On Tue, 2 Jul 2019, Tamar Christina wrote:
>
> Hi All,
>
> Here's an updated patch with the changes processed from the previous review.
>
> I've bootstrapped and regtested on aarch64-none-linux-gnu and
> x86_64-pc-linux-gnu and no issues.
>
> Ok for trunk?
+ (if (TYPE_OVERFLOW_WRAPS (TREE_TYPE (@1)))
+ (op @1 (convert @2))
+ (with { tree utype = unsigned_type_for (TREE_TYPE (@1)); }
+ (convert (op (convert:utype @1)
indenting is off, one space more for (convert (it's inside the with)
+ (convert:utype @2)))))
+ (with { tree arg0 = strip_float_extensions (@1);
indenting is off here, one space less for the (with please.
you'll run into strip_float_extensions for integer types as well so
please move the FLOAT_TYPE_P (type) check before the with like
(if (FLOAT_TYPE_P (type)
&& DECIMAL_FLOAT_TYPE_P (TREE_TPE (@0)) == DECIMAL_FLOAT_TYPE_P
(type))
(with { tree arg0 = strip_float_extensions (@1);
+ (if ((newtype == dfloat32_type_node
+ || newtype == dfloat64_type_node
+ || newtype == dfloat128_type_node)
+ && newtype == type)
+ (convert:newtype (op (convert:newtype @1) (convert:newtype
@2)))
I think you want to elide the outermost convert:newtype here and use
(op (convert:newtype @1) (convert:newtype @2))
newtype == type check you also want to write types_match_p (newtype, type)
+ (if (TYPE_PRECISION (newtype) < TYPE_PRECISION (itype)
+ && (flag_unsafe_math_optimizations
+ || (TYPE_PRECISION (newtype) == TYPE_PRECISION
(type)
+ && real_can_shorten_arithmetic (TYPE_MODE
(itype),
+ TYPE_MODE
(type))
+ && !excess_precision_type (newtype))))
+ (convert:newtype (op (convert:newtype @1)
+ (convert:newtype @2)))
here the outermost convert looks bogus - you need to build an
expression of type 'type' thus
(convert:type (op (convert:newtype @1) (convert:newtype @2)))
I think you also want to avoid endless recursion by adding a
&& !types_match_p (itype, newtype)
since in that case you've re-created the original expression.
OK with those changes.
Thanks,
Richard.
> Thanks,
> Tamar
>
> The 07/02/2019 11:20, Richard Biener wrote:
> > On Tue, 2 Jul 2019, Tamar Christina wrote:
> >
> > > Hi Richi,
> > >
> > > The 06/25/2019 10:02, Richard Biener wrote:
> > > >
> > > > This looks like a literal 1:1 translation plus merging with the
> > > > existing pattern around integers. You changed
> > > > (op:s@0 (convert@3 @1) (convert?@4 @2)) to
> > > > (op:s@0 (convert1?@3 @1) (convert2?@4 @2)) where this now also
> > > > matches if there are no inner conversions at all - was that a
> > > > desired change or did you merely want to catch when the first
> > > > operand is not a conversion but the second is, possibly only
> > > > for the RDIV_EXPR case?
> > > >
> > >
> > > Yes, the ? ? is for the RDIV case, I really only want (c a) `op` (c b),
> > > a `op` (c b) and (c a) `op` b. But didn't find a way to do this.
> >
> > One way would be to do
> >
> > (simplify
> > (convert (op:sc@0 (convert @1) (convert? @2)))
> >
> > but that doesn't work for RDIV. Using :C is tempting but you
> > do not get to know the original operand order which you of
> > course need. So I guess the way you do it is fine - you
> > could guard all of the code with a few types_match () checks
> > but I'm not sure it is worth the trouble.
> >
> > Richard.
> >
> > > The only thing I can think of that gets this is without overmatching is
> > > to either duplicate the code or move this back to a C helper function and
> > > call that from match.pd. But I was hoping to have it all in match.pd
> > > instead of hiding it away in a C call.
> > >
> > > Do you have a better way of doing it or a preference to an approach?
> > >
> > > > +(for op (plus minus mult rdiv)
> > > > + (simplify
> > > > + (convert (op:s@0 (convert1?@3 @1) (convert2?@4 @2)))
> > > > + (with { tree arg0 = strip_float_extensions (@1);
> > > > + tree arg1 = strip_float_extensions (@2);
> > > > + tree itype = TREE_TYPE (@0);
> > > >
> > > > you now unconditionally call strip_float_extensions on each operand
> > > > even for the integer case, please sink stuff only used in one
> > > > case arm. I guess keeping the integer case first via
> > > >
> > >
> > > Done, Initially didn't think it would be an issue since I don't use the
> > > value it
> > > creates in the integer case. But I re-ordered it.
> > >
> > > > should work (with the 'with' being in the ifs else position).
> > > >
> > > > + (if (code == REAL_TYPE)
> > > > + /* Ignore the conversion if we don't need to store intermediate
> > > > + results and neither type is a decimal float. */
> > > > + (if (!(flag_float_store
> > > > + || DECIMAL_FLOAT_TYPE_P (type)
> > > > + || DECIMAL_FLOAT_TYPE_P (itype))
> > > > + && types_match (ty1, ty2))
> > > > + (convert (op (convert:ty1 @1) (convert:ty2 @2)))))
> > > >
> > > > this looks prone to the same recursion issue you described above.
> > >
> > > It's to break the recursion when you don't match anything. Indeed don't
> > > need it if
> > > I change the match condition above.
> > > Thanks,
> > > Tamar
> > > >
> > > > 'code' is used exactly once, using SCALAR_FLOAT_TYPE_P (itype)
> > > > in the above test would be clearer. Also both ifs can be combined.
> > > > The snipped above also doesn't appear in the convert.c code you
> > > > remove and the original one is
> > > >
> > > > switch (TREE_CODE (TREE_TYPE (expr)))
> > > > {
> > > > case REAL_TYPE:
> > > > /* Ignore the conversion if we don't need to store intermediate
> > > > results and neither type is a decimal float. */
> > > > return build1_loc (loc,
> > > > (flag_float_store
> > > > || DECIMAL_FLOAT_TYPE_P (type)
> > > > || DECIMAL_FLOAT_TYPE_P (itype))
> > > > ? CONVERT_EXPR : NOP_EXPR, type, expr);
> > > >
> > > > which as far as I can see doesn't do anything besides
> > > > exchanging CONVERT_EXPR for NOP_EXPR which is a noop to the IL.
> > > > So it appears this shouldn't be moved to match.pd at all?
> > > > It's also not a 1:1 move since you are changing 'expr'.
> > > >
> > > > Thanks,
> > > > Richard.
> > > >
> > > > > > Thanks,
> > > > > > Tamar
> > > > > >
> > > > > > Concretely it makes both these cases behave the same
> > > > > >
> > > > > > float e = (float)a * (float)b;
> > > > > > *c = (_Float16)e;
> > > > > >
> > > > > > and
> > > > > >
> > > > > > *c = (_Float16)((float)a * (float)b);
> > > > > >
> > > > > > Thanks,
> > > > > > Tamar
> > > > > >
> > > > > > gcc/ChangeLog:
> > > > > >
> > > > > > 2019-06-25 Tamar Christina <tamar.christ...@arm.com>
> > > > > >
> > > > > > * convert.c (convert_to_real_1): Move part of conversion code...
> > > > > > * match.pd: ...To here.
> > > > > >
> > > > > > gcc/testsuite/ChangeLog:
> > > > > >
> > > > > > 2019-06-25 Tamar Christina <tamar.christ...@arm.com>
> > > > > >
> > > > > > * gcc.dg/type-convert-var.c: New test.
> > > > > >
> > > > > > --
> > > > >
> > > >
> > > > --
> > > > Richard Biener <rguent...@suse.de>
> > > > SUSE Linux GmbH, Maxfeldstrasse 5, 90409 Nuernberg, Germany;
> > > > GF: Felix Imendörffer, Mary Higgins, Sri Rasiah; HRB 21284 (AG Nürnberg)
> > >
> > >
> >
> > --
> > Richard Biener <rguent...@suse.de>
> > SUSE Linux GmbH, Maxfeldstrasse 5, 90409 Nuernberg, Germany;
> > GF: Felix Imendörffer, Mary Higgins, Sri Rasiah; HRB 21284 (AG Nürnberg)
>
>
--
Richard Biener <rguent...@suse.de>
SUSE Linux GmbH, Maxfeldstrasse 5, 90409 Nuernberg, Germany;
GF: Felix Imendörffer, Mary Higgins, Sri Rasiah; HRB 21284 (AG Nürnberg)
