Merge lp:~ams-codesourcery/gcc-linaro/discourage-neon-on-a8 into lp:gcc-linaro/4.6

[Andrew Stubbs]

Discourage use of NEON for integer operations on Cortex-A8.

Transfers from NEON/VFP registers to core registers are prohibitively expensive on A8. Modelling this cost is difficult, so simply discourage the use of NEON for integers. (Float values must be transferred anyway, so leave those unaffected.)

This is merged from gcc-linaro/4.5,revno=99353.

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[Ramana Radhakrishnan (ramana)]

I have marked this as needs information as the cbuild run didn't seem to have a baseline to compare the test results with .

I would think this is largely ok because this has been approved upstream into trunk.

http://patchwork.ozlabs.org/patch/87927/

cheers
Ramana

review: Needs Information

[Ira Rosen (irar)]

I am out of the office until 17/04/2011.

Note: This is an automated response to your message "Re: [Merge]
lp:~ams-codesourcery/gcc-linaro/discourage-neon-on-a8 into
lp:gcc-linaro/4.6" sent on 12/4/11 15:49:29.

This is the only notification you will receive while this person is away.

Unmerged revisions

106730. By Andrew Stubbs on 2011-03-25

Discourage use of NEON on Cortex-A8.

Backport from FSF.

=== modified file 'ChangeLog.linaro'
--- ChangeLog.linaro	2011-04-05 16:18:11 +0000
+++ ChangeLog.linaro	2011-04-06 13:23:50 +0000
@@ -1,3 +1,4 @@
+<<<<<<< TREE
 2011-03-23  Andrew Stubbs  <[e-mail]>
 
 	Backport from FSF:
@@ -12,6 +13,26 @@
 
 	Merge from FSF GCC 4.6 (svn branches/gcc-4_6-branch 171336).
 
+=======
[phone]  Andrew Stubbs  <[e-mail]>
+
+	Backport from FSF:
+
+	2011-03-25  Bernd Schmidt  <[e-mail]>
+		    Andrew Stubbs  <[e-mail]>
+
+	gcc/
+	* config/arm/vfp.md (arm_movdi_vfp): Enable only when not tuning
+	for Cortex-A8.
+	(arm_movdi_vfp_cortexa8): New pattern.
+	* config/arm/neon.md (adddi3_neon, subdi3_neon, anddi3_neon,
+	iordi3_neon, xordi3_neon): Add alternatives to discourage Neon
+	instructions when tuning for Cortex-A8.  Set attribute "arch".
+	* config/arm/arm.md: Move include arm-tune.md up a bit.
+	(define_attr "arch"): Add "onlya8" and "nota8" values.
+	(define_attr "arch_enabled"): Handle "onlya8" and "nota8".
+
+>>>>>>> MERGE-SOURCE
 2011-03-22  Andrew Stubbs  <[e-mail]>
 
 	Backport from FSF:

=== modified file 'gcc/config/arm/arm.md'
--- gcc/config/arm/arm.md	2011-03-15 19:59:25 +0000
+++ gcc/config/arm/arm.md	2011-04-06 13:23:50 +0000
@@ -149,6 +149,9 @@
 ;;---------------------------------------------------------------------------
 ;; Attributes
 
+;; Processor type.  This is created automatically from arm-cores.def.
+(include "arm-tune.md")
+
 ; IS_THUMB is set to 'yes' when we are generating Thumb code, and 'no' when
 ; generating ARM code.  This is used to control the length of some insn
 ; patterns that share the same RTL in both ARM and Thumb code.
@@ -192,7 +195,7 @@
 ; for ARM or Thumb-2 with arm_arch6, and nov6 for ARM without
 ; arm_arch6.  This attribute is used to compute attribute "enabled",
 ; use type "any" to enable an alternative in all cases.
-(define_attr "arch" "any,a,t,32,t1,t2,v6,nov6"
+(define_attr "arch" "any,a,t,32,t1,t2,v6,nov6,onlya8,nota8"
   (const_string "any"))
 
 (define_attr "arch_enabled" "no,yes"
@@ -225,6 +228,14 @@
 
 	 (and (eq_attr "arch" "nov6")
 	      (ne (symbol_ref "(TARGET_32BIT && !arm_arch6)") (const_int 0)))
+	 (const_string "yes")
+
+	 (and (eq_attr "arch" "onlya8")
+	      (eq_attr "tune" "cortexa8"))
+	 (const_string "yes")
+
+	 (and (eq_attr "arch" "nota8")
+	      (not (eq_attr "tune" "cortexa8")))
 	 (const_string "yes")]
 	(const_string "no")))
 
@@ -485,9 +496,6 @@
 ;;---------------------------------------------------------------------------
 ;; Pipeline descriptions
 
-;; Processor type.  This is created automatically from arm-cores.def.
-(include "arm-tune.md")
-
 (define_attr "tune_cortexr4" "yes,no"
   (const (if_then_else
 	  (eq_attr "tune" "cortexr4,cortexr4f")

=== modified file 'gcc/config/arm/neon.md'
--- gcc/config/arm/neon.md	2011-01-03 20:52:22 +0000
+++ gcc/config/arm/neon.md	2011-04-06 13:23:50 +0000
@@ -583,23 +583,25 @@
 )
 
 (define_insn "adddi3_neon"
-  [(set (match_operand:DI 0 "s_register_operand" "=w,?&r,?&r")
-        (plus:DI (match_operand:DI 1 "s_register_operand" "%w,0,0")
-                 (match_operand:DI 2 "s_register_operand" "w,r,0")))
+  [(set (match_operand:DI 0 "s_register_operand" "=w,?&r,?&r,?w")
+        (plus:DI (match_operand:DI 1 "s_register_operand" "%w,0,0,w")
+                 (match_operand:DI 2 "s_register_operand" "w,r,0,w")))
    (clobber (reg:CC CC_REGNUM))]
   "TARGET_NEON"
 {
   switch (which_alternative)
     {
-    case 0: return "vadd.i64\t%P0, %P1, %P2";
+    case 0: /* fall through */
+    case 3: return "vadd.i64\t%P0, %P1, %P2";
     case 1: return "#";
     case 2: return "#";
     default: gcc_unreachable ();
     }
 }
-  [(set_attr "neon_type" "neon_int_1,*,*")
-   (set_attr "conds" "*,clob,clob")
-   (set_attr "length" "*,8,8")]
+  [(set_attr "neon_type" "neon_int_1,*,*,neon_int_1")
+   (set_attr "conds" "*,clob,clob,*")
+   (set_attr "length" "*,8,8,*")
+   (set_attr "arch" "nota8,*,*,onlya8")]
 )
 
 (define_insn "*sub<mode>3_neon"
@@ -617,24 +619,26 @@
 )
 
 (define_insn "subdi3_neon"
-  [(set (match_operand:DI 0 "s_register_operand" "=w,?&r,?&r,?&r")
-        (minus:DI (match_operand:DI 1 "s_register_operand" "w,0,r,0")
-                  (match_operand:DI 2 "s_register_operand" "w,r,0,0")))
+  [(set (match_operand:DI 0 "s_register_operand" "=w,?&r,?&r,?&r,?w")
+        (minus:DI (match_operand:DI 1 "s_register_operand" "w,0,r,0,w")
+                  (match_operand:DI 2 "s_register_operand" "w,r,0,0,w")))
    (clobber (reg:CC CC_REGNUM))]
   "TARGET_NEON"
 {
   switch (which_alternative)
     {
-    case 0: return "vsub.i64\t%P0, %P1, %P2";
+    case 0: /* fall through */
+    case 4: return "vsub.i64\t%P0, %P1, %P2";
     case 1: /* fall through */ 
     case 2: /* fall through */
     case 3: return  "subs\\t%Q0, %Q1, %Q2\;sbc\\t%R0, %R1, %R2";
     default: gcc_unreachable ();
     }
 }
-  [(set_attr "neon_type" "neon_int_2,*,*,*")
-   (set_attr "conds" "*,clob,clob,clob")
-   (set_attr "length" "*,8,8,8")]
+  [(set_attr "neon_type" "neon_int_2,*,*,*,neon_int_2")
+   (set_attr "conds" "*,clob,clob,clob,*")
+   (set_attr "length" "*,8,8,8,*")
+   (set_attr "arch" "nota8,*,*,*,onlya8")]
 )
 
 (define_insn "*mul<mode>3_neon"
@@ -720,23 +724,26 @@
 )
 
 (define_insn "iordi3_neon"
-  [(set (match_operand:DI 0 "s_register_operand" "=w,w,?&r,?&r")
-        (ior:DI (match_operand:DI 1 "s_register_operand" "%w,0,0,r")
-		(match_operand:DI 2 "neon_logic_op2" "w,Dl,r,r")))]
+  [(set (match_operand:DI 0 "s_register_operand" "=w,w,?&r,?&r,?w,?w")
+        (ior:DI (match_operand:DI 1 "s_register_operand" "%w,0,0,r,w,0")
+		(match_operand:DI 2 "neon_logic_op2" "w,Dl,r,r,w,Dl")))]
   "TARGET_NEON"
 {
   switch (which_alternative)
     {
-    case 0: return "vorr\t%P0, %P1, %P2";
-    case 1: return neon_output_logic_immediate ("vorr", &operands[2],
+    case 0: /* fall through */
+    case 4: return "vorr\t%P0, %P1, %P2";
+    case 1: /* fall through */
+    case 5: return neon_output_logic_immediate ("vorr", &operands[2],
 		     DImode, 0, VALID_NEON_QREG_MODE (DImode));
     case 2: return "#";
     case 3: return "#";
     default: gcc_unreachable ();
     }
 }
-  [(set_attr "neon_type" "neon_int_1,neon_int_1,*,*")
-   (set_attr "length" "*,*,8,8")]
+  [(set_attr "neon_type" "neon_int_1,neon_int_1,*,*,neon_int_1,neon_int_1")
+   (set_attr "length" "*,*,8,8,*,*")
+   (set_attr "arch" "nota8,nota8,*,*,onlya8,onlya8")]
 )
 
 ;; The concrete forms of the Neon immediate-logic instructions are vbic and
@@ -762,23 +769,26 @@
 )
 
 (define_insn "anddi3_neon"
-  [(set (match_operand:DI 0 "s_register_operand" "=w,w,?&r,?&r")
-        (and:DI (match_operand:DI 1 "s_register_operand" "%w,0,0,r")
-		(match_operand:DI 2 "neon_inv_logic_op2" "w,DL,r,r")))]
+  [(set (match_operand:DI 0 "s_register_operand" "=w,w,?&r,?&r,?w,?w")
+        (and:DI (match_operand:DI 1 "s_register_operand" "%w,0,0,r,w,0")
+		(match_operand:DI 2 "neon_inv_logic_op2" "w,DL,r,r,w,DL")))]
   "TARGET_NEON"
 {
   switch (which_alternative)
     {
-    case 0: return "vand\t%P0, %P1, %P2";
-    case 1: return neon_output_logic_immediate ("vand", &operands[2],
+    case 0: /* fall through */
+    case 4: return "vand\t%P0, %P1, %P2";
+    case 1: /* fall through */
+    case 5: return neon_output_logic_immediate ("vand", &operands[2],
     		     DImode, 1, VALID_NEON_QREG_MODE (DImode));
     case 2: return "#";
     case 3: return "#";
     default: gcc_unreachable ();
     }
 }
-  [(set_attr "neon_type" "neon_int_1,neon_int_1,*,*")
-   (set_attr "length" "*,*,8,8")]
+  [(set_attr "neon_type" "neon_int_1,neon_int_1,*,*,neon_int_1,neon_int_1")
+   (set_attr "length" "*,*,8,8,*,*")
+   (set_attr "arch" "nota8,nota8,*,*,onlya8,onlya8")]
 )
 
 (define_insn "orn<mode>3_neon"
@@ -836,16 +846,18 @@
 )
 
 (define_insn "xordi3_neon"
-  [(set (match_operand:DI 0 "s_register_operand" "=w,?&r,?&r")
-        (xor:DI (match_operand:DI 1 "s_register_operand" "%w,0,r")
-	        (match_operand:DI 2 "s_register_operand" "w,r,r")))]
+  [(set (match_operand:DI 0 "s_register_operand" "=w,?&r,?&r,?w")
+        (xor:DI (match_operand:DI 1 "s_register_operand" "%w,0,r,w")
+	        (match_operand:DI 2 "s_register_operand" "w,r,r,w")))]
   "TARGET_NEON"
   "@
    veor\t%P0, %P1, %P2
    #
-   #"
-  [(set_attr "neon_type" "neon_int_1,*,*")
-   (set_attr "length" "*,8,8")]
+   #
+   veor\t%P0, %P1, %P2"
+  [(set_attr "neon_type" "neon_int_1,*,*,neon_int_1")
+   (set_attr "length" "*,8,8,*")
+   (set_attr "arch" "nota8,*,*,onlya8")]
 )
 
 (define_insn "one_cmpl<mode>2"

=== modified file 'gcc/config/arm/vfp.md'
--- gcc/config/arm/vfp.md	2011-01-20 22:03:29 +0000
+++ gcc/config/arm/vfp.md	2011-04-06 13:23:50 +0000
@@ -134,9 +134,51 @@
 ;; DImode moves
 
 (define_insn "*arm_movdi_vfp"
-  [(set (match_operand:DI 0 "nonimmediate_di_operand" "=r, r,m,w,r,w,w, Uv")
-	(match_operand:DI 1 "di_operand"              "rIK,mi,r,r,w,w,Uvi,w"))]
-  "TARGET_ARM && TARGET_HARD_FLOAT && TARGET_VFP
+  [(set (match_operand:DI 0 "nonimmediate_di_operand" "=r, r, m,w,r,w,w, Uv")
+	(match_operand:DI 1 "di_operand"              "rIK,mi,r,r,w,w,Uvi,w"))]
+  "TARGET_ARM && TARGET_HARD_FLOAT && TARGET_VFP && arm_tune != cortexa8
+   && (   register_operand (operands[0], DImode)
+       || register_operand (operands[1], DImode))"
+  "*
+  switch (which_alternative)
+    {
+    case 0: 
+      return \"#\";
+    case 1:
+    case 2:
+      return output_move_double (operands);
+    case 3:
+      return \"fmdrr%?\\t%P0, %Q1, %R1\\t%@ int\";
+    case 4:
+      return \"fmrrd%?\\t%Q0, %R0, %P1\\t%@ int\";
+    case 5:
+      if (TARGET_VFP_SINGLE)
+	return \"fcpys%?\\t%0, %1\\t%@ int\;fcpys%?\\t%p0, %p1\\t%@ int\";
+      else
+	return \"fcpyd%?\\t%P0, %P1\\t%@ int\";
+    case 6: case 7:
+      return output_move_vfp (operands);
+    default:
+      gcc_unreachable ();
+    }
+  "
+  [(set_attr "type" "*,load2,store2,r_2_f,f_2_r,ffarithd,f_loadd,f_stored")
+   (set_attr "neon_type" "*,*,*,neon_mcr_2_mcrr,neon_mrrc,neon_vmov,*,*")
+   (set (attr "length") (cond [(eq_attr "alternative" "0,1,2") (const_int 8)
+			       (eq_attr "alternative" "5")
+				(if_then_else
+				 (eq (symbol_ref "TARGET_VFP_SINGLE") (const_int 1))
+				 (const_int 8)
+				 (const_int 4))]
+			      (const_int 4)))
+   (set_attr "pool_range"     "*,1020,*,*,*,*,1020,*")
+   (set_attr "neg_pool_range" "*,1008,*,*,*,*,1008,*")]
+)
+
+(define_insn "*arm_movdi_vfp_cortexa8"
+  [(set (match_operand:DI 0 "nonimmediate_di_operand" "=r, r,m,w,!r,w,w, Uv")
+	(match_operand:DI 1 "di_operand"              "rIK,mi,r,r,w,w,Uvi,w"))]
+  "TARGET_ARM && TARGET_HARD_FLOAT && TARGET_VFP && arm_tune == cortexa8
    && (   register_operand (operands[0], DImode)
        || register_operand (operands[1], DImode))"
   "*