vendor/compiler-rt/compiler-rt-r224034

1 files changed, 55 insertions, 0 deletions

diff --git a/lib/builtins/ppc/gcc_qdiv.c b/lib/builtins/ppc/gcc_qdiv.c
new file mode 100644
index 000000000000..70aa00b64400
--- /dev/null
+++ b/lib/builtins/ppc/gcc_qdiv.c
@@ -0,0 +1,55 @@
+/* This file is distributed under the University of Illinois Open Source
+ * License. See LICENSE.TXT for details.
+ */
+
+/* long double __gcc_qdiv(long double x, long double y);
+ * This file implements the PowerPC 128-bit double-double division operation.
+ * This implementation is shamelessly cribbed from Apple's DDRT, circa 1993(!)
+ */
+
+#include "DD.h"
+
+long double __gcc_qdiv(long double a, long double b)
+{	
+	static const uint32_t infinityHi = UINT32_C(0x7ff00000);
+	DD dst = { .ld = a }, src = { .ld = b };
+	
+	register double x = dst.s.hi, x1 = dst.s.lo,
+					y = src.s.hi, y1 = src.s.lo;
+	
+    double yHi, yLo, qHi, qLo;
+    double yq, tmp, q;
+	
+    q = x / y;
+	
+	/* Detect special cases */
+	if (q == 0.0) {
+		dst.s.hi = q;
+		dst.s.lo = 0.0;
+		return dst.ld;
+	}
+	
+	const doublebits qBits = { .d = q };
+	if (((uint32_t)(qBits.x >> 32) & infinityHi) == infinityHi) {
+		dst.s.hi = q;
+		dst.s.lo = 0.0;
+		return dst.ld;
+	}
+	
+    yHi = high26bits(y);
+    qHi = high26bits(q);
+	
+    yq = y * q;
+    yLo = y - yHi;
+    qLo = q - qHi;
+	
+    tmp = LOWORDER(yq, yHi, yLo, qHi, qLo);
+    tmp = (x - yq) - tmp;
+    tmp = ((tmp + x1) - y1 * q) / y;
+    x = q + tmp;
+	
+    dst.s.lo = (q - x) + tmp;
+    dst.s.hi = x;
+	
+    return dst.ld;
+}