tools: Remove feature-sync-compare-and-swap feature detection

Since the __sync functions have been removed from perf, it's needless
for perf tool to test the feature sync-compare-and-swap.

The feature test is not used by any other components, remove it.
Signed-off-by: NLeo Yan <leo.yan@linaro.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Andrii Nakryiko <andriin@fb.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Daniel Díaz <daniel.diaz@linaro.org>
Cc: Frank Ch. Eigler <fche@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
Cc: Michael Petlan <mpetlan@redhat.com>
Cc: Mike Leach <mike.leach@linaro.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Sedat Dilek <sedat.dilek@gmail.com>
Cc: Song Liu <songliubraving@fb.com>
Cc: Suzuki Poulouse <suzuki.poulose@arm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: coresight@lists.linaro.org
Cc: x86@kernel.org
Link: http://lore.kernel.org/lkml/20210809111407.596077-10-leo.yan@linaro.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

tools/build/Makefile.feature

@@ -34,7 +34,6 @@ FEATURE_TESTS_BASIC :=                  \
         dwarf_getlocations              \
         eventfd                         \
         fortify-source                  \
-        sync-compare-and-swap           \
         get_current_dir_name            \
         gettid				\
         glibc                           \

tools/build/feature/Makefile

@@ -9,7 +9,6 @@ FILES=                                          \
          test-dwarf_getlocations.bin            \
          test-eventfd.bin                       \
          test-fortify-source.bin                \
-         test-sync-compare-and-swap.bin         \
          test-get_current_dir_name.bin          \
          test-glibc.bin                         \
          test-gtk2.bin                          \
@@ -260,9 +259,6 @@ $(OUTPUT)test-libdw-dwarf-unwind.bin:
 $(OUTPUT)test-libbabeltrace.bin:
 	$(BUILD) # -lbabeltrace provided by $(FEATURE_CHECK_LDFLAGS-libbabeltrace)
 
-$(OUTPUT)test-sync-compare-and-swap.bin:
-	$(BUILD)
-
 $(OUTPUT)test-compile-32.bin:
 	$(CC) -m32 -o $@ test-compile.c
 

tools/build/feature/test-all.c

@@ -106,10 +106,6 @@
 # include "test-libdw-dwarf-unwind.c"
 #undef main
 
-#define main main_test_sync_compare_and_swap
-# include "test-sync-compare-and-swap.c"
-#undef main
-
 #define main main_test_zlib
 # include "test-zlib.c"
 #undef main

tools/build/feature/test-sync-compare-and-swap.c

-// SPDX-License-Identifier: GPL-2.0
-#include <stdint.h>
-
-volatile uint64_t x;
-
-int main(int argc, char *argv[])
-{
-	uint64_t old, new = argc;
-
-	(void)argv;
-	do {
-		old = __sync_val_compare_and_swap(&x, 0, 0);
-	} while (!__sync_bool_compare_and_swap(&x, old, new));
-	return old == new;
-}