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Fixing gcc.c-torture/compile/pr44707.c for CRIS v32 2/2: RFC: CONSTANT_ADDRESS_P and its default are evil!
- From: Hans-Peter Nilsson <hans-peter dot nilsson at axis dot com>
- To: gcc-patches at gcc dot gnu dot org
- Date: Mon, 16 Jul 2012 05:53:03 +0200
- Subject: Fixing gcc.c-torture/compile/pr44707.c for CRIS v32 2/2: RFC: CONSTANT_ADDRESS_P and its default are evil!
I think CONSTANT_ADDRESS_P can and should be eliminated,
replaced by something like
CONSTANT_P (x) && targetm.legitimate_address_p (QImode, x, false)
(or QImode replaced by the known used mode) in the code
currently calling it.
It should, because the default definition is redundant and evil;
easy to miss for targets where (mem (const x)) is not valid for
any arbitrary generic x (symbol_ref, label_ref or const_int,
including offsetted ones; (plus x (const_int N)).
This is the case for CRIS v32, for which only (mem reg) and (mem
(post_inc reg)) are valid. Like ia64 it has no offsettable
addressing mode. For example, the constraint in
gcc.c-torture/compile/pr44707.c of "nro" can only match for the
"r" part.
If your target fails gcc.c-torture/compile/pr44707.c, this might
be the reason.
No regressions for cris-elf nor crisv32-elf; fixes
gcc.c-torture/compile/pr44707.c for the latter. Committed.
* config/cris/cris-protos.h (cris_legitimate_address_p): Declare.
* config/cris/cris.h (CONSTANT_ADDRESS_P): Define in terms of
CONSTANT_P and cris_legitimate_address_p.
* config/cris/cris.c (cris_legitimate_address_p): Make non-static.
Index: config/cris/cris.c
===================================================================
--- config/cris/cris.c (revision 189506)
+++ config/cris/cris.c (working copy)
@@ -127,8 +127,6 @@ static void cris_init_libfuncs (void);
static reg_class_t cris_preferred_reload_class (rtx, reg_class_t);
-static bool cris_legitimate_address_p (enum machine_mode, rtx, bool);
-
static int cris_register_move_cost (enum machine_mode, reg_class_t, reg_class_t);
static int cris_memory_move_cost (enum machine_mode, reg_class_t, bool);
static bool cris_rtx_costs (rtx, int, int, int, int *, bool);
@@ -1414,7 +1412,7 @@ cris_biap_index_p (const_rtx x, bool str
here (but is thankfully a general_operand in itself). A local PIC
symbol is valid for the plain "symbol + offset" case. */
-static bool
+bool
cris_legitimate_address_p (enum machine_mode mode, rtx x, bool strict)
{
const_rtx x1, x2;
Index: config/cris/cris.h
===================================================================
--- config/cris/cris.h (revision 189504)
+++ config/cris/cris.h (working copy)
@@ -778,6 +778,9 @@ struct cum_args {int regs;};
#define HAVE_POST_INCREMENT 1
+#define CONSTANT_ADDRESS_P(X) \
+ (CONSTANT_P (X) && cris_legitimate_address_p (QImode, X, false))
+
/* Must be a compile-time constant, so we go with the highest value
among all CRIS variants. */
#define MAX_REGS_PER_ADDRESS 2
Index: config/cris/cris-protos.h
===================================================================
--- config/cris/cris-protos.h (revision 189499)
+++ config/cris/cris-protos.h (working copy)
@@ -40,6 +40,7 @@ extern bool cris_base_p (const_rtx, bool
extern bool cris_base_or_autoincr_p (const_rtx, bool);
extern bool cris_bdap_index_p (const_rtx, bool);
extern bool cris_biap_index_p (const_rtx, bool);
+extern bool cris_legitimate_address_p (enum machine_mode, rtx, bool);
extern bool cris_store_multiple_op_p (rtx);
extern bool cris_movem_load_rest_p (rtx, int);
extern void cris_asm_output_symbol_ref (FILE *, rtx);
brgds, H-P