Merge commit 'a39d4083cab589d7cd6a13e8a4b8db8875261d75'

[gnulib.git] / m4 / remainderf.m4

diff --git a/m4/remainderf.m4 b/m4/remainderf.m4
index 4332bb9..5e34551 100644 (file)
--- a/m4/remainderf.m4
+++ b/m4/remainderf.m4
@@ -1,5 +1,5 @@
-# remainderf.m4 serial 2
-dnl Copyright (C) 2012 Free Software Foundation, Inc.
+# remainderf.m4 serial 8
+dnl Copyright (C) 2012-2014 Free Software Foundation, Inc.
 dnl This file is free software; the Free Software Foundation
 dnl gives unlimited permission to copy and/or distribute it,
 dnl with or without modifications, as long as this notice is preserved.
@@ -10,6 +10,9 @@ AC_DEFUN([gl_FUNC_REMAINDERF],
   AC_REQUIRE([gl_MATH_H_DEFAULTS])
   AC_REQUIRE([gl_FUNC_REMAINDER])
 
+  dnl Persuade glibc <math.h> to declare remainderf().
+  AC_REQUIRE([gl_USE_SYSTEM_EXTENSIONS])
+
   dnl Test whether remainderf() exists. Assume that remainderf(), if it exists, is
   dnl defined in the same library as remainder().
   save_LIBS="$LIBS"
@@ -23,6 +26,11 @@ AC_DEFUN([gl_FUNC_REMAINDERF],
              # define __NO_MATH_INLINES 1 /* for glibc */
              #endif
              #include <math.h>
+             extern
+             #ifdef __cplusplus
+             "C"
+             #endif
+             float remainderf (float, float);
              float (*funcptr) (float, float) = remainderf;
              float x;
              float y;]],
@@ -34,8 +42,19 @@ AC_DEFUN([gl_FUNC_REMAINDERF],
   LIBS="$save_LIBS"
   if test $gl_cv_func_remainderf = yes; then
     REMAINDERF_LIBM="$REMAINDER_LIBM"
+
+    save_LIBS="$LIBS"
+    LIBS="$LIBS $REMAINDERF_LIBM"
+    gl_FUNC_REMAINDERF_WORKS
+    LIBS="$save_LIBS"
+    case "$gl_cv_func_remainderf_works" in
+      *yes) ;;
+      *) REPLACE_REMAINDERF=1 ;;
+    esac
+
     m4_ifdef([gl_FUNC_REMAINDERF_IEEE], [
       if test $gl_remainderf_required = ieee && test $REPLACE_REMAINDERF = 0; then
+        AC_REQUIRE([AC_CANONICAL_HOST]) dnl for cross-compiles
         AC_CACHE_CHECK([whether remainderf works according to ISO C 99 with IEC 60559],
           [gl_cv_func_remainderf_ieee],
           [
@@ -47,6 +66,11 @@ AC_DEFUN([gl_FUNC_REMAINDERF],
 # define __NO_MATH_INLINES 1 /* for glibc */
 #endif
 #include <math.h>
+extern
+#ifdef __cplusplus
+"C"
+#endif
+float remainderf (float, float);
 /* Compare two numbers with ==.
    This is a separate function because IRIX 6.5 "cc -O" miscompiles an
    'x == x' test.  */
@@ -59,7 +83,6 @@ static float dummy (float x, float y) { return 0; }
 int main (int argc, char *argv[])
 {
   float (*my_remainderf) (float, float) = argc ? remainderf : dummy;
-  float i;
   float f;
   /* Test remainderf(...,0.0f).
      This test fails on OSF/1 5.1.  */
@@ -71,7 +94,13 @@ int main (int argc, char *argv[])
               ]])],
               [gl_cv_func_remainderf_ieee=yes],
               [gl_cv_func_remainderf_ieee=no],
-              [gl_cv_func_remainderf_ieee="guessing no"])
+              [case "$host_os" in
+                         # Guess yes on glibc systems.
+                 *-gnu*) gl_cv_func_remainderf_ieee="guessing yes" ;;
+                         # If we don't know, assume the worst.
+                 *)      gl_cv_func_remainderf_ieee="guessing no" ;;
+               esac
+              ])
             LIBS="$save_LIBS"
           ])
         case "$gl_cv_func_remainderf_ieee" in
@@ -91,20 +120,73 @@ int main (int argc, char *argv[])
         [Define to 1 if the remainder() function is available in libc or libm.])
       REMAINDERF_LIBM="$REMAINDER_LIBM"
     else
-      AC_REQUIRE([gl_FUNC_ROUNDF])
-      AC_REQUIRE([gl_FUNC_FMAF])
+      AC_REQUIRE([gl_FUNC_FABSF])
+      AC_REQUIRE([gl_FUNC_FMODF])
+      AC_REQUIRE([gl_FUNC_ISNANF])
       REMAINDERF_LIBM=
-      dnl Append $ROUNDF_LIBM to REMAINDERF_LIBM, avoiding gratuitous duplicates.
+      dnl Append $FABSF_LIBM to REMAINDERF_LIBM, avoiding gratuitous duplicates.
       case " $REMAINDERF_LIBM " in
-        *" $ROUNDF_LIBM "*) ;;
-        *) REMAINDERF_LIBM="$REMAINDERF_LIBM $ROUNDF_LIBM" ;;
+        *" $FABSF_LIBM "*) ;;
+        *) REMAINDERF_LIBM="$REMAINDERF_LIBM $FABSF_LIBM" ;;
       esac
-      dnl Append $FMAF_LIBM to REMAINDERF_LIBM, avoiding gratuitous duplicates.
+      dnl Append $FMODF_LIBM to REMAINDERF_LIBM, avoiding gratuitous duplicates.
       case " $REMAINDERF_LIBM " in
-        *" $FMAF_LIBM "*) ;;
-        *) REMAINDERF_LIBM="$REMAINDERF_LIBM $FMAF_LIBM" ;;
+        *" $FMODF_LIBM "*) ;;
+        *) REMAINDERF_LIBM="$REMAINDERF_LIBM $FMODF_LIBM" ;;
+      esac
+      dnl Append $ISNANF_LIBM to REMAINDERF_LIBM, avoiding gratuitous duplicates.
+      case " $REMAINDERF_LIBM " in
+        *" $ISNANF_LIBM "*) ;;
+        *) REMAINDERF_LIBM="$REMAINDERF_LIBM $ISNANF_LIBM" ;;
       esac
     fi
   fi
   AC_SUBST([REMAINDERF_LIBM])
 ])
+
+dnl Test whether remainderf() works.
+dnl It runs into an endless loop on IRIX 6.5.
+AC_DEFUN([gl_FUNC_REMAINDERF_WORKS],
+[
+  AC_REQUIRE([AC_PROG_CC])
+  AC_REQUIRE([AC_CANONICAL_HOST]) dnl for cross-compiles
+  AC_CHECK_DECLS_ONCE([alarm])
+  AC_CACHE_CHECK([whether remainderf works], [gl_cv_func_remainderf_works],
+    [
+      AC_RUN_IFELSE(
+        [AC_LANG_SOURCE([[
+#include <math.h>
+#if HAVE_DECL_ALARM
+# include <signal.h>
+# include <unistd.h>
+#endif
+extern
+#ifdef __cplusplus
+"C"
+#endif
+float remainderf (float, float);
+volatile float x;
+volatile float y;
+float z;
+int main ()
+{
+#if HAVE_DECL_ALARM
+  signal (SIGALRM, SIG_DFL);
+  alarm (5);
+#endif
+  /* This test fails on IRIX 6.5.  */
+  x = 9.316161e+37f;
+  y = 0.5475547314f;
+  z = remainderf (x, y);
+  return 0;
+}
+]])],
+        [gl_cv_func_remainderf_works=yes],
+        [gl_cv_func_remainderf_works=no],
+        [case "$host_os" in
+           irix*) gl_cv_func_remainderf_works="guessing no";;
+           *)     gl_cv_func_remainderf_works="guessing yes";;
+         esac
+        ])
+    ])
+])