Attempt to support platforms which don't have fenv.h.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@114196 91177308-0d34-0410-b5e6-96231b3b80d8

3 files changed, 56 insertions, 0 deletions

diff --git a/include/llvm/Config/config.h.cmake b/include/llvm/Config/config.h.cmake
index e8feabffda..5e0fa1ea9a 100644
--- a/include/llvm/Config/config.h.cmake
+++ b/include/llvm/Config/config.h.cmake
@@ -461,6 +461,9 @@
 /* Define to 1 if you have the <valgrind/valgrind.h> header file. */
 #cmakedefine HAVE_VALGRIND_VALGRIND_H ${HAVE_VALGRIND_VALGRIND_H}
 
+/* Define to 1 if you have the <fenv.h> header file. */
+#cmakedefine HAVE_FENV_H ${HAVE_FENV_H}
+
 /* Define to 1 if you have the <windows.h> header file. */
 #cmakedefine HAVE_WINDOWS_H ${HAVE_WINDOWS_H}
 
diff --git a/include/llvm/Config/config.h.in b/include/llvm/Config/config.h.in
index d62da1ab03..6fd274d875 100644
--- a/include/llvm/Config/config.h.in
+++ b/include/llvm/Config/config.h.in
@@ -455,6 +455,9 @@
 /* Define to 1 if you have the <valgrind/valgrind.h> header file. */
 #undef HAVE_VALGRIND_VALGRIND_H
 
+/* Define to 1 if you have the <fenv.h> header file. */
+#undef HAVE_FENV_H
+
 /* Define to 1 if you have the <windows.h> header file. */
 #undef HAVE_WINDOWS_H
 
diff --git a/include/llvm/System/FEnv.h b/include/llvm/System/FEnv.h
new file mode 100644
index 0000000000..4c72eb2ab2
--- /dev/null
+++ b/include/llvm/System/FEnv.h
@@ -0,0 +1,50 @@
+//===- llvm/System/FEnv.h - Host floating-point exceptions ------*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file provides an operating system independent interface to
+// floating-point exception interfaces.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_SYSTEM_FENV_H
+#define LLVM_SYSTEM_FENV_H
+
+#include "llvm/Config/config.h"
+#include <cerrno>
+#ifdef HAVE_FENV_H
+#include <fenv.h>
+#endif
+
+namespace llvm {
+namespace sys {
+
+/// llvm_fenv_clearexcept - Clear the floating-point exception state.
+static inline void llvm_fenv_clearexcept() {
+#ifdef HAVE_FENV_H
+  feclearexcept(FE_ALL_EXCEPT);
+#endif
+  errno = 0;
+}
+
+/// llvm_fenv_testexcept - Test if a floating-point exception was raised.
+static inline bool llvm_fenv_testexcept() {
+  int errno_val = errno;
+  if (errno_val == ERANGE || errno_val == EDOM)
+    return true;
+#ifdef HAVE_FENV_H
+  if (fetestexcept(FE_ALL_EXCEPT))
+    return true;
+#endif
+  return false;
+}
+
+} // End sys namespace
+} // End llvm namespace
+
+#endif