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From: Taylor Simpson <tsimpson@quicinc.com>
To: Richard Henderson <richard.henderson@linaro.org>,
	"qemu-devel@nongnu.org" <qemu-devel@nongnu.org>
Cc: "ale@rev.ng" <ale@rev.ng>, Brian Cain <bcain@quicinc.com>,
	"philmd@redhat.com" <philmd@redhat.com>
Subject: RE: [PATCH v2 16/21] Hexagon (target/hexagon) add A4_addp_c/A4_subp_c
Date: Tue, 6 Apr 2021 21:58:21 +0000	[thread overview]
Message-ID: <BYAPR02MB4886E7E5281B7B3C4B5F80F6DE769@BYAPR02MB4886.namprd02.prod.outlook.com> (raw)
In-Reply-To: <97ee7d14-fdfb-30d8-0b75-42df768d35ef@linaro.org>



> -----Original Message-----
> From: Richard Henderson <richard.henderson@linaro.org>
> Sent: Tuesday, April 6, 2021 4:12 PM
> To: Taylor Simpson <tsimpson@quicinc.com>; qemu-devel@nongnu.org
> Cc: philmd@redhat.com; ale@rev.ng; Brian Cain <bcain@quicinc.com>
> Subject: Re: [PATCH v2 16/21] Hexagon (target/hexagon) add
> A4_addp_c/A4_subp_c
>
> On 3/31/21 8:53 PM, Taylor Simpson wrote:
> > +#define fGEN_TCG_A4_addp_c(SHORTCODE) \
> > +    do { \
> > +        TCGv_i64 carry = tcg_temp_new_i64(); \
> > +        TCGv_i64 zero = tcg_const_i64(0); \
> > +        tcg_gen_extu_i32_i64(carry, PxV); \
> > +        tcg_gen_andi_i64(carry, carry, 1); \
> > +        tcg_gen_add2_i64(RddV, carry, RssV, zero, carry, zero); \
> > +        tcg_gen_add2_i64(RddV, carry, RddV, carry, RttV, zero); \
> > +        tcg_gen_extrl_i64_i32(PxV, carry); \
>
> Note that this is already a single bit, always.

Yes, we just need an _i32 instead of an _i64.

> > +static TCGv gen_8bitsof(TCGv result, TCGv value)
> > +{
> > +    TCGv zero = tcg_const_tl(0);
> > +    TCGv ones = tcg_const_tl(0xff);
> > +    tcg_gen_movcond_tl(TCG_COND_NE, result, value, zero, ones, zero);
> > +    tcg_temp_free(zero);
> > +    tcg_temp_free(ones);
> > +
> > +    return result;
>
> There's little point in a conditional move.
> Just multiply by 0xff.
>
> Unless you had another non-boolean use for gen_8bitsof?

Yes, there are instances of that.

> Anyway, I guess it's all sane,
> Reviewed-by: Richard Henderson <richard.henderson@linaro.org>

Thanks!



  reply	other threads:[~2021-04-06 21:59 UTC|newest]

Thread overview: 49+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-04-01  3:53 [PATCH v2 00/21] Hexagon (target/hexagon) update Taylor Simpson
2021-04-01  3:53 ` [PATCH v2 01/21] Hexagon (target/hexagon) TCG generation cleanup Taylor Simpson
2021-04-02 17:25   ` Richard Henderson
2021-04-02 17:46   ` Richard Henderson
2021-04-02 19:42     ` Taylor Simpson
2021-04-02 20:00       ` Richard Henderson
2021-04-01  3:53 ` [PATCH v2 02/21] Hexagon (target/hexagon) remove unnecessary inline directives Taylor Simpson
2021-04-02 17:26   ` Richard Henderson
2021-04-01  3:53 ` [PATCH v2 03/21] Hexagon (target/hexagon) use env_archcpu and env_cpu Taylor Simpson
2021-04-02 17:27   ` Richard Henderson
2021-04-01  3:53 ` [PATCH v2 04/21] Hexagon (target/hexagon) properly generate TB end for DISAS_NORETURN Taylor Simpson
2021-04-02 17:34   ` Richard Henderson
2021-04-01  3:53 ` [PATCH v2 05/21] Hexagon (target/hexagon) decide if pred has been written at TCG gen time Taylor Simpson
2021-04-02 17:44   ` Richard Henderson
2021-04-01  3:53 ` [PATCH v2 06/21] Hexagon (target/hexagon) change variables from int to bool when appropriate Taylor Simpson
2021-04-01  3:53 ` [PATCH v2 07/21] Hexagon (target/hexagon) remove unused carry_from_add64 function Taylor Simpson
2021-04-01  3:53 ` [PATCH v2 08/21] Hexagon (target/hexagon) change type of softfloat_roundingmodes Taylor Simpson
2021-04-01  3:53 ` [PATCH v2 09/21] Hexagon (target/hexagon) use softfloat default NaN and tininess Taylor Simpson
2021-04-02 17:48   ` Richard Henderson
2021-04-01  3:53 ` [PATCH v2 10/21] Hexagon (target/hexagon) replace float32_mul_pow2 with float32_scalbn Taylor Simpson
2021-04-01  3:53 ` [PATCH v2 11/21] Hexagon (target/hexagon) use softfloat for float-to-int conversions Taylor Simpson
2021-04-06 20:09   ` Richard Henderson
2021-04-01  3:53 ` [PATCH v2 12/21] Hexagon (target/hexagon) add F2_sfrecipa instruction Taylor Simpson
2021-04-06 20:30   ` Richard Henderson
2021-04-06 20:46   ` Richard Henderson
2021-04-06 21:55     ` Taylor Simpson
2021-04-06 22:13       ` Richard Henderson
2021-04-01  3:53 ` [PATCH v2 13/21] Hexagon (target/hexagon) add F2_sfinvsqrta Taylor Simpson
2021-04-06 20:47   ` Richard Henderson
2021-04-01  3:53 ` [PATCH v2 14/21] Hexagon (target/hexagon) add A5_ACS (vacsh) Taylor Simpson
2021-04-06 20:51   ` Richard Henderson
2021-04-06 21:31     ` Taylor Simpson
2021-04-01  3:53 ` [PATCH v2 15/21] Hexagon (target/hexagon) add A6_vminub_RdP Taylor Simpson
2021-04-06 20:57   ` Richard Henderson
2021-04-01  3:53 ` [PATCH v2 16/21] Hexagon (target/hexagon) add A4_addp_c/A4_subp_c Taylor Simpson
2021-04-06 21:11   ` Richard Henderson
2021-04-06 21:58     ` Taylor Simpson [this message]
2021-04-01  3:53 ` [PATCH v2 17/21] Hexagon (target/hexagon) circular addressing Taylor Simpson
2021-04-06 22:11   ` Richard Henderson
2021-04-07  3:11     ` Taylor Simpson
2021-04-07 16:27       ` Taylor Simpson
2021-04-01  3:53 ` [PATCH v2 18/21] Hexagon (target/hexagon) bit reverse (brev) addressing Taylor Simpson
2021-04-06 22:35   ` Richard Henderson
2021-04-01  3:53 ` [PATCH v2 19/21] Hexagon (target/hexagon) load and unpack bytes instructions Taylor Simpson
2021-04-06 22:46   ` Richard Henderson
2021-04-01  3:53 ` [PATCH v2 20/21] Hexagon (target/hexagon) load into shifted register instructions Taylor Simpson
2021-04-06 22:50   ` Richard Henderson
2021-04-01  3:53 ` [PATCH v2 21/21] Hexagon (target/hexagon) CABAC decode bin Taylor Simpson
2021-04-06 22:54   ` Richard Henderson

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