Patchwork [16/28] math: Use wordsize-64 version for finite

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Submitter Adhemerval Zanella Netto
Date March 29, 2019, 1:35 p.m.
Message ID <20190329133529.22523-17-adhemerval.zanella@linaro.org>
Download mbox | patch
Permalink /patch/32073/
State New
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Comments

Adhemerval Zanella Netto - March 29, 2019, 1:35 p.m.
- math.h will use compiler builtin for gcc 4.4+ when built without
    -fsignaling-nans and the builtin is expanded inline for all
    supported architectures.  As an example, there is no intra finite
    call on libm for the architecture I checked (x86, arm, aarch64,
    and powerpc).

  - The resulting binary difference on 32 bits architecture is minimum
    for the non hotspot symbol.

  - It helps wordsize-64 architectures that use ldbl-opt.

  - It add some code simplification with reduction of duplicated
    implementations.

Checked on powerpc-linux-gnu (built without --with-cpu, with
--with-cpu=power4 and with --with-cpu=power5+ and --disable-multi-arch),
powerpc64-linux-gnu (built without --with-cp and with --with-cpu=power5+
and --disable-multi-arch).

	* sysdeps/ieee754/dbl-64/wordsize-64/s_finite.c: Move to ...
	* sysdeps/ieee754/dbl-64/s_finite.c: ... here and format code.
---
 sysdeps/ieee754/dbl-64/s_finite.c             | 22 +++-------
 sysdeps/ieee754/dbl-64/wordsize-64/s_finite.c | 43 -------------------
 2 files changed, 7 insertions(+), 58 deletions(-)
 delete mode 100644 sysdeps/ieee754/dbl-64/wordsize-64/s_finite.c
Gabriel F. T. Gomes - June 11, 2019, 4:20 p.m.
On Fri, Mar 29 2019, Adhemerval Zanella wrote:
> 
>   - The resulting binary difference on 32 bits architecture is minimum
>     for the non hotspot symbol.
> 
>   - It helps wordsize-64 architectures that use ldbl-opt.

Same comments I made for patch 12/28 [1], apply here.

[1] https://sourceware.org/ml/libc-alpha/2019-06/msg00085.html

Patch

diff --git a/sysdeps/ieee754/dbl-64/s_finite.c b/sysdeps/ieee754/dbl-64/s_finite.c
index da1519b1d0..98a40fbff6 100644
--- a/sysdeps/ieee754/dbl-64/s_finite.c
+++ b/sysdeps/ieee754/dbl-64/s_finite.c
@@ -1,4 +1,3 @@ 
-/* @(#)s_finite.c 5.1 93/09/24 */
 /*
  * ====================================================
  * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
@@ -10,10 +9,6 @@ 
  * ====================================================
  */
 
-#if defined(LIBM_SCCS) && !defined(lint)
-static char rcsid[] = "$NetBSD: s_finite.c,v 1.8 1995/05/10 20:47:17 jtc Exp $";
-#endif
-
 /*
  * finite(x) returns 1 is x is finite, else 0;
  * no branching!
@@ -23,18 +18,15 @@  static char rcsid[] = "$NetBSD: s_finite.c,v 1.8 1995/05/10 20:47:17 jtc Exp $";
 #include <math_private.h>
 #include <ldbl-classify-compat.h>
 #include <shlib-compat.h>
+#include <stdint.h>
 
-#undef __finite
-
-#ifndef FINITE
-# define FINITE __finite
-#endif
-
-int FINITE(double x)
+int
+__finite (double x)
 {
-  int32_t hx;
-  GET_HIGH_WORD (hx, x);
-  return (int) ((uint32_t) ((hx & 0x7ff00000) - 0x7ff00000) >> 31);
+  int64_t lx;
+  EXTRACT_WORDS64 (lx,x);
+  return (int)((uint64_t)((lx & INT64_C(0x7ff0000000000000))
+			  - INT64_C (0x7ff0000000000000)) >> 63);
 }
 hidden_def (__finite)
 weak_alias (__finite, finite)
diff --git a/sysdeps/ieee754/dbl-64/wordsize-64/s_finite.c b/sysdeps/ieee754/dbl-64/wordsize-64/s_finite.c
deleted file mode 100644
index 40676924fe..0000000000
--- a/sysdeps/ieee754/dbl-64/wordsize-64/s_finite.c
+++ /dev/null
@@ -1,43 +0,0 @@ 
-/*
- * ====================================================
- * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
- *
- * Developed at SunPro, a Sun Microsystems, Inc. business.
- * Permission to use, copy, modify, and distribute this
- * software is freely granted, provided that this notice
- * is preserved.
- * ====================================================
- */
-
-/*
- * finite(x) returns 1 is x is finite, else 0;
- * no branching!
- */
-
-#include <math.h>
-#include <math_private.h>
-#include <ldbl-classify-compat.h>
-#include <shlib-compat.h>
-#include <stdint.h>
-
-#undef __finite
-int
-__finite(double x)
-{
-  int64_t lx;
-  EXTRACT_WORDS64(lx,x);
-  return (int)((uint64_t)((lx&INT64_C(0x7ff0000000000000))-INT64_C(0x7ff0000000000000))>>63);
-}
-hidden_def (__finite)
-weak_alias (__finite, finite)
-#ifdef NO_LONG_DOUBLE
-# if LDBL_CLASSIFY_COMPAT
-#  if SHLIB_COMPAT (libc, GLIBC_2_0, GLIBC_2_23)
-compat_symbol (libc, __finite, __finitel, GLIBC_2_0);
-#  endif
-#  if SHLIB_COMPAT (libm, GLIBC_2_1, GLIBC_2_23)
-compat_symbol (libm, __finite, __finitel, GLIBC_2_1);
-#  endif
-# endif
-weak_alias (__finite, finitel)
-#endif