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Reapply r230021, r276851 and a few other commits to compiler-rt

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Reapply r230021 (by ed):

Add a workaround to prevent endless recursion in compiler-rt.

SPARC and MIPS CPUs don't have special instructions to count
leading/trailing zeroes. The compiler-rt library provides fallback
rountines for these. The 64-bit routines, __clzdi2 and __ctzdi2, are
implemented as simple wrappers around the compiler built-in
__builtin_clz(), assuming these will expand to either 32-bit
CPU instructions or calls to __clzsi2 and __ctzsi2.

Unfortunately, our GCC 4.2 probably thinks that because the operand is
stored in a 64-bit register, it might just be a better idea to invoke
its 64-bit equivalent, simply resulting into endless recursion. Fix this
by defining __builtin_clz and __builtin_ctz to __clzsi2 and __ctzsi2
explicitly.

Reapply r276851:

Update compiler-rt to trunk r224034.  This brings a number of new
builtins, and also the various sanitizers.  Support for these will be
added in a later commit.
This commit is contained in:
Dimitry Andric 2020-08-02 18:07:16 +00:00
parent 979e22ff1a
commit 71daeec70a
1 changed files with 26 additions and 1 deletions
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27
contrib/llvm-project/compiler-rt/lib/builtins/int_lib.h
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@ -21,7 +21,9 @@
// ABI macro definitions
#if __ARM_EABI__
#ifdef COMPILER_RT_ARMHF_TARGET
#if defined(COMPILER_RT_ARMHF_TARGET) || (!defined(__clang__) && \
defined(__GNUC__) && (__GNUC__ < 4 || __GNUC__ == 4 && __GNUC_MINOR__ < 5))
// The pcs attribute was introduced in GCC 4.5.0
#define COMPILER_RT_ABI
#else
#define COMPILER_RT_ABI __attribute__((__pcs__("aapcs")))
@ -92,6 +94,29 @@
// Include internal utility function declarations.
#include "int_util.h"
/*
* Workaround for LLVM bug 11663. Prevent endless recursion in
* __c?zdi2(), where calls to __builtin_c?z() are expanded to
* __c?zdi2() instead of __c?zsi2().
*
* Instead of placing this workaround in c?zdi2.c, put it in this
* global header to prevent other C files from making the detour
* through __c?zdi2() as well.
*
* This problem has been observed on FreeBSD for sparc64 and
* mips64 with GCC 4.2.1, and for riscv with GCC 5.2.0.
* Presumably it's any version of GCC, and targeting an arch that
* does not have dedicated bit counting instructions.
*/
#if defined(__FreeBSD__) && (defined(__sparc64__) || \
defined(__mips_n32) || defined(__mips_n64) || defined(__mips_o64) || \
defined(__riscv))
si_int __clzsi2(si_int);
si_int __ctzsi2(si_int);
#define __builtin_clz __clzsi2
#define __builtin_ctz __ctzsi2
#endif /* FreeBSD && (sparc64 || mips_n32 || mips_n64 || mips_o64 || riscv) */
COMPILER_RT_ABI int __paritysi2(si_int a);
COMPILER_RT_ABI int __paritydi2(di_int a);