Re: [PATCH v3 32/42] target/arm: Extract HA and HD in aa64_va_parameters
On Fri, 7 Oct 2022 at 17:13, Richard Henderson wrote: > > On 10/7/22 09:11, Peter Maydell wrote: > > On Fri, 7 Oct 2022 at 16:37, Richard Henderson > > wrote: > >> > >> On 10/7/22 02:24, Peter Maydell wrote: > +.ha = ha, > +.hd = ha & hd, > >>> > >>> This is a bitwise operation on two bools, should be && ? > >> > >> Bitwise works fine, but I can use boolean if you like. > >> > >> I'd be surprised (and filing a missed optimization bug) if the compiler > >> treated these two > >> operations differently in this case (simple bool operands with no side > >> effects). > > > > The different treatment I would expect would be that in the '&' > > case it warns you about using a bitwise operation on a boolean :-) > > Oh, well, no compiler should ever do that, because bool implicitly converts > to int for any > arithmetic, just like char. Yeah, but -Wbool-operation is there to catch bugs where the bitwise operation was unintended and the wrong behaviour. -- PMM
Re: [PATCH v3 32/42] target/arm: Extract HA and HD in aa64_va_parameters
On 10/7/22 02:24, Peter Maydell wrote: +.ha = ha, +.hd = ha & hd, This is a bitwise operation on two bools, should be && ? Bitwise works fine, but I can use boolean if you like. I'd be surprised (and filing a missed optimization bug) if the compiler treated these two operations differently in this case (simple bool operands with no side effects). r~
Re: [PATCH v3 32/42] target/arm: Extract HA and HD in aa64_va_parameters
On Fri, 7 Oct 2022 at 16:37, Richard Henderson wrote: > > On 10/7/22 02:24, Peter Maydell wrote: > >> +.ha = ha, > >> +.hd = ha & hd, > > > > This is a bitwise operation on two bools, should be && ? > > Bitwise works fine, but I can use boolean if you like. > > I'd be surprised (and filing a missed optimization bug) if the compiler > treated these two > operations differently in this case (simple bool operands with no side > effects). The different treatment I would expect would be that in the '&' case it warns you about using a bitwise operation on a boolean :-) -- PMM
Re: [PATCH v3 32/42] target/arm: Extract HA and HD in aa64_va_parameters
On 10/7/22 09:11, Peter Maydell wrote: On Fri, 7 Oct 2022 at 16:37, Richard Henderson wrote: On 10/7/22 02:24, Peter Maydell wrote: +.ha = ha, +.hd = ha & hd, This is a bitwise operation on two bools, should be && ? Bitwise works fine, but I can use boolean if you like. I'd be surprised (and filing a missed optimization bug) if the compiler treated these two operations differently in this case (simple bool operands with no side effects). The different treatment I would expect would be that in the '&' case it warns you about using a bitwise operation on a boolean :-) Oh, well, no compiler should ever do that, because bool implicitly converts to int for any arithmetic, just like char. r~
Re: [PATCH v3 32/42] target/arm: Extract HA and HD in aa64_va_parameters
On Sat, 1 Oct 2022 at 17:42, Richard Henderson wrote: > > Signed-off-by: Richard Henderson > --- > target/arm/internals.h | 2 ++ > target/arm/helper.c| 8 +++- > 2 files changed, 9 insertions(+), 1 deletion(-) > > diff --git a/target/arm/internals.h b/target/arm/internals.h > index a50189e2e4..e95b6b1b8f 100644 > --- a/target/arm/internals.h > +++ b/target/arm/internals.h > @@ -1014,6 +1014,8 @@ typedef struct ARMVAParameters { > bool using64k : 1; > bool tsz_oob: 1; /* tsz has been clamped to legal range */ > bool ds : 1; > +bool ha : 1; > +bool hd : 1; > } ARMVAParameters; > > ARMVAParameters aa64_va_parameters(CPUARMState *env, uint64_t va, > diff --git a/target/arm/helper.c b/target/arm/helper.c > index 19a03eb200..70ae3816b9 100644 > --- a/target/arm/helper.c > +++ b/target/arm/helper.c > @@ -10280,7 +10280,7 @@ ARMVAParameters aa64_va_parameters(CPUARMState *env, > uint64_t va, > ARMMMUIdx mmu_idx, bool data) > { > uint64_t tcr = regime_tcr(env, mmu_idx); > -bool epd, hpd, using16k, using64k, tsz_oob, ds; > +bool epd, hpd, using16k, using64k, tsz_oob, ds, ha, hd; > int select, tsz, tbi, max_tsz, min_tsz, ps, sh; > ARMCPU *cpu = env_archcpu(env); > > @@ -10298,6 +10298,8 @@ ARMVAParameters aa64_va_parameters(CPUARMState *env, > uint64_t va, > epd = false; > sh = extract32(tcr, 12, 2); > ps = extract32(tcr, 16, 3); > +ha = extract32(tcr, 21, 1) && cpu_isar_feature(aa64_hafs, cpu); > +hd = extract32(tcr, 22, 1) && cpu_isar_feature(aa64_hdbs, cpu); > ds = extract64(tcr, 32, 1); > } else { > /* > @@ -10322,6 +10324,8 @@ ARMVAParameters aa64_va_parameters(CPUARMState *env, > uint64_t va, > hpd = extract64(tcr, 42, 1); > } > ps = extract64(tcr, 32, 3); > +ha = extract64(tcr, 39, 1) && cpu_isar_feature(aa64_hafs, cpu); > +hd = extract64(tcr, 40, 1) && cpu_isar_feature(aa64_hdbs, cpu); > ds = extract64(tcr, 59, 1); > } > > @@ -10393,6 +10397,8 @@ ARMVAParameters aa64_va_parameters(CPUARMState *env, > uint64_t va, > .using64k = using64k, > .tsz_oob = tsz_oob, > .ds = ds, > +.ha = ha, > +.hd = ha & hd, This is a bitwise operation on two bools, should be && ? Otherwise Reviewed-by: Peter Maydell thanks -- PMM