IOR_REG_SET (new_live_at_end, sb->global_live_at_start);
}
- /* Force the stack pointer to be live -- which might not already be
- the case for blocks within infinite loops. */
- SET_REGNO_REG_SET (new_live_at_end, STACK_POINTER_REGNUM);
-
- /* Similarly for the frame pointer before reload. Any reference
- to any pseudo before reload is a potential reference of the
- frame pointer. */
+ /* Before reload, there are a few registers that must be forced
+ live everywhere -- which might not already be the case for
+ blocks within infinite loops. */
if (! reload_completed)
- SET_REGNO_REG_SET (new_live_at_end, FRAME_POINTER_REGNUM);
+ {
+ /* The all-important stack pointer. */
+ SET_REGNO_REG_SET (new_live_at_end, STACK_POINTER_REGNUM);
+
+ /* Any reference to any pseudo before reload is a potential
+ reference of the frame pointer. */
+ SET_REGNO_REG_SET (new_live_at_end, FRAME_POINTER_REGNUM);
+
+#if FRAME_POINTER_REGNUM != ARG_POINTER_REGNUM
+ /* Pseudos with argument area equivalences may require
+ reloading via the argument pointer. */
+ if (fixed_regs[ARG_POINTER_REGNUM])
+ SET_REGNO_REG_SET (new_live_at_end, ARG_POINTER_REGNUM);
+#endif
+
+#ifdef PIC_OFFSET_TABLE_REGNUM
+ /* Any constant, or pseudo with constant equivalences, may
+ require reloading from memory using the pic register. */
+ if (fixed_regs[PIC_OFFSET_TABLE_REGNUM])
+ SET_REGNO_REG_SET (new_live_at_end, PIC_OFFSET_TABLE_REGNUM);
+#endif
+ }
/* Regs used in phi nodes are not included in
global_live_at_start, since they are live only along a
if (regno == STACK_POINTER_REGNUM)
return 0;
+ /* ??? These bits might be redundant with the force live bits
+ in calculate_global_regs_live. We would delete from
+ sequential sets; whether this actually affects real code
+ for anything but the stack pointer I don't know. */
/* Make sure insns to set the frame pointer aren't deleted. */
if (regno == FRAME_POINTER_REGNUM
&& (! reload_completed || frame_pointer_needed))
return 0;
#endif
-#ifdef PIC_OFFSET_TABLE_REGNUM
- /* Before reload, do not allow sets of the pic register
- to be deleted. Reload can insert references to
- constant pool memory anywhere in the function, making
- the PIC register live where it wasn't before. */
- if (regno == PIC_OFFSET_TABLE_REGNUM && fixed_regs[regno]
- && ! reload_completed)
- return 0;
-#endif
-
/* Otherwise, the set is dead. */
return 1;
}