/* Emit RTL for the GCC expander.
Copyright (C) 1987, 1988, 1992, 1993, 1994, 1995, 1996, 1997, 1998,
- 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008
+ 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009
Free Software Foundation, Inc.
This file is part of GCC.
return 0;
}
+/* Return OFFSET if XEXP (MEM, 0) - OFFSET is known to be ALIGN
+ bits aligned for 0 <= OFFSET < ALIGN / BITS_PER_UNIT, or
+ -1 if not known. */
+
+int
+get_mem_align_offset (rtx mem, int align)
+{
+ tree expr;
+ unsigned HOST_WIDE_INT offset;
+
+ /* This function can't use
+ if (!MEM_EXPR (mem) || !MEM_OFFSET (mem)
+ || !CONST_INT_P (MEM_OFFSET (mem))
+ || (get_object_alignment (MEM_EXPR (mem), MEM_ALIGN (mem), align)
+ < align))
+ return -1;
+ else
+ return (- INTVAL (MEM_OFFSET (mem))) & (align / BITS_PER_UNIT - 1);
+ for two reasons:
+ - COMPONENT_REFs in MEM_EXPR can have NULL first operand,
+ for <variable>. get_inner_reference doesn't handle it and
+ even if it did, the alignment in that case needs to be determined
+ from DECL_FIELD_CONTEXT's TYPE_ALIGN.
+ - it would do suboptimal job for COMPONENT_REFs, even if MEM_EXPR
+ isn't sufficiently aligned, the object it is in might be. */
+ gcc_assert (MEM_P (mem));
+ expr = MEM_EXPR (mem);
+ if (expr == NULL_TREE
+ || MEM_OFFSET (mem) == NULL_RTX
+ || !CONST_INT_P (MEM_OFFSET (mem)))
+ return -1;
+
+ offset = INTVAL (MEM_OFFSET (mem));
+ if (DECL_P (expr))
+ {
+ if (DECL_ALIGN (expr) < align)
+ return -1;
+ }
+ else if (INDIRECT_REF_P (expr))
+ {
+ if (TYPE_ALIGN (TREE_TYPE (expr)) < (unsigned int) align)
+ return -1;
+ }
+ else if (TREE_CODE (expr) == COMPONENT_REF)
+ {
+ while (1)
+ {
+ tree inner = TREE_OPERAND (expr, 0);
+ tree field = TREE_OPERAND (expr, 1);
+ tree byte_offset = component_ref_field_offset (expr);
+ tree bit_offset = DECL_FIELD_BIT_OFFSET (field);
+
+ if (!byte_offset
+ || !host_integerp (byte_offset, 1)
+ || !host_integerp (bit_offset, 1))
+ return -1;
+
+ offset += tree_low_cst (byte_offset, 1);
+ offset += tree_low_cst (bit_offset, 1) / BITS_PER_UNIT;
+
+ if (inner == NULL_TREE)
+ {
+ if (TYPE_ALIGN (DECL_FIELD_CONTEXT (field))
+ < (unsigned int) align)
+ return -1;
+ break;
+ }
+ else if (DECL_P (inner))
+ {
+ if (DECL_ALIGN (inner) < align)
+ return -1;
+ break;
+ }
+ else if (TREE_CODE (inner) != COMPONENT_REF)
+ return -1;
+ expr = inner;
+ }
+ }
+ else
+ return -1;
+
+ return offset & ((align / BITS_PER_UNIT) - 1);
+}
+
/* Given REF (a MEM) and T, either the type of X or the expression
corresponding to REF, set the memory attributes. OBJECTP is nonzero
if we are making a new object of this type. BITPOS is nonzero if
new_rtx = change_address_1 (memref, mode, addr, validate);
+ /* If the address is a REG, change_address_1 rightfully returns memref,
+ but this would destroy memref's MEM_ATTRS. */
+ if (new_rtx == memref && offset != 0)
+ new_rtx = copy_rtx (new_rtx);
+
/* Compute the new values of the memory attributes due to this adjustment.
We add the offsets and update the alignment. */
if (memoffset)
return new_rtx;
}
\f
+/* A fake decl that is used as the MEM_EXPR of spill slots. */
+static GTY(()) tree spill_slot_decl;
+
+tree
+get_spill_slot_decl (bool force_build_p)
+{
+ tree d = spill_slot_decl;
+ rtx rd;
+
+ if (d || !force_build_p)
+ return d;
+
+ d = build_decl (VAR_DECL, get_identifier ("%sfp"), void_type_node);
+ DECL_ARTIFICIAL (d) = 1;
+ DECL_IGNORED_P (d) = 1;
+ TREE_USED (d) = 1;
+ TREE_THIS_NOTRAP (d) = 1;
+ spill_slot_decl = d;
+
+ rd = gen_rtx_MEM (BLKmode, frame_pointer_rtx);
+ MEM_NOTRAP_P (rd) = 1;
+ MEM_ATTRS (rd) = get_mem_attrs (new_alias_set (), d, const0_rtx,
+ NULL_RTX, 0, BLKmode);
+ SET_DECL_RTL (d, rd);
+
+ return d;
+}
+
+/* Given MEM, a result from assign_stack_local, fill in the memory
+ attributes as appropriate for a register allocator spill slot.
+ These slots are not aliasable by other memory. We arrange for
+ them all to use a single MEM_EXPR, so that the aliasing code can
+ work properly in the case of shared spill slots. */
+
+void
+set_mem_attrs_for_spill (rtx mem)
+{
+ alias_set_type alias;
+ rtx addr, offset;
+ tree expr;
+
+ expr = get_spill_slot_decl (true);
+ alias = MEM_ALIAS_SET (DECL_RTL (expr));
+
+ /* We expect the incoming memory to be of the form:
+ (mem:MODE (plus (reg sfp) (const_int offset)))
+ with perhaps the plus missing for offset = 0. */
+ addr = XEXP (mem, 0);
+ offset = const0_rtx;
+ if (GET_CODE (addr) == PLUS
+ && GET_CODE (XEXP (addr, 1)) == CONST_INT)
+ offset = XEXP (addr, 1);
+
+ MEM_ATTRS (mem) = get_mem_attrs (alias, expr, offset,
+ MEM_SIZE (mem), MEM_ALIGN (mem),
+ GET_MODE (mem));
+ MEM_NOTRAP_P (mem) = 1;
+}
+\f
/* Return a newly created CODE_LABEL rtx with a unique label number. */
rtx
/* Replace insn with an deleted instruction note. */
-void set_insn_deleted (rtx insn)
+void
+set_insn_deleted (rtx insn)
{
df_insn_delete (BLOCK_FOR_INSN (insn), INSN_UID (insn));
PUT_CODE (insn, NOTE);
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