Re: [Qemu-devel] [PATCH 06/27] Correct ppc popcntb logic, implement popcntw and popcntd
On Fri, Apr 01, 2011 at 08:02:24PM +0200, Alexander Graf wrote:
> On 01.04.2011, at 19:58, Aurelien Jarno wrote:
> > On Fri, Apr 01, 2011 at 03:15:13PM +1100, David Gibson wrote:
[snip]
> >> +target_ulong helper_popcntd (target_ulong val)
> >> +{
> >> +val = (val & 0xULL) + ((val >> 1) &
> >> + 0xULL);
> >> +val = (val & 0xULL) + ((val >> 2) &
> >> + 0xULL);
> >> +val = (val & 0x0f0f0f0f0f0f0f0fULL) + ((val >> 4) &
> >> + 0x0f0f0f0f0f0f0f0fULL);
> >> +val = (val & 0x00ff00ff00ff00ffULL) + ((val >> 8) &
> >> + 0x00ff00ff00ff00ffULL);
> >> +val = (val & 0xULL) + ((val >> 16) &
> >> + 0xULL);
> >> +val = (val & 0xULL) + ((val >> 32) &
> >> + 0xULL);
> >> +return val;
> >> +}
> >
> > I probably arrive a bit late, but note that for this one you can use
> > ctpop64() (from host-utils.h), which also uses a GCC builtin when
> > available.
>
> Ah, nice. David - sounds like a good chance for a follow-up patch :)
Done. I'll send it when I next send a batch for merging.
--
David Gibson| I'll have my music baroque, and my code
david AT gibson.dropbear.id.au | minimalist, thank you. NOT _the_ _other_
| _way_ _around_!
http://www.ozlabs.org/~dgibson
Re: [Qemu-devel] [PATCH 06/27] Correct ppc popcntb logic, implement popcntw and popcntd
On 01.04.2011, at 19:58, Aurelien Jarno wrote:
> On Fri, Apr 01, 2011 at 03:15:13PM +1100, David Gibson wrote:
>> From: David Gibson
>>
>> qemu already includes support for the popcntb instruction introduced
>> in POWER5 (although it doesn't actually allow you to choose POWER5).
>>
>> However, the logic is slightly incorrect: it will generate results
>> truncated to 32-bits when the CPU is in 32-bit mode. This is not
>> normal for powerpc - generally arithmetic instructions on a 64-bit
>> powerpc cpu will generate full 64 bit results, it's just that only the
>> low 32 bits will be significant for condition codes.
>>
>> This patch corrects this nit, which actually simplifies the code slightly.
>>
>> In addition, this patch implements the popcntw and popcntd
>> instructions added in POWER7, in preparation for allowing POWER7 as an
>> emulated CPU.
>>
>> Signed-off-by: David Gibson
>> ---
>> target-ppc/cpu.h |2 +
>> target-ppc/helper.h|3 +-
>> target-ppc/op_helper.c | 55 +++
>> target-ppc/translate.c | 20 +
>> 4 files changed, 69 insertions(+), 11 deletions(-)
>>
>> diff --git a/target-ppc/cpu.h b/target-ppc/cpu.h
>> index f293f85..37dde39 100644
>> --- a/target-ppc/cpu.h
>> +++ b/target-ppc/cpu.h
>> @@ -1505,6 +1505,8 @@ enum {
>> PPC_DCRX = 0x2000ULL,
>> /* user-mode DCR access, implemented in PowerPC 460
>> */
>> PPC_DCRUX = 0x4000ULL,
>> +/* popcntw and popcntd instructions
>> */
>> +PPC_POPCNTWD = 0x8000ULL,
>> };
>>
>> /*/
>> diff --git a/target-ppc/helper.h b/target-ppc/helper.h
>> index 2b4744d..7c02be9 100644
>> --- a/target-ppc/helper.h
>> +++ b/target-ppc/helper.h
>> @@ -38,10 +38,11 @@ DEF_HELPER_2(mulldo, i64, i64, i64)
>>
>> DEF_HELPER_FLAGS_1(cntlzw, TCG_CALL_CONST | TCG_CALL_PURE, tl, tl)
>> DEF_HELPER_FLAGS_1(popcntb, TCG_CALL_CONST | TCG_CALL_PURE, tl, tl)
>> +DEF_HELPER_FLAGS_1(popcntw, TCG_CALL_CONST | TCG_CALL_PURE, tl, tl)
>> DEF_HELPER_2(sraw, tl, tl, tl)
>> #if defined(TARGET_PPC64)
>> DEF_HELPER_FLAGS_1(cntlzd, TCG_CALL_CONST | TCG_CALL_PURE, tl, tl)
>> -DEF_HELPER_FLAGS_1(popcntb_64, TCG_CALL_CONST | TCG_CALL_PURE, tl, tl)
>> +DEF_HELPER_FLAGS_1(popcntd, TCG_CALL_CONST | TCG_CALL_PURE, tl, tl)
>> DEF_HELPER_2(srad, tl, tl, tl)
>> #endif
>>
>> diff --git a/target-ppc/op_helper.c b/target-ppc/op_helper.c
>> index aa2e8ba..b1b883d 100644
>> --- a/target-ppc/op_helper.c
>> +++ b/target-ppc/op_helper.c
>> @@ -499,6 +499,50 @@ target_ulong helper_srad (target_ulong value,
>> target_ulong shift)
>> }
>> #endif
>>
>> +#if defined(TARGET_PPC64)
>> +target_ulong helper_popcntb (target_ulong val)
>> +{
>> +val = (val & 0xULL) + ((val >> 1) &
>> + 0xULL);
>> +val = (val & 0xULL) + ((val >> 2) &
>> + 0xULL);
>> +val = (val & 0x0f0f0f0f0f0f0f0fULL) + ((val >> 4) &
>> + 0x0f0f0f0f0f0f0f0fULL);
>> +return val;
>> +}
>> +
>> +target_ulong helper_popcntw (target_ulong val)
>> +{
>> +val = (val & 0xULL) + ((val >> 1) &
>> + 0xULL);
>> +val = (val & 0xULL) + ((val >> 2) &
>> + 0xULL);
>> +val = (val & 0x0f0f0f0f0f0f0f0fULL) + ((val >> 4) &
>> + 0x0f0f0f0f0f0f0f0fULL);
>> +val = (val & 0x00ff00ff00ff00ffULL) + ((val >> 8) &
>> + 0x00ff00ff00ff00ffULL);
>> +val = (val & 0xULL) + ((val >> 16) &
>> + 0xULL);
>> +return val;
>> +}
>> +
>> +target_ulong helper_popcntd (target_ulong val)
>> +{
>> +val = (val & 0xULL) + ((val >> 1) &
>> + 0xULL);
>> +val = (val & 0xULL) + ((val >> 2) &
>> + 0xULL);
>> +val = (val & 0x0f0f0f0f0f0f0f0fULL) + ((val >> 4) &
>> + 0x0f0f0f0f0f0f0f0fULL);
>> +val = (val & 0x00ff00ff00ff00ffULL) + ((val >> 8) &
>> + 0x00ff00ff00ff00ffULL);
>> +val = (val & 0xULL) + ((val >> 16) &
>> + 0xULL);
>> +val = (val & 0xULL) + ((val >> 32) &
>> + 0xULL);
>> +return val;
>> +}
>
> I probably arrive a bit late, but note that for this one you can use
Re: [Qemu-devel] [PATCH 06/27] Correct ppc popcntb logic, implement popcntw and popcntd
On Fri, Apr 01, 2011 at 03:15:13PM +1100, David Gibson wrote:
> From: David Gibson
>
> qemu already includes support for the popcntb instruction introduced
> in POWER5 (although it doesn't actually allow you to choose POWER5).
>
> However, the logic is slightly incorrect: it will generate results
> truncated to 32-bits when the CPU is in 32-bit mode. This is not
> normal for powerpc - generally arithmetic instructions on a 64-bit
> powerpc cpu will generate full 64 bit results, it's just that only the
> low 32 bits will be significant for condition codes.
>
> This patch corrects this nit, which actually simplifies the code slightly.
>
> In addition, this patch implements the popcntw and popcntd
> instructions added in POWER7, in preparation for allowing POWER7 as an
> emulated CPU.
>
> Signed-off-by: David Gibson
> ---
> target-ppc/cpu.h |2 +
> target-ppc/helper.h|3 +-
> target-ppc/op_helper.c | 55 +++
> target-ppc/translate.c | 20 +
> 4 files changed, 69 insertions(+), 11 deletions(-)
>
> diff --git a/target-ppc/cpu.h b/target-ppc/cpu.h
> index f293f85..37dde39 100644
> --- a/target-ppc/cpu.h
> +++ b/target-ppc/cpu.h
> @@ -1505,6 +1505,8 @@ enum {
> PPC_DCRX = 0x2000ULL,
> /* user-mode DCR access, implemented in PowerPC 460
> */
> PPC_DCRUX = 0x4000ULL,
> +/* popcntw and popcntd instructions
> */
> +PPC_POPCNTWD = 0x8000ULL,
> };
>
>
> /*/
> diff --git a/target-ppc/helper.h b/target-ppc/helper.h
> index 2b4744d..7c02be9 100644
> --- a/target-ppc/helper.h
> +++ b/target-ppc/helper.h
> @@ -38,10 +38,11 @@ DEF_HELPER_2(mulldo, i64, i64, i64)
>
> DEF_HELPER_FLAGS_1(cntlzw, TCG_CALL_CONST | TCG_CALL_PURE, tl, tl)
> DEF_HELPER_FLAGS_1(popcntb, TCG_CALL_CONST | TCG_CALL_PURE, tl, tl)
> +DEF_HELPER_FLAGS_1(popcntw, TCG_CALL_CONST | TCG_CALL_PURE, tl, tl)
> DEF_HELPER_2(sraw, tl, tl, tl)
> #if defined(TARGET_PPC64)
> DEF_HELPER_FLAGS_1(cntlzd, TCG_CALL_CONST | TCG_CALL_PURE, tl, tl)
> -DEF_HELPER_FLAGS_1(popcntb_64, TCG_CALL_CONST | TCG_CALL_PURE, tl, tl)
> +DEF_HELPER_FLAGS_1(popcntd, TCG_CALL_CONST | TCG_CALL_PURE, tl, tl)
> DEF_HELPER_2(srad, tl, tl, tl)
> #endif
>
> diff --git a/target-ppc/op_helper.c b/target-ppc/op_helper.c
> index aa2e8ba..b1b883d 100644
> --- a/target-ppc/op_helper.c
> +++ b/target-ppc/op_helper.c
> @@ -499,6 +499,50 @@ target_ulong helper_srad (target_ulong value,
> target_ulong shift)
> }
> #endif
>
> +#if defined(TARGET_PPC64)
> +target_ulong helper_popcntb (target_ulong val)
> +{
> +val = (val & 0xULL) + ((val >> 1) &
> + 0xULL);
> +val = (val & 0xULL) + ((val >> 2) &
> + 0xULL);
> +val = (val & 0x0f0f0f0f0f0f0f0fULL) + ((val >> 4) &
> + 0x0f0f0f0f0f0f0f0fULL);
> +return val;
> +}
> +
> +target_ulong helper_popcntw (target_ulong val)
> +{
> +val = (val & 0xULL) + ((val >> 1) &
> + 0xULL);
> +val = (val & 0xULL) + ((val >> 2) &
> + 0xULL);
> +val = (val & 0x0f0f0f0f0f0f0f0fULL) + ((val >> 4) &
> + 0x0f0f0f0f0f0f0f0fULL);
> +val = (val & 0x00ff00ff00ff00ffULL) + ((val >> 8) &
> + 0x00ff00ff00ff00ffULL);
> +val = (val & 0xULL) + ((val >> 16) &
> + 0xULL);
> +return val;
> +}
> +
> +target_ulong helper_popcntd (target_ulong val)
> +{
> +val = (val & 0xULL) + ((val >> 1) &
> + 0xULL);
> +val = (val & 0xULL) + ((val >> 2) &
> + 0xULL);
> +val = (val & 0x0f0f0f0f0f0f0f0fULL) + ((val >> 4) &
> + 0x0f0f0f0f0f0f0f0fULL);
> +val = (val & 0x00ff00ff00ff00ffULL) + ((val >> 8) &
> + 0x00ff00ff00ff00ffULL);
> +val = (val & 0xULL) + ((val >> 16) &
> + 0xULL);
> +val = (val & 0xULL) + ((val >> 32) &
> + 0xULL);
> +return val;
> +}
I probably arrive a bit late, but note that for this one you can use
ctpop64() (from host-utils.h), which also uses a GCC builtin when
available.
> +#else
> target_ulong helper_popcntb (target_ulong val)
>
