Re: [Qemu-devel] [RFC v1 13/13] target-ppc: introduce opc4 for Expanded Opcode

[David Gibson <david@gibson.dropbear.id.au>]

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On Mon, Jul 18, 2016 at 10:35:17PM +0530, Nikunj A Dadhania wrote:
> ISA 3.0 has introduced EO - Expanded Opcode. Introduce third level
> indirect opcode table and corresponding parsing routines.
> 
> EO (11:12) Expanded opcode field
> Formats: XX1
> 
> EO (11:15) Expanded opcode field
> Formats: VX, X, XX2
> 
> Signed-off-by: Nikunj A Dadhania <nikunj@linux.vnet.ibm.com>
> ---
>  target-ppc/translate.c      |  73 +++++++++++++++++++++++++------
>  target-ppc/translate_init.c | 103 ++++++++++++++++++++++++++++++++------------
>  2 files changed, 136 insertions(+), 40 deletions(-)
> 
> diff --git a/target-ppc/translate.c b/target-ppc/translate.c
> index 6c5a4a6..733d68d 100644
> --- a/target-ppc/translate.c
> +++ b/target-ppc/translate.c
> @@ -40,6 +40,7 @@
>  /* Include definitions for instructions classes and implementations flags */
>  //#define PPC_DEBUG_DISAS
>  //#define DO_PPC_STATISTICS
> +//#define PPC_DUMP_CPU
>  
>  #ifdef PPC_DEBUG_DISAS
>  #  define LOG_DISAS(...) qemu_log_mask(CPU_LOG_TB_IN_ASM, ## __VA_ARGS__)
> @@ -367,12 +368,15 @@ GEN_OPCODE2(name, onam, opc1, opc2, opc3, inval, type, PPC_NONE)
>  #define GEN_HANDLER2_E(name, onam, opc1, opc2, opc3, inval, type, type2)      \
>  GEN_OPCODE2(name, onam, opc1, opc2, opc3, inval, type, type2)
>  
> +#define GEN_HANDLER_E_2(name, opc1, opc2, opc3, opc4, inval, type, type2)     \
> +GEN_OPCODE3(name, opc1, opc2, opc3, opc4, inval, type, type2)
> +
>  typedef struct opcode_t {
> -    unsigned char opc1, opc2, opc3;
> +    unsigned char opc1, opc2, opc3, opc4;
>  #if HOST_LONG_BITS == 64 /* Explicitly align to 64 bits */
> -    unsigned char pad[5];
> +    unsigned char pad[4];
>  #else
> -    unsigned char pad[1];
> +    unsigned char pad[4]; /* 4-byte pad to maintain pad in opcode table */

IIUC the point here is to align entries to the wordsize.  If the
worsize is 32-bit you shouldn't need any extra padding here.

-- 
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

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