Re: [PATCH][ARM]Use of vcvt for float to fixed point conversions.

[Renlin Li <renlin dot li at arm dot com>]

Hi Christophe,

There is a minor issue about this test case. It requires the `float-abi` 
of your target to be either `softfp` or `hard` (to utilize the floating 
point hardware).
Could you please check whether this solves the problem or not?

I should add it to the `dg-options` section of the test case and a patch 
is on the way.

Thank you for your notification!

Kind regards,
Renlin Li


On 08/01/14 16:43, Christophe Lyon wrote:
> Hi Renlin,
>
> The new test you added introduces 2 new FAILs when the target is
> arm-none-linux-gnueabi (as opposed to arm-none-linux-gnueabihf).
>
> Christophe.
>
>
> On 24 December 2013 15:46, Renlin Li <renlin.li@arm.com> wrote:
> > Hi,
> >
> > I just updated my patch according your suggestion.
> > Thank you for committing it for me!
> >
> > All you guys have a nice Xmas break!
> >
> > Kind regards,
> > Renlin Li
> >
> >
> > On 04/12/13 11:23, Ramana Radhakrishnan wrote:
> > > Sorry about the slow response. Been on holiday.
> > >
> > > On 20/11/13 16:27, Renlin Li wrote:
> > > > Hi all,
> > > >
> > > > This patch will make the arm back-end use vcvt for float to fixed point
> > > > conversions when applicable.
> > > >
> > > > Test on arm-none-linux-gnueabi has been done on the model.
> > > > Okay for trunk?
> > > >
> > > > + (define_insn "*combine_vcvtf2i"
> > > > +   [(set (match_operand:SI 0 "s_register_operand" "=r")
> > > > +       (fix:SI (fix:SF (mult:SF (match_operand:SF 1 "s_register_operand"
> > > > "t")
> > > > +                                (match_operand 2
> > > > +                                "const_double_vcvt_power_of_two"
> > > > "Dp")))))]
> > > > +   "TARGET_32BIT && TARGET_HARD_FLOAT && TARGET_VFP3 &&
> > > > !flag_rounding_math"
> > > > +   "vcvt%?.s32.f32\\t%1, %1, %v2\;vmov%?\\t%0, %1"
> > > > +   [(set_attr "predicable" "yes")
> > > > +    (set_attr "predicable_short_it" "no")
> > > > +    (set_attr "ce_count" "2")
> > > > +    (set_attr "type" "f_cvtf2i")]
> > > > + )
> > > > +
> > > You need to set length to 8.
> > >
> > > > --- /dev/null
> > > > +++ b/gcc/testsuite/gcc.target/arm/fixed_float_conversion.c
> > > > @@ -0,0 +1,15 @@
> > > > +/* Check that vcvt is used for fixed and float data conversions.  */
> > > > +/* { dg-do compile } */
> > > > +/* { dg-options "-O1 -mfpu=vfp3" } */
> > > > +/* { dg-require-effective-target arm_vfp_ok } */
> > > > +float fixed_to_float(int i)
> > > > +{
> > > > +    return ((float)i / (1 << 16));
> > > > +}
> > > > +
> > > > +int float_to_fixed(float f)
> > > > +{
> > > > +    return ((int)(f*(1 << 16)));
> > > > +}
> > > > +/* { dg-final { scan-assembler "vcvt.f32.s32" } } */
> > > > +/* { dg-final { scan-assembler "vcvt.s32.f32" } } */
> > >
> > > GNU coding style for functions.
> > >
> > > Ok with those changes.
> > >
> > >
> > >
> > >
> > > regards
> > > Ramana
> > >
> > >
> > > > Kind regards,
> > > > Renlin Li
> > > >
> > > >
> > > > gcc/ChangeLog:
> > > >
> > > > 2013-11-20  Renlin Li  <Renlin.Li@arm.com>
> > > >
> > > >         * config/arm/arm-protos.h (vfp_const_double_for_bits): Declare.
> > > >         * config/arm/constraints.md (Dp): Define new constraint.
> > > >         * config/arm/predicates.md ( const_double_vcvt_power_of_two):
> > > > Define
> > > >         new predicate.
> > > >         * config/arm/arm.c (arm_print_operand): Add print for new
> > > > fucntion.
> > > >         (vfp3_const_double_for_bits): New function.
> > > >         * config/arm/vfp.md (combine_vcvtf2i): Define new instruction.
> > > >
> > > > gcc/testsuite/ChangeLog:
> > > >
> > > > 2013-11-20  Renlin Li  <Renlin.Li@arm.com>
> > > >
> > > >         * gcc.target/arm/fixed_float_conversion.c: New test case.