Turn SECONDARY_MEMORY_NEEDED_MODE into a target hook

This includes a change to LRA.  Previously the code was:

    if (sclass == NO_REGS && dclass == NO_REGS)
      return false;
  #ifdef SECONDARY_MEMORY_NEEDED
    if (SECONDARY_MEMORY_NEEDED (sclass, dclass, GET_MODE (src))
  #ifdef SECONDARY_MEMORY_NEEDED_MODE
        && ((sclass != NO_REGS && dclass != NO_REGS)
            || GET_MODE (src) != SECONDARY_MEMORY_NEEDED_MODE (GET_MODE (src)))
  #endif
        )
      {
        *sec_mem_p = true;
        return false;
      }
  #endif

in which the positioning of the second ifdef meant that defining
SECONDARY_MEMORY_NEEDED_MODE to its default value was not a no-op:
without a definition, we would consider using secondary reloads for
mem<-reg and reg<-mem reloads even if the secondary memory has the
same mode as the original mem, while defining it would avoid this.
The latter behaviour seems correct.

The default is different for reload and LRA.  For LRA the default is
to use the original mode, while reload promotes smaller-than-word
integral modes to word mode:

  if (GET_MODE_BITSIZE (mode) < BITS_PER_WORD && INTEGRAL_MODE_P (mode))
    mode = mode_for_size (BITS_PER_WORD,
                          GET_MODE_CLASS (mode), 0).require ();

Some of the ports that have switched to LRA seemed to have
SECONDARY_MEMORY_NEEDED_MDOEs based on the old reload definition,
and still referred to the reload.c:get_secondary_mem function in
the comments.  The patch just keeps them as-is.

2017-09-13  Richard Sandiford  <richard.sandiford@linaro.org>
	    Alan Hayward  <alan.hayward@arm.com>
	    David Sherwood  <david.sherwood@arm.com>

gcc/
	* target.def (secondary_memory_needed_mode): New hook:
	* targhooks.c (default_secondary_memory_needed_mode): Declare.
	* targhooks.h (default_secondary_memory_needed_mode): New function.
	* doc/tm.texi.in (SECONDARY_MEMORY_NEEDED_MODE): Replace with...
	(TARGET_SECONDARY_MEMORY_NEEDED_MODE): ...this.
	* doc/tm.texi: Regenerate.
	* lra-constraints.c (check_and_process_move): Use
	targetm.secondary_memory_needed_mode instead of
	TARGET_SECONDARY_MEMORY_NEEDED_MODE.
	(curr_insn_transform): Likewise.
	* reload.c (get_secondary_mem): Likewise.
	* config/alpha/alpha.h (SECONDARY_MEMORY_NEEDED_MODE): Delete.
	* config/alpha/alpha.c (alpha_secondary_memory_needed_mode): New
	function.
	(TARGET_SECONDARY_MEMORY_NEEDED_MODE): Redefine.
	* config/i386/i386.h (SECONDARY_MEMORY_NEEDED_MODE): Delete.
	* config/i386/i386.c (ix86_secondary_memory_needed_mode): New function.
	(TARGET_SECONDARY_MEMORY_NEEDED_MODE): Redefine.
	* config/powerpcspe/powerpcspe.h (SECONDARY_MEMORY_NEEDED_MODE):
	Delete.
	* config/powerpcspe/powerpcspe-protos.h
	(rs6000_secondary_memory_needed_mode): Delete.
	* config/powerpcspe/powerpcspe.c
	(TARGET_SECONDARY_MEMORY_NEEDED_MODE): Redefine.
	(rs6000_secondary_memory_needed_mode): Make static.
	* config/rs6000/rs6000.h (SECONDARY_MEMORY_NEEDED_MODE): Delete.
	* config/rs6000/rs6000-protos.h (rs6000_secondary_memory_needed_mode):
	Delete.
	* config/rs6000/rs6000.c (TARGET_SECONDARY_MEMORY_NEEDED_MODE):
	Redefine.
	(rs6000_secondary_memory_needed_mode): Make static.
	* config/s390/s390.h (SECONDARY_MEMORY_NEEDED_MODE): Delete.
	* config/s390/s390.c (s390_secondary_memory_needed_mode): New function.
	(TARGET_SECONDARY_MEMORY_NEEDED_MODE): Redefine.
	* config/sparc/sparc.h (SECONDARY_MEMORY_NEEDED_MODE): Delete.
	* config/sparc/sparc.c (TARGET_SECONDARY_MEMORY_NEEDED_MODE):
	Redefine.
	(sparc_secondary_memory_needed_mode): New function.
	* system.h (TARGET_SECONDARY_MEMORY_NEEDED_MODE): Poison.

Co-Authored-By: Alan Hayward <alan.hayward@arm.com>
Co-Authored-By: David Sherwood <david.sherwood@arm.com>

From-SVN: r252455

14 files changed, 85 insertions, 61 deletions

diff --git a/gcc/config/alpha/alpha.c b/gcc/config/alpha/alpha.c
index ecc915d..28fe467 100644
--- a/gcc/config/alpha/alpha.c
+++ b/gcc/config/alpha/alpha.c
@@ -1688,6 +1688,21 @@ alpha_secondary_reload (bool in_p, rtx x, reg_class_t rclass_i,
 
   return NO_REGS;
 }
+
+/* Implement TARGET_SECONDARY_MEMORY_NEEDED_MODE.  If MODE is
+   floating-point, use it.  Otherwise, widen to a word like the default.
+   This is needed because we always store integers in FP registers in
+   quadword format.  This whole area is very tricky!  */
+
+static machine_mode
+alpha_secondary_memory_needed_mode (machine_mode mode)
+{
+  if (GET_MODE_CLASS (mode) == MODE_FLOAT)
+    return mode;
+  if (GET_MODE_SIZE (mode) >= 4)
+    return mode;
+  return mode_for_size (BITS_PER_WORD, GET_MODE_CLASS (mode), 0).require ();
+}
 
 /* Given SEQ, which is an INSN list, look for any MEMs in either
    a SET_DEST or a SET_SRC and copy the in-struct, unchanging, and
@@ -10062,6 +10077,8 @@ alpha_modes_tieable_p (machine_mode mode1, machine_mode mode2)
 
 #undef TARGET_SECONDARY_RELOAD
 #define TARGET_SECONDARY_RELOAD alpha_secondary_reload
+#undef TARGET_SECONDARY_MEMORY_NEEDED_MODE
+#define TARGET_SECONDARY_MEMORY_NEEDED_MODE alpha_secondary_memory_needed_mode
 
 #undef TARGET_SCALAR_MODE_SUPPORTED_P
 #define TARGET_SCALAR_MODE_SUPPORTED_P alpha_scalar_mode_supported_p
diff --git a/gcc/config/alpha/alpha.h b/gcc/config/alpha/alpha.h
index 56ba895..10f32b7 100644
--- a/gcc/config/alpha/alpha.h
+++ b/gcc/config/alpha/alpha.h
@@ -486,16 +486,6 @@ enum reg_class {
  (! TARGET_FIX && (((CLASS1) == FLOAT_REGS && (CLASS2) != FLOAT_REGS) \
                    || ((CLASS2) == FLOAT_REGS && (CLASS1) != FLOAT_REGS)))
 
-/* Specify the mode to be used for memory when a secondary memory
-   location is needed.  If MODE is floating-point, use it.  Otherwise,
-   widen to a word like the default.  This is needed because we always
-   store integers in FP registers in quadword format.  This whole
-   area is very tricky! */
-#define SECONDARY_MEMORY_NEEDED_MODE(MODE)		\
-  (GET_MODE_CLASS (MODE) == MODE_FLOAT ? (MODE)		\
-   : GET_MODE_SIZE (MODE) >= 4 ? (MODE)			\
-   : mode_for_size (BITS_PER_WORD, GET_MODE_CLASS (MODE), 0).require ())
-
 /* Return the class of registers that cannot change mode from FROM to TO.  */
 
 #define CANNOT_CHANGE_MODE_CLASS(FROM, TO, CLASS)		\
diff --git a/gcc/config/i386/i386.c b/gcc/config/i386/i386.c
index edcc2d6..a508f56 100644
--- a/gcc/config/i386/i386.c
+++ b/gcc/config/i386/i386.c
@@ -41162,6 +41162,20 @@ ix86_secondary_memory_needed (enum reg_class class1, enum reg_class class2,
   return inline_secondary_memory_needed (class1, class2, mode, strict);
 }
 
+/* Implement TARGET_SECONDARY_MEMORY_NEEDED_MODE.
+
+   get_secondary_mem widens integral modes to BITS_PER_WORD.
+   There is no need to emit full 64 bit move on 64 bit targets
+   for integral modes that can be moved using 32 bit move.  */
+
+static machine_mode
+ix86_secondary_memory_needed_mode (machine_mode mode)
+{
+  if (GET_MODE_BITSIZE (mode) < 32 && INTEGRAL_MODE_P (mode))
+    return mode_for_size (32, GET_MODE_CLASS (mode), 0).require ();
+  return mode;
+}
+
 /* Implement the TARGET_CLASS_MAX_NREGS hook.
 
    On the 80386, this is the size of MODE in words,
@@ -53206,6 +53220,8 @@ ix86_run_selftests (void)
 
 #undef TARGET_SECONDARY_RELOAD
 #define TARGET_SECONDARY_RELOAD ix86_secondary_reload
+#undef TARGET_SECONDARY_MEMORY_NEEDED_MODE
+#define TARGET_SECONDARY_MEMORY_NEEDED_MODE ix86_secondary_memory_needed_mode
 
 #undef TARGET_CLASS_MAX_NREGS
 #define TARGET_CLASS_MAX_NREGS ix86_class_max_nregs
diff --git a/gcc/config/i386/i386.h b/gcc/config/i386/i386.h
index a89782a..09b8da5 100644
--- a/gcc/config/i386/i386.h
+++ b/gcc/config/i386/i386.h
@@ -1524,14 +1524,6 @@ enum reg_class
 #define SECONDARY_MEMORY_NEEDED(CLASS1, CLASS2, MODE) \
   ix86_secondary_memory_needed ((CLASS1), (CLASS2), (MODE), 1)
 
-/* Get_secondary_mem widens integral modes to BITS_PER_WORD.
-   There is no need to emit full 64 bit move on 64 bit targets
-   for integral modes that can be moved using 32 bit move.  */
-#define SECONDARY_MEMORY_NEEDED_MODE(MODE)			\
-  (GET_MODE_BITSIZE (MODE) < 32 && INTEGRAL_MODE_P (MODE)	\
-   ? mode_for_size (32, GET_MODE_CLASS (MODE), 0).require ()	\
-   : MODE)
-
 /* Return a class of registers that cannot change FROM mode to TO mode.  */
 
 #define CANNOT_CHANGE_MODE_CLASS(FROM, TO, CLASS) \
diff --git a/gcc/config/powerpcspe/powerpcspe-protos.h b/gcc/config/powerpcspe/powerpcspe-protos.h
index 20587ba..f3aa41b 100644
--- a/gcc/config/powerpcspe/powerpcspe-protos.h
+++ b/gcc/config/powerpcspe/powerpcspe-protos.h
@@ -154,7 +154,6 @@ extern void rs6000_emit_le_vsx_move (rtx, rtx, machine_mode);
 extern bool valid_sf_si_move (rtx, rtx, machine_mode);
 extern void rs6000_emit_move (rtx, rtx, machine_mode);
 extern rtx rs6000_secondary_memory_needed_rtx (machine_mode);
-extern machine_mode rs6000_secondary_memory_needed_mode (machine_mode);
 extern rtx (*rs6000_legitimize_reload_address_ptr) (rtx, machine_mode,
 						    int, int, int, int *);
 extern bool rs6000_legitimate_offset_address_p (machine_mode, rtx,
diff --git a/gcc/config/powerpcspe/powerpcspe.c b/gcc/config/powerpcspe/powerpcspe.c
index 7784676..9b8d68b 100644
--- a/gcc/config/powerpcspe/powerpcspe.c
+++ b/gcc/config/powerpcspe/powerpcspe.c
@@ -1897,6 +1897,8 @@ static const struct attribute_spec rs6000_attribute_table[] =
 
 #undef TARGET_SECONDARY_RELOAD
 #define TARGET_SECONDARY_RELOAD rs6000_secondary_reload
+#undef TARGET_SECONDARY_MEMORY_NEEDED_MODE
+#define TARGET_SECONDARY_MEMORY_NEEDED_MODE rs6000_secondary_memory_needed_mode
 
 #undef TARGET_LEGITIMATE_ADDRESS_P
 #define TARGET_LEGITIMATE_ADDRESS_P rs6000_legitimate_address_p
@@ -21811,10 +21813,9 @@ rs6000_secondary_memory_needed_rtx (machine_mode mode)
   return ret;
 }
 
-/* Return the mode to be used for memory when a secondary memory
-   location is needed.  For SDmode values we need to use DDmode, in
-   all other cases we can use the same mode.  */
-machine_mode
+/* Implement TARGET_SECONDARY_MEMORY_NEEDED_MODE.  For SDmode values we
+   need to use DDmode, in all other cases we can use the same mode.  */
+static machine_mode
 rs6000_secondary_memory_needed_mode (machine_mode mode)
 {
   if (lra_in_progress && mode == SDmode)
diff --git a/gcc/config/powerpcspe/powerpcspe.h b/gcc/config/powerpcspe/powerpcspe.h
index c4b6dc3..5d1a138 100644
--- a/gcc/config/powerpcspe/powerpcspe.h
+++ b/gcc/config/powerpcspe/powerpcspe.h
@@ -1611,13 +1611,6 @@ extern enum reg_class rs6000_constraints[RS6000_CONSTRAINT_MAX];
 #define SECONDARY_MEMORY_NEEDED_RTX(MODE) \
   rs6000_secondary_memory_needed_rtx (MODE)
 
-/* Specify the mode to be used for memory when a secondary memory
-   location is needed.  For cpus that cannot load/store SDmode values
-   from the 64-bit FP registers without using a full 64-bit
-   load/store, we need a wider mode.  */
-#define SECONDARY_MEMORY_NEEDED_MODE(MODE)		\
-  rs6000_secondary_memory_needed_mode (MODE)
-
 /* Return the maximum number of consecutive registers
    needed to represent mode MODE in a register of class CLASS.
 
diff --git a/gcc/config/rs6000/rs6000-protos.h b/gcc/config/rs6000/rs6000-protos.h
index f9be5d3..b21652b 100644
--- a/gcc/config/rs6000/rs6000-protos.h
+++ b/gcc/config/rs6000/rs6000-protos.h
@@ -155,7 +155,6 @@ extern void rs6000_emit_le_vsx_permute (rtx, rtx, machine_mode);
 extern void rs6000_emit_le_vsx_move (rtx, rtx, machine_mode);
 extern bool valid_sf_si_move (rtx, rtx, machine_mode);
 extern void rs6000_emit_move (rtx, rtx, machine_mode);
-extern machine_mode rs6000_secondary_memory_needed_mode (machine_mode);
 extern rtx (*rs6000_legitimize_reload_address_ptr) (rtx, machine_mode,
 						    int, int, int, int *);
 extern bool rs6000_legitimate_offset_address_p (machine_mode, rtx,
diff --git a/gcc/config/rs6000/rs6000.c b/gcc/config/rs6000/rs6000.c
index 1338371..a4a89d0 100644
--- a/gcc/config/rs6000/rs6000.c
+++ b/gcc/config/rs6000/rs6000.c
@@ -1876,6 +1876,8 @@ static const struct attribute_spec rs6000_attribute_table[] =
 
 #undef TARGET_SECONDARY_RELOAD
 #define TARGET_SECONDARY_RELOAD rs6000_secondary_reload
+#undef TARGET_SECONDARY_MEMORY_NEEDED_MODE
+#define TARGET_SECONDARY_MEMORY_NEEDED_MODE rs6000_secondary_memory_needed_mode
 
 #undef TARGET_LEGITIMATE_ADDRESS_P
 #define TARGET_LEGITIMATE_ADDRESS_P rs6000_legitimate_address_p
@@ -19242,10 +19244,9 @@ mems_ok_for_quad_peep (rtx mem1, rtx mem2)
   return 1;
 }
 
-/* Return the mode to be used for memory when a secondary memory
-   location is needed.  For SDmode values we need to use DDmode, in
-   all other cases we can use the same mode.  */
-machine_mode
+/* Implement TARGET_SECONDARY_RELOAD_NEEDED_MODE.  For SDmode values we
+   need to use DDmode, in all other cases we can use the same mode.  */
+static machine_mode
 rs6000_secondary_memory_needed_mode (machine_mode mode)
 {
   if (lra_in_progress && mode == SDmode)
diff --git a/gcc/config/rs6000/rs6000.h b/gcc/config/rs6000/rs6000.h
index 7ac6e3b..1a7ce96 100644
--- a/gcc/config/rs6000/rs6000.h
+++ b/gcc/config/rs6000/rs6000.h
@@ -1514,13 +1514,6 @@ extern enum reg_class rs6000_constraints[RS6000_CONSTRAINT_MAX];
 #define SECONDARY_MEMORY_NEEDED(CLASS1,CLASS2,MODE)			\
   rs6000_secondary_memory_needed_ptr (CLASS1, CLASS2, MODE)
 
-/* Specify the mode to be used for memory when a secondary memory
-   location is needed.  For cpus that cannot load/store SDmode values
-   from the 64-bit FP registers without using a full 64-bit
-   load/store, we need a wider mode.  */
-#define SECONDARY_MEMORY_NEEDED_MODE(MODE)		\
-  rs6000_secondary_memory_needed_mode (MODE)
-
 /* Return the maximum number of consecutive registers
    needed to represent mode MODE in a register of class CLASS.
 
diff --git a/gcc/config/s390/s390.c b/gcc/config/s390/s390.c
index 46d6c32..1319f68 100644
--- a/gcc/config/s390/s390.c
+++ b/gcc/config/s390/s390.c
@@ -4409,6 +4409,19 @@ s390_secondary_reload (bool in_p, rtx x, reg_class_t rclass_i,
   return NO_REGS;
 }
 
+/* Implement TARGET_SECONDARY_MEMORY_NEEDED_MODE.
+
+   get_secondary_mem widens its argument to BITS_PER_WORD which loses on 64bit
+   because the movsi and movsf patterns don't handle r/f moves.  */
+
+static machine_mode
+s390_secondary_memory_needed_mode (machine_mode mode)
+{
+  if (GET_MODE_BITSIZE (mode) < 32)
+    return mode_for_size (32, GET_MODE_CLASS (mode), 0).require ();
+  return mode;
+}
+
 /* Generate code to load SRC, which is PLUS that is not a
    legitimate operand for the LA instruction, into TARGET.
    SCRATCH may be used as scratch register.  */
@@ -15959,6 +15972,8 @@ s390_asan_shadow_offset (void)
 
 #undef TARGET_SECONDARY_RELOAD
 #define TARGET_SECONDARY_RELOAD s390_secondary_reload
+#undef TARGET_SECONDARY_MEMORY_NEEDED_MODE
+#define TARGET_SECONDARY_MEMORY_NEEDED_MODE s390_secondary_memory_needed_mode
 
 #undef TARGET_LIBGCC_CMP_RETURN_MODE
 #define TARGET_LIBGCC_CMP_RETURN_MODE s390_libgcc_cmp_return_mode
diff --git a/gcc/config/s390/s390.h b/gcc/config/s390/s390.h
index 0682fb6..b4a23c3 100644
--- a/gcc/config/s390/s390.h
+++ b/gcc/config/s390/s390.h
@@ -599,13 +599,6 @@ extern const enum reg_class regclass_map[FIRST_PSEUDO_REGISTER];
    && (!TARGET_VX || (SCALAR_FLOAT_MODE_P (MODE)			\
 			  && GET_MODE_SIZE (MODE) > 8)))
 
-/* Get_secondary_mem widens its argument to BITS_PER_WORD which loses on 64bit
-   because the movsi and movsf patterns don't handle r/f moves.  */
-#define SECONDARY_MEMORY_NEEDED_MODE(MODE)			\
- (GET_MODE_BITSIZE (MODE) < 32					\
-  ? mode_for_size (32, GET_MODE_CLASS (MODE), 0).require ()	\
-  : (MODE))
-
 
 /* Stack layout and calling conventions.  */
 
diff --git a/gcc/config/sparc/sparc.c b/gcc/config/sparc/sparc.c
index 9a7e467..469b03d 100644
--- a/gcc/config/sparc/sparc.c
+++ b/gcc/config/sparc/sparc.c
@@ -672,6 +672,7 @@ static void sparc_print_operand_address (FILE *, machine_mode, rtx);
 static reg_class_t sparc_secondary_reload (bool, rtx, reg_class_t,
 					   machine_mode,
 					   secondary_reload_info *);
+static machine_mode sparc_secondary_memory_needed_mode (machine_mode);
 static scalar_int_mode sparc_cstore_mode (enum insn_code icode);
 static void sparc_atomic_assign_expand_fenv (tree *, tree *, tree *);
 static bool sparc_fixed_condition_code_regs (unsigned int *, unsigned int *);
@@ -859,6 +860,8 @@ char sparc_hard_reg_printed[8];
 
 #undef TARGET_SECONDARY_RELOAD
 #define TARGET_SECONDARY_RELOAD sparc_secondary_reload
+#undef TARGET_SECONDARY_MEMORY_NEEDED_MODE
+#define TARGET_SECONDARY_MEMORY_NEEDED_MODE sparc_secondary_memory_needed_mode
 
 #undef TARGET_CONDITIONAL_REGISTER_USAGE
 #define TARGET_CONDITIONAL_REGISTER_USAGE sparc_conditional_register_usage
@@ -13050,6 +13053,30 @@ sparc_secondary_reload (bool in_p, rtx x, reg_class_t rclass_i,
   return NO_REGS;
 }
 
+/* Implement TARGET_SECONDARY_MEMORY_NEEDED_MODE.
+
+   get_secondary_mem widens its argument to BITS_PER_WORD which loses on v9
+   because the movsi and movsf patterns don't handle r/f moves.
+   For v8 we copy the default definition.  */
+
+static machine_mode
+sparc_secondary_memory_needed_mode (machine_mode mode)
+{
+  if (TARGET_ARCH64)
+    {
+      if (GET_MODE_BITSIZE (mode) < 32)
+	return mode_for_size (32, GET_MODE_CLASS (mode), 0).require ();
+      return mode;
+    }
+  else
+    {
+      if (GET_MODE_BITSIZE (mode) < BITS_PER_WORD)
+	return mode_for_size (BITS_PER_WORD,
+			      GET_MODE_CLASS (mode), 0).require ();
+      return mode;
+    }
+}
+
 /* Emit code to conditionally move either OPERANDS[2] or OPERANDS[3] into
    OPERANDS[0] in MODE.  OPERANDS[1] is the operator of the condition.  */
 
diff --git a/gcc/config/sparc/sparc.h b/gcc/config/sparc/sparc.h
index e037897..51bc318 100644
--- a/gcc/config/sparc/sparc.h
+++ b/gcc/config/sparc/sparc.h
@@ -1055,18 +1055,6 @@ extern char leaf_reg_remap[];
        || GET_MODE_SIZE (MODE) > 8 \
        || GET_MODE_SIZE (MODE) < 4))
 
-/* Get_secondary_mem widens its argument to BITS_PER_WORD which loses on v9
-   because the movsi and movsf patterns don't handle r/f moves.
-   For v8 we copy the default definition.  */
-#define SECONDARY_MEMORY_NEEDED_MODE(MODE)				   \
-  (TARGET_ARCH64							   \
-   ? (GET_MODE_BITSIZE (MODE) < 32					   \
-      ? mode_for_size (32, GET_MODE_CLASS (MODE), 0).require ()		   \
-      : MODE)								   \
-   : (GET_MODE_BITSIZE (MODE) < BITS_PER_WORD				   \
-      ? mode_for_size (BITS_PER_WORD, GET_MODE_CLASS (MODE), 0).require () \
-      : MODE))
-
 /* Return the maximum number of consecutive registers
    needed to represent mode MODE in a register of class CLASS.  */
 /* On SPARC, this is the size of MODE in words.  */