Initial import of compiler-rt.

 -

llvm-svn: 74292

1 files changed, 34 insertions, 0 deletions

diff --git a/compiler-rt/lib/divti3.c b/compiler-rt/lib/divti3.c
new file mode 100644
index 00000000000..b8eda254cba
--- /dev/null
+++ b/compiler-rt/lib/divti3.c
@@ -0,0 +1,34 @@
+//===-- divti3.c - Implement __divti3 -------------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file implements __divti3 for the compiler_rt library.
+//
+//===----------------------------------------------------------------------===//
+
+#if __x86_64
+
+#include "int_lib.h"
+
+tu_int __udivmodti4(tu_int a, tu_int b, tu_int* rem);
+
+// Returns: a / b
+
+ti_int
+__divti3(ti_int a, ti_int b)
+{
+    const int bits_in_tword_m1 = (int)(sizeof(ti_int) * CHAR_BIT) - 1;
+    ti_int s_a = a >> bits_in_tword_m1;           // s_a = a < 0 ? -1 : 0
+    ti_int s_b = b >> bits_in_tword_m1;           // s_b = b < 0 ? -1 : 0
+    a = (a ^ s_a) - s_a;                         // negate if s_a == -1
+    b = (b ^ s_b) - s_b;                         // negate if s_b == -1
+    s_a ^= s_b;                                  // sign of quotient
+    return (__udivmodti4(a, b, (tu_int*)0) ^ s_a) - s_a;  // negate if s_a == -1
+}
+
+#endif