compiler_rt: Import lshrdi3.c file

Imported from the LLVM compiler_rt library on master branch as of
30 Oct 2018 (SVN revision: r345645).

This is to get the __aeabi_llsr() builtin, which is required by a
subsequent patch that uses a logical right shift operator in AArch32.

Change-Id: I9884139a12855a8a87206fb572aaa7dd35582b09
Signed-off-by: Sandrine Bailleux <sandrine.bailleux@arm.com>
This commit is contained in:
Sandrine Bailleux 2018-10-31 13:37:42 +01:00
parent ecc35992f3
commit 638d2b5141
2 changed files with 47 additions and 1 deletions

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@ -0,0 +1,45 @@
/* ===-- lshrdi3.c - Implement __lshrdi3 -----------------------------------===
*
* 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 __lshrdi3 for the compiler_rt library.
*
* ===----------------------------------------------------------------------===
*/
#include "int_lib.h"
/* Returns: logical a >> b */
/* Precondition: 0 <= b < bits_in_dword */
COMPILER_RT_ABI di_int
__lshrdi3(di_int a, si_int b)
{
const int bits_in_word = (int)(sizeof(si_int) * CHAR_BIT);
udwords input;
udwords result;
input.all = a;
if (b & bits_in_word) /* bits_in_word <= b < bits_in_dword */
{
result.s.high = 0;
result.s.low = input.s.high >> (b - bits_in_word);
}
else /* 0 <= b < bits_in_word */
{
if (b == 0)
return a;
result.s.high = input.s.high >> b;
result.s.low = (input.s.high << (bits_in_word - b)) | (input.s.low >> b);
}
return result.all;
}
#if defined(__ARM_EABI__)
AEABI_RTABI di_int __aeabi_llsr(di_int a, si_int b) COMPILER_RT_ALIAS(__lshrdi3);
#endif

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@ -31,5 +31,6 @@
ifeq (${ARCH},aarch32)
COMPILER_RT_SRCS := lib/compiler-rt/builtins/arm/aeabi_uldivmod.S \
lib/compiler-rt/builtins/udivmoddi4.c \
lib/compiler-rt/builtins/ctzdi2.c
lib/compiler-rt/builtins/ctzdi2.c \
lib/compiler-rt/builtins/lshrdi3.c
endif