Clear non-significant bits of address on memory access

[deliverable/binutils-gdb.git] / gdb / gdbarch.h

diff --git a/gdb/gdbarch.h b/gdb/gdbarch.h
index d2e6b6f63ecd6de28deb032f259549b20e9411a1..1a654b625000a887e2545b604855d0d371a400f5 100644 (file)
--- a/gdb/gdbarch.h
+++ b/gdb/gdbarch.h
@@ -677,6 +677,14 @@ typedef CORE_ADDR (gdbarch_addr_bits_remove_ftype) (struct gdbarch *gdbarch, COR
 extern CORE_ADDR gdbarch_addr_bits_remove (struct gdbarch *gdbarch, CORE_ADDR addr);
 extern void set_gdbarch_addr_bits_remove (struct gdbarch *gdbarch, gdbarch_addr_bits_remove_ftype *addr_bits_remove);
 
+/* On some machines, not all bits of an address word are significant.
+   For example, on AArch64, the top bits of an address known as the "tag"
+   are ignored by the kernel, the hardware, etc. and can be regarded as
+   additional data associated with the address. */
+
+extern int gdbarch_significant_addr_bit (struct gdbarch *gdbarch);
+extern void set_gdbarch_significant_addr_bit (struct gdbarch *gdbarch, int significant_addr_bit);
+
 /* FIXME/cagney/2001-01-18: This should be split in two.  A target method that
    indicates if the target needs software single step.  An ISA method to
    implement it.