From 59077a9fd34986482ee980cc6b1b989fced0d65a Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Timo=20Ter=C3=A4s?= <timo.teras@iki.fi>
Date: Tue, 1 Apr 2014 10:53:23 +0300
Subject: [PATCH 1/1] use armv6+ opcodes for atomics if targetting such
 architecture

---
 Makefile                | 6 ++++++
 arch/arm/atomic.h       | 4 ++++
 arch/arm/pthread_arch.h | 7 ++++++-
 src/thread/arm/tls.S    | 9 +++++++++
 src/thread/arm/tls.s    | 4 ----
 5 files changed, 25 insertions(+), 5 deletions(-)
 create mode 100644 src/thread/arm/tls.S
 delete mode 100644 src/thread/arm/tls.s

diff --git a/Makefile b/Makefile
index 0ab0bfd..b96c76b 100644
--- a/Makefile
+++ b/Makefile
@@ -111,6 +111,9 @@ $(foreach s,$(wildcard src/*/$(ARCH)*/*.s),$(eval $(call mkasmdep,$(s))))
 %.o: $(ARCH)/%.s
 	$(CC) $(CFLAGS_ALL_STATIC) -c -o $@ $<
 
+%.o: $(ARCH)/%.s
+	$(CC) $(CFLAGS_ALL_STATIC) -c -o $@ $<
+
 %.o: %.c $(GENH) $(IMPH)
 	$(CC) $(CFLAGS_ALL_STATIC) -c -o $@ $<
 
@@ -120,6 +123,9 @@ $(foreach s,$(wildcard src/*/$(ARCH)*/*.s),$(eval $(call mkasmdep,$(s))))
 %.lo: $(ARCH)/%.s
 	$(CC) $(CFLAGS_ALL_SHARED) -c -o $@ $<
 
+%.lo: $(ARCH)/%.S
+	$(CC) $(CFLAGS_ALL_SHARED) -c -o $@ $<
+
 %.lo: %.c $(GENH) $(IMPH)
 	$(CC) $(CFLAGS_ALL_SHARED) -c -o $@ $<
 
diff --git a/arch/arm/atomic.h b/arch/arm/atomic.h
index 734d287..cb8fb31 100644
--- a/arch/arm/atomic.h
+++ b/arch/arm/atomic.h
@@ -22,7 +22,11 @@ static inline int a_ctz_64(uint64_t x)
 	return a_ctz_l(y);
 }
 
+#ifdef __GCC_HAVE_SYNC_COMPARE_AND_SWAP_4
+#define __k_cas(t, s, p) (!__sync_bool_compare_and_swap(p, t, s))
+#else
 #define __k_cas ((int (*)(int, int, volatile int *))0xffff0fc0)
+#endif
 
 static inline int a_cas(volatile int *p, int t, int s)
 {
diff --git a/arch/arm/pthread_arch.h b/arch/arm/pthread_arch.h
index 43a1c01..3ac2779 100644
--- a/arch/arm/pthread_arch.h
+++ b/arch/arm/pthread_arch.h
@@ -1,7 +1,12 @@
+#ifdef __GCC_HAVE_SYNC_COMPARE_AND_SWAP_4
+char *__aeabi_read_tp(void) __attribute__((const));
+#define __pthread_self() \
+	((pthread_t)((char *)__aeabi_read_tp()+8-sizeof(struct pthread)))
+#else
 typedef char *(*__ptr_func_t)(void) __attribute__((const));
-
 #define __pthread_self() \
 	((pthread_t)(((__ptr_func_t)0xffff0fe0)()+8-sizeof(struct pthread)))
+#endif
 
 #define TLS_ABOVE_TP
 #define TP_ADJ(p) ((char *)(p) + sizeof(struct pthread) - 8)
diff --git a/src/thread/arm/tls.S b/src/thread/arm/tls.S
new file mode 100644
index 0000000..f255e83
--- /dev/null
+++ b/src/thread/arm/tls.S
@@ -0,0 +1,9 @@
+.global __aeabi_read_tp
+.type __aeabi_read_tp,%function
+__aeabi_read_tp:
+#ifdef __GCC_HAVE_SYNC_COMPARE_AND_SWAP_4
+	.inst 0xee1d0f70 /* mrc 15,0,r0,cr13,cr0,{3} */
+	bx lr
+#else
+	ldr pc,=0xffff0fe0
+#endif
diff --git a/src/thread/arm/tls.s b/src/thread/arm/tls.s
deleted file mode 100644
index 59736ac..0000000
--- a/src/thread/arm/tls.s
+++ /dev/null
@@ -1,4 +0,0 @@
-.global __aeabi_read_tp
-.type __aeabi_read_tp,%function
-__aeabi_read_tp:
-	ldr pc,=0xffff0fe0
-- 
1.9.1