===================================================================
@@ -5973,6 +5973,33 @@ memory-mapped peripherals that may lie o
volatile int porta __attribute__((address (0x600)));
@end smallexample
+@item absdata
+@cindex @code{absdata} variable attribute, AVR
+Variables in static storage and with the @code{absdata} attribute can
+be accessed by the @code{LDS} and @code{STS} instructions which take
+absolute addresses.
+
+@itemize @bullet
+@item
+This attribute is only supported for the reduced AVR Tiny core
+like ATtiny40.
+
+@item
+You must make sure that respective data is located in the
+address range @code{0x40}@dots{}@code{0xbf} accessible by
+@code{LDS} and @code{STS}. One way to achieve this as an
+appropriate linker description file.
+
+@item
+If the location does not fit the address range of @code{LDS}
+and @code{STS}, there is currently (Binutils 2.26) just an unspecific
+warning like
+@quotation
+@code{module.c:(.text+0x1c): warning: internal error: out of range error}
+@end quotation
+
+@end itemize
+
@end table
@node Blackfin Variable Attributes
===================================================================
@@ -84,6 +84,10 @@
#define AVR_SYMBOL_FLAG_TINY_PM \
(SYMBOL_FLAG_MACH_DEP << 7)
+/* (AVR_TINY only): Symbol has attribute absdata */
+#define AVR_SYMBOL_FLAG_TINY_ABSDATA \
+ (SYMBOL_FLAG_MACH_DEP << 8)
+
#define TINY_ADIW(REG1, REG2, I) \
"subi " #REG1 ",lo8(-(" #I "))" CR_TAB \
"sbci " #REG2 ",hi8(-(" #I "))"
@@ -1790,6 +1794,28 @@ avr_mode_dependent_address_p (const_rtx
}
+/* Return true if rtx X is a CONST_INT, CONST or SYMBOL_REF
+ address with the `absdata' variable attribute, i.e. respective
+ data can be read / written by LDS / STS instruction.
+ This is used only for AVR_TINY. */
+
+static bool
+avr_address_tiny_absdata_p (rtx x, machine_mode mode)
+{
+ if (CONST == GET_CODE (x))
+ x = XEXP (XEXP (x, 0), 0);
+
+ if (SYMBOL_REF_P (x))
+ return SYMBOL_REF_FLAGS (x) & AVR_SYMBOL_FLAG_TINY_ABSDATA;
+
+ if (CONST_INT_P (x)
+ && IN_RANGE (INTVAL (x), 0, 0xc0 - GET_MODE_SIZE (mode)))
+ return true;
+
+ return false;
+}
+
+
/* Helper function for `avr_legitimate_address_p'. */
static inline bool
@@ -1874,8 +1900,7 @@ avr_legitimate_address_p (machine_mode m
/* avrtiny's load / store instructions only cover addresses 0..0xbf:
IN / OUT range is 0..0x3f and LDS / STS can access 0x40..0xbf. */
- ok = (CONST_INT_P (x)
- && IN_RANGE (INTVAL (x), 0, 0xc0 - GET_MODE_SIZE (mode)));
+ ok = avr_address_tiny_absdata_p (x, mode);
}
if (avr_log.legitimate_address_p)
@@ -1917,8 +1942,7 @@ avr_legitimize_address (rtx x, rtx oldx,
if (AVR_TINY)
{
if (CONSTANT_ADDRESS_P (x)
- && !(CONST_INT_P (x)
- && IN_RANGE (INTVAL (x), 0, 0xc0 - GET_MODE_SIZE (mode))))
+ && ! avr_address_tiny_absdata_p (x, mode))
{
x = force_reg (Pmode, x);
}
@@ -9148,6 +9172,32 @@ avr_handle_fntype_attribute (tree *node,
}
static tree
+avr_handle_absdata_attribute (tree *node, tree name, tree /* args */,
+ int /* flags */, bool *no_add)
+{
+ location_t loc = DECL_SOURCE_LOCATION (*node);
+
+ if (AVR_TINY)
+ {
+ if (TREE_CODE (*node) != VAR_DECL
+ || (!TREE_STATIC (*node) && !DECL_EXTERNAL (*node)))
+ {
+ warning_at (loc, OPT_Wattributes, "%qE attribute only applies to"
+ " variables in static storage", name);
+ *no_add = true;
+ }
+ }
+ else
+ {
+ warning_at (loc, OPT_Wattributes, "%qE attribute only supported"
+ " for reduced Tiny cores", name);
+ *no_add = true;
+ }
+
+ return NULL_TREE;
+}
+
+static tree
avr_handle_addr_attribute (tree *node, tree name, tree args,
int flags ATTRIBUTE_UNUSED, bool *no_add)
{
@@ -9217,8 +9267,8 @@ avr_eval_addr_attrib (rtx x)
if (SYMBOL_REF_FLAGS (x) & SYMBOL_FLAG_IO)
{
attr = lookup_attribute ("io", DECL_ATTRIBUTES (decl));
- if (!attr || !TREE_VALUE (attr))
- attr = lookup_attribute ("io_low", DECL_ATTRIBUTES (decl));
+ if (!attr || !TREE_VALUE (attr))
+ attr = lookup_attribute ("io_low", DECL_ATTRIBUTES (decl));
gcc_assert (attr);
}
if (!attr || !TREE_VALUE (attr))
@@ -9254,6 +9304,8 @@ avr_attribute_table[] =
false },
{ "address", 1, 1, false, false, false, avr_handle_addr_attribute,
false },
+ { "absdata", 0, 0, true, false, false, avr_handle_absdata_attribute,
+ false },
{ NULL, 0, 0, false, false, false, NULL, false }
};
@@ -9338,6 +9390,17 @@ avr_progmem_p (tree decl, tree attribute
}
+/* Return true if DECL has attribute `absdata' set. This function should
+ only be used for AVR_TINY. */
+
+static bool
+avr_decl_absdata_p (tree decl, tree attributes)
+{
+ return (TREE_CODE (decl) == VAR_DECL
+ && NULL_TREE != lookup_attribute ("absdata", attributes));
+}
+
+
/* Scan type TYP for pointer references to address space ASn.
Return ADDR_SPACE_GENERIC (i.e. 0) if all pointers targeting
the AS are also declared to be CONST.
@@ -9693,6 +9756,8 @@ avr_section_type_flags (tree decl, const
static void
avr_encode_section_info (tree decl, rtx rtl, int new_decl_p)
{
+ tree addr_attr = NULL_TREE;
+
/* In avr_handle_progmem_attribute, DECL_INITIAL is not yet
readily available, see PR34734. So we postpone the warning
about uninitialized data in program memory section until here. */
@@ -9734,7 +9799,7 @@ avr_encode_section_info (tree decl, rtx
tree io_low_attr = lookup_attribute ("io_low", attr);
tree io_attr = lookup_attribute ("io", attr);
- tree addr_attr;
+
if (io_low_attr
&& TREE_VALUE (io_low_attr) && TREE_VALUE (TREE_VALUE (io_low_attr)))
addr_attr = io_attr;
@@ -9762,14 +9827,32 @@ avr_encode_section_info (tree decl, rtx
if (AVR_TINY
&& decl
&& VAR_DECL == TREE_CODE (decl)
- && -1 == avr_progmem_p (decl, DECL_ATTRIBUTES (decl))
&& MEM_P (rtl)
&& SYMBOL_REF_P (XEXP (rtl, 0)))
{
- /* Tag symbols for later addition of 0x4000 (AVR_TINY_PM_OFFSET). */
-
rtx sym = XEXP (rtl, 0);
- SYMBOL_REF_FLAGS (sym) |= AVR_SYMBOL_FLAG_TINY_PM;
+
+ if (-1 == avr_progmem_p (decl, DECL_ATTRIBUTES (decl)))
+ {
+ // Tag symbols for later addition of 0x4000 (AVR_TINY_PM_OFFSET).
+ SYMBOL_REF_FLAGS (sym) |= AVR_SYMBOL_FLAG_TINY_PM;
+ }
+
+ if (avr_decl_absdata_p (decl, DECL_ATTRIBUTES (decl))
+ || (addr_attr
+ // If addr_attr is non-null, it has an argument. Peek into it.
+ && TREE_INT_CST_LOW (TREE_VALUE (TREE_VALUE (addr_attr))) < 0xc0))
+ {
+ // May be accessed by LDS / STS.
+ SYMBOL_REF_FLAGS (sym) |= AVR_SYMBOL_FLAG_TINY_ABSDATA;
+ }
+
+ if (-1 == avr_progmem_p (decl, DECL_ATTRIBUTES (decl))
+ && avr_decl_absdata_p (decl, DECL_ATTRIBUTES (decl)))
+ {
+ error ("%q+D has incompatible attributes %qs and %qs",
+ decl, "progmem", "absdata");
+ }
}
}
@@ -10899,6 +10982,10 @@ avr_address_cost (rtx x, machine_mode mo
if (optimize > 0
&& io_address_operand (x, QImode))
cost = 2;
+
+ if (AVR_TINY
+ && avr_address_tiny_absdata_p (x, QImode))
+ cost = 2;
}
if (avr_log.address_cost)
===================================================================
@@ -0,0 +1,70 @@
+/* { dg-do compile } */
+/* { dg-require-effective-target avr_tiny } */
+
+typedef struct
+{
+ char a, b, c;
+} abc_t;
+
+extern char varA __attribute__((absdata));
+extern char varB __attribute__((absdata));
+
+extern int arrayA[] __attribute__((absdata));
+extern int arrayB[] __attribute__((absdata));
+extern char arrayC[] __attribute__((address(0x80)));
+
+extern abc_t abc __attribute__((absdata));
+
+char get_1 (void)
+{
+ return varA;
+}
+
+int get_2 (void)
+{
+ return arrayA[3];
+}
+
+char get_3 (void)
+{
+ return abc.a + abc.b + abc.c;
+}
+
+
+void put_1 (char b)
+{
+ varB = b;
+}
+
+void put_2 (int b)
+{
+ arrayB[3] = b;
+}
+
+void put_3 (void)
+{
+ abc.a = abc.b = abc.c = 0;
+}
+
+void put_4 (void)
+{
+ arrayC[0] = arrayC[1] = arrayC[2] = 0;
+}
+
+/* { dg-final { scan-assembler "lds r\[0-9\]+,varA" } } */
+/* { dg-final { scan-assembler "lds r\[0-9\]+,arrayA\\+6" } } */
+/* { dg-final { scan-assembler "lds r\[0-9\]+,arrayA\\+6\\+1" } } */
+/* { dg-final { scan-assembler "lds r\[0-9\]+,abc" } } */
+/* { dg-final { scan-assembler "lds r\[0-9\]+,abc\\+1" } } */
+/* { dg-final { scan-assembler "lds r\[0-9\]+,abc\\+2" } } */
+
+/* { dg-final { scan-assembler "sts varB," } } */
+/* { dg-final { scan-assembler "sts arrayB\\+6," } } */
+/* { dg-final { scan-assembler "sts arrayB\\+6\\+1," } } */
+/* { dg-final { scan-assembler "sts arrayC," } } */
+/* { dg-final { scan-assembler "sts arrayC\\+1," } } */
+/* { dg-final { scan-assembler "sts arrayC\\+2," } } */
+
+/* { dg-final { scan-assembler "sts abc," } } */
+/* { dg-final { scan-assembler "sts abc\\+1," } } */
+/* { dg-final { scan-assembler "sts abc\\+2," } } */
===================================================================
@@ -7618,6 +7618,24 @@ proc check_effective_target_aarch64_larg
}
}
+
+# Return 1 if this is a reduced AVR Tiny core. Such cores have different
+# register set, instruction set, addressing capabilities and ABI.
+
+proc check_effective_target_avr_tiny { } {
+ if { [istarget avr*-*-*] } {
+ return [check_no_compiler_messages avr_tiny object {
+ #ifdef __AVR_TINY__
+ int dummy;
+ #else
+ #error target not a reduced AVR Tiny core
+ #endif
+ }]
+ } else {
+ return 0
+ }
+}
+
# Return 1 if <fenv.h> is available with all the standard IEEE
# exceptions and floating-point exceptions are raised by arithmetic
# operations. (If the target requires special options for "inexact"