This built-in basically returns the high byte of a 24-bit address.
It can be used to test at run time where a pointer points to (Flash or RAM).
Ok for trunk?
Johann
* doc/extend.texi (AVR Built-in Functions): Document
__builtin_avr_flash_segment.
* config/avr/builtins.def (__builtin_avr_flash_segment): New entry.
* config/avr/avr.md (flash_segment, flash_segment1): New expanders.
(*split.flash_segment): New insn-and-split.
* config/avr/avr.c (avr_init_builtins): Add local variables:
const_memx_void_node, const_memx_ptr_type_node,
char_ftype_const_memx_ptr.
Index: doc/extend.texi
===================================================================
--- doc/extend.texi (revision 184739)
+++ doc/extend.texi (working copy)
@@ -8809,7 +8809,18 @@ might increase delay time. @code{ticks}
integer constant; delays with a variable number of cycles are not supported.
@smallexample
- unsigned char __builtin_avr_insert_bits (unsigned long map, unsigned char bits, unsigned char val)
+char __builtin_avr_flash_segment (const __memx void*)
+@end smallexample
+
+@noindent
+This built-in takes a byte address to the 24-bit
+@ref{AVR Named Address Spaces,address space} @code{__memx} and returns
+the number of the flash segment (the 64 KiB chunk) where the address
+points to. Counting starts at @code{0}.
+If the address does not point to flash memory, return @code{-1}.
+
+@smallexample
+unsigned char __builtin_avr_insert_bits (unsigned long map, unsigned char bits, unsigned char val)
@end smallexample
@noindent
Index: config/avr/builtins.def
===================================================================
--- config/avr/builtins.def (revision 184659)
+++ config/avr/builtins.def (working copy)
@@ -48,3 +48,4 @@ DEF_BUILTIN ("__builtin_avr_fmulsu", 2,
/* More complex stuff that cannot be mapped 1:1 to an instruction. */
DEF_BUILTIN ("__builtin_avr_delay_cycles", -1, AVR_BUILTIN_DELAY_CYCLES, void_ftype_ulong, -1)
DEF_BUILTIN ("__builtin_avr_insert_bits", 3, AVR_BUILTIN_INSERT_BITS, uchar_ftype_ulong_uchar_uchar, CODE_FOR_insert_bits)
+DEF_BUILTIN ("__builtin_avr_flash_segment", 1, AVR_BUILTIN_FLASH_SEGMENT, char_ftype_const_memx_ptr, CODE_FOR_flash_segment)
Index: config/avr/avr.md
===================================================================
--- config/avr/avr.md (revision 184659)
+++ config/avr/avr.md (working copy)
@@ -5393,6 +5393,53 @@ (define_insn "insert_bits"
(set_attr "cc" "clobber")])
+;; __builtin_avr_flash_segment
+
+;; Just a helper for the next "official" expander.
+
+(define_expand "flash_segment1"
+ [(set (match_operand:QI 0 "register_operand" "")
+ (subreg:QI (match_operand:PSI 1 "register_operand" "")
+ 2))
+ (set (cc0)
+ (compare (match_dup 0)
+ (const_int 0)))
+ (set (pc)
+ (if_then_else (ge (cc0)
+ (const_int 0))
+ (label_ref (match_operand 2 "" ""))
+ (pc)))
+ (set (match_dup 0)
+ (const_int -1))])
+
+(define_expand "flash_segment"
+ [(parallel [(match_operand:QI 0 "register_operand" "")
+ (match_operand:PSI 1 "register_operand" "")])]
+ ""
+ {
+ rtx label = gen_label_rtx ();
+ emit (gen_flash_segment1 (operands[0], operands[1], label));
+ emit_label (label);
+ DONE;
+ })
+
+;; Actually, it's too late now to work out address spaces known at compiletime.
+;; Best place would be to fold ADDR_SPACE_CONVERT_EXPR in avr_fold_builtin.
+;; However, avr_addr_space_convert can add some built-in knowledge for PSTR
+;; so that ADDR_SPACE_CONVERT_EXPR in the built-in must not be resolved.
+
+(define_insn_and_split "*split.flash_segment"
+ [(set (match_operand:QI 0 "register_operand" "=d")
+ (subreg:QI (lo_sum:PSI (match_operand:QI 1 "nonmemory_operand" "ri")
+ (match_operand:HI 2 "register_operand" "r"))
+ 2))]
+ ""
+ { gcc_unreachable(); }
+ ""
+ [(set (match_dup 0)
+ (match_dup 1))])
+
+
;; Parity
;; Postpone expansion of 16-bit parity to libgcc call until after combine for
Index: config/avr/avr.c
===================================================================
--- config/avr/avr.c (revision 184661)
+++ config/avr/avr.c (working copy)
@@ -10432,6 +10432,19 @@ avr_init_builtins (void)
unsigned_char_type_node,
NULL_TREE);
+ tree const_memx_void_node
+ = build_qualified_type (void_type_node,
+ TYPE_QUAL_CONST
+ | ENCODE_QUAL_ADDR_SPACE (ADDR_SPACE_MEMX));
+
+ tree const_memx_ptr_type_node
+ = build_pointer_type_for_mode (const_memx_void_node, PSImode, false);
+
+ tree char_ftype_const_memx_ptr
+ = build_function_type_list (char_type_node,
+ const_memx_ptr_type_node,
+ NULL);
+
#define DEF_BUILTIN(NAME, N_ARGS, ID, TYPE, CODE) \
add_builtin_function (NAME, TYPE, ID, BUILT_IN_MD, NULL, NULL_TREE);
#include "builtins.def"
