Import builtins from LLVM compiler-rt project
These are needed to provide division and modulo operations
for the AArch32 target.
This code is entirely unmodified. Imported from compiler-rt
master branch as of May 4 2017.
Change-Id: I001e1809f2afd4bf8d4cc3d2296798809f607144
Signed-off-by: dp-arm <dimitris.papastamos@arm.com>
diff --git a/lib/compiler-rt/builtins/udivmoddi4.c b/lib/compiler-rt/builtins/udivmoddi4.c
new file mode 100644
index 0000000..0c8b4ff
--- /dev/null
+++ b/lib/compiler-rt/builtins/udivmoddi4.c
@@ -0,0 +1,231 @@
+/* ===-- udivmoddi4.c - Implement __udivmoddi4 -----------------------------===
+ *
+ * The LLVM Compiler Infrastructure
+ *
+ * This file is dual licensed under the MIT and the University of Illinois Open
+ * Source Licenses. See LICENSE.TXT for details.
+ *
+ * ===----------------------------------------------------------------------===
+ *
+ * This file implements __udivmoddi4 for the compiler_rt library.
+ *
+ * ===----------------------------------------------------------------------===
+ */
+
+#include "int_lib.h"
+
+/* Effects: if rem != 0, *rem = a % b
+ * Returns: a / b
+ */
+
+/* Translated from Figure 3-40 of The PowerPC Compiler Writer's Guide */
+
+COMPILER_RT_ABI du_int
+__udivmoddi4(du_int a, du_int b, du_int* rem)
+{
+ const unsigned n_uword_bits = sizeof(su_int) * CHAR_BIT;
+ const unsigned n_udword_bits = sizeof(du_int) * CHAR_BIT;
+ udwords n;
+ n.all = a;
+ udwords d;
+ d.all = b;
+ udwords q;
+ udwords r;
+ unsigned sr;
+ /* special cases, X is unknown, K != 0 */
+ if (n.s.high == 0)
+ {
+ if (d.s.high == 0)
+ {
+ /* 0 X
+ * ---
+ * 0 X
+ */
+ if (rem)
+ *rem = n.s.low % d.s.low;
+ return n.s.low / d.s.low;
+ }
+ /* 0 X
+ * ---
+ * K X
+ */
+ if (rem)
+ *rem = n.s.low;
+ return 0;
+ }
+ /* n.s.high != 0 */
+ if (d.s.low == 0)
+ {
+ if (d.s.high == 0)
+ {
+ /* K X
+ * ---
+ * 0 0
+ */
+ if (rem)
+ *rem = n.s.high % d.s.low;
+ return n.s.high / d.s.low;
+ }
+ /* d.s.high != 0 */
+ if (n.s.low == 0)
+ {
+ /* K 0
+ * ---
+ * K 0
+ */
+ if (rem)
+ {
+ r.s.high = n.s.high % d.s.high;
+ r.s.low = 0;
+ *rem = r.all;
+ }
+ return n.s.high / d.s.high;
+ }
+ /* K K
+ * ---
+ * K 0
+ */
+ if ((d.s.high & (d.s.high - 1)) == 0) /* if d is a power of 2 */
+ {
+ if (rem)
+ {
+ r.s.low = n.s.low;
+ r.s.high = n.s.high & (d.s.high - 1);
+ *rem = r.all;
+ }
+ return n.s.high >> __builtin_ctz(d.s.high);
+ }
+ /* K K
+ * ---
+ * K 0
+ */
+ sr = __builtin_clz(d.s.high) - __builtin_clz(n.s.high);
+ /* 0 <= sr <= n_uword_bits - 2 or sr large */
+ if (sr > n_uword_bits - 2)
+ {
+ if (rem)
+ *rem = n.all;
+ return 0;
+ }
+ ++sr;
+ /* 1 <= sr <= n_uword_bits - 1 */
+ /* q.all = n.all << (n_udword_bits - sr); */
+ q.s.low = 0;
+ q.s.high = n.s.low << (n_uword_bits - sr);
+ /* r.all = n.all >> sr; */
+ r.s.high = n.s.high >> sr;
+ r.s.low = (n.s.high << (n_uword_bits - sr)) | (n.s.low >> sr);
+ }
+ else /* d.s.low != 0 */
+ {
+ if (d.s.high == 0)
+ {
+ /* K X
+ * ---
+ * 0 K
+ */
+ if ((d.s.low & (d.s.low - 1)) == 0) /* if d is a power of 2 */
+ {
+ if (rem)
+ *rem = n.s.low & (d.s.low - 1);
+ if (d.s.low == 1)
+ return n.all;
+ sr = __builtin_ctz(d.s.low);
+ q.s.high = n.s.high >> sr;
+ q.s.low = (n.s.high << (n_uword_bits - sr)) | (n.s.low >> sr);
+ return q.all;
+ }
+ /* K X
+ * ---
+ * 0 K
+ */
+ sr = 1 + n_uword_bits + __builtin_clz(d.s.low) - __builtin_clz(n.s.high);
+ /* 2 <= sr <= n_udword_bits - 1
+ * q.all = n.all << (n_udword_bits - sr);
+ * r.all = n.all >> sr;
+ */
+ if (sr == n_uword_bits)
+ {
+ q.s.low = 0;
+ q.s.high = n.s.low;
+ r.s.high = 0;
+ r.s.low = n.s.high;
+ }
+ else if (sr < n_uword_bits) // 2 <= sr <= n_uword_bits - 1
+ {
+ q.s.low = 0;
+ q.s.high = n.s.low << (n_uword_bits - sr);
+ r.s.high = n.s.high >> sr;
+ r.s.low = (n.s.high << (n_uword_bits - sr)) | (n.s.low >> sr);
+ }
+ else // n_uword_bits + 1 <= sr <= n_udword_bits - 1
+ {
+ q.s.low = n.s.low << (n_udword_bits - sr);
+ q.s.high = (n.s.high << (n_udword_bits - sr)) |
+ (n.s.low >> (sr - n_uword_bits));
+ r.s.high = 0;
+ r.s.low = n.s.high >> (sr - n_uword_bits);
+ }
+ }
+ else
+ {
+ /* K X
+ * ---
+ * K K
+ */
+ sr = __builtin_clz(d.s.high) - __builtin_clz(n.s.high);
+ /* 0 <= sr <= n_uword_bits - 1 or sr large */
+ if (sr > n_uword_bits - 1)
+ {
+ if (rem)
+ *rem = n.all;
+ return 0;
+ }
+ ++sr;
+ /* 1 <= sr <= n_uword_bits */
+ /* q.all = n.all << (n_udword_bits - sr); */
+ q.s.low = 0;
+ if (sr == n_uword_bits)
+ {
+ q.s.high = n.s.low;
+ r.s.high = 0;
+ r.s.low = n.s.high;
+ }
+ else
+ {
+ q.s.high = n.s.low << (n_uword_bits - sr);
+ r.s.high = n.s.high >> sr;
+ r.s.low = (n.s.high << (n_uword_bits - sr)) | (n.s.low >> sr);
+ }
+ }
+ }
+ /* Not a special case
+ * q and r are initialized with:
+ * q.all = n.all << (n_udword_bits - sr);
+ * r.all = n.all >> sr;
+ * 1 <= sr <= n_udword_bits - 1
+ */
+ su_int carry = 0;
+ for (; sr > 0; --sr)
+ {
+ /* r:q = ((r:q) << 1) | carry */
+ r.s.high = (r.s.high << 1) | (r.s.low >> (n_uword_bits - 1));
+ r.s.low = (r.s.low << 1) | (q.s.high >> (n_uword_bits - 1));
+ q.s.high = (q.s.high << 1) | (q.s.low >> (n_uword_bits - 1));
+ q.s.low = (q.s.low << 1) | carry;
+ /* carry = 0;
+ * if (r.all >= d.all)
+ * {
+ * r.all -= d.all;
+ * carry = 1;
+ * }
+ */
+ const di_int s = (di_int)(d.all - r.all - 1) >> (n_udword_bits - 1);
+ carry = s & 1;
+ r.all -= d.all & s;
+ }
+ q.all = (q.all << 1) | carry;
+ if (rem)
+ *rem = r.all;
+ return q.all;
+}