Move original compiler-rt functions (libgcc replacement) to lib/builtins directory

llvm-svn: 201393

1 files changed, 36 insertions, 0 deletions

diff --git a/compiler-rt/lib/builtins/ppc/floatditf.c b/compiler-rt/lib/builtins/ppc/floatditf.c
new file mode 100644
index 00000000000..beabdd01742
--- /dev/null
+++ b/compiler-rt/lib/builtins/ppc/floatditf.c
@@ -0,0 +1,36 @@
+/* This file is distributed under the University of Illinois Open Source
+ * License. See LICENSE.TXT for details.
+ */
+
+/* long double __floatditf(long long x); */
+/* This file implements the PowerPC long long -> long double conversion */
+
+#include "DD.h"
+
+long double __floatditf(int64_t a) {
+	
+	static const double twop32 = 0x1.0p32;
+	static const double twop52 = 0x1.0p52;
+	
+	doublebits low  = { .d = twop52 };
+	low.x |= a & UINT64_C(0x00000000ffffffff);	/* 0x1.0p52 + low 32 bits of a. */
+	
+	const double high_addend = (double)((int32_t)(a >> 32))*twop32 - 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;
+	
+}