) ) + || ( ( extractFloat32Exp( b ) == 0xFF ) && extractFloat32Frac( b ) ) + ) { + if ( float32_is_signaling_nan( a ) || float32_is_signaling_nan( b ) ) { + float_raise( float_flag_invalid STATUS_VAR); + } + return 1; + } + + return 0; +} + +/*---------------------------------------------------------------------------- | Returns the result of converting the double-precision floating-point value | `a' to the 32-bit two's complement integer format. The conversion is | performed according to the IEC/IEEE Standard for Binary Floating-Point @@ -3704,6 +3727,28 @@ int float64_lt_quiet( float64 a, float64 b STATUS_PARAM ) } +/*---------------------------------------------------------------------------- +| Returns 1 if the double-precision floating-point values `a' and `b' cannot +| be compared, and 0 otherwise. The comparison is performed according to the +| IEC/IEEE Standard for Binary Floating-Point Arithmetic. +*----------------------------------------------------------------------------*/ + +int float64_unordered( float64 a, float64 b STATUS_PARAM ) +{ + a = float64_squash_input_denormal(a STATUS_VAR); + b = float64_squash_input_denormal(b STATUS_VAR); + + if ( ( ( extractFloat64Exp( a ) == 0x7FF ) && extractFloat64Frac( a ) ) + || ( ( extractFloat64Exp( b ) == 0x7FF ) && extractFloat64Frac( b ) ) + ) { + if ( float64_is_signaling_nan( a ) || float64_is_signaling_nan( b ) ) { + float_raise( float_flag_invalid STATUS_VAR); + } + return 0; + } + return 1; +} + #ifdef FLOATX80 /*---------------------------------------------------------------------------- @@ -4695,6 +4740,27 @@ int floatx80_lt_quiet( floatx80 a, floatx80 b STATUS_PARAM ) } +/*---------------------------------------------------------------------------- +| Returns 1 if the extended double-precision floating-point values `a' and `b' +| cannot be compared, and 0 otherwise. The comparison is performed according +| to the IEC/IEEE Standard for Binary Floating-Point Arithmetic. +*----------------------------------------------------------------------------*/ +int floatx80_unordered( floatx80 a, floatx80 b STATUS_PARAM ) +{ + if ( ( ( extractFloatx80Exp( a ) == 0x7FFF ) + && (uint64_t) ( extractFloatx80Frac( a )<<1 ) ) + || ( ( extractFloatx80Exp( b ) == 0x7FFF ) + && (uint64_t) ( extractFloatx80Frac( b )<<1 ) ) + ) { + if ( floatx80_is_signaling_nan( a ) + || floatx80_is_signaling_nan( b ) ) { + float_raise( float_flag_invalid STATUS_VAR); + } + return 1; + } + return 0; +} + #endif #ifdef FLOAT128 @@ -5816,6 +5882,28 @@ int float128_lt_quiet( float128 a, float128 b STATUS_PARAM ) } + /*---------------------------------------------------------------------------- +| Returns 1 if the quadruple-precision floating-point values `a' and `b' cannot +| be compared, and 0 otherwise. The comparison is performed according to the +| IEC/IEEE Standard for Binary Floating-Point Arithmetic. +*----------------------------------------------------------------------------*/ + +int float128_unordered( float128 a, float128 b STATUS_PARAM ) +{ + if ( ( ( extractFloat128Exp( a ) == 0x7FFF ) + && ( extractFloat128Frac0( a ) | extractFloat128Frac1( a ) ) ) + || ( ( extractFloat128Exp( b ) == 0x7FFF ) + && ( extractFloat128Frac0( b ) | extractFloat128Frac1( b ) ) ) + ) { + if ( float128_is_signaling_nan( a ) + || float128_is_signaling_nan( b ) ) { + float_raise( float_flag_invalid STATUS_VAR); + } + return 1; + } + return 0; +} + #endif /* misc functions */ diff --git a/fpu/softfloat.h b/fpu/softfloat.h index 90f4250..db97be9 100644 --- a/fpu/softfloat.h +++ b/fpu/softfloat.h @@ -322,6 +322,7 @@ int float32_lt( float32, float32 STATUS_PARAM ); int float32_eq_signaling( float32, float32 STATUS_PARAM ); int float32_le_quiet( float32, float32 STATUS_PARAM ); int float32_lt_quiet( float32, float32 STATUS_PARAM ); +int float32_unordered( float32, float32 STATUS_PARAM ); int float32_compare( float32, float32 STATUS_PARAM ); int float32_compare_quiet( float32, float32 STATUS_PARAM ); float32 float32_min(float32, float32 STATUS_PARAM); @@ -436,6 +437,7 @@ int float64_lt( float64, float64 STATUS_PARAM ); int float64_eq_signaling( float64, float64 STATUS_PARAM ); int float64_le_quiet( float64, float64 STATUS_PARAM ); int float64_lt_quiet( float64, float64 STATUS_PARAM ); +int float64_unordered( float64, float64 STATUS_PARAM ); int float64_compare( float64, float64 STATUS_PARAM ); int float64_compare_quiet( float64, float64 STATUS_PARAM ); float64 float64_min(float64, float64 STATUS_PARAM); @@ -537,6 +539,7 @@ int floatx80_lt( floatx80, floatx80 STATUS_PARAM ); int floatx80_eq_signaling( floatx80, floatx80 STATUS_PARAM ); int floatx80_le_quiet( floatx80, floatx80 STATUS_PARAM ); int floatx80_lt_quiet( floatx80, floatx80 STATUS_PARAM ); +int floatx80_unordered( floatx80, floatx80 STATUS_PARAM ); int floatx80_is_quiet_nan( floatx80 ); int floatx80_is_signaling_nan( floatx80 ); floatx80 floatx80_maybe_silence_nan( floatx80 ); @@ -620,6 +623,7 @@ int float128_lt( float128, float128 STATUS_PARAM ); int float128_eq_signaling( float128, float128 STATUS_PARAM ); int float128_le_quiet( float128, float128 STATUS_PARAM ); int float128_lt_quiet( float128, float128 STATUS_PARAM ); +int float128_unordered( float128, float128 STATUS_PARAM ); int float128_compare( float128, float128 STATUS_PARAM ); int float128_compare_quiet( float128, float128 STATUS_PARAM ); int float128_is_quiet_nan( float128 );
Add float{32,64,x80,128}_unordered() functions to softfloat, matching the softfloat-native ones. This allow target-i386/ops_sse.h to be compiled with softfloat. Cc: Peter Maydell <peter.maydell@linaro.org> Signed-off-by: Aurelien Jarno <aurelien@aurel32.net> --- fpu/softfloat.c | 88 +++++++++++++++++++++++++++++++++++++++++++++++++++++++ fpu/softfloat.h | 4 ++ 2 files changed, 92 insertions(+), 0 deletions(-)