1 files changed, 106 insertions, 0 deletions
diff --git a/m4/float_h.m4 b/m4/float_h.m4
new file mode 100644
index 0000000..0e84572
--- /dev/null
+++ b/m4/float_h.m4
@@ -0,0 +1,106 @@
+# float_h.m4 serial 13
+dnl Copyright (C) 2007, 2009-2022 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.
+
+AC_DEFUN([gl_FLOAT_H],
+[
+  AC_REQUIRE([AC_PROG_CC])
+  AC_REQUIRE([AC_CANONICAL_HOST])
+  GL_GENERATE_FLOAT_H=false
+  REPLACE_FLOAT_LDBL=0
+  case "$host_os" in
+    aix* | beos* | openbsd* | mirbsd* | irix*)
+      GL_GENERATE_FLOAT_H=true
+      ;;
+    freebsd* | dragonfly*)
+      case "$host_cpu" in
+changequote(,)dnl
+        i[34567]86 )
+changequote([,])dnl
+          GL_GENERATE_FLOAT_H=true
+          ;;
+        x86_64 )
+          # On x86_64 systems, the C compiler may still be generating
+          # 32-bit code.
+          AC_COMPILE_IFELSE(
+            [AC_LANG_SOURCE(
+               [[#if defined __LP64__ || defined __x86_64__ || defined __amd64__
+                  int ok;
+                 #else
+                  error fail
+                 #endif
+               ]])],
+            [],
+            [GL_GENERATE_FLOAT_H=true])
+          ;;
+      esac
+      ;;
+    linux*)
+      case "$host_cpu" in
+        powerpc*)
+          GL_GENERATE_FLOAT_H=true
+          ;;
+      esac
+      ;;
+  esac
+  case "$host_os" in
+    aix* | freebsd* | dragonfly* | linux*)
+      if $GL_GENERATE_FLOAT_H; then
+        REPLACE_FLOAT_LDBL=1
+      fi
+      ;;
+  esac
+
+  dnl Test against glibc-2.7 Linux/SPARC64 bug.
+  REPLACE_ITOLD=0
+  AC_CACHE_CHECK([whether conversion from 'int' to 'long double' works],
+    [gl_cv_func_itold_works],
+    [
+      AC_RUN_IFELSE(
+        [AC_LANG_SOURCE([[
+int i = -1;
+volatile long double ld;
+int main ()
+{
+  ld += i * 1.0L;
+  if (ld > 0)
+    return 1;
+  return 0;
+}]])],
+        [gl_cv_func_itold_works=yes],
+        [gl_cv_func_itold_works=no],
+        [case "$host" in
+           sparc*-*-linux*)
+             AC_COMPILE_IFELSE(
+               [AC_LANG_SOURCE(
+                 [[#if defined __LP64__ || defined __arch64__
+                    int ok;
+                   #else
+                    error fail
+                   #endif
+                 ]])],
+               [gl_cv_func_itold_works="guessing no"],
+               [gl_cv_func_itold_works="guessing yes"])
+             ;;
+                   # Guess yes on native Windows.
+           mingw*) gl_cv_func_itold_works="guessing yes" ;;
+           *)      gl_cv_func_itold_works="guessing yes" ;;
+         esac
+        ])
+    ])
+  case "$gl_cv_func_itold_works" in
+    *no)
+      REPLACE_ITOLD=1
+      dnl We add the workaround to <float.h> but also to <math.h>,
+      dnl to increase the chances that the fix function gets pulled in.
+      GL_GENERATE_FLOAT_H=true
+      ;;
+  esac
+
+  if $GL_GENERATE_FLOAT_H; then
+    gl_NEXT_HEADERS([float.h])
+  fi
+  AC_SUBST([REPLACE_ITOLD])
+])