[compiler-rt] Add AArch64 to CMake configuration and several missing builtins

Summary:
Currently CMake doesn't build builtins for AArch64 and if one does this anyway
it's likely that at least `__multc3`, `__floatditf` and `__floatunditf` will be
missing.  There is actually more builtins to add, but these come from
different libc implementations, thus providing them makes compiler-rt for
AArch64 good enough at least for basic usage.

Builtins implementation were originally taken from FreeBSD project:

 * [[ https://reviews.freebsd.org/D2173 | __multc3 ]]
 * [[ https://reviews.freebsd.org/D2174 | __floatditf and __floatunditf ]]

Until they have been tested to find mistakes in `__float*` functions.
`__floatditf` was based on `__floatsitf`, which had the same mistakes
(fixed it in r243746).

Version of the builtins in this patch are fixed and complemented with basic
tests.  Additionally they were tested via GCC's torture (this is what revealed
these issues).

P.S. Ed (author of FreeBSD patches) asked for feedback on the list some time ago (here [[ http://lists.cs.uiuc.edu/pipermail/llvmdev/2015-March/084064.html | here ]])
and got no response, but it seems to be worth adding these builtins as is and
extracting common part later.

Reviewers: howard.hinnant, t.p.northover, jmolloy, enefaim, rengolin, zatrazz

Subscribers: asl, emaste, samsonov, aemerson, llvm-commits, rengolin

Differential Revision: http://reviews.llvm.org/D11679

git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk@245296 91177308-0d34-0410-b5e6-96231b3b80d8

3 files changed, 138 insertions, 2 deletions

diff --git a/test/builtins/Unit/floatditf_test.c b/test/builtins/Unit/floatditf_test.c
new file mode 100644
index 000000000..8cf8a0859
--- /dev/null
+++ b/test/builtins/Unit/floatditf_test.c
@@ -0,0 +1,69 @@
+//===-- floatditf_test.c - Test __floatditf -------------------------------===//
+//
+//                     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 tests __floatditf for the compiler_rt library.
+//
+//===----------------------------------------------------------------------===//
+
+#include "int_lib.h"
+#include <math.h>
+#include <complex.h>
+#include <stdio.h>
+
+#if __LDBL_MANT_DIG__ == 113
+
+#include "fp_test.h"
+
+// Returns: long integer converted to long double
+
+COMPILER_RT_ABI long double __floatditf(long long a);
+
+int test__floatditf(long long a, uint64_t expectedHi, uint64_t expectedLo)
+{
+    long double x = __floatditf(a);
+    int ret = compareResultLD(x, expectedHi, expectedLo);
+
+    if (ret)
+        printf("error in __floatditf(%Ld) = %.20Lf, "
+               "expected %.20Lf\n", a, x, fromRep128(expectedHi, expectedLo));
+    return ret;
+}
+
+char assumption_1[sizeof(long double) * CHAR_BIT == 128] = {0};
+
+#endif
+
+int main()
+{
+#if __LDBL_MANT_DIG__ == 113
+    if (test__floatditf(0x7fffffffffffffff, UINT64_C(0x403dffffffffffff), UINT64_C(0xfffc000000000000)))
+        return 1;
+    if (test__floatditf(0x123456789abcdef1, UINT64_C(0x403b23456789abcd), UINT64_C(0xef10000000000000)))
+        return 1;
+    if (test__floatditf(0x2, UINT64_C(0x4000000000000000), UINT64_C(0x0)))
+        return 1;
+    if (test__floatditf(0x1, UINT64_C(0x3fff000000000000), UINT64_C(0x0)))
+        return 1;
+    if (test__floatditf(0x0, UINT64_C(0x0), UINT64_C(0x0)))
+        return 1;
+    if (test__floatditf(0xffffffffffffffff, UINT64_C(0xbfff000000000000), UINT64_C(0x0)))
+        return 1;
+    if (test__floatditf(0xfffffffffffffffe, UINT64_C(0xc000000000000000), UINT64_C(0x0)))
+        return 1;
+    if (test__floatditf(-0x123456789abcdef1, UINT64_C(0xc03b23456789abcd), UINT64_C(0xef10000000000000)))
+        return 1;
+    if (test__floatditf(0x8000000000000000, UINT64_C(0xc03e000000000000), UINT64_C(0x0)))
+        return 1;
+
+#else
+    printf("skipped\n");
+
+#endif
+    return 0;
+}
diff --git a/test/builtins/Unit/floatunditf_test.c b/test/builtins/Unit/floatunditf_test.c
new file mode 100644
index 000000000..b66a174a3
--- /dev/null
+++ b/test/builtins/Unit/floatunditf_test.c
@@ -0,0 +1,67 @@
+//===-- floatunditf_test.c - Test __floatunditf ---------------------------===//
+//
+//                     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 tests __floatunditf for the compiler_rt library.
+//
+//===----------------------------------------------------------------------===//
+
+#include "int_lib.h"
+#include <math.h>
+#include <complex.h>
+#include <stdio.h>
+
+#if __LDBL_MANT_DIG__ == 113
+
+#include "fp_test.h"
+
+// Returns: long integer converted to long double
+
+COMPILER_RT_ABI long double __floatunditf(unsigned long long a);
+
+int test__floatunditf(unsigned long long a, uint64_t expectedHi, uint64_t expectedLo)
+{
+    long double x = __floatunditf(a);
+    int ret = compareResultLD(x, expectedHi, expectedLo);
+
+    if (ret)
+        printf("error in __floatunditf(%Lu) = %.20Lf, "
+               "expected %.20Lf\n", a, x, fromRep128(expectedHi, expectedLo));
+    return ret;
+}
+
+char assumption_1[sizeof(long double) * CHAR_BIT == 128] = {0};
+
+#endif
+
+int main()
+{
+#if __LDBL_MANT_DIG__ == 113
+    if (test__floatunditf(0xffffffffffffffffULL, UINT64_C(0x403effffffffffff), UINT64_C(0xfffe000000000000)))
+        return 1;
+    if (test__floatunditf(0xfffffffffffffffeULL, UINT64_C(0x403effffffffffff), UINT64_C(0xfffc000000000000)))
+        return 1;
+    if (test__floatunditf(0x8000000000000000ULL, UINT64_C(0x403e000000000000), UINT64_C(0x0)))
+        return 1;
+    if (test__floatunditf(0x7fffffffffffffffULL, UINT64_C(0x403dffffffffffff), UINT64_C(0xfffc000000000000)))
+        return 1;
+    if (test__floatunditf(0x123456789abcdef1ULL, UINT64_C(0x403b23456789abcd), UINT64_C(0xef10000000000000)))
+        return 1;
+    if (test__floatunditf(0x2ULL, UINT64_C(0x4000000000000000), UINT64_C(0x0)))
+        return 1;
+    if (test__floatunditf(0x1ULL, UINT64_C(0x3fff000000000000), UINT64_C(0x0)))
+        return 1;
+    if (test__floatunditf(0x0ULL, UINT64_C(0x0), UINT64_C(0x0)))
+        return 1;
+
+#else
+    printf("skipped\n");
+
+#endif
+    return 0;
+}
diff --git a/test/builtins/Unit/multc3_test.c b/test/builtins/Unit/multc3_test.c
index b1482638a..f6cf4ca87 100644
--- a/test/builtins/Unit/multc3_test.c
+++ b/test/builtins/Unit/multc3_test.c
@@ -13,7 +13,7 @@
 
 #include <stdio.h>
 
-#if _ARCH_PPC
+#if _ARCH_PPC || __aarch64__
 
 #include "int_lib.h"
 #include <math.h>
@@ -357,7 +357,7 @@ long double x[][2] =
 
 int main()
 {
-#if _ARCH_PPC
+#if _ARCH_PPC || __aarch64__
     const unsigned N = sizeof(x) / sizeof(x[0]);
     unsigned i, j;
     for (i = 0; i < N; ++i)