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

["David Sherwood" <david dot sherwood at arm dot com>]

Hi All,

For what it's worth I have uploaded a new patch that changes the name
from STRICT_FMIN/MAX to just FMIN/FMAX, although I realise that this
discussion has not yet been resolved. I have also added scheduling
attributes to the aarch64 instructions.

Regards,
David Sherwood.

ChangeLog:

2015-08-28  David Sherwood  <david.sherwood@arm.com>

    gcc/
	* builtins.c (integer_valued_real_p): Add FMIN_EXPR and FMAX_EXPR.
	(fold_builtin_fmin_fmax): For strict math, convert builtins fmin and
	fmax to FMIN_EXPR and FMIN_EXPR, respectively.
	* expr.c (expand_expr_real_2): Add FMIN_EXPR and FMAX_EXPR.
	* fold-const.c (const_binop): Likewise.
	(fold_binary_loc, tree_binary_nonnegative_warnv_p): Likewise.
	(tree_binary_nonzero_warnv_p): Likewise.
	* optabs.h (fminmax_support): Declare.
	* optabs.def: Add new optabs fmax_optab/fmin_optab.
	* optabs.c (optab_for_tree_code): Return new optabs for FMIN_EXPR and
	FMAX_EXPR.
	(fminmax_support): New function.
	* real.c (real_arithmetic): Add FMIN_EXPR and FMAX_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.
	* config/aarch64/aarch64.md: New pattern.
	* config/aarch64/aarch64-simd.md: Likewise.
	* config/aarch64/iterators.md: New unspecs, iterators.
	* config/arm/iterators.md: New iterators.
	* config/arm/unspecs.md: New unspecs.
	* config/arm/neon.md: New pattern.
	* config/arm/vfp.md: Likewise.
        * doc/generic.texi: Add FMAX_EXPR and FMIN_EXPR.
        * doc/md.texi: Add fmin and fmax patterns.
    gcc/testsuite
        * gcc.target/aarch64/fmaxmin.c: New test.
        * gcc.target/arm/fmaxmin.c: New test.


> -----Original Message-----
> From: Richard Biener [mailto:richard.guenther@gmail.com]
> Sent: 19 August 2015 14:41
> To: Richard Biener; David Sherwood; GCC Patches; Richard Sandiford
> Subject: Re: [PING][Patch] Add support for IEEE-conformant versions of scalar fmin* and fmax*
> 
> On Wed, Aug 19, 2015 at 3:06 PM, Richard Sandiford
> <richard.sandiford@arm.com> wrote:
> > Richard Biener <richard.guenther@gmail.com> writes:
> >> As an additional point for many math functions we have to support errno
> >> which means, like, BUILT_IN_SQRT can be rewritten to SQRT_EXPR
> >> only if -fno-math-errno is in effect.  But then code has to handle
> >> both variants for things like constant folding and expression combining.
> >> That's very unfortunate and something we want to avoid (one reason
> >> the POW_EXPR thing didn't fly when I tried).  STRICT_FMIN/MAX_EXPR
> >> is an example where this doesn't apply, of course (but I detest the name,
> >> just use FMIN/FMAX_EXPR?).  Still you'd need to handle both,
> >> FMIN_EXPR and BUILT_IN_FMIN, in code doing analysis/transform.
> >
> > Yeah, but match.pd makes that easy, right? ;-)
> 
> Sure, but that only addresses stmt combining, not other passes.  And of course
> it causes {gimple,generic}-match.c to become even bigger ;)
> 
> Richard.

Attachment: fmaxmin.patch
Description: Binary data