Re: [PING][Patch] Add support for IEEE-conformant versions of scalar fmin* and fmax*

[Richard Biener <richard.guenther@gmail.com>]

On Thu, Aug 13, 2015 at 12:11 PM, David Sherwood <david.sherwood@arm.com> wrote:
> Hi,
>
> Sorry to bother people again. Is this OK to go now?

Hmm, why don't you go the vectorized function call path for this,
implementing the builtin_vectorized_function target hook?

Richard.

> Thanks!
> David.
>
>> >
>> > > On Mon, 29 Jun 2015, David Sherwood wrote:
>> > >
>> > > > Hi,
>> > > >
>> > > > I have added new STRICT_MAX_EXPR and STRICT_MIN_EXPR expressions to support the
>> > > > IEEE versions of fmin and fmax. This is done by recognising the math library
>> > > > "fmax" and "fmin" builtin functions in a similar way to how this is done for
>> > > > -ffast-math. This also allows us to vectorise the IEEE max/min functions for
>> > > > targets that support it, for example aarch64/aarch32.
>> > >
>> > > This patch is missing documentation.  You need to document the new insn
>> > > patterns in md.texi and the new tree codes in generic.texi.
>> >
>> > Hi, I've uploaded a new patch with the documentation. Hope this is ok.
>>
>> In various places where you refer to one operand being NaN, I think you
>> mean one operand being a *quiet* NaN (if one is a signaling NaN - only
>> supported by GCC if -fsignaling-nans - the IEEE minNum and maxNum
>> operations raise "invalid" and return a quiet NaN).
>
> Hi, I have a new patch that hopefully addresses the documentation issues.
>
> Thanks,
> David.
>
> ChangeLog:
>
> 2015-07-15  David Sherwood  <david.sherwood@arm.com>
>
> gcc/
>     * builtins.c (integer_valued_real_p): Add STRICT_MIN_EXPR and
>     STRICT_MAX_EXPR.
>     (fold_builtin_fmin_fmax): For strict math, convert builting fmin and
>     fmax to STRICT_MIN_EXPR and STRICT_MIN_EXPR, respectively.
>     * expr.c (expand_expr_real_2): Add STRICT_MIN_EXPR and STRICT_MAX_EXPR.
>     * fold-const.c (const_binop): Likewise.
>     (fold_binary_loc, tree_binary_nonnegative_warnv_p): Likewise.
>     (tree_binary_nonzero_warnv_p): Likewise.
>     * optabs.h (strict_minmax_support): Declare.
>     * optabs.def: Add new optabs strict_max_optab/strict_min_optab.
>     * optabs.c (optab_for_tree_code): Return new optabs for STRICT_MIN_EXPR
>     and STRICT_MAX_EXPR.
>     (strict_minmax_support): New function.
>     * real.c (real_arithmetic): Add STRICT_MIN_EXPR and STRICT_MAX_EXPR.
>     * tree.def: Likewise.
>     * tree.c (associative_tree_code, commutative_tree_code): Likewise.
>     * tree-cfg.c (verify_expr): Likewise.
>     (verify_gimple_assign_binary): Likewise.
>     * tree-inline.c (estimate_operator_cost): Likewise.
>     * tree-pretty-print.c (dump_generic_node, op_code_prio): Likewise.
>     (op_symbol_code): Likewise.
> gcc/config:
>     * aarch64/aarch64.md: New pattern.
>     * aarch64/aarch64-simd.md: Likewise.
>     * aarch64/iterators.md: New unspecs, iterators.
>     * arm/iterators.md: New iterators.
>     * arm/unspecs.md: New unspecs.
>     * arm/neon.md: New pattern.
>     * arm/vfp.md: Likewise.
> gcc/doc:
>     * generic.texi: Add STRICT_MAX_EXPR and STRICT_MIN_EXPR.
>     * md.texi: Add strict_min and strict_max patterns.
> gcc/testsuite
>     * gcc.target/aarch64/maxmin_strict.c: New test.
>     * gcc.target/arm/maxmin_strict.c: New test.