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Diffstat (limited to 'contrib/compiler-rt/lib/builtins/ppc/gcc_qdiv.c')
-rw-r--r--contrib/compiler-rt/lib/builtins/ppc/gcc_qdiv.c55
1 files changed, 55 insertions, 0 deletions
diff --git a/contrib/compiler-rt/lib/builtins/ppc/gcc_qdiv.c b/contrib/compiler-rt/lib/builtins/ppc/gcc_qdiv.c
new file mode 100644
index 000000000000..70aa00b64400
--- /dev/null
+++ b/contrib/compiler-rt/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;
+}