Skip to content

GitLab

Switch branch/tag
Find file BlameHistoryPermalink
  • Sandrine Bailleux's avatar
    Import ctzdi2.c from LLVM compiler-rt · 7bba6884
    Sandrine Bailleux authored 
    
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: default avatarSandrine Bailleux <sandrine.bailleux@arm.com>
    7bba6884
ctzdi2.c 836 Bytes
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 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)));
}