From 7def0928040f29a3496b5e5b7c64a95b8b2ff8ad Mon Sep 17 00:00:00 2001
From: nobu <nobu@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>
Date: Tue, 28 Feb 2017 02:58:12 +0000
Subject: [PATCH] Makefile.sub: ULL_TO_DOUBLE

* win32/Makefile.sub (config.h): define ULL_TO_DOUBLE for
  conversion from unsigned __int64 to double, which is not
  implemented in till Visual Studio.NET 2003, aka VC7.1.

* bignum.c (estimate_initial_sqrt): use ULL_TO_DOUBLE if defined.

* numeric.c (BDIGIT_DBL_TO_DOUBLE): ditto.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@57740 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
---
 bignum.c           | 10 ++++++++--
 numeric.c          |  8 +++++++-
 win32/Makefile.sub |  2 ++
 3 files changed, 17 insertions(+), 3 deletions(-)

diff --git a/bignum.c b/bignum.c
index 99dbfc148a..8c723300f4 100644
--- a/bignum.c
+++ b/bignum.c
@@ -6765,9 +6765,15 @@ rb_big_even_p(VALUE num)
 unsigned long rb_ulong_isqrt(unsigned long);
 #if SIZEOF_BDIGIT*2 > SIZEOF_LONG
 BDIGIT rb_bdigit_dbl_isqrt(BDIGIT_DBL);
+# ifdef ULL_TO_DOUBLE
+#   define BDIGIT_DBL_TO_DOUBLE(n) ULL_TO_DOUBLE(n)
+# endif
 #else
 # define rb_bdigit_dbl_isqrt(x) (BDIGIT)rb_ulong_isqrt(x)
 #endif
+#ifndef BDIGIT_DBL_TO_DOUBLE
+# define BDIGIT_DBL_TO_DOUBLE(n) (double)(n)
+#endif
 
 static BDIGIT *
 estimate_initial_sqrt(VALUE *xp, const size_t xn, const BDIGIT *nds, size_t len)
@@ -6789,9 +6795,9 @@ estimate_initial_sqrt(VALUE *xp, const size_t xn, const BDIGIT *nds, size_t len)
 	d <<= -rshift;
 	d |= nds[len-dbl_per_bdig-1] >> (BITSPERDIG+rshift);
     }
-    f = sqrt((double)d);
+    f = sqrt(BDIGIT_DBL_TO_DOUBLE(d));
     d = (BDIGIT_DBL)ceil(f);
-    if ((double)d == f) {
+    if (BDIGIT_DBL_TO_DOUBLE(d) == f) {
 	if (lowbits || (lowbits = !bary_zero_p(nds, len-dbl_per_bdig)))
 	    ++d;
     }
diff --git a/numeric.c b/numeric.c
index a8b932a4c6..8c52630ce0 100644
--- a/numeric.c
+++ b/numeric.c
@@ -5140,7 +5140,7 @@ prefix##_isqrt(argtype n) \
 	while ((t = n/x) < (argtype)x) x = (rettype)((x + t) >> 1); \
 	return x; \
     } \
-    return (rettype)sqrt((double)n); \
+    return (rettype)sqrt(argtype##_TO_DOUBLE(n)); \
 }
 
 #if SIZEOF_LONG*CHAR_BIT > DBL_MANT_DIG
@@ -5148,6 +5148,7 @@ prefix##_isqrt(argtype n) \
 #else
 # define RB_ULONG_IN_DOUBLE_P(n) 1
 #endif
+#define RB_ULONG_TO_DOUBLE(n) (double)(n)
 #define RB_ULONG unsigned long
 DEFINE_INT_SQRT(unsigned long, rb_ulong, RB_ULONG)
 
@@ -5157,6 +5158,11 @@ DEFINE_INT_SQRT(unsigned long, rb_ulong, RB_ULONG)
 # else
 #   define BDIGIT_DBL_IN_DOUBLE_P(n) 1
 # endif
+# ifdef ULL_TO_DOUBLE
+#   define BDIGIT_DBL_TO_DOUBLE(n) ULL_TO_DOUBLE(n)
+# else
+#   define BDIGIT_DBL_TO_DOUBLE(n) (double)(n)
+# endif
 DEFINE_INT_SQRT(BDIGIT, rb_bdigit_dbl, BDIGIT_DBL)
 #endif
 
diff --git a/win32/Makefile.sub b/win32/Makefile.sub
index f37b6c654b..790b41a4f1 100644
--- a/win32/Makefile.sub
+++ b/win32/Makefile.sub
@@ -550,6 +550,8 @@ $(CONFIG_H): $(MKFILES) $(srcdir)/win32/Makefile.sub $(win_srcdir)/Makefile.sub
 #define HAVE_MEMORY_H 1
 !if $(MSC_VER) >= 1400
 #define HAVE_LONG_LONG 1
+!else
+#define ULL_TO_DOUBLE(n) ((double)(unsigned long)((n)>>32) * (1I64 << 32) + (unsigned long)(n))
 !endif
 #define HAVE_OFF_T 1
 #define SIZEOF_INT 4