From 194098779f7d28ee8f147b0fa8a8423a53149afa Mon Sep 17 00:00:00 2001
From: Dimitry Andric <dim@FreeBSD.org>
Date: Tue, 8 Sep 2020 20:28:39 +0000
Subject: [PATCH] Revert r365471 as it is breaking with old gcc on various
 arches:

MFC r364753:

Add atomic and bswap functions to libcompiler_rt

There have been several mentions on our mailing lists about missing
atomic functions in our system libraries (e.g. __atomic_load_8 and
friends), and recently I saw __bswapdi2 and __bswapsi2 mentioned too.

To address this, add implementations for the functions from compiler-rt
to the system compiler support libraries, e.g. libcompiler_rt.a and and
libgcc_s.so.

This also needs a small fixup in compiler-rt's atomic.c, to ensure that
32-bit mips can build correctly.

Bump __FreeBSD_version to make it easier for port maintainers to detect
when these functions were added.

PR:		230888
Differential Revision: https://reviews.freebsd.org/D26159

MFC r364782:

After r364753, there should be no need to suppress -Watomic-alignment
warnings anymore for compiler-rt's atomic.c. This occurred because the
IS_LOCK_FREE_8 macro was not correctly defined to 0 for mips, and this
caused the compiler to emit a runtime call to __atomic_is_lock_free(),
and that triggers the warning.
---
 .../compiler-rt/lib/builtins/atomic.c          |  4 ++--
 lib/libcompiler_rt/Makefile.inc                | 18 +++++++++++++++---
 2 files changed, 17 insertions(+), 5 deletions(-)

diff --git a/contrib/llvm-project/compiler-rt/lib/builtins/atomic.c b/contrib/llvm-project/compiler-rt/lib/builtins/atomic.c
index 4573a547eb6..ee790235cb8 100644
--- a/contrib/llvm-project/compiler-rt/lib/builtins/atomic.c
+++ b/contrib/llvm-project/compiler-rt/lib/builtins/atomic.c
@@ -124,8 +124,8 @@ static __inline Lock *lock_for_pointer(void *ptr) {
 #define IS_LOCK_FREE_2 __c11_atomic_is_lock_free(2)
 #define IS_LOCK_FREE_4 __c11_atomic_is_lock_free(4)
 
-/// 32 bit MIPS and PowerPC don't support 8-byte lock_free atomics
-#if defined(__mips__) || (!defined(__powerpc64__) && defined(__powerpc__))
+/// 32 bit PowerPC doesn't support 8-byte lock_free atomics
+#if !defined(__powerpc64__) && defined(__powerpc__)
 #define IS_LOCK_FREE_8 0
 #else
 #define IS_LOCK_FREE_8 __c11_atomic_is_lock_free(8)
diff --git a/lib/libcompiler_rt/Makefile.inc b/lib/libcompiler_rt/Makefile.inc
index 7fb5c6217ce..4d77b9bb710 100644
--- a/lib/libcompiler_rt/Makefile.inc
+++ b/lib/libcompiler_rt/Makefile.inc
@@ -18,9 +18,6 @@ SRCF+=		ashldi3
 SRCF+=		ashlti3
 SRCF+=		ashrdi3
 SRCF+=		ashrti3
-SRCF+=		atomic
-SRCF+=		bswapdi2
-SRCF+=		bswapsi2
 SRCF+=		clear_cache
 SRCF+=		clzdi2
 SRCF+=		clzsi2
@@ -216,6 +213,12 @@ CFLAGS+=	-DEMIT_SYNC_ATOMICS
 SRCF+=		stdatomic
 .endif
 
+.if "${COMPILER_TYPE}" == "clang" && \
+    (${MACHINE_ARCH} == "powerpc" || ${MACHINE_ARCH} == "powerpcspe")
+SRCS+=          atomic.c
+CFLAGS.atomic.c+=      -Wno-atomic-alignment
+.endif
+
 .for file in ${SRCF}
 .if ${MACHINE_ARCH:Marmv[67]*} && (!defined(CPUTYPE) || ${CPUTYPE:M*soft*} == "") \
     && exists(${CRTSRC}/${CRTARCH}/${file}vfp.S)
@@ -237,9 +240,18 @@ SRCS+=		aeabi_memmove.S
 SRCS+=		aeabi_memset.S
 SRCS+=		aeabi_uidivmod.S
 SRCS+=		aeabi_uldivmod.S
+SRCS+=		bswapdi2.S
+SRCS+=		bswapsi2.S
 SRCS+=		switch16.S
 SRCS+=		switch32.S
 SRCS+=		switch8.S
 SRCS+=		switchu8.S
 SRCS+=		sync_synchronize.S
 .endif
+
+# On some archs GCC-6.3 requires bswap32 built-in.
+.if ${MACHINE_CPUARCH} == "mips" || ${MACHINE_CPUARCH} == "riscv" || \
+    ${MACHINE_CPUARCH} == "sparc64"
+SRCS+=		bswapdi2.c
+SRCS+=		bswapsi2.c
+.endif
-- 
2.45.0