public inbox for gcc-patches@gcc.gnu.org
 help / color / mirror / Atom feed
* [PATCH] Add targetm.libm_function_max_error
@ 2023-04-26 14:21 Jakub Jelinek
  2023-04-26 16:10 ` Michael Matz
  2023-04-27  7:18 ` Richard Biener
  0 siblings, 2 replies; 11+ messages in thread
From: Jakub Jelinek @ 2023-04-26 14:21 UTC (permalink / raw)
  To: Aldy Hernandez, Richard Biener, Joseph S. Myers
  Cc: gcc-patches, Siddhesh Poyarekar, Andrew MacLeod

[-- Attachment #1: Type: text/plain, Size: 21563 bytes --]

Hi!

As has been discussed before, the following patch adds target hook
for math library function maximum errors measured in ulps.
The default is to return ~0U which is a magic maximum value which means
nothing is known about precision of the match function.

The first argument is unsigned int because enum combined_fn isn't available
everywhere where target hooks are included but is expected to be given
the enum combined_fn value, although it should be used solely to find out
which kind of match function (say sin vs. cos vs. sqrt vs. exp10) rather
than its variant (f suffix, no suffix, l suffix, f128 suffix, ...), for
which there is the machine_mode argument.
The last argument is a bool, if it is false, the function should return
maximum known error in ulps for a given function (taking -frounding-math
into account if enabled), with 0.5ulps being represented as 0.
If it is true, it is about whether the function can return values outside of
an intrinsic finite range for the function and by how many ulps.
E.g. sin/cos should return result in [-1.,1], if the function is expected
to never return values outside of that finite interval, the hook should
return 0.  Similarly for sqrt such range is [-0.,+Inf].

The patch implements it for glibc only so far, I hope other maintainers
can submit details for Solaris, musl, perhaps BSDs, etc.
For glibc I've gathered data from:
1) https://www.gnu.org/software/libc/manual/html_node/Errors-in-Math-Functions.html
   as latest published glibc data
2) https://www.gnu.org/software/libc/manual/2.22/html_node/Errors-in-Math-Functions.html
   as a few years old glibc data
3) using attached libc-ulps.sh script from glibc git
4) using attached ulp-tester.c (how to invoke in file comment; tested
   both x86_64, ppc64, ppc64le 50M pseudo-random values in all 4 rounding
   modes, plus on x86_64 float/double sin/cos using libmvec - see
   attached libmvec-wrapper.c as well)
5) using attached boundary-tester.c to test for whether sin/cos/sqrt return
   values outside of the intrinsic ranges for those functions (again,
   tested on x86_64, ppc64, ppc64le plus on x86_64 using libmvec as well;
   libmvec with non-default rounding modes is pretty much random number
   generator it seems)

The data is added to various hooks, the generic and generic glibc versions
being in targhooks.c so that the various targets can easily override it.
The intent is that the generic glibc version handles most of the stuff
and specific target arch overrides handle the outliers or special cases.
The patch has special case for x86_64 when __FAST_MATH__ is defined (as
one can use in that case either libm or libmvec and we don't know which
one will be used; so it uses maximum of what libm provides and libmvec),
rs6000 (had to add one because cosf has 3ulps on ppc* rather than 1-2ulps
on most other targets; MODE_COMPOSITE_P could be in theory handled in the
generic code too, but as we have rs6000-linux specific function, it can be
done just there), arc-linux (because DFmode sin has 7ulps there compared to
1ulps on other targets, both in default rounding mode and in others) and
or1k-linux (while DFmode sin has 1ulps there for default rounding mode,
for other rounding modes it has up to 7ulps).
Now, for -frounding-math I'm trying to add a few ulps more because I expect
it to be much less tested, except that for boundary_p I try to use
the numbers I got from the 5) tester.

So far built on x86_64-linux, powerpc64le-linux, arc-linux and or1k-linux,
ok for trunk if it passes bootstrap/regtest?

2023-04-26  Jakub Jelinek  <jakub@redhat.com>

	* target.def (libm_function_max_error): New target hook.
	* doc/tm.texi.in (TARGET_LIBM_FUNCTION_MAX_ERROR): Add.
	* doc/tm.texi: Regenerated.
	* targhooks.h (default_libm_function_max_error,
	glibc_linux_libm_function_max_error): Declare.
	* targhooks.cc: Include case-cfn-macros.h.
	(default_libm_function_max_error,
	glibc_linux_libm_function_max_error): New functions.
	* config/linux.h (TARGET_LIBM_FUNCTION_MAX_ERROR): Redefine.
	* config/linux-protos.h (linux_libm_function_max_error): Declare.
	* config/linux.cc: Include target.h and targhooks.h.
	(linux_libm_function_max_error): New function.
	* config/arc/arc.cc: Include targhooks.h and case-cfn-macros.h.
	(arc_libm_function_max_error): New function.
	(TARGET_LIBM_FUNCTION_MAX_ERROR): Redefine.
	* config/i386/i386.cc (ix86_libc_has_fast_function): Formatting fix.
	(ix86_libm_function_max_error): New function.
	(TARGET_LIBM_FUNCTION_MAX_ERROR): Redefine.
	* config/rs6000/rs6000-protos.h
	(rs6000_linux_libm_function_max_error): Declare.
	* config/rs6000/rs6000-linux.cc: Include target.h, targhooks.h, tree.h
	and case-cfn-macros.h.
	(rs6000_linux_libm_function_max_error): New function.
	* config/rs6000/linux.h (TARGET_LIBM_FUNCTION_MAX_ERROR): Redefine.
	* config/rs6000/linux64.h (TARGET_LIBM_FUNCTION_MAX_ERROR): Redefine.
	* config/or1k/or1k.cc: Include targhooks.h and case-cfn-macros.h.
	(or1k_libm_function_max_error): New function.
	(TARGET_LIBM_FUNCTION_MAX_ERROR): Redefine.

--- gcc/target.def.jj	2023-04-26 08:32:38.118070594 +0200
+++ gcc/target.def	2023-04-26 08:33:01.752718215 +0200
@@ -2670,6 +2670,23 @@ DEFHOOK
  bool, (int fcode),
  default_libc_has_fast_function)
 
+DEFHOOK
+(libm_function_max_error,
+ "This hook determines expected maximum errors for math functions measured\n\
+in ulps (units of the last place).  0 means 0.5ulps precision (correctly\n\
+rounded).  ~0U means unknown errors.  The @code{combined_fn} @var{cfn}\n\
+argument should identify just which math built-in function it is rather than\n\
+its variant, @var{mode} the variant in terms of floating-point machine mode.\n\
+The hook should also take into account @code{flag_rounding_math} whether it\n\
+is maximum error just in default rounding mode, or in all possible rounding\n\
+modes.  @var{boundary_p} is @code{true} for maximum errors on intrinsic math\n\
+boundaries of functions rather than errors inside of the usual result ranges\n\
+of the functions.  E.g.@ the sin/cos function finite result is in between\n\
+-1.0 and 1.0 inclusive, with @var{boundary_p} true the function returns how\n\
+many ulps below or above those boundaries result could be.",
+ unsigned, (unsigned cfn, machine_mode mode, bool boundary_p),
+ default_libm_function_max_error)
+
 /* True if new jumps cannot be created, to replace existing ones or
    not, at the current point in the compilation.  */
 DEFHOOK
--- gcc/doc/tm.texi.in.jj	2023-04-26 08:32:38.116070623 +0200
+++ gcc/doc/tm.texi.in	2023-04-26 08:33:01.751718229 +0200
@@ -4004,6 +4004,8 @@ macro, a reasonable default is used.
 
 @hook TARGET_LIBC_HAS_FAST_FUNCTION
 
+@hook TARGET_LIBM_FUNCTION_MAX_ERROR
+
 @defmac NEXT_OBJC_RUNTIME
 Set this macro to 1 to use the "NeXT" Objective-C message sending conventions
 by default.  This calling convention involves passing the object, the selector
--- gcc/doc/tm.texi.jj	2023-04-26 08:32:38.090071011 +0200
+++ gcc/doc/tm.texi	2023-04-26 08:33:01.750718244 +0200
@@ -5760,6 +5760,21 @@ This hook determines whether a function
 @code{(enum function_class)}@var{fcode} has a fast implementation.
 @end deftypefn
 
+@deftypefn {Target Hook} unsigned TARGET_LIBM_FUNCTION_MAX_ERROR (unsigned @var{cfn}, machine_mode @var{mode}, bool @var{boundary_p})
+This hook determines expected maximum errors for math functions measured
+in ulps (units of the last place).  0 means 0.5ulps precision (correctly
+rounded).  ~0U means unknown errors.  The @code{combined_fn} @var{cfn}
+argument should identify just which math built-in function it is rather than
+its variant, @var{mode} the variant in terms of floating-point machine mode.
+The hook should also take into account @code{flag_rounding_math} whether it
+is maximum error just in default rounding mode, or in all possible rounding
+modes.  @var{boundary_p} is @code{true} for maximum errors on intrinsic math
+boundaries of functions rather than errors inside of the usual result ranges
+of the functions.  E.g.@ the sin/cos function finite result is in between
+-1.0 and 1.0 inclusive, with @var{boundary_p} true the function returns how
+many ulps below or above those boundaries result could be.
+@end deftypefn
+
 @defmac NEXT_OBJC_RUNTIME
 Set this macro to 1 to use the "NeXT" Objective-C message sending conventions
 by default.  This calling convention involves passing the object, the selector
--- gcc/targhooks.h.jj	2023-04-26 08:32:38.118070594 +0200
+++ gcc/targhooks.h	2023-04-26 08:33:01.748718274 +0200
@@ -219,6 +219,9 @@ extern bool default_libc_has_fast_functi
 extern bool no_c99_libc_has_function (enum function_class, tree);
 extern bool gnu_libc_has_function (enum function_class, tree);
 extern bool bsd_libc_has_function (enum function_class, tree);
+extern unsigned default_libm_function_max_error (unsigned, machine_mode, bool);
+extern unsigned glibc_linux_libm_function_max_error (unsigned, machine_mode,
+						     bool);
 
 extern tree default_builtin_tm_load_store (tree);
 
--- gcc/targhooks.cc.jj	2023-04-26 08:32:38.118070594 +0200
+++ gcc/targhooks.cc	2023-04-26 13:21:26.776752299 +0200
@@ -94,6 +94,7 @@ along with GCC; see the file COPYING3.
 #include "cfgloop.h"
 #include "tree-vectorizer.h"
 #include "options.h"
+#include "case-cfn-macros.h"
 
 bool
 default_legitimate_address_p (machine_mode mode ATTRIBUTE_UNUSED,
@@ -1903,6 +1904,70 @@ bsd_libc_has_function (enum function_cla
   return false;
 }
 
+unsigned
+default_libm_function_max_error (unsigned, machine_mode, bool)
+{
+  return ~0U;
+}
+
+unsigned
+glibc_linux_libm_function_max_error (unsigned cfn, machine_mode mode,
+				     bool boundary_p)
+{
+  /* Let's use
+     https://www.gnu.org/software/libc/manual/2.22/html_node/Errors-in-Math-Functions.html
+     https://www.gnu.org/software/libc/manual/html_node/Errors-in-Math-Functions.html
+     with usual values recorded here and significant outliers handled in
+     target CPU specific overriders.  The tables only record default
+     rounding to nearest, for -frounding-math let's add some extra ulps.
+     For boundary_p values (say finite results outside of [-1.,1.] for
+     sin/cos, or [-0.,+Inf] for sqrt etc. let's use custom random testers.  */
+  int rnd = flag_rounding_math ? 4 : 0;
+  bool sf = (REAL_MODE_FORMAT (mode) == &ieee_single_format
+	     || REAL_MODE_FORMAT (mode) == &mips_single_format
+	     || REAL_MODE_FORMAT (mode) == &motorola_single_format);
+  bool df = (REAL_MODE_FORMAT (mode) == &ieee_double_format
+	     || REAL_MODE_FORMAT (mode) == &mips_double_format
+	     || REAL_MODE_FORMAT (mode) == &motorola_double_format);
+  bool xf = (REAL_MODE_FORMAT (mode) == &ieee_extended_intel_96_format
+	     || REAL_MODE_FORMAT (mode) == &ieee_extended_intel_128_format
+	     || REAL_MODE_FORMAT (mode) == &ieee_extended_motorola_format);
+  bool tf = (REAL_MODE_FORMAT (mode) == &ieee_quad_format
+	     || REAL_MODE_FORMAT (mode) == &mips_quad_format);
+
+  switch (cfn)
+    {
+    CASE_CFN_SQRT_ALL:
+      if (boundary_p)
+	/* https://gcc.gnu.org/pipermail/gcc-patches/2023-April/616595.html */
+	return 0;
+      if (sf || df || xf || tf)
+	return 0 + rnd;
+      break;
+    CASE_CFN_COS_ALL:
+      /* cos is generally errors like sin, but far more arches have 2ulps
+	 for double.  */
+      if (!boundary_p && df)
+	return 2 + rnd;
+      gcc_fallthrough ();
+    CASE_CFN_SIN_ALL:
+      if (boundary_p)
+	/* According to
+	   https://sourceware.org/pipermail/gcc-patches/2023-April/616315.html
+	   seems default rounding sin/cos stay strictly in [-1.,1.] range,
+	   with rounding to infinity it can be 1ulp larger/smaller.  */
+	return flag_rounding_math ? 1 : 0;
+      if (sf || df)
+	return 1 + rnd;
+      if (xf || tf)
+	return 2 + rnd;
+      break;
+    default:
+      break;
+    }
+
+  return default_libm_function_max_error (cfn, mode, boundary_p);
+}
 
 tree
 default_builtin_tm_load_store (tree ARG_UNUSED (type))
--- gcc/config/linux.h.jj	2023-04-26 08:32:38.055071533 +0200
+++ gcc/config/linux.h	2023-04-26 08:33:01.747718289 +0200
@@ -212,4 +212,7 @@ see the files COPYING3 and COPYING.RUNTI
 # undef TARGET_LIBC_HAS_FUNCTION
 # define TARGET_LIBC_HAS_FUNCTION linux_libc_has_function
 
+# undef TARGET_LIBM_FUNCTION_MAX_ERROR
+# define TARGET_LIBM_FUNCTION_MAX_ERROR linux_libm_function_max_error
+
 #endif
--- gcc/config/linux-protos.h.jj	2023-04-26 08:32:38.055071533 +0200
+++ gcc/config/linux-protos.h	2023-04-26 08:33:01.747718289 +0200
@@ -20,3 +20,5 @@ along with GCC; see the file COPYING3.
 extern bool linux_has_ifunc_p (void);
 
 extern bool linux_libc_has_function (enum function_class fn_class, tree);
+
+extern unsigned linux_libm_function_max_error (unsigned, machine_mode, bool);
--- gcc/config/linux.cc.jj	2023-04-26 08:32:38.055071533 +0200
+++ gcc/config/linux.cc	2023-04-26 08:33:01.747718289 +0200
@@ -23,6 +23,8 @@ along with GCC; see the file COPYING3.
 #include "tm.h"
 #include "tree.h"
 #include "linux-protos.h"
+#include "target.h"
+#include "targhooks.h"
 
 bool
 linux_libc_has_function (enum function_class fn_class,
@@ -38,3 +40,12 @@ linux_libc_has_function (enum function_c
 
   return false;
 }
+
+unsigned
+linux_libm_function_max_error (unsigned cfn, machine_mode mode,
+			       bool boundary_p)
+{
+  if (OPTION_GLIBC)
+    return glibc_linux_libm_function_max_error (cfn, mode, boundary_p);
+  return default_libm_function_max_error (cfn, mode, boundary_p);
+}
--- gcc/config/arc/arc.cc.jj	2023-01-02 09:33:00.219738627 +0100
+++ gcc/config/arc/arc.cc	2023-04-26 14:59:20.440175058 +0200
@@ -68,6 +68,8 @@ along with GCC; see the file COPYING3.
 #include "alias.h"
 #include "opts.h"
 #include "hw-doloop.h"
+#include "targhooks.h"
+#include "case-cfn-macros.h"
 
 /* Which cpu we're compiling for (ARC600, ARC601, ARC700).  */
 static char arc_cpu_name[10] = "";
@@ -11808,6 +11810,35 @@ arc_insn_cost (rtx_insn *insn, bool spee
   return cost;
 }
 
+static unsigned
+arc_libm_function_max_error (unsigned cfn, machine_mode mode,
+			     bool boundary_p)
+{
+#ifdef OPTION_GLIBC
+  bool glibc_p = OPTION_GLIBC;
+#else
+  bool glibc_p = false;
+#endif
+  if (glibc_p)
+    {
+      int rnd = flag_rounding_math ? 4 : 0;
+      switch (cfn)
+	{
+	CASE_CFN_SIN_ALL:
+	  if (!boundary_p && mode == DFmode)
+	    return 7 + rnd;
+	  break;
+	CASE_CFN_COS_ALL:
+	  if (!boundary_p && mode == DFmode)
+	    return 4 + rnd;
+	default:
+	  break;
+	}
+      return glibc_linux_libm_function_max_error (cfn, mode, boundary_p);
+    }
+  return default_libm_function_max_error (cfn, mode, boundary_p);
+}
+
 #undef TARGET_USE_ANCHORS_FOR_SYMBOL_P
 #define TARGET_USE_ANCHORS_FOR_SYMBOL_P arc_use_anchors_for_symbol_p
 
@@ -11832,6 +11863,9 @@ arc_insn_cost (rtx_insn *insn, bool spee
 #undef  TARGET_INSN_COST
 #define TARGET_INSN_COST arc_insn_cost
 
+#undef  TARGET_LIBM_FUNCTION_MAX_ERROR
+#define TARGET_LIBM_FUNCTION_MAX_ERROR arc_libm_function_max_error
+
 struct gcc_target targetm = TARGET_INITIALIZER;
 
 #include "gt-arc.h"
--- gcc/config/i386/i386.cc.jj	2023-04-22 10:23:40.539613820 +0200
+++ gcc/config/i386/i386.cc	2023-04-26 13:37:56.273154402 +0200
@@ -25250,7 +25250,8 @@ ix86_libgcc_floating_mode_supported_p
 #undef TARGET_MEMTAG_TAG_SIZE
 #define TARGET_MEMTAG_TAG_SIZE ix86_memtag_tag_size
 
-static bool ix86_libc_has_fast_function (int fcode ATTRIBUTE_UNUSED)
+static bool
+ix86_libc_has_fast_function (int fcode ATTRIBUTE_UNUSED)
 {
 #ifdef OPTION_GLIBC
   if (OPTION_GLIBC)
@@ -25265,6 +25266,56 @@ static bool ix86_libc_has_fast_function
 #undef TARGET_LIBC_HAS_FAST_FUNCTION
 #define TARGET_LIBC_HAS_FAST_FUNCTION ix86_libc_has_fast_function
 
+static unsigned
+ix86_libm_function_max_error (unsigned cfn, machine_mode mode,
+			      bool boundary_p)
+{
+#ifdef OPTION_GLIBC
+  bool glibc_p = OPTION_GLIBC;
+#else
+  bool glibc_p = false;
+#endif
+  if (glibc_p)
+    {
+      /* If __FAST_MATH__ is defined, glibc provides libmvec.  */
+      unsigned int libmvec_ret = 0;
+      if (!flag_trapping_math
+	  && flag_unsafe_math_optimizations
+	  && flag_finite_math_only
+	  && !flag_signed_zeros
+	  && !flag_errno_math)
+	switch (cfn)
+	  {
+	  CASE_CFN_COS_ALL:
+	  CASE_CFN_SIN_ALL:
+	    if (!boundary_p)
+	      {
+		/* With non-default rounding modes, libmvec provides
+		   complete garbage in results.  E.g.
+		   _ZGVcN8v_sinf for 1.40129846e-45f in FE_UPWARD
+		   returns 0.00333309174f rather than 1.40129846e-45f.  */
+		if (flag_rounding_math)
+		  return ~0U;
+		/* https://www.gnu.org/software/libc/manual/html_node/Errors-in-Math-Functions.html
+		   claims libmvec maximum error is 4ulps.
+		   My own random testing indicates 2ulps for SFmode and
+		   0.5ulps for DFmode, but let's go with the 4ulps.  */
+		libmvec_ret = 4;
+	      }
+	    break;
+	  default:
+	    break;
+	  }
+      unsigned int ret = glibc_linux_libm_function_max_error (cfn, mode,
+							      boundary_p);
+      return MAX (ret, libmvec_ret);
+    }
+  return default_libm_function_max_error (cfn, mode, boundary_p);
+}
+
+#undef TARGET_LIBM_FUNCTION_MAX_ERROR
+#define TARGET_LIBM_FUNCTION_MAX_ERROR ix86_libm_function_max_error
+
 #if CHECKING_P
 #undef TARGET_RUN_TARGET_SELFTESTS
 #define TARGET_RUN_TARGET_SELFTESTS selftest::ix86_run_selftests
--- gcc/config/rs6000/rs6000-protos.h.jj	2023-04-26 08:32:38.072071280 +0200
+++ gcc/config/rs6000/rs6000-protos.h	2023-04-26 08:33:01.748718274 +0200
@@ -334,6 +334,8 @@ extern unsigned char rs6000_class_max_nr
 extern unsigned char rs6000_hard_regno_nregs[][FIRST_PSEUDO_REGISTER];
 
 extern bool rs6000_linux_float_exceptions_rounding_supported_p (void);
+extern unsigned rs6000_linux_libm_function_max_error (unsigned, machine_mode,
+						      bool);
 
 /* Pass management.  */
 namespace gcc { class context; }
--- gcc/config/rs6000/rs6000-linux.cc.jj	2023-04-26 08:32:38.055071533 +0200
+++ gcc/config/rs6000/rs6000-linux.cc	2023-04-26 13:30:57.231335122 +0200
@@ -23,6 +23,10 @@ along with GCC; see the file COPYING3.
 #include "system.h"
 #include "coretypes.h"
 #include "tm.h"
+#include "target.h"
+#include "targhooks.h"
+#include "tree.h"
+#include "case-cfn-macros.h"
 
 /* Implement TARGET_FLOAT_EXCEPTIONS_ROUNDING_SUPPORTED_P.  */
 
@@ -36,3 +40,36 @@ rs6000_linux_float_exceptions_rounding_s
   else
     return TARGET_HARD_FLOAT;
 }
+
+/* Implement TARGET_LIBM_FUNCTION_MAX_ERROR.  */
+
+unsigned
+rs6000_linux_libm_function_max_error (unsigned cfn, machine_mode mode,
+				      bool boundary_p)
+{
+  if (OPTION_GLIBC)
+    {
+      int rnd = flag_rounding_math ? 4 : 0;
+      switch (cfn)
+	{
+	CASE_CFN_SQRT_ALL:
+	  if (!boundary_p && MODE_COMPOSITE_P (mode))
+	    return 1 + rnd;
+	  break;
+	CASE_CFN_COS_ALL:
+	  if (!boundary_p && mode == SFmode)
+	    return 3 + rnd;
+	  if (!boundary_p && MODE_COMPOSITE_P (mode))
+	    return 4 + rnd;
+	  break;
+	CASE_CFN_SIN_ALL:
+	  if (!boundary_p && MODE_COMPOSITE_P (mode))
+	    return 1 + rnd;
+	  break;
+	default:
+	  break;
+	}
+      return glibc_linux_libm_function_max_error (cfn, mode, boundary_p);
+    }
+  return default_libm_function_max_error (cfn, mode, boundary_p);
+}
--- gcc/config/rs6000/linux.h.jj	2023-01-16 11:52:16.022734963 +0100
+++ gcc/config/rs6000/linux.h	2023-04-26 15:57:23.636976113 +0200
@@ -50,6 +50,9 @@
 #undef TARGET_LIBC_HAS_FUNCTION
 #define TARGET_LIBC_HAS_FUNCTION linux_libc_has_function
 
+#undef TARGET_LIBM_FUNCTION_MAX_ERROR
+#define TARGET_LIBM_FUNCTION_MAX_ERROR rs6000_linux_libm_function_max_error
+
 #undef  TARGET_OS_CPP_BUILTINS
 #define TARGET_OS_CPP_BUILTINS()			\
   do							\
--- gcc/config/rs6000/linux64.h.jj	2023-01-16 11:52:16.022734963 +0100
+++ gcc/config/rs6000/linux64.h	2023-04-26 15:57:32.019853082 +0200
@@ -288,6 +288,9 @@ extern int dot_symbols;
 #undef TARGET_LIBC_HAS_FUNCTION
 #define TARGET_LIBC_HAS_FUNCTION linux_libc_has_function
 
+#undef TARGET_LIBM_FUNCTION_MAX_ERROR
+#define TARGET_LIBM_FUNCTION_MAX_ERROR rs6000_linux_libm_function_max_error
+
 #undef  TARGET_OS_CPP_BUILTINS
 #define TARGET_OS_CPP_BUILTINS()			\
   do							\
--- gcc/config/or1k/or1k.cc.jj	2023-01-16 11:52:16.004735229 +0100
+++ gcc/config/or1k/or1k.cc	2023-04-26 15:02:23.434480484 +0200
@@ -44,6 +44,8 @@
 #include "explow.h"
 #include "cfgrtl.h"
 #include "alias.h"
+#include "targhooks.h"
+#include "case-cfn-macros.h"
 
 /* These 4 are needed to allow using satisfies_constraint_J.  */
 #include "insn-config.h"
@@ -2191,6 +2193,31 @@ or1k_output_mi_thunk (FILE *file, tree t
   epilogue_completed = 0;
 }
 
+static unsigned
+or1k_libm_function_max_error (unsigned cfn, machine_mode mode,
+			      bool boundary_p)
+{
+#ifdef OPTION_GLIBC
+  bool glibc_p = OPTION_GLIBC;
+#else
+  bool glibc_p = false;
+#endif
+  if (glibc_p)
+    {
+      switch (cfn)
+	{
+	CASE_CFN_SIN_ALL:
+	  if (!boundary_p && mode == DFmode && flag_rounding_math)
+	    return 7;
+	  break;
+	default:
+	  break;
+	}
+      return glibc_linux_libm_function_max_error (cfn, mode, boundary_p);
+    }
+  return default_libm_function_max_error (cfn, mode, boundary_p);
+}
+
 #undef  TARGET_ASM_OUTPUT_MI_THUNK
 #define TARGET_ASM_OUTPUT_MI_THUNK or1k_output_mi_thunk
 #undef  TARGET_ASM_CAN_OUTPUT_MI_THUNK
@@ -2214,6 +2241,9 @@ or1k_output_mi_thunk (FILE *file, tree t
 #undef  TARGET_HAVE_SPECULATION_SAFE_VALUE
 #define TARGET_HAVE_SPECULATION_SAFE_VALUE speculation_safe_value_not_needed
 
+#undef  TARGET_LIBM_FUNCTION_MAX_ERROR
+#define TARGET_LIBM_FUNCTION_MAX_ERROR or1k_libm_function_max_error
+
 /* Calling Conventions.  */
 #undef  TARGET_FUNCTION_VALUE
 #define TARGET_FUNCTION_VALUE or1k_function_value

	Jakub

[-- Attachment #2: libc-ulps.sh --]
[-- Type: application/x-sh, Size: 500 bytes --]

[-- Attachment #3: ulp-tester.c --]
[-- Type: text/plain, Size: 7285 bytes --]

/* gcc -g -O2 -o ulp-tester ulp-tester.c -lmpfr -lm
   for i in tonearest upward downward towardzero; do ( ./ulp-tester 50000000 $i > /tmp/$i 2>&1 & ); done
   gcc -g -O2 -DLIBMVEC_TEST -o ulp-tester2 ulp-tester.c ./libmvec-wrapper.so -lmpfr -lm
   for j in b c d e; do for i in tonearest upward downward towardzero; do ( LIBMVEC_LEVEL=$j ./ulp-tester2 50000000 $i > /tmp/${i}-${j} 2>&1 & ); done; done
 */

#ifdef THIS_TYPE
static THIS_TYPE
THIS_FUNC (ulp) (THIS_TYPE val)
{
  if (__builtin_isnormal (val))
    return THIS_FUNC (ldexp) (THIS_LIT (1.0), THIS_FUNC (ilogb) (val) - THIS_MANT_DIG + 1);
  else
    return THIS_FUNC (ldexp) (THIS_LIT (1.0), THIS_MIN_EXP - THIS_MANT_DIG);
}

static void
THIS_FUNC (test) (THIS_TYPE (*fn) (THIS_TYPE),
		  int (*mpfr_fn) (mpfr_ptr, mpfr_srcptr, mpfr_rnd_t),
		  const char *name,
		  unsigned long count)
{
  char buf1[256], buf2[256], buf3[256];
  mpfr_set_default_prec (THIS_MANT_DIG);
  mpfr_t v;
  mpfr_init2 (v, THIS_MANT_DIG);
  THIS_TYPE max_ulp = THIS_LIT (0.0);
  volatile THIS_TYPE val = THIS_LIT (0.0);
  int m = 0;
  for (unsigned long i = 0; i < count; ++i)
    {
      if (m == 0)
	m = 1;
      else if (m <= 10)
	{
	  val = THIS_FUNC (nextafter) (val, THIS_LIT (1.0));
	  if ((m == 1 && val == THIS_MIN) || m > 1)
	    ++m;
	}
      else if (m == 11)
	{
	  val = THIS_LIT (1.0);
	  for (int j = 0; j < 10; j++)
	    val = THIS_FUNC (nextafter) (val, THIS_LIT (0.0));
	  ++m;
	}
      else if (m <= 32)
	{
	  val = THIS_FUNC (nextafter) (val, THIS_LIT (1.0));
	  ++m;
	}
      else if (m == 33)
	{
	  val = THIS_MAX;
	  for (int j = 0; j < 10; j++)
	    val = THIS_FUNC (nextafter) (val, THIS_LIT (0.0));
	  ++m;
	}
      else if (m <= 45)
	{
	  val = THIS_FUNC (nextafter) (val, THIS_LIT (1.0));
	  ++m;
	}
      else
	val = THIS_FUNC (get_rand) ();
      if (__builtin_isnan (val))
	continue;
      THIS_TYPE given = fn (val);
      THIS_MPFR_SET (v, val, MPFR_RNDN);
      mpfr_fn (v, v, MPFR_RNDN);
      THIS_TYPE expected = THIS_MPFR_GET (v, MPFR_RNDN);
      if ((!__builtin_isnan (given)) != (!__builtin_isnan (expected))
	  || __builtin_isinf (given) != __builtin_isinf (expected))
	{
	  THIS_SNPRINTF (buf1, val);
	  THIS_SNPRINTF (buf2, given);
	  THIS_SNPRINTF (buf3, expected);
	  printf ("%s (%s) = %s rather than %s\n", name, buf1, buf2, buf3);
	}
      else if (!__builtin_isnan (given) && !__builtin_isinf (given))
	{
	  THIS_TYPE this_ulp
	    = THIS_FUNC (fabs) (given - expected) / THIS_FUNC (ulp) (expected);
	  if (this_ulp > max_ulp)
	    max_ulp = this_ulp;
	}
    }
  printf ("%s max error %.1fulp\n", name, (float) max_ulp);
}

#undef THIS_TYPE
#undef THIS_LIT
#undef THIS_FUNC
#undef THIS_MIN_EXP
#undef THIS_MANT_DIG
#undef THIS_MIN
#undef THIS_MAX
#undef THIS_MPFR_SET
#undef THIS_MPFR_GET
#undef THIS_SNPRINTF
#else
#define _GNU_SOURCE 1
#include <stdio.h>
#include <stdint.h>
#include <stdlib.h>
#include <string.h>
#include <math.h>
#include <fenv.h>

#if defined(__FLT128_DIG__) && defined(__GLIBC_PREREQ)
#if __GLIBC_PREREQ (2, 26)
#define TEST_FLT128
#define MPFR_WANT_FLOAT128
#endif
#endif

#include <gmp.h>
#include <mpfr.h>

static long rand_n;
static int rand_c;

static uint32_t
get_rand32 (void)
{
  uint32_t ret = 0;
  if (rand_c == 0)
    {
      ret = random () & 0x7fffffff;
      rand_c = 31;
    }
  else
    ret = rand_n & (((uint32_t) 1 << rand_c) - 1);
  ret <<= (32 - rand_c);
  rand_n = random ();
  ret |= rand_n & (((uint32_t) 1 << (32 - rand_c)) - 1);
  rand_n >>= (32 - rand_c);
  rand_c = 31 - (32 - rand_c);
  return ret;
}

static uint64_t
get_rand64 (void)
{
  return (((uint64_t) get_rand32 ()) << 32) | get_rand32 ();
}

static float
get_randf (void)
{
  uint32_t i = get_rand32 ();
  float f;
  memcpy (&f, &i, sizeof (f));
  return f;
}

static double
get_rand (void)
{
  uint64_t i = get_rand64 ();
  double d;
  memcpy (&d, &i, sizeof (d));
  return d;
}

static long double
get_randl (void)
{
  long double ld;
  uint64_t i = get_rand64 ();
  memcpy (&ld, &i, sizeof (i));
  if (sizeof (long double) == 12)
    {
      uint32_t j = get_rand32 ();
      memcpy ((char *) &ld + 8, &j, sizeof (j));
    }
  else if (sizeof (long double) == 16)
    {
      i = get_rand64 ();
      memcpy ((char *) &ld + 8, &i, sizeof (i));
    }
  return ld;
}

#ifdef TEST_FLT128
static long double
get_randf128 (void)
{
  _Float128 f128;
  uint64_t i = get_rand64 ();
  memcpy (&f128, &i, sizeof (i));
  i = get_rand64 ();
  memcpy ((char *) &f128 + 8, &i, sizeof (i));
  return f128;
}
#endif

#define THIS_TYPE float
#define THIS_LIT(v) v##f
#define THIS_FUNC(v) v##f
#define THIS_MIN_EXP __FLT_MIN_EXP__
#define THIS_MANT_DIG __FLT_MANT_DIG__
#define THIS_MIN __FLT_MIN__
#define THIS_MAX __FLT_MAX__
#define THIS_MPFR_SET mpfr_set_flt
#define THIS_MPFR_GET mpfr_get_flt
#define THIS_SNPRINTF(buf, x) snprintf ((buf), sizeof (buf), "%a", (x));
#include "ulp-tester.c"

#define THIS_TYPE double
#define THIS_LIT(v) v
#define THIS_FUNC(v) v
#define THIS_MIN_EXP __DBL_MIN_EXP__
#define THIS_MANT_DIG __DBL_MANT_DIG__
#define THIS_MIN __DBL_MIN__
#define THIS_MAX __DBL_MAX__
#define THIS_MPFR_SET mpfr_set_d
#define THIS_MPFR_GET mpfr_get_d
#define THIS_SNPRINTF(buf, x) snprintf ((buf), sizeof (buf), "%a", (x));
#include "ulp-tester.c"

#define THIS_TYPE long double
#define THIS_LIT(v) v##L
#define THIS_FUNC(v) v##l
#define THIS_MIN_EXP __LDBL_MIN_EXP__
#define THIS_MANT_DIG __LDBL_MANT_DIG__
#define THIS_MIN __LDBL_MIN__
#define THIS_MAX __LDBL_MAX__
#define THIS_MPFR_SET mpfr_set_ld
#define THIS_MPFR_GET mpfr_get_ld
#define THIS_SNPRINTF(buf, x) snprintf ((buf), sizeof (buf), "%La", (x));
#include "ulp-tester.c"

#ifdef TEST_FLT128
#define THIS_TYPE _Float128
#define THIS_LIT(v) v##F128
#define THIS_FUNC(v) v##f128
#define THIS_MIN_EXP __FLT128_MIN_EXP__
#define THIS_MANT_DIG __FLT128_MANT_DIG__
#define THIS_MIN __FLT128_MIN__
#define THIS_MAX __FLT128_MAX__
#define THIS_MPFR_SET mpfr_set_float128
#define THIS_MPFR_GET mpfr_get_float128
#define THIS_SNPRINTF(buf, x) strfromf128 ((buf), sizeof (buf), "%a", (x));
#include "ulp-tester.c"
#else
#define testf128(fn, mpfr_fn, name, count) do { } while (0)
#endif

int
main (int argc, const char **argv)
{
  const char *arg;
  char *endptr;
  (void) argc;
  if (argc <= 1)
    arg = "";
  else
    arg = argv[1];
  unsigned long count = strtoul (arg, &endptr, 10);
  if (endptr == arg)
    {
      fprintf (stderr, "ulp-tester number_of_iterations rnd\n");
      return 1;
    }
  const char *rnd = "tonearest";
  if (argc >= 3)
    rnd = argv[2];
  if (strcmp (rnd, "upward") == 0)
    fesetround (FE_UPWARD);
  else if (strcmp (rnd, "downward") == 0)
    fesetround (FE_DOWNWARD);
  else if (strcmp (rnd, "towardzero") == 0)
    fesetround (FE_TOWARDZERO);
#ifdef LIBMVEC_TEST
  extern float wsinf (float);
  extern float wcosf (float);
  extern double wsin (double);
  extern double wcos (double);
#define TESTS(fn) \
  testf (w##fn##f, mpfr_##fn, #fn "f", count);		\
  test (w##fn, mpfr_##fn, #fn, count);
  TESTS (sin);
  TESTS (cos);
#else
  testf (fn##f, mpfr_##fn, #fn "f", count);		\
  test (fn, mpfr_##fn, #fn, count);			\
  testl (fn##l, mpfr_##fn, #fn "l", count);		\
  testf128 (fn##f128, mpfr_##fn, #fn "f128", count)
  TESTS (sqrt);
  TESTS (sin);
  TESTS (cos);
  TESTS (exp10);
#endif
}
#endif

[-- Attachment #4: libmvec-wrapper.c --]
[-- Type: text/plain, Size: 4069 bytes --]

/* gcc -shared -O3 -ffast-math -fvect-cost-model=unlimited -fpic -o libmvec-wrapper.{so,c} -lmvec
 */

#include <math.h>

__attribute__((noipa, visibility ("hidden"))) void
sinfb (float *__restrict a, float *__restrict b)
{
  for (int i = 0; i < 4; i++)
    a[i] = sinf (b[i]);
}

__attribute__((noipa, visibility ("hidden"), target ("avx"))) void
sinfc (float *__restrict a, float *__restrict b)
{
  for (int i = 0; i < 8; i++)
    a[i] = sinf (b[i]);
}

__attribute__((noipa, visibility ("hidden"), target ("avx2"))) void
sinfd (float *__restrict a, float *__restrict b)
{
  for (int i = 0; i < 8; i++)
    a[i] = sinf (b[i]);
}

__attribute__((noipa, visibility ("hidden"), target ("avx512f"))) void
sinfe (float *__restrict a, float *__restrict b)
{
  for (int i = 0; i < 16; i++)
    a[i] = sinf (b[i]);
}

__attribute__((noipa, visibility ("hidden"))) void
cosfb (float *__restrict a, float *__restrict b)
{
  for (int i = 0; i < 4; i++)
    a[i] = cosf (b[i]);
}

__attribute__((noipa, visibility ("hidden"), target ("avx"))) void
cosfc (float *__restrict a, float *__restrict b)
{
  for (int i = 0; i < 8; i++)
    a[i] = cosf (b[i]);
}

__attribute__((noipa, visibility ("hidden"), target ("avx2"))) void
cosfd (float *__restrict a, float *__restrict b)
{
  for (int i = 0; i < 8; i++)
    a[i] = cosf (b[i]);
}

__attribute__((noipa, visibility ("hidden"), target ("avx512f"))) void
cosfe (float *__restrict a, float *__restrict b)
{
  for (int i = 0; i < 16; i++)
    a[i] = cosf (b[i]);
}

__attribute__((noipa, visibility ("hidden"))) void
sinb (double *__restrict a, double *__restrict b)
{
  for (int i = 0; i < 4; i++)
    a[i] = sin (b[i]);
}

__attribute__((noipa, visibility ("hidden"), target ("avx"))) void
sinc (double *__restrict a, double *__restrict b)
{
  for (int i = 0; i < 4; i++)
    a[i] = sin (b[i]);
}

__attribute__((noipa, visibility ("hidden"), target ("avx2"))) void
sind (double *__restrict a, double *__restrict b)
{
  for (int i = 0; i < 4; i++)
    a[i] = sin (b[i]);
}

__attribute__((noipa, visibility ("hidden"), target ("avx512f"))) void
sine (double *__restrict a, double *__restrict b)
{
  for (int i = 0; i < 8; i++)
    a[i] = sin (b[i]);
}

__attribute__((noipa, visibility ("hidden"))) void
cosb (double *__restrict a, double *__restrict b)
{
  for (int i = 0; i < 4; i++)
    a[i] = cos (b[i]);
}

__attribute__((noipa, visibility ("hidden"), target ("avx"))) void
cosc (double *__restrict a, double *__restrict b)
{
  for (int i = 0; i < 4; i++)
    a[i] = cos (b[i]);
}

__attribute__((noipa, visibility ("hidden"), target ("avx2"))) void
cosd (double *__restrict a, double *__restrict b)
{
  for (int i = 0; i < 4; i++)
    a[i] = cos (b[i]);
}

__attribute__((noipa, visibility ("hidden"), target ("avx512f"))) void
cose (double *__restrict a, double *__restrict b)
{
  for (int i = 0; i < 8; i++)
    a[i] = cos (b[i]);
}
#include <stdlib.h>

int level;

__attribute__((constructor)) static void
init (void)
{
  const char *p = getenv ("LIBMVEC_LEVEL");
  if (!p)
    return;
  if (*p == 'c')
    level = 1;
  else if (*p == 'd')
    level = 2;
  else if (*p == 'e')
    level = 3;
}

float
wsinf (float x)
{
  float a[16], b[16] = { x };
  switch (level)
    {
    default: sinfb (a, b); break;
    case 1: sinfc (a, b); break;
    case 2: sinfd (a, b); break;
    case 3: sinfe (a, b); break;
    }
  return a[0];
}

float
wcosf (float x)
{
  float a[16], b[16] = { x };
  switch (level)
    {
    default: cosfb (a, b); break;
    case 1: cosfc (a, b); break;
    case 2: cosfd (a, b); break;
    case 3: cosfe (a, b); break;
    }
  return a[0];
}

double
wsin (double x)
{
  double a[8], b[8] = { x };
  switch (level)
    {
    default: sinb (a, b); break;
    case 1: sinc (a, b); break;
    case 2: sind (a, b); break;
    case 3: sine (a, b); break;
    }
  return a[0];
}

double
wcos (double x)
{
  double a[8], b[8] = { x };
  switch (level)
    {
    default: cosb (a, b); break;
    case 1: cosc (a, b); break;
    case 2: cosd (a, b); break;
    case 3: cose (a, b); break;
    }
  return a[0];
}

[-- Attachment #5: boundary-tester.c --]
[-- Type: text/plain, Size: 2842 bytes --]

/* for i in FLOAT DOUBLE LDOUBLE FLOAT128; do for j in TONEAREST UPWARD DOWNWARD TOWARDZERO; do gcc -D$i -DROUND=FE_$j -g -O1 -o boundary-tester{,.c} -lm; ./boundary-tester || echo $i $j; done; done
   for i in FLOAT DOUBLE; do for j in TONEAREST UPWARD DOWNWARD TOWARDZERO; do gcc -DLIBMVEC_TEST -D$i -DROUND=FE_$j -g -O1 -o boundary-tester{2,.c} ./libmvec-wrapper.so -lm; ./boundary-tester2 || echo $i $j; done; done
 */

#define _GNU_SOURCE
#include <math.h>
#include <fenv.h>
#include <stdio.h>
#include <stdlib.h>

#ifdef FLOAT
#define TYPE float
#ifdef LIBMVEC_TEST
extern float wsinf (float);
extern float wcosf (float);
#define SIN wsinf
#define COS wcosf
#else
#define SIN sinf
#define COS cosf
#endif
#define SQRT sqrtf
#ifdef M_PI_2f
#define PI2 M_PI_2f
#else
#define PI2 1.570796326794896619231321691639751442f
#endif
#define PRINT(str) printf ("%s %.20a %.20a\n", str, val, res)
#define NEXTAFTER nextafterf
#elif defined DOUBLE
#define TYPE double
#ifdef LIBMVEC_TEST
extern double wsin (double);
extern double wcos (double);
#define SIN wsin
#define COS wcos
#else
#define SIN sin
#define COS cos
#endif
#define SQRT sqrt
#ifdef M_PI_2
#define PI2 M_PI_2
#else
#define PI2 1.570796326794896619231321691639751442f
#endif
#define NEXTAFTER nextafter
#define PRINT(str) printf ("%s %.20a %.20a\n", str, val, res)
#elif defined LDOUBLE
#define TYPE long double
#define SIN sinl
#define COS cosl
#define SQRT sqrtl
#ifdef M_PI_2l
#define PI2 M_PI_2l
#else
#define PI2 1.570796326794896619231321691639751442f
#endif
#define NEXTAFTER nextafterl
#define PRINT(str) printf ("%s %.20La %.20La\n", str, val, res)
#elif defined FLOAT128
#define TYPE _Float128
#define SIN sinf128
#define COS cosf128
#define SQRT sqrtf128
#ifdef M_PI_2f128
#define PI2 M_PI_2f128
#else
#define PI2 1.570796326794896619231321691639751442f
#endif
#define NEXTAFTER nextafterf128
#define PRINT(str) __builtin_abort ()
#endif

int
main ()
{
  int ret = 0;
#ifdef ROUND
  fesetround (ROUND);
#endif
  for (int i = -1024; i <= 1024; i++)
    for (int j = -1; j <= 1; j += 2)
      {
        TYPE val = ((TYPE) i) * PI2;
        TYPE inf = j * __builtin_inf ();
        for (int k = 0; k < 1000; k++)
          {
            TYPE res = SIN (val);
            if (res < (TYPE) -1.0 || res > (TYPE) 1.0)
              { PRINT ("sin"); ret = 1; }
            asm volatile ("" : "+g" (val));
	    res = COS (val);
            if (res < (TYPE) -1.0 || res > (TYPE) 1.0)
	      { PRINT ("cos"); ret = 1; }
	    val = NEXTAFTER (val, inf);
          }
      }
  for (int j = -1; j <= 1; j += 2)
    {
      TYPE val = 0;
      TYPE inf = j * __builtin_inf ();
      if (j < 0)
	val = -val;
      for (int k = 0; k < 1000; k++)
        {
          TYPE res = SQRT (val);
          if (res < (TYPE) -0.0)
	    { PRINT ("sqrt"); ret = 1; }
        }
    }
  return ret;
}

^ permalink raw reply	[flat|nested] 11+ messages in thread
end of thread, other threads:[~2023-04-28 11:39 UTC | newest]

Thread overview: 11+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2023-04-26 14:21 [PATCH] Add targetm.libm_function_max_error Jakub Jelinek
2023-04-26 16:10 ` Michael Matz
2023-04-27  8:59   ` Jakub Jelinek
2023-04-27 11:05     ` Jakub Jelinek
2023-04-27 14:48       ` Michael Matz
2023-04-27  7:18 ` Richard Biener
2023-04-27  9:20   ` Jakub Jelinek
2023-04-27 10:34     ` Richard Biener
2023-04-27 11:08       ` [PATCH] v2: " Jakub Jelinek
2023-04-28 11:29         ` Richard Sandiford
2023-04-28 11:39           ` Jakub Jelinek

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).