On Fri, Apr 01, 2011 at 03:15:13PM +1100, David Gibson wrote:
> From: David Gibson <d...@au1.ibm.com>
>
> 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 <d...@au1.ibm.com>
> ---
> 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 = 0x2000000000000000ULL,
> /* user-mode DCR access, implemented in PowerPC 460
> */
> PPC_DCRUX = 0x4000000000000000ULL,
> + /* popcntw and popcntd instructions
> */
> + PPC_POPCNTWD = 0x8000000000000000ULL,
> };
>
>
> /*****************************************************************************/
> 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 & 0x5555555555555555ULL) + ((val >> 1) &
> + 0x5555555555555555ULL);
> + val = (val & 0x3333333333333333ULL) + ((val >> 2) &
> + 0x3333333333333333ULL);
> + val = (val & 0x0f0f0f0f0f0f0f0fULL) + ((val >> 4) &
> + 0x0f0f0f0f0f0f0f0fULL);
> + return val;
> +}
> +
> +target_ulong helper_popcntw (target_ulong val)
> +{
> + val = (val & 0x5555555555555555ULL) + ((val >> 1) &
> + 0x5555555555555555ULL);
> + val = (val & 0x3333333333333333ULL) + ((val >> 2) &
> + 0x3333333333333333ULL);
> + val = (val & 0x0f0f0f0f0f0f0f0fULL) + ((val >> 4) &
> + 0x0f0f0f0f0f0f0f0fULL);
> + val = (val & 0x00ff00ff00ff00ffULL) + ((val >> 8) &
> + 0x00ff00ff00ff00ffULL);
> + val = (val & 0x0000ffff0000ffffULL) + ((val >> 16) &
> + 0x0000ffff0000ffffULL);
> + return val;
> +}
> +
> +target_ulong helper_popcntd (target_ulong val)
> +{
> + val = (val & 0x5555555555555555ULL) + ((val >> 1) &
> + 0x5555555555555555ULL);
> + val = (val & 0x3333333333333333ULL) + ((val >> 2) &
> + 0x3333333333333333ULL);
> + val = (val & 0x0f0f0f0f0f0f0f0fULL) + ((val >> 4) &
> + 0x0f0f0f0f0f0f0f0fULL);
> + val = (val & 0x00ff00ff00ff00ffULL) + ((val >> 8) &
> + 0x00ff00ff00ff00ffULL);
> + val = (val & 0x0000ffff0000ffffULL) + ((val >> 16) &
> + 0x0000ffff0000ffffULL);
> + val = (val & 0x00000000ffffffffULL) + ((val >> 32) &
> + 0x00000000ffffffffULL);
> + 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)
> {
> val = (val & 0x55555555) + ((val >> 1) & 0x55555555);
> @@ -507,12 +551,13 @@ target_ulong helper_popcntb (target_ulong val)
> return val;
> }
>
> -#if defined(TARGET_PPC64)
> -target_ulong helper_popcntb_64 (target_ulong val)
> +target_ulong helper_popcntw (target_ulong val)
> {
> - val = (val & 0x5555555555555555ULL) + ((val >> 1) &
> 0x5555555555555555ULL);
> - val = (val & 0x3333333333333333ULL) + ((val >> 2) &
> 0x3333333333333333ULL);
> - val = (val & 0x0f0f0f0f0f0f0f0fULL) + ((val >> 4) &
> 0x0f0f0f0f0f0f0f0fULL);
> + val = (val & 0x55555555) + ((val >> 1) & 0x55555555);
> + val = (val & 0x33333333) + ((val >> 2) & 0x33333333);
> + val = (val & 0x0f0f0f0f) + ((val >> 4) & 0x0f0f0f0f);
> + val = (val & 0x00ff00ff) + ((val >> 8) & 0x00ff00ff);
> + val = (val & 0x0000ffff) + ((val >> 16) & 0x0000ffff);
> return val;
> }
> #endif
> diff --git a/target-ppc/translate.c b/target-ppc/translate.c
> index 0b6bfe7..0547047 100644
> --- a/target-ppc/translate.c
> +++ b/target-ppc/translate.c
> @@ -1483,13 +1483,21 @@ static void gen_xoris(DisasContext *ctx)
> /* popcntb : PowerPC 2.03 specification */
> static void gen_popcntb(DisasContext *ctx)
> {
> + gen_helper_popcntb(cpu_gpr[rA(ctx->opcode)], cpu_gpr[rS(ctx->opcode)]);
> +}
> +
> +static void gen_popcntw(DisasContext *ctx)
> +{
> + gen_helper_popcntw(cpu_gpr[rA(ctx->opcode)], cpu_gpr[rS(ctx->opcode)]);
> +}
> +
> #if defined(TARGET_PPC64)
> - if (ctx->sf_mode)
> - gen_helper_popcntb_64(cpu_gpr[rA(ctx->opcode)],
> cpu_gpr[rS(ctx->opcode)]);
> - else
> -#endif
> - gen_helper_popcntb(cpu_gpr[rA(ctx->opcode)],
> cpu_gpr[rS(ctx->opcode)]);
> +/* popcntd: PowerPC 2.06 specification */
> +static void gen_popcntd(DisasContext *ctx)
> +{
> + gen_helper_popcntd(cpu_gpr[rA(ctx->opcode)], cpu_gpr[rS(ctx->opcode)]);
> }
> +#endif
>
> #if defined(TARGET_PPC64)
> /* extsw & extsw. */
> @@ -8226,7 +8234,9 @@ GEN_HANDLER(oris, 0x19, 0xFF, 0xFF, 0x00000000,
> PPC_INTEGER),
> GEN_HANDLER(xori, 0x1A, 0xFF, 0xFF, 0x00000000, PPC_INTEGER),
> GEN_HANDLER(xoris, 0x1B, 0xFF, 0xFF, 0x00000000, PPC_INTEGER),
> GEN_HANDLER(popcntb, 0x1F, 0x03, 0x03, 0x0000F801, PPC_POPCNTB),
> +GEN_HANDLER(popcntw, 0x1F, 0x1A, 0x0b, 0x0000F801, PPC_POPCNTWD),
> #if defined(TARGET_PPC64)
> +GEN_HANDLER(popcntd, 0x1F, 0x1A, 0x0F, 0x0000F801, PPC_POPCNTWD),
> GEN_HANDLER(cntlzd, 0x1F, 0x1A, 0x01, 0x00000000, PPC_64B),
> #endif
> GEN_HANDLER(rlwimi, 0x14, 0xFF, 0xFF, 0x00000000, PPC_INTEGER),
> --
> 1.7.1
>
>
>
--
Aurelien Jarno GPG: 1024D/F1BCDB73
aurel...@aurel32.net http://www.aurel32.net
