From 8d236bc0b150b531acc121d657428bf824a9ca35 Mon Sep 17 00:00:00 2001
From: shirosaki <shirosaki@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>
Date: Fri, 12 Oct 2012 13:30:17 +0000
Subject: win32.h: set floating point precision for pow()

* include/ruby/win32.h (rb_w32_pow): set floating point precision
  for mingw-w64 x86 pow(). This improves the precision of pow() on
  Windows XP for TestFloat#test_round_with_precision failure.
  [ruby-core:47911] [Bug #7142]

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@37168 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
---
 include/ruby/win32.h | 20 +++++++++++++++++++-
 1 file changed, 19 insertions(+), 1 deletion(-)

(limited to 'include')

diff --git a/include/ruby/win32.h b/include/ruby/win32.h
index 718da1376c..a2eec0cf19 100644
--- a/include/ruby/win32.h
+++ b/include/ruby/win32.h
@@ -764,7 +764,7 @@ uintptr_t rb_w32_asynchronize(asynchronous_func_t func, uintptr_t self, int argc
 }  /* extern "C" { */
 #endif
 
-#ifdef __MINGW64__
+#if defined(__MINGW64__)
 /*
  * Use powl() instead of broken pow() of x86_64-w64-mingw32.
  * This workaround will fix test failures in test_bignum.rb,
@@ -775,6 +775,24 @@ rb_w32_pow(double x, double y)
 {
     return powl(x, y);
 }
+#elif defined(__MINGW64_VERSION_MAJOR)
+/*
+ * Set floating point precision for pow() of mingw-w64 x86.
+ * With default precision the result is not proper on WinXP.
+ */
+static inline double
+rb_w32_pow(double x, double y)
+{
+    double r;
+    unsigned int default_control = _controlfp(0, 0);
+    _controlfp(_PC_64, _MCW_PC);
+    r = pow(x, y);
+    /* Restore setting */
+    _controlfp(default_control, _MCW_PC);
+    return r;
+}
+#endif
+#if defined(__MINGW64_VERSION_MAJOR) || defined(__MINGW64__)
 #define pow rb_w32_pow
 #endif
 
-- 
cgit v1.2.3