[4/4] arc: Update legitimate small data address.

Message ID 20200226145914.1358913-4-claziss@gmail.com
State New
Headers show
Series
  • [1/4] arc: Add length attribute to eh_return pattern.
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Commit Message

Claudiu Zissulescu Feb. 26, 2020, 2:59 p.m.
All ARC's small data adressing is using address scaling feature of the
load/store instructions (i.e., the address is made of a general
pointer plus a shifted offset. The shift amount depends on the
addressing mode).  This patch is checking the offset of an address if
it fits the scalled constraint.  If so, a small data access is
generated.  This patch fixes execute' pr93249 failure.

gcc/
xxxx-xx-xx  Claudiu Zissulescu  <claziss@synopsys.com>

	* config/arc/arc.c (leigitimate_small_data_address_p): Check if an
	address has an offset which fits the scalling constraint for a
	load/store operation.
	(legitimate_scaled_address_p): Update use
	leigitimate_small_data_address_p.
	(arc_print_operand): Likewise.
	(arc_legitimate_address_p): Likewise.
	(legitimate_small_data_address_p): Likewise.

Signed-off-by: Claudiu Zissulescu <claziss@gmail.com>

---
 gcc/config/arc/arc.c | 36 ++++++++++++++++++++++++++----------
 1 file changed, 26 insertions(+), 10 deletions(-)

-- 
2.24.1

Comments

Jeff Law Feb. 28, 2020, 9:15 p.m. | #1
On Wed, 2020-02-26 at 16:59 +0200, Claudiu Zissulescu wrote:
> All ARC's small data adressing is using address scaling feature of the

> load/store instructions (i.e., the address is made of a general

> pointer plus a shifted offset. The shift amount depends on the

> addressing mode).  This patch is checking the offset of an address if

> it fits the scalled constraint.  If so, a small data access is

> generated.  This patch fixes execute' pr93249 failure.


> 

> gcc/

> xxxx-xx-xx  Claudiu Zissulescu  <claziss@synopsys.com>

> 

> 	* config/arc/arc.c (leigitimate_small_data_address_p): Check if an

> 	address has an offset which fits the scalling constraint for a

> 	load/store operation.

> 	(legitimate_scaled_address_p): Update use

> 	leigitimate_small_data_address_p.

> 	(arc_print_operand): Likewise.

> 	(arc_legitimate_address_p): Likewise.

> 	(legitimate_small_data_address_p): Likewise.

OK.
jeff
>
Claudiu Zissulescu March 3, 2020, 8:48 a.m. | #2
Thank you for your review. All 4 patches are pushed.

Claudiu
________________________________
From: Jeff Law <law@redhat.com>

Sent: Friday, February 28, 2020 11:15 PM
To: Claudiu Zissulescu <claziss@gmail.com>; gcc-patches@gcc.gnu.org <gcc-patches@gcc.gnu.org>
Cc: Claudiu Zissulescu <claziss@synopsys.com>; Francois Bedard <fbedard@synopsys.com>; andrew.burgess@embecosm.com <andrew.burgess@embecosm.com>
Subject: Re: [PATCH 4/4] arc: Update legitimate small data address.

On Wed, 2020-02-26 at 16:59 +0200, Claudiu Zissulescu wrote:
> All ARC's small data adressing is using address scaling feature of the

> load/store instructions (i.e., the address is made of a general

> pointer plus a shifted offset. The shift amount depends on the

> addressing mode).  This patch is checking the offset of an address if

> it fits the scalled constraint.  If so, a small data access is

> generated.  This patch fixes execute' pr93249 failure.


>

> gcc/

> xxxx-xx-xx  Claudiu Zissulescu  <claziss@synopsys.com>

>

>        * config/arc/arc.c (leigitimate_small_data_address_p): Check if an

>        address has an offset which fits the scalling constraint for a

>        load/store operation.

>        (legitimate_scaled_address_p): Update use

>        leigitimate_small_data_address_p.

>        (arc_print_operand): Likewise.

>        (arc_legitimate_address_p): Likewise.

>        (legitimate_small_data_address_p): Likewise.

OK.
jeff
>

Patch

diff --git a/gcc/config/arc/arc.c b/gcc/config/arc/arc.c
index 960645fdfbf..af26e5b9711 100644
--- a/gcc/config/arc/arc.c
+++ b/gcc/config/arc/arc.c
@@ -463,21 +463,37 @@  get_symbol_alignment (rtx x)
 /* Return true if x is ok to be used as a small data address.  */
 
 static bool
-legitimate_small_data_address_p (rtx x)
+legitimate_small_data_address_p (rtx x, machine_mode mode)
 {
   switch (GET_CODE (x))
     {
     case CONST:
-      return legitimate_small_data_address_p (XEXP (x, 0));
+      return legitimate_small_data_address_p (XEXP (x, 0), mode);
     case SYMBOL_REF:
       return SYMBOL_REF_SMALL_P (x);
     case PLUS:
       {
 	bool p0 = (GET_CODE (XEXP (x, 0)) == SYMBOL_REF)
 	  && SYMBOL_REF_SMALL_P (XEXP (x, 0));
-	bool p1 = CONST_INT_P (XEXP (x, 1))
-	  && (INTVAL (XEXP (x, 1)) <= g_switch_value);
-	return p0 && p1;
+
+	/* If no constant then we cannot do small data.  */
+	if (!CONST_INT_P (XEXP (x, 1)))
+	  return false;
+
+	/* Small data relocs works with scalled addresses, check if
+	   the immediate fits the requirements.  */
+	switch (GET_MODE_SIZE (mode))
+	  {
+	  case 1:
+	    return p0;
+	  case 2:
+	    return p0 && ((INTVAL (XEXP (x, 1)) & 0x1) == 0);
+	  case 4:
+	  case 8:
+	    return p0 && ((INTVAL (XEXP (x, 1)) & 0x3) == 0);
+	  default:
+	    return false;
+	  }
       }
     default:
       return false;
@@ -531,7 +547,7 @@  legitimate_scaled_address_p (machine_mode mode, rtx op, bool strict)
     }
 
   /* Scalled addresses for sdata is done other places.  */
-  if (legitimate_small_data_address_p (op))
+  if (legitimate_small_data_address_p (op, mode))
     return false;
 
   if (CONSTANT_P (XEXP (op, 1)))
@@ -4825,7 +4841,7 @@  arc_print_operand (FILE *file, rtx x, int code)
 	      break;
 	    case SYMBOL_REF:
 	    case CONST:
-	      if (legitimate_small_data_address_p (addr)
+	      if (legitimate_small_data_address_p (addr, GET_MODE (x))
 		  && GET_MODE_SIZE (GET_MODE (x)) > 1)
 		{
 		  int align = get_symbol_alignment (addr);
@@ -4958,7 +4974,7 @@  arc_print_operand (FILE *file, rtx x, int code)
 	rtx addr = XEXP (x, 0);
 	int size = GET_MODE_SIZE (GET_MODE (x));
 
-	if (legitimate_small_data_address_p (addr))
+	if (legitimate_small_data_address_p (addr, GET_MODE (x)))
 	  output_sdata = 1;
 
 	fputc ('[', file);
@@ -6716,7 +6732,7 @@  arc_legitimate_address_p (machine_mode mode, rtx x, bool strict)
      return true;
   if (legitimate_scaled_address_p (mode, x, strict))
     return true;
-  if (legitimate_small_data_address_p (x))
+  if (legitimate_small_data_address_p (x, mode))
      return true;
   if (GET_CODE (x) == CONST_INT && LARGE_INT (INTVAL (x)))
      return true;
@@ -8870,7 +8886,7 @@  compact_sda_memory_operand (rtx op, machine_mode mode, bool short_p)
   /* Decode the address now.  */
   addr = XEXP (op, 0);
 
-  if (!legitimate_small_data_address_p (addr))
+  if (!legitimate_small_data_address_p (addr, mode))
     return false;
 
   if (!short_p || size == 1)