Re: [PATCH, version 3], Add support for _Float<N> and _Float<N>X sqrt, fma, fmin, fmax built-in functions

[Michael Meissner <meissner at linux dot vnet dot ibm dot com>]

On Thu, Oct 19, 2017 at 10:15:44PM +0000, Joseph Myers wrote:
> On Thu, 19 Oct 2017, Michael Meissner wrote:
> 
> >     1)	I switched to use DEF_EXT_LIB_BUILTIN to declare the _Float<N> and
> > 	_Float<N>X functions.  This allows treating __builtin_sqrtf128 the same
> > 	as sqrtf128.
> 
> It's not correct to do that unconditionally for all the existing 
> DEF_GCC_FLOATN_NX_BUILTINS functions.  There should not be a public 
> huge_valf128 function any more than a public huge_val function, just 
> __builtin_huge_valf128.
> 
> Rather, you should add a new DEF_EXT_LIB_FLOATN_NX_BUILTINS.  It should be 
> used by the new functions, and by the existing copysign / fabs / nan 
> functions.  It should not be used by the existing huge_val / inf / nans 
> functions.

This patch adds a new switch (-fimplicit-math-floatn) that when enabled, it
will add implicit declarations for copysign, fabs, fma, fmax, fmin, nan, and
sqrt _Float<N> and _Float<N>X variants.  Like the previous patch, it adds fma,
fmax, fmin, and sqrt builtins to the machine independent built-in support, and
removed the PowerPC specific __builtin_{sqrt,fma}f128 functions.

I have bootstrapped this patch on a little endian power8 system and an x86-64
system.  There were no regressions in either system.  I added powerpc specific
tests for -f{,no-}implicit-math-floatn.  Can I check this patch into the trunk?

[gcc]
2017-10-24  Michael Meissner  <meissner@linux.vnet.ibm.com>

	* builtins.c (CASE_MATHFN_FLOATN): New helper macro to add cases
	for math functions that have _Float<N> and _Float<N>X variants.
	(mathfn_built_in_2): Add support for math functions that have
	_Float<N> and _Float<N>X variants.
	(DEF_INTERNAL_FLT_FLOATN_FN): New helper macro.
	(expand_builtin_mathfn_ternary): Add support for fma with
	_Float<N> and _Float<N>X variants.
	(expand_builtin): Likewise.
	(fold_builtin_3): Likewise.
	* builtins.def (DEF_FLOATFN_BUILTIN_2): New macros.  If
	-fimplicit-math-floatn is on, treat the _Float<N> and _Float<N>X
	variants like DEF_EXT_LIB_BUILTINs where both <foo> and
	__builtin_<foo> are implicitly declared.  If
	-fimplicit-math-floatn is off, treat the variants like
	DEF_GCC_BUILTIN where only the __builtin_<foo> is implicitly
	declared.
	(DEF_FLOATFN_BUILTINS): Likewise.
	(BUILT_IN_COPYSIGN _Float<N> and _Float<N>X variants) Replace
	DEF_GCC_FLOATN_NX_BUILTINS with DEF_FLOATFN_BUILTINS.  Add fma,
	fmax, fmin, sqrt versions.  Do not replace huge_val, inf, and
	nans.
	(BUILT_IN_FABS _Float<N> and _Float<N>X variants): Likewise.
	(BUILT_IN_FMA _Float<N> and _Float<N>X variants): Likewise.
	(BUILT_IN_FMAX _Float<N> and _Float<N>X variants): Likewise.
	(BUILT_IN_FMIN _Float<N> and _Float<N>X variants): Likewise.
	(BUILT_IN_NAN _Float<N> and _Float<N>X variants): Likewise.
	(BUILT_IN_SQRT _Float<N> and _Float<N>X variants): Likewise.
	* builtin-types.def (BT_FN_FLOAT16_FLOAT16_FLOAT16_FLOAT16): New
	function signatures for fma _Float<N> and _Float<N>X variants.
	(BT_FN_FLOAT32_FLOAT32_FLOAT32_FLOAT32): Likewise.
	(BT_FN_FLOAT64_FLOAT64_FLOAT64_FLOAT64): Likewise.
	(BT_FN_FLOAT128_FLOAT128_FLOAT128_FLOAT128): Likewise.
	(BT_FN_FLOAT32X_FLOAT32X_FLOAT32X_FLOAT32X): Likewise.
	(BT_FN_FLOAT64X_FLOAT64X_FLOAT64X_FLOAT64X): Likewise.
	(BT_FN_FLOAT128X_FLOAT128X_FLOAT128X_FLOAT128X): Likewise.
	* gencfn-macros.c (print_case_cfn): Add support for math functions
	that have _Float<N> and _Float<N>X variants.
	(print_define_operator_list): Likewise.
	(fltfn_suffixes): Likewise.
	(main): Likewise.
	* internal-fn.def (DEF_INTERNAL_FLT_FLOATN_FN): New helper macro
	for math functions that have _Float<N> and _Float<N>X variants.
	(SQRT): Add support for sqrt, copysign, fmin and fmax _Float<N>
	and _Float<N>X variants.
	(COPYSIGN): Likewise.
	(FMIN): Likewise.
	(FMAX): Likewise.
	* fold-const.c (tree_call_nonnegative_warnv_p): Add support for
	copysign, fma, fmax, fmin, and sqrt _Float<N> and _Float<N>X
	variants.
	(integer_valued_read_call_p): Likewise.
	* fold-const-call.c (fold_const_call_ss): Likewise.
	(fold_const_call_sss): Add support for copysign, fmin, and fmax
	_Float<N> and _Float<N>X variants.
	(fold_const_call_ssss): Add support for fma _Float<N> and
	_Float<N>X variants.
	* gimple-ssa-backprop.c (backprop::process_builtin_call_use): Add
	support for copysign and fma _Float<N> and _Float<N>X variants.
	(backprop::process_builtin_call_use): Likewise.
	* tree-call-cdce.c (can_test_argument_range); Add support for
	sqrt _Float<N> and _Float<N>X variants.
	(edom_only_function): Likewise.
	(get_no_error_domain): Likewise.
	* tree-ssa-math-opts.c (internal_fn_reciprocal): Likewise.
	* tree-ssa-reassoc.c (attempt_builtin_copysign): Add support for
	copysign _Float<N> and _Float<N>X variants.
	* config/rs6000/rs6000-builtin.def (SQRTF128): Delete, this is now
	handled by machine independent code.
	(FMAF128): Likewise.
	* doc/invoke.texi (C Dialect Options): Document
	-fimplicit-math-floatn.

[gcc/c]
2017-10-24  Michael Meissner  <meissner@linux.vnet.ibm.com>

	* c-decl.c (header_for_builtin_fn): Add support for copysign, fma,
	fmax, fmin, and sqrt _Float<N> and _Float<N>X variants.

[gcc/c-family]
2017-10-24  Michael Meissner  <meissner@linux.vnet.ibm.com>

	* c-cppbuiltin.c (mode_has_fma): Add support for PowerPC KFmode.
	(c_cpp_builtins): If -fimplicit-math-floatn and the machine has a
	fast fma _Float<N> and _Float<N>X variant, define __FP_FAST_FMA<N>
	and __FP_FAST_FMA<N>X.
	* c.opt (-fimplicit-math-floatn): New switch to enable making
	_Float<N> and _Float<N>X variant math functions implicitly
	declared without the __builtin_ prefix.

[gcc/testsuite]
2017-10-24  Michael Meissner  <meissner@linux.vnet.ibm.com>

	* gcc.target/powerpc/float128-hw.c: Add support for all 4 FMA
	variants.  Check conversion from __float128 to float uses truncate
	with round to odd.  Use {\m...\M} in the tests.
	* gcc.target/powerpc/float128-hw2.c: New test for
	-fimplicit-math-floatn.
	* gcc.target/powerpc/float128-hw3.c: New test for
	-fno-implicit-math-floatn.
	* gcc.target/powerpc/float128-fma2.c: Delete, test is no longer
	valid.
	* gcc.target/powerpc/float128-sqrt2.c: Likewise.

-- 
Michael Meissner, IBM
IBM, M/S 2506R, 550 King Street, Littleton, MA 01460-6245, USA
email: meissner@linux.vnet.ibm.com, phone: +1 (978) 899-4797

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