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Re: [Qemu-devel] [PATCH v2 12/27] tcg-ppc64: Improve and_i32 with consta
From: |
Aurelien Jarno |
Subject: |
Re: [Qemu-devel] [PATCH v2 12/27] tcg-ppc64: Improve and_i32 with constant |
Date: |
Mon, 1 Apr 2013 16:55:39 +0200 |
User-agent: |
Mutt/1.5.21 (2010-09-15) |
On Mon, Mar 04, 2013 at 04:32:55PM -0800, Richard Henderson wrote:
> Use RLWINM
>
> Signed-off-by: Richard Henderson <address@hidden>
> ---
> tcg/ppc64/tcg-target.c | 50
> +++++++++++++++++++++++++++++++++++++++++++++++++-
> 1 file changed, 49 insertions(+), 1 deletion(-)
>
> diff --git a/tcg/ppc64/tcg-target.c b/tcg/ppc64/tcg-target.c
> index 9718ef6..ad6db6c 100644
> --- a/tcg/ppc64/tcg-target.c
> +++ b/tcg/ppc64/tcg-target.c
> @@ -527,6 +527,48 @@ static void tcg_out_movi(TCGContext *s, TCGType type,
> TCGReg ret,
> }
> }
>
> +static inline bool mask_operand(uint32_t c, int *mb, int *me)
> +{
> + uint32_t lsb, test;
> +
> + /* Accept a bit pattern like:
> + 0....01....1
> + 1....10....0
> + 0..01..10..0
> + Keep track of the transitions. */
> + if (c == 0 || c == -1) {
> + return false;
> + }
> + test = c;
> + lsb = test & -test;
> + test += lsb;
> + if (test & (test - 1)) {
> + return false;
> + }
> +
> + *me = clz32(lsb);
> + *mb = test ? clz32(test & -test) + 1 : 0;
> + return true;
> +}
> +
> +static void tcg_out_andi32(TCGContext *s, TCGReg dst, TCGReg src, uint32_t c)
> +{
> + int mb, me;
> +
> + if ((c & 0xffff) == c) {
> + tcg_out32(s, ANDI | SAI(src, dst, c));
> + return;
> + } else if ((c & 0xffff0000) == c) {
> + tcg_out32(s, ANDIS | SAI(src, dst, c >> 16));
> + return;
> + } else if (mask_operand(c, &mb, &me)) {
> + tcg_out_rlw(s, RLWINM, dst, src, 0, mb, me);
> + } else {
> + tcg_out_movi(s, TCG_TYPE_I32, 0, c);
> + tcg_out32(s, AND | SAB(src, dst, 0));
Give it's a 32-bit constant, wouldn't it be better to use ANDI +
ANDIS here?
> + }
> +}
> +
> static void tcg_out_zori32(TCGContext *s, TCGReg dst, TCGReg src, uint32_t c,
> int op_lo, int op_hi)
> {
> @@ -1346,9 +1388,15 @@ static void tcg_out_op (TCGContext *s, TCGOpcode opc,
> const TCGArg *args,
> }
> break;
>
> - case INDEX_op_and_i64:
> case INDEX_op_and_i32:
> if (const_args[2]) {
> + tcg_out_andi32(s, args[0], args[1], args[2]);
> + } else {
> + tcg_out32(s, AND | SAB(args[1], args[0], args[2]));
> + }
> + break;
> + case INDEX_op_and_i64:
> + if (const_args[2]) {
> if ((args[2] & 0xffff) == args[2]) {
> tcg_out32(s, ANDI | SAI(args[1], args[0], args[2]));
> } else if ((args[2] & 0xffff0000) == args[2]) {
> --
> 1.8.1.2
>
>
>
--
Aurelien Jarno GPG: 1024D/F1BCDB73
address@hidden http://www.aurel32.net
- Re: [Qemu-devel] [PATCH v2 12/27] tcg-ppc64: Improve and_i32 with constant,
Aurelien Jarno <=