extend.texi (Named Address Spaces): New section.

2009-10-26  Ben Elliston  <bje@au.ibm.com>
	    Michael Meissner  <meissner@linux.vnet.ibm.com>
	    Ulrich Weigand  <uweigand@de.ibm.com>

	* doc/extend.texi (Named Address Spaces): New section.
	* coretypes.h (addr_space_t): New type.
	(ADDR_SPACE_GENERIC): New define.
	(ADDR_SPACE_GENERIC_P): New macro.

	* doc/tm.texi (Named Address Spaces): New section.
	(TARGET_ADDR_SPACE_LEGITIMATE_ADDRESS_P): Document.
	(TARGET_ADDR_SPACE_LEGITIMIZE_ADDRESS): Document.
	(TARGET_ADDR_SPACE_SUBSET_P): Document.
	(TARGET_ADDR_SPACE_CONVERT): Document.
	* target.h (struct gcc_target): Add addr_space substructure.
	* target-def.h (TARGET_ADDR_SPACE_LEGITIMATE_ADDRESS_P): Define.
	(TARGET_ADDR_SPACE_LEGITIMIZE_ADDRESS): Likewise.
	(TARGET_ADDR_SPACE_SUBSET_P): Likewise.
	(TARGET_ADDR_SPACE_CONVERT): Likewise.
	(TARGET_ADDR_SPACE_HOOKS): Likewise.
	(TARGET_INITIALIZER): Initialize addr_space hooks.
	* targhooks.c (default_addr_space_legitimate_address_p): New function.
	(default_addr_space_legitimize_address): Likewise.
	(default_addr_space_subset_p): Likewise.
	(default_addr_space_convert): Likewise.
	* targhooks.h (default_addr_space_legitimate_address_p): Add prototype.
	(default_addr_space_legitimize_address): Likewise.
	(default_addr_space_subset_p): Likewise.
	(default_addr_space_convert): Likewise.

	* doc/rtl.texi (MEM_ADDR_SPACE): Document.
	* rtl.h (mem_attrs): Add ADDRSPACE memory attribute.
	(MEM_ADDR_SPACE): New macro.
	* emit-rtl.c (get_mem_attrs): Add ADDRSPACE argument and set
	address space memory attribute.
	(mem_attrs_htab_hash): Handle address space memory attribute.
	(mem_attrs_htab_eq): Likewise.
	(set_mem_attributes_minus_bitpos): Likewise.
	(set_mem_alias_set): Likewise.
	(set_mem_align): Likewise.
	(set_mem_expr): Likewise.
	(set_mem_offset): Likewise.
	(set_mem_size): Likewise.
	(adjust_address_1): Likewise.
	(offset_address): Likewise.
	(widen_memoy_address): Likewise.
	(get_spill_slot_decl): Likewise.
	(set_mem_attrs_for_spill): Likewise.
	(set_mem_addr_space): New function.
	* emit-rtl.h (set_mem_addr_space): Add prototype.
	* print-rtl.c (print_rtx): Print address space memory attribute.
	* expr.c (expand_assignment): Set address space memory attribute
	of generated MEM RTXes as appropriate.
	(expand_expr_real_1): Likewise.
	* cfgexpand.c (expand_debug_expr): Likewise.
	* tree-ssa-loop-ivopts.c (produce_memory_decl_rtl): Likewise.

	* tree.h (struct tree_base): Add address_space bitfield.  Reduce
	size of "spare" bitfield.
	(TYPE_ADDR_SPACE): New macro.
	(ENCODE_QUAL_ADDR_SPACE): Likewise.
	(DECODE_QUAL_ADDR_SPACE): Likewise.
	(CLEAR_QUAL_ADDR_SPACE): Likewise.
	(KEEP_QUAL_ADDR_SPACE): Likewise.
	(TYPE_QUALS): Encode type address space.
	(TYPE_QUALS_NO_ADDR_SPACE): New macro.
	* tree.c (set_type_quals): Set type address space.
	(build_array_type): Inherit array address space from element type.
	* print-tree.c (print_node_brief): Print type address space.
	(print_node): Likewise.
	* tree-pretty-print.c (dump_generic_node): Likewise.

	* explow.c (memory_address): Rename to ...
	(memory_address_addr_space): ... this.  Add ADDRSPACE argument.
	Use address-space aware variants of memory address routines.
	* recog.c (memory_address_p): Rename to ...
	(memory_address_addr_space_p): ... this.  Add ADDSPACE argument.
	Use address-space aware variants of memory address routines.
	(offsettable_address_p): Rename to ...
	(offsettable_address_addr_space_p): ... this.  Add ADDRSPACE argument.
	Use address-space aware variants of memory address routines.
	* reload.c (strict_memory_address_p): Rename to ...
	(strict_memory_address_addr_space_p): ... this.  Add ADDSPACE argument.
	Use address-space aware variants of memory address routines.
	(maybe_memory_address_p): Rename to ...
	(maybe_memory_address_addr_space_p): ... this.  Add ADDSPACE argument.
	Use address-space aware variants of memory address routines.
	* expr.h (memory_address_addr_space): Add prototype.
	(memory_address): Define as macro.
	* recog.h (memory_address_addr_space_p): Add prototype.
	(memory_address_p): Define as macro.
	(offsettable_address_addr_space_p): Add prototype.
	(offsettable_address_p): Define as macro.
	(strict_memory_address_addr_space_p): Add prototype.
	(strict_memory_address_p): Define as macro.

	* combine.c (find_split_point): Use address-space aware variants
	of memory address routines.
	* emit-rtl.c (operand_subword): Likewise.
	(change_address_1): Likewise.
	(adjust_address_1): Likewise.
	(offset_address): Likewise.
	* expr.c (emit_move_insn): Likewise.
	(expand_assignment): Likewise.
	(expand_expr_real_1): Likewise.
	* recog.c (verify_changes): Likewise.
	(general_operand): Likewise.
	(offsettable_memref_p): Likewise.
	(offsettable_nonstrict_memref_p): Likewise.
	(constrain_operands): Likewise.
	* reload.c (get_secondary_mem): Likewise.
	(find_reloads_toplev): Likewise.
	(find_reloads_address): Likewise.
	(find_reloads_subreg_address): Likewise.
	* reload1.c (reload): Likewise.
	* rtlhooks.c (gen_lowpart_if_possible): Likewise.
	* rtl.h (address_cost): Add ADDRSPACE argument.
	* rtlanal.c (address_cost): Add ADDRSPACE argument.  Use address-space
	aware variant of memory address routines.
	* loop-invariant.c (create_new_invariant): Update address_cost call.
	* tree-ssa-loop-ivopts.c (computation_cost): Likewise.
	* fwprop.c (should_replace_address): Add ADDRSPACE argument.
	Use address-space aware variant of memory address routines.
	(propagate_rtx_1): Update call to should_replace_address.
	* tree-flow.h (multiplier_allowed_in_address_p): Add ADDRSPACE
	argument.
	* tree-ssa-loop-ivopts.c (multiplier_allowed_in_address_p): Add
	ADDRSPACE argument.  Use per-address-space instead of global cache.
	Use address-space aware variant of memory address routines.
	(get_address_cost): Likewise.
	(get_computation_cost_at): Update calls.
	* tree-ssa-address.c (valid_mem_ref_p): Add ADDRSPACE argument.
	Use address-space aware variant of memory address routines.
	(create_mem_ref_raw): Update call to valid_mem_ref_p.
	(most_expensive_mult_to_index): Update call to
	multiplier_allowed_in_address_p.

	* dwarf2out.c (modified_type_die): Output DW_AT_address_class
	attribute to indicate named address spaces.

	* varasm.c (get_variable_section): DECLs in named address spaces
	cannot be "common".

	* reload.c (find_reloads_address): Do not use LEGITIMIZE_RELOAD_ADDRESS
	for addresses in a non-generic address space.

	* expr.c (emit_block_move_hints): Do not use libcalls for
	memory in non-generic address spaces.
	(clear_storage_hints): Likewise.
	(expand_assignment): Likewise.

	* fold-const.c (operand_equal_p): Expressions refering to different
	address spaces are not equivalent.

	* rtl.c (rtx_equal_p_cb): MEMs refering to different address
	spaces are not equivalent.
	(rtx_equal_p): Likewise.
	* cse.c (exp_equiv_p): Likewise.
	* jump.c (rtx_renumbered_equal_p): Likewise.
	* reload.c (operands_match_p): Likewise.

	* alias.c (nonoverlapping_memrefs_p): MEMs refering to different
	address spaces may alias.
	(true_dependence): Likewise.
	(canon_true_dependence): Likewise.
	(write_dependence_p): Likewise.

	* dse.c (canon_address): Handle named address spaces.
	* ifcvt.c (noce_try_cmove_arith): Likewise.

	* tree.def (ADDR_SPACE_CONVERT_EXPR): New tree code.
	* expr.c (expand_expr_real_2): Expand ADDR_SPACE_CONVERT_EXPR.
	* convert.c (convert_to_pointer): Generate ADDR_SPACE_CONVERT_EXPR
	to handle conversions between different address spaces.
	* fold-const.c (fold_convert_loc): Likewise.
	(fold_unary_loc): Handle ADDR_SPACE_CONVERT_EXPR.
	* tree-pretty-print.c (dump_generic_node): Likewise.
	* gimple-pretty-print.c (dump_unary_rhs): Likewise.
	* tree-cfg.c (verify_gimple_assign_unary): Likewise.
	* tree-inline.c (estimate_operator_cost): Likewise.
	* tree-ssa.c (useless_type_conversion_p): Conversions between pointers
	to different address spaces are not useless.

Co-Authored-By: Michael Meissner <meissner@linux.vnet.ibm.com>
Co-Authored-By: Ulrich Weigand <uweigand@de.ibm.com>

From-SVN: r153572

3 files changed, 95 insertions, 0 deletions

diff --git a/gcc/doc/extend.texi b/gcc/doc/extend.texi
index 6883766..cb764c6 100644
--- a/gcc/doc/extend.texi
+++ b/gcc/doc/extend.texi
@@ -39,6 +39,7 @@ extensions, accepted by GCC in C89 mode and in C++.
 * Decimal Float::       Decimal Floating Types. 
 * Hex Floats::          Hexadecimal floating-point constants.
 * Fixed-Point::         Fixed-Point Types.
+* Named Address Spaces::Named address spaces.
 * Zero Length::         Zero-length arrays.
 * Variable Length::     Arrays whose length is computed at run time.
 * Empty Structures::    Structures with no members.
@@ -1197,6 +1198,31 @@ Pragmas to control overflow and rounding behaviors are not implemented.
 
 Fixed-point types are supported by the DWARF2 debug information format.
 
+@node Named Address Spaces
+@section Named address spaces
+@cindex named address spaces
+
+As an extension, the GNU C compiler supports named address spaces as
+defined in the N1275 draft of ISO/IEC DTR 18037.  Support for named
+address spaces in GCC will evolve as the draft technical report changes.
+Calling conventions for any target might also change.  At present, only
+the SPU target supports other address spaces.  On the SPU target, for
+example, variables may be declared as belonging to another address space
+by qualifying the type with the @code{__ea} address space identifier:
+
+@smallexample
+extern int __ea i;
+@end smallexample
+
+When the variable @code{i} is accessed, the compiler will generate
+special code to access this variable.  It may use runtime library
+support, or generate special machine instructions to access that address
+space.
+
+The @code{__ea} identifier may be used exactly like any other C type
+qualifier (e.g., @code{const} or @code{volatile}).  See the N1275
+document for more details.
+
 @node Zero Length
 @section Arrays of Length Zero
 @cindex arrays of length zero
diff --git a/gcc/doc/rtl.texi b/gcc/doc/rtl.texi
index e28ba03..4888eb3 100644
--- a/gcc/doc/rtl.texi
+++ b/gcc/doc/rtl.texi
@@ -420,6 +420,11 @@ the size is implied by the mode.
 @findex MEM_ALIGN
 @item MEM_ALIGN (@var{x})
 The known alignment in bits of the memory reference.
+
+@findex MEM_ADDR_SPACE
+@item MEM_ADDR_SPACE (@var{x})
+The address space of the memory reference.  This will commonly be zero
+for the generic address space.
 @end table
 
 @item REG
diff --git a/gcc/doc/tm.texi b/gcc/doc/tm.texi
index ba86a08..4a2fe56 100644
--- a/gcc/doc/tm.texi
+++ b/gcc/doc/tm.texi
@@ -55,6 +55,7 @@ through the macros defined in the @file{.h} file.
 * MIPS Coprocessors::   MIPS coprocessor support and how to customize it.
 * PCH Target::          Validity checking for precompiled headers.
 * C++ ABI::             Controlling C++ ABI changes.
+* Named Address Spaces:: Adding support for named address spaces
 * Misc::                Everything else.
 @end menu
 
@@ -9825,6 +9826,69 @@ defined.  Use this hook to make adjustments to the class (eg, tweak
 visibility or perform any other required target modifications).
 @end deftypefn
 
+@node Named Address Spaces
+@section Adding support for named address spaces
+@cindex named address spaces
+
+The draft technical report of the ISO/IEC JTC1 S22 WG14 N1275
+standards committee, @cite{Programming Languages - C - Extensions to
+support embedded processors}, specifies a syntax for embedded
+processors to specify alternate address spaces.  You can configure a
+GCC port to support section 5.1 of the draft report to add support for
+address spaces other than the default address space.  These address
+spaces are new keywords that are similar to the @code{volatile} and
+@code{const} type attributes.
+
+Pointers to named address spaces can a a different size than
+pointers to the generic address space.
+
+For example, the SPU port uses the @code{__ea} address space to refer
+to memory in the host processor, rather than memory local to the SPU
+processor.  Access to memory in the @code{__ea} address space involves
+issuing DMA operations to move data between the host processor and the
+local processor memory address space.  Pointers in the @code{__ea}
+address space are either 32 bits or 64 bits based on the
+@option{-mea32} or @option{-mea64} switches (native SPU pointers are
+always 32 bits).
+
+Internally, address spaces are represented as a small integer in the
+range 0 to 15 with address space 0 being reserved for the generic
+address space.
+
+@deftypefn {Target Hook} {bool} TARGET_ADDR_SPACE_LEGITIMATE_ADDRESS_P (enum machine_mode @var{mode}, rtx @var{exp}, bool @var{strict}, addr_space_t @var{as})
+Define this to return true if @var{exp} is a valid address for mode
+@var{mode} in the named address space @var{as}.  The @var{strict}
+parameter says whether strict addressing is in effect after reload has
+finished.  This target hook is the same as the
+@code{TARGET_LEGITIMATE_ADDRESS_P} target hook, except that it includes
+explicit named address space support.
+@end deftypefn
+
+@deftypefn {Target Hook} {rtx} TARGET_ADDR_SPACE_LEGITIMIZE_ADDRESS (rtx @var{x}, rtx @var{oldx}, enum machine_mode @var{mode}, addr_space_t @var{as})
+Define this to modify an invalid address @var{x} to be a valid address
+with mode @var{mode} in the named address space @var{as}.  This target
+hook is the same as the @code{TARGET_LEGITIMIZE_ADDRESS} target hook,
+except that it includes explicit named address space support.
+@end deftypefn
+
+@deftypefn {Target Hook} {bool} TARGET_ADDR_SPACE_SUBSET_P (addr_space_t @var{superset}, addr_space_t @var{subset})
+Define this to return whether the @var{subset} named address space is
+contained within the @var{superset} named address space.  Pointers to
+a named address space that is a subset of another named address space
+will be converted automatically without a cast if used together in
+arithmetic operations.  Pointers to a superset address space can be
+converted to pointers to a subset address space via explict casts.
+@end deftypefn
+
+@deftypefn {Target Hook} {rtx} TARGET_ADDR_SPACE_CONVERT (rtx @var{op}, tree @var{from_type}, tree @var{to_type})
+Define this to convert the pointer expression represented by the RTL
+@var{op} with type @var{from_type} that points to a named address
+space to a new pointer expression with type @var{to_type} that points
+to a different named address space.  When this hook it called, it is
+guaranteed that one of the two address spaces is a subset of the other,
+as determined by the @code{TARGET_ADDR_SPACE_SUBSET_P} target hook.
+@end deftypefn
+
 @node Misc
 @section Miscellaneous Parameters
 @cindex parameters, miscellaneous