From 102b0d2daa97dae68d3eed54d8fe37a9cc38a892 Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Sun, 28 Apr 2024 11:13:47 +0200 Subject: Adding upstream version 2.8.0+dfsg. Signed-off-by: Daniel Baumann --- lib/compiler-rt/builtins/ctzdi2.c | 35 +++++++++++++++++++++++++++++++++++ 1 file changed, 35 insertions(+) create mode 100644 lib/compiler-rt/builtins/ctzdi2.c (limited to 'lib/compiler-rt/builtins/ctzdi2.c') diff --git a/lib/compiler-rt/builtins/ctzdi2.c b/lib/compiler-rt/builtins/ctzdi2.c new file mode 100644 index 0000000..26c908d --- /dev/null +++ b/lib/compiler-rt/builtins/ctzdi2.c @@ -0,0 +1,35 @@ +//===-- ctzdi2.c - Implement __ctzdi2 -------------------------------------===// +// +// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. +// See https://llvm.org/LICENSE.txt for license information. +// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception +// +//===----------------------------------------------------------------------===// +// +// This file implements __ctzdi2 for the compiler_rt library. +// +//===----------------------------------------------------------------------===// + +#include "int_lib.h" + +// Returns: the number of trailing 0-bits + +#if !defined(__clang__) && \ + ((defined(__sparc__) && defined(__arch64__)) || defined(__mips64) || \ + (defined(__riscv) && __SIZEOF_POINTER__ >= 8)) +// On 64-bit architectures with neither a native clz instruction nor a native +// ctz instruction, gcc resolves __builtin_ctz to __ctzdi2 rather than +// __ctzsi2, leading to infinite recursion. +#define __builtin_ctz(a) __ctzsi2(a) +extern int __ctzsi2(si_int); +#endif + +// Precondition: a != 0 + +COMPILER_RT_ABI int __ctzdi2(di_int a) { + dwords x; + x.all = a; + const si_int f = -(x.s.low == 0); + return ctzsi((x.s.high & f) | (x.s.low & ~f)) + + (f & ((si_int)(sizeof(si_int) * CHAR_BIT))); +} -- cgit v1.2.3