OK for 4.6?
2012-06-18 Joey Ye <joey...@arm.com>
Backport from mainline
2011-10-14 David Alan Gilbert <david.gilb...@linaro.org>
PR target/48126
* config/arm/arm.c (arm_output_sync_loop): Move label before
barrier.
Index: gcc/config/arm/arm.c
===================================================================
--- gcc/config/arm/arm.c (revision 188331)
+++ gcc/config/arm/arm.c (working copy)
@@ -23423,8 +23423,11 @@
}
}
+ /* Note: label is before barrier so that in cmp failure case we still get
+ a barrier to stop subsequent loads floating upwards past the ldrex
+ PR target/48126. */
+ arm_output_asm_insn (emit, 1, operands, "%sLSYB%%=:",
LOCAL_LABEL_PREFIX);
arm_process_output_memory_barrier (emit, NULL);
- arm_output_asm_insn (emit, 1, operands, "%sLSYB%%=:",
LOCAL_LABEL_PREFIX);
}
static rtx
Index: gcc/config/arm/arm.h
===================================================================
--- gcc/config/arm/arm.h (revision 188331)
+++ gcc/config/arm/arm.h (working copy)
@@ -294,7 +294,8 @@
#define TARGET_HAVE_DMB (arm_arch7)
/* Nonzero if this chip implements a memory barrier via CP15. */
-#define TARGET_HAVE_DMB_MCR (arm_arch6k && ! TARGET_HAVE_DMB)
+#define TARGET_HAVE_DMB_MCR (arm_arch6 && ! TARGET_HAVE_DMB \
+ && ! TARGET_THUMB1)
/* Nonzero if this chip implements a memory barrier instruction. */
#define TARGET_HAVE_MEMORY_BARRIER (TARGET_HAVE_DMB || TARGET_HAVE_DMB_MCR)
