Import ctzdi2.c from LLVM compiler-rt
When using __builtin_ctzll() in AArch32 code, the compiler may translate
that into a call to the __ctzdi2() function. In this case, the linking
phase fails because TF doesn't provide an implementation for it.
This patch imports the implementation of the __ctzdi2() function from
LLVM's compiler-rt project and hooks it into TF's build system. The
ctzdi2.c file is an unmodified copy from the master branch as of
July 19 2017 (SVN revision: 308480).
Change-Id: I96766a025ba28e1afc6ef6a5c4ef91d85fc8f32b
Signed-off-by: Sandrine Bailleux <sandrine.bailleux@arm.com>
diff --git a/lib/compiler-rt/builtins/ctzdi2.c b/lib/compiler-rt/builtins/ctzdi2.c
new file mode 100644
index 0000000..db3c6fd
--- /dev/null
+++ b/lib/compiler-rt/builtins/ctzdi2.c
@@ -0,0 +1,29 @@
+/* ===-- ctzdi2.c - Implement __ctzdi2 -------------------------------------===
+ *
+ * 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 __ctzdi2 for the compiler_rt library.
+ *
+ * ===----------------------------------------------------------------------===
+ */
+
+#include "int_lib.h"
+
+/* Returns: the number of trailing 0-bits */
+
+/* Precondition: a != 0 */
+
+COMPILER_RT_ABI si_int
+__ctzdi2(di_int a)
+{
+ dwords x;
+ x.all = a;
+ const si_int f = -(x.s.low == 0);
+ return __builtin_ctz((x.s.high & f) | (x.s.low & ~f)) +
+ (f & ((si_int)(sizeof(si_int) * CHAR_BIT)));
+}
diff --git a/lib/compiler-rt/compiler-rt.mk b/lib/compiler-rt/compiler-rt.mk
index 3bdd319..cb5ab31 100644
--- a/lib/compiler-rt/compiler-rt.mk
+++ b/lib/compiler-rt/compiler-rt.mk
@@ -30,5 +30,6 @@
ifeq (${ARCH},aarch32)
COMPILER_RT_SRCS := lib/compiler-rt/builtins/arm/aeabi_uldivmod.S \
- lib/compiler-rt/builtins/udivmoddi4.c
+ lib/compiler-rt/builtins/udivmoddi4.c \
+ lib/compiler-rt/builtins/ctzdi2.c
endif
