+/* Is this register part of the register window system? A yes answer
+ implies that 1) The name of this register will not be the same in
+ other frames, and 2) This register is automatically "saved" upon
+ subroutine calls and thus there is no need to search more than one
+ stack frame for it.
+
+ On the i960, in fact, the name of this register in another frame is
+ "mud" -- there is no overlap between the windows. Each window is
+ simply saved into the stack (true for our purposes, after having been
+ flushed; normally they reside on-chip and are restored from on-chip
+ without ever going to memory). */
+
+static int
+register_in_window_p (int regnum)
+{
+ return regnum <= R15_REGNUM;
+}
+
+/* i960_find_saved_register ()
+
+ Return the address in which frame FRAME's value of register REGNUM
+ has been saved in memory. Or return zero if it has not been saved.
+ If REGNUM specifies the SP, the value we return is actually the SP
+ value, not an address where it was saved. */
+
+static CORE_ADDR
+i960_find_saved_register (struct frame_info *frame, int regnum)
+{
+ register struct frame_info *frame1 = NULL;
+ register CORE_ADDR addr = 0;
+
+ if (frame == NULL) /* No regs saved if want current frame */
+ return 0;
+
+ /* We assume that a register in a register window will only be saved
+ in one place (since the name changes and/or disappears as you go
+ towards inner frames), so we only call get_frame_saved_regs on
+ the current frame. This is directly in contradiction to the
+ usage below, which assumes that registers used in a frame must be
+ saved in a lower (more interior) frame. This change is a result
+ of working on a register window machine; get_frame_saved_regs
+ always returns the registers saved within a frame, within the
+ context (register namespace) of that frame. */
+
+ /* However, note that we don't want this to return anything if
+ nothing is saved (if there's a frame inside of this one). Also,
+ callers to this routine asking for the stack pointer want the
+ stack pointer saved for *this* frame; this is returned from the
+ next frame. */
+
+ if (register_in_window_p (regnum))
+ {
+ frame1 = get_next_frame (frame);
+ if (!frame1)
+ return 0; /* Registers of this frame are active. */
+
+ /* Get the SP from the next frame in; it will be this
+ current frame. */
+ if (regnum != SP_REGNUM)
+ frame1 = frame;
+
+ FRAME_INIT_SAVED_REGS (frame1);
+ return frame1->saved_regs[regnum]; /* ... which might be zero */
+ }
+
+ /* Note that this next routine assumes that registers used in
+ frame x will be saved only in the frame that x calls and
+ frames interior to it. This is not true on the sparc, but the
+ above macro takes care of it, so we should be all right. */
+ while (1)
+ {
+ QUIT;
+ frame1 = get_next_frame (frame);
+ if (frame1 == 0)
+ break;
+ frame = frame1;
+ FRAME_INIT_SAVED_REGS (frame1);
+ if (frame1->saved_regs[regnum])
+ addr = frame1->saved_regs[regnum];
+ }
+
+ return addr;
+}
+
+/* i960_get_saved_register ()
+
+ Find register number REGNUM relative to FRAME and put its (raw,
+ target format) contents in *RAW_BUFFER. Set *OPTIMIZED if the
+ variable was optimized out (and thus can't be fetched). Set *LVAL
+ to lval_memory, lval_register, or not_lval, depending on whether
+ the value was fetched from memory, from a register, or in a strange
+ and non-modifiable way (e.g. a frame pointer which was calculated
+ rather than fetched). Set *ADDRP to the address, either in memory
+ on as a REGISTER_BYTE offset into the registers array.
+
+ Note that this implementation never sets *LVAL to not_lval. But it
+ can be replaced by defining GET_SAVED_REGISTER and supplying your
+ own.
+
+ The argument RAW_BUFFER must point to aligned memory. */
+
+void
+i960_get_saved_register (char *raw_buffer,
+ int *optimized,
+ CORE_ADDR *addrp,
+ struct frame_info *frame,
+ int regnum,
+ enum lval_type *lval)
+{
+ CORE_ADDR addr;
+
+ if (!target_has_registers)
+ error ("No registers.");
+
+ /* Normal systems don't optimize out things with register numbers. */
+ if (optimized != NULL)
+ *optimized = 0;
+ addr = i960_find_saved_register (frame, regnum);
+ if (addr != 0)
+ {
+ if (lval != NULL)
+ *lval = lval_memory;
+ if (regnum == SP_REGNUM)
+ {
+ if (raw_buffer != NULL)
+ {
+ /* Put it back in target format. */
+ store_address (raw_buffer, REGISTER_RAW_SIZE (regnum),
+ (LONGEST) addr);
+ }
+ if (addrp != NULL)
+ *addrp = 0;
+ return;
+ }
+ if (raw_buffer != NULL)
+ target_read_memory (addr, raw_buffer, REGISTER_RAW_SIZE (regnum));
+ }
+ else
+ {
+ if (lval != NULL)
+ *lval = lval_register;
+ addr = REGISTER_BYTE (regnum);
+ if (raw_buffer != NULL)
+ read_register_gen (regnum, raw_buffer);
+ }
+ if (addrp != NULL)
+ *addrp = addr;
+}
+\f