Import libcompiler_rt into HEAD and add Makefiles.

Obtained from:	user/ed/compiler-rt

1 files changed, 42 insertions, 0 deletions

diff --git a/contrib/compiler-rt/lib/ppc/floatunditf.c b/contrib/compiler-rt/lib/ppc/floatunditf.c
new file mode 100644
index 0000000..20a3b71
--- /dev/null
+++ b/contrib/compiler-rt/lib/ppc/floatunditf.c
@@ -0,0 +1,42 @@
+/* This file is distributed under the University of Illinois Open Source
+ * License. See LICENSE.TXT for details.
+ */
+
+/* long double __floatunditf(unsigned long long x); */
+/* This file implements the PowerPC unsigned long long -> long double conversion */
+
+#include "DD.h"
+#include <stdint.h>
+
+long double __floatunditf(uint64_t a) {
+	
+	/* Begins with an exact copy of the code from __floatundidf */
+	
+	static const double twop52 = 0x1.0p52;
+	static const double twop84 = 0x1.0p84;
+	static const double twop84_plus_twop52 = 0x1.00000001p84;
+	
+	doublebits high = { .d = twop84 };
+	doublebits low  = { .d = twop52 };
+	
+	high.x |= a >> 32;							/* 0x1.0p84 + high 32 bits of a */
+	low.x |= a & UINT64_C(0x00000000ffffffff);	/* 0x1.0p52 + low 32 bits of a */
+	
+	const double high_addend = high.d - twop84_plus_twop52;
+	
+	/* At this point, we have two double precision numbers
+	 * high_addend and low.d, and we wish to return their sum
+	 * as a canonicalized long double:
+	 */
+
+	/* This implementation sets the inexact flag spuriously. */
+	/* This could be avoided, but at some substantial cost. */
+	
+	DD result;
+	
+	result.s.hi = high_addend + low.d;
+	result.s.lo = (high_addend - result.s.hi) + low.d;
+	
+	return result.ld;
+	
+}