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Re: [Qemu-devel] [PULL 01/12] target-ppc: optimize cmp translation
From: |
David Gibson |
Subject: |
Re: [Qemu-devel] [PULL 01/12] target-ppc: optimize cmp translation |
Date: |
Fri, 19 Jan 2018 10:28:29 +1100 |
User-agent: |
Mutt/1.9.1 (2017-09-22) |
On Thu, Jan 18, 2018 at 05:36:40PM +0100, Paolo Bonzini wrote:
> On 08/01/2018 06:53, David Gibson wrote:
> > From: "address@hidden" <address@hidden>
> >
> > We know that only one bit (in addition to SO) is going to be set in
> > the condition register, so do two movconds instead of three setconds,
> > three shifts and two ORs.
> >
> > For ppc64-linux-user, the code size reduction is around 5% and the
> > performance improvement slightly less than 10%. For softmmu, the
> > improvement is around 5%.
> >
> > Signed-off-by: Paolo Bonzini <address@hidden>
> > Signed-off-by: David Gibson <address@hidden>
> > ---
> > target/ppc/translate.c | 29 ++++++++++++-----------------
> > 1 file changed, 12 insertions(+), 17 deletions(-)
> >
> > diff --git a/target/ppc/translate.c b/target/ppc/translate.c
> > index 4075fc8589..8a6bd329d0 100644
> > --- a/target/ppc/translate.c
> > +++ b/target/ppc/translate.c
> > @@ -605,27 +605,22 @@ static opc_handler_t invalid_handler = {
> > static inline void gen_op_cmp(TCGv arg0, TCGv arg1, int s, int crf)
> > {
> > TCGv t0 = tcg_temp_new();
> > - TCGv_i32 t1 = tcg_temp_new_i32();
> > -
> > - tcg_gen_trunc_tl_i32(cpu_crf[crf], cpu_so);
> > -
> > - tcg_gen_setcond_tl((s ? TCG_COND_LT: TCG_COND_LTU), t0, arg0, arg1);
> > - tcg_gen_trunc_tl_i32(t1, t0);
> > - tcg_gen_shli_i32(t1, t1, CRF_LT_BIT);
> > - tcg_gen_or_i32(cpu_crf[crf], cpu_crf[crf], t1);
> > + TCGv t1 = tcg_temp_new();
> > + TCGv_i32 t = tcg_temp_new_i32();
> >
> > - tcg_gen_setcond_tl((s ? TCG_COND_GT: TCG_COND_GTU), t0, arg0, arg1);
> > - tcg_gen_trunc_tl_i32(t1, t0);
> > - tcg_gen_shli_i32(t1, t1, CRF_GT_BIT);
> > - tcg_gen_or_i32(cpu_crf[crf], cpu_crf[crf], t1);
> > + tcg_gen_movi_tl(t0, CRF_EQ);
> > + tcg_gen_movi_tl(t1, CRF_LT);
> > + tcg_gen_movcond_tl((s ? TCG_COND_LT : TCG_COND_LTU), t0, arg0, arg1,
> > t1, t0);
> > + tcg_gen_movi_tl(t1, CRF_GT);
> > + tcg_gen_movcond_tl((s ? TCG_COND_GT : TCG_COND_GTU), t0, arg0, arg1,
> > t1, t0);
> >
> > - tcg_gen_setcond_tl(TCG_COND_EQ, t0, arg0, arg1);
> > - tcg_gen_trunc_tl_i32(t1, t0);
> > - tcg_gen_shli_i32(t1, t1, CRF_EQ_BIT);
> > - tcg_gen_or_i32(cpu_crf[crf], cpu_crf[crf], t1);
> > + tcg_gen_trunc_tl_i32(t, t0);
> > + tcg_gen_trunc_tl_i32(cpu_crf[crf], cpu_so);
> > + tcg_gen_or_i32(cpu_crf[crf], cpu_crf[crf], t);
> >
> > tcg_temp_free(t0);
> > - tcg_temp_free_i32(t1);
> > + tcg_temp_free(t1);
> > + tcg_temp_free_i32(t);
> > }
> >
> > static inline void gen_op_cmpi(TCGv arg0, target_ulong arg1, int s, int
> > crf)
> >
>
> David, can you queue this again now that the ARM backend has been
> fixed?
Done, thanks.
--
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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- [Qemu-devel] [PULL 00/12] ppc-for-2.12 queue 20180108, David Gibson, 2018/01/08
- [Qemu-devel] [PULL 01/12] target-ppc: optimize cmp translation, David Gibson, 2018/01/08
- [Qemu-devel] [PULL 04/12] sm501: Add some more unimplemented registers, David Gibson, 2018/01/08
- [Qemu-devel] [PULL 03/12] sm501: Add panel hardware cursor registers also to read function, David Gibson, 2018/01/08
- [Qemu-devel] [PULL 06/12] spapr_pci: use warn_report(), David Gibson, 2018/01/08
- [Qemu-devel] [PULL 09/12] target/ppc: more use of the PPC_*() macros, David Gibson, 2018/01/08
- [Qemu-devel] [PULL 05/12] ppc4xx_i2c: Implement basic I2C functions, David Gibson, 2018/01/08
- [Qemu-devel] [PULL 10/12] Update dtc to fix compilation problem on Mac OS 10.6, David Gibson, 2018/01/08
- [Qemu-devel] [PULL 11/12] hw/ppc: Remove the deprecated spapr-pci-vfio-host-bridge device, David Gibson, 2018/01/08
- [Qemu-devel] [PULL 12/12] spapr: Correct compatibility mode setting for hotplugged CPUs, David Gibson, 2018/01/08
- [Qemu-devel] [PULL 07/12] hw/ide: Emulate SiI3112 SATA controller, David Gibson, 2018/01/08
- [Qemu-devel] [PULL 08/12] ppc/pnv: change powernv_ prefix to pnv_ for overall naming consistency, David Gibson, 2018/01/08