| Message ID | 20250217125055.160887-9-peter.maydell@linaro.org |
|---|---|
| State | New |
| Headers | show |
| Series | fpu: Remove remaining target ifdefs and build only once | expand |
On 17/2/25 13:50, Peter Maydell wrote: > Currently we have a compile-time shortcut where we return a hardcode > value from snan_bit_is_one() on everything except MIPS, because we > know that's the only target that needs to change > status->no_signaling_nans at runtime. > > Remove the ifdef, so we always look at the status flag. This means > we must update the two targets (HPPA and SH4) that were previously > hardcoded to return true so that they set the status flag correctly. > > This has no behavioural change, but will be necessary if we want to > build softfloat once for all targets. > > Signed-off-by: Peter Maydell <peter.maydell@linaro.org> > --- > target/hppa/fpu_helper.c | 1 + > target/sh4/cpu.c | 1 + > fpu/softfloat-specialize.c.inc | 7 ------- > 3 files changed, 2 insertions(+), 7 deletions(-) Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
On 2/17/25 04:50, Peter Maydell wrote: > Currently we have a compile-time shortcut where we return a hardcode > value from snan_bit_is_one() on everything except MIPS, because we > know that's the only target that needs to change > status->no_signaling_nans at runtime. Pasto from the previous patch on the variable name. Reviewed-by: Richard Henderson <richard.henderson@linaro.org> r~ > > Remove the ifdef, so we always look at the status flag. This means > we must update the two targets (HPPA and SH4) that were previously > hardcoded to return true so that they set the status flag correctly. > > This has no behavioural change, but will be necessary if we want to > build softfloat once for all targets. > > Signed-off-by: Peter Maydell <peter.maydell@linaro.org> > --- > target/hppa/fpu_helper.c | 1 + > target/sh4/cpu.c | 1 + > fpu/softfloat-specialize.c.inc | 7 ------- > 3 files changed, 2 insertions(+), 7 deletions(-) > > diff --git a/target/hppa/fpu_helper.c b/target/hppa/fpu_helper.c > index 8ff4b448049..a62d9d30831 100644 > --- a/target/hppa/fpu_helper.c > +++ b/target/hppa/fpu_helper.c > @@ -67,6 +67,7 @@ void HELPER(loaded_fr0)(CPUHPPAState *env) > set_float_infzeronan_rule(float_infzeronan_dnan_never, &env->fp_status); > /* Default NaN: sign bit clear, msb-1 frac bit set */ > set_float_default_nan_pattern(0b00100000, &env->fp_status); > + set_snan_bit_is_one(true, &env->fp_status); > /* > * "PA-RISC 2.0 Architecture" says it is IMPDEF whether the flushing > * enabled by FPSR.D happens before or after rounding. We pick "before" > diff --git a/target/sh4/cpu.c b/target/sh4/cpu.c > index 4ac693d99bd..ccfe222bdf3 100644 > --- a/target/sh4/cpu.c > +++ b/target/sh4/cpu.c > @@ -128,6 +128,7 @@ static void superh_cpu_reset_hold(Object *obj, ResetType type) > set_flush_to_zero(1, &env->fp_status); > #endif > set_default_nan_mode(1, &env->fp_status); > + set_snan_bit_is_one(true, &env->fp_status); > /* sign bit clear, set all frac bits other than msb */ > set_float_default_nan_pattern(0b00111111, &env->fp_status); > /* > diff --git a/fpu/softfloat-specialize.c.inc b/fpu/softfloat-specialize.c.inc > index a2c6afad5da..ba4fa08b7be 100644 > --- a/fpu/softfloat-specialize.c.inc > +++ b/fpu/softfloat-specialize.c.inc > @@ -93,17 +93,10 @@ static inline bool no_signaling_nans(float_status *status) > * In IEEE 754-1985 this was implementation defined, but in IEEE 754-2008 > * the msb must be zero. MIPS is (so far) unique in supporting both the > * 2008 revision and backward compatibility with their original choice. > - * Thus for MIPS we must make the choice at runtime. > */ > static inline bool snan_bit_is_one(float_status *status) > { > -#if defined(TARGET_MIPS) > return status->snan_bit_is_one; > -#elif defined(TARGET_HPPA) || defined(TARGET_SH4) > - return 1; > -#else > - return 0; > -#endif > } > > /*----------------------------------------------------------------------------
diff --git a/target/hppa/fpu_helper.c b/target/hppa/fpu_helper.c index 8ff4b448049..a62d9d30831 100644 --- a/target/hppa/fpu_helper.c +++ b/target/hppa/fpu_helper.c @@ -67,6 +67,7 @@ void HELPER(loaded_fr0)(CPUHPPAState *env) set_float_infzeronan_rule(float_infzeronan_dnan_never, &env->fp_status); /* Default NaN: sign bit clear, msb-1 frac bit set */ set_float_default_nan_pattern(0b00100000, &env->fp_status); + set_snan_bit_is_one(true, &env->fp_status); /* * "PA-RISC 2.0 Architecture" says it is IMPDEF whether the flushing * enabled by FPSR.D happens before or after rounding. We pick "before" diff --git a/target/sh4/cpu.c b/target/sh4/cpu.c index 4ac693d99bd..ccfe222bdf3 100644 --- a/target/sh4/cpu.c +++ b/target/sh4/cpu.c @@ -128,6 +128,7 @@ static void superh_cpu_reset_hold(Object *obj, ResetType type) set_flush_to_zero(1, &env->fp_status); #endif set_default_nan_mode(1, &env->fp_status); + set_snan_bit_is_one(true, &env->fp_status); /* sign bit clear, set all frac bits other than msb */ set_float_default_nan_pattern(0b00111111, &env->fp_status); /* diff --git a/fpu/softfloat-specialize.c.inc b/fpu/softfloat-specialize.c.inc index a2c6afad5da..ba4fa08b7be 100644 --- a/fpu/softfloat-specialize.c.inc +++ b/fpu/softfloat-specialize.c.inc @@ -93,17 +93,10 @@ static inline bool no_signaling_nans(float_status *status) * In IEEE 754-1985 this was implementation defined, but in IEEE 754-2008 * the msb must be zero. MIPS is (so far) unique in supporting both the * 2008 revision and backward compatibility with their original choice. - * Thus for MIPS we must make the choice at runtime. */ static inline bool snan_bit_is_one(float_status *status) { -#if defined(TARGET_MIPS) return status->snan_bit_is_one; -#elif defined(TARGET_HPPA) || defined(TARGET_SH4) - return 1; -#else - return 0; -#endif } /*----------------------------------------------------------------------------
Currently we have a compile-time shortcut where we return a hardcode value from snan_bit_is_one() on everything except MIPS, because we know that's the only target that needs to change status->no_signaling_nans at runtime. Remove the ifdef, so we always look at the status flag. This means we must update the two targets (HPPA and SH4) that were previously hardcoded to return true so that they set the status flag correctly. This has no behavioural change, but will be necessary if we want to build softfloat once for all targets. Signed-off-by: Peter Maydell <peter.maydell@linaro.org> --- target/hppa/fpu_helper.c | 1 + target/sh4/cpu.c | 1 + fpu/softfloat-specialize.c.inc | 7 ------- 3 files changed, 2 insertions(+), 7 deletions(-)