re PR target/36467 ([avr] Missed optimization with pointer arithmetic and mul*)

	PR target/36467
	PR target/49687
	* config/avr/avr.md (mulhi3): Use register_or_s9_operand for
	operand2 and expand appropriately if there is a CONST_INT in
	operand2.
	(usmulqihi3): New insn.
	(*sumulqihi3): New insn.
	(*osmulqihi3): New insn.
	(*oumulqihi3): New insn.
	(*muluqihi3.uconst): New insn_and_split.
	(*muluqihi3.sconst): New insn_and_split.
	(*mulsqihi3.sconst): New insn_and_split.
	(*mulsqihi3.uconst): New insn_and_split.
	(*mulsqihi3.oconst): New insn_and_split.
	(*ashifthi3.signx.const): New insn_and_split.
	(*ashifthi3.signx.const7): New insn_and_split.
	(*ashifthi3.zerox.const): New insn_and_split.
	(mulsqihi3): New insn.
	(muluqihi3): New insn.
	(muloqihi3): New insn.
	* config/avr/predicates.md (const_2_to_7_operand): New.
	(const_2_to_6_operand): New.
	(u8_operand): New.
	(s8_operand): New.
	(o8_operand): New.
	(s9_operand): New.
	(register_or_s9_operand): New.

From-SVN: r176527

gcc/ChangeLog

+2011-07-20  Georg-Johann Lay  <avr@gjlay.de>
+	
+	PR target/36467
+	PR target/49687
+	* config/avr/avr.md (mulhi3): Use register_or_s9_operand for
+	operand2 and expand appropriately if there is a CONST_INT in
+	operand2.
+	(usmulqihi3): New insn.
+	(*sumulqihi3): New insn.
+	(*osmulqihi3): New insn.
+	(*oumulqihi3): New insn.
+	(*muluqihi3.uconst): New insn_and_split.
+	(*muluqihi3.sconst): New insn_and_split.
+	(*mulsqihi3.sconst): New insn_and_split.
+	(*mulsqihi3.uconst): New insn_and_split.
+	(*mulsqihi3.oconst): New insn_and_split.
+	(*ashifthi3.signx.const): New insn_and_split.
+	(*ashifthi3.signx.const7): New insn_and_split.
+	(*ashifthi3.zerox.const): New insn_and_split.
+	(mulsqihi3): New insn.
+	(muluqihi3): New insn.
+	(muloqihi3): New insn.
+	* config/avr/predicates.md (const_2_to_7_operand): New.
+	(const_2_to_6_operand): New.
+	(u8_operand): New.
+	(s8_operand): New.
+	(o8_operand): New.
+	(s9_operand): New.
+	(register_or_s9_operand): New.
+
 2011-07-20  Kai Tietz  <ktietz@redhat.com>
 
 	* builtins.c (fold_builtin_expect): See through the cast

gcc/config/avr/avr.c

@@ -5464,7 +5464,42 @@ avr_rtx_costs (rtx x, int codearg, int outer_code ATTRIBUTE_UNUSED, int *total,
 
 	case HImode:
 	  if (AVR_HAVE_MUL)
-	    *total = COSTS_N_INSNS (!speed ? 7 : 10);
+            {
+              rtx op0 = XEXP (x, 0);
+              rtx op1 = XEXP (x, 1);
+              enum rtx_code code0 = GET_CODE (op0);
+              enum rtx_code code1 = GET_CODE (op1);
+              bool ex0 = SIGN_EXTEND == code0 || ZERO_EXTEND == code0;
+              bool ex1 = SIGN_EXTEND == code1 || ZERO_EXTEND == code1;
+
+              if (ex0
+                  && (u8_operand (op1, HImode)
+                      || s8_operand (op1, HImode)))
+                {
+                  *total = COSTS_N_INSNS (!speed ? 4 : 6);
+                  return true;
+                }
+              if (ex0
+                  && register_operand (op1, HImode))
+                {
+                  *total = COSTS_N_INSNS (!speed ? 5 : 8);
+                  return true;
+                }
+              else if (ex0 || ex1)
+                {
+                  *total = COSTS_N_INSNS (!speed ? 3 : 5);
+                  return true;
+                }
+              else if (register_operand (op0, HImode)
+                       && (u8_operand (op1, HImode)
+                           || s8_operand (op1, HImode)))
+                {
+                  *total = COSTS_N_INSNS (!speed ? 6 : 9);
+                  return true;
+                }
+              else
+                *total = COSTS_N_INSNS (!speed ? 7 : 10);
+            }
 	  else if (!speed)
 	    *total = COSTS_N_INSNS (AVR_HAVE_JMP_CALL ? 2 : 1);
 	  else
@@ -5547,6 +5582,17 @@ avr_rtx_costs (rtx x, int codearg, int outer_code ATTRIBUTE_UNUSED, int *total,
 	  break;
 
 	case HImode:
+          if (AVR_HAVE_MUL)
+            {
+              if (const_2_to_7_operand (XEXP (x, 1), HImode)
+                  && (SIGN_EXTEND == GET_CODE (XEXP (x, 0))
+                      || ZERO_EXTEND == GET_CODE (XEXP (x, 0))))
+                {
+                  *total = COSTS_N_INSNS (!speed ? 4 : 6);
+                  return true;
+                }
+            }
+          
 	  if (GET_CODE (XEXP (x, 1)) != CONST_INT)
 	    {
 	      *total = COSTS_N_INSNS (!speed ? 5 : 41);

gcc/config/avr/avr.md

@@ -1017,19 +1017,301 @@
   [(set_attr "length" "3")
    (set_attr "cc" "clobber")])
 
+(define_insn "usmulqihi3"
+  [(set (match_operand:HI 0 "register_operand"                         "=r")
+        (mult:HI (zero_extend:HI (match_operand:QI 1 "register_operand" "a"))
+                 (sign_extend:HI (match_operand:QI 2 "register_operand" "a"))))]
+  "AVR_HAVE_MUL"
+  "mulsu %2,%1
+	movw %0,r0
+	clr __zero_reg__"
+  [(set_attr "length" "3")
+   (set_attr "cc" "clobber")])
+
+;; Above insn is not canonicalized by insn combine, so here is a version with
+;; operands swapped.
+
+(define_insn "*sumulqihi3"
+  [(set (match_operand:HI 0 "register_operand"                         "=r")
+        (mult:HI (sign_extend:HI (match_operand:QI 1 "register_operand" "a"))
+                 (zero_extend:HI (match_operand:QI 2 "register_operand" "a"))))]
+  "AVR_HAVE_MUL"
+  "mulsu %1,%2
+	movw %0,r0
+	clr __zero_reg__"
+  [(set_attr "length" "3")
+   (set_attr "cc" "clobber")])
+
+;; One-extend operand 1
+
+(define_insn "*osmulqihi3"
+  [(set (match_operand:HI 0 "register_operand"                                        "=&r")
+        (mult:HI (not:HI (zero_extend:HI (not:QI (match_operand:QI 1 "register_operand" "a"))))
+                 (sign_extend:HI (match_operand:QI 2 "register_operand"                 "a"))))]
+  "AVR_HAVE_MUL"
+  "mulsu %2,%1
+	movw %0,r0
+	sub %B0,%2
+	clr __zero_reg__"
+  [(set_attr "length" "4")
+   (set_attr "cc" "clobber")])
+
+(define_insn "*oumulqihi3"
+  [(set (match_operand:HI 0 "register_operand"                                        "=&r")
+        (mult:HI (not:HI (zero_extend:HI (not:QI (match_operand:QI 1 "register_operand" "r"))))
+                 (zero_extend:HI (match_operand:QI 2 "register_operand"                 "r"))))]
+  "AVR_HAVE_MUL"
+  "mul %2,%1
+	movw %0,r0
+	sub %B0,%2
+	clr __zero_reg__"
+  [(set_attr "length" "4")
+   (set_attr "cc" "clobber")])
+
+
+;******************************************************************************
+; mul HI: $1 = sign/zero-extend, $2 = small constant
+;******************************************************************************
+
+(define_insn_and_split "*muluqihi3.uconst"
+  [(set (match_operand:HI 0 "register_operand"                         "=r")
+        (mult:HI (zero_extend:HI (match_operand:QI 1 "register_operand" "r"))
+                 (match_operand:HI 2 "u8_operand"                       "M")))
+   (clobber (match_scratch:QI 3                                       "=&d"))]
+  "AVR_HAVE_MUL"
+  "#"
+  "&& reload_completed"
+  [(set (match_dup 3)
+        (match_dup 2))
+   ; umulqihi3
+   (set (match_dup 0)
+        (mult:HI (zero_extend:HI (match_dup 1))
+                 (zero_extend:HI (match_dup 3))))]
+  {
+    operands[2] = gen_int_mode (INTVAL (operands[2]), QImode);
+  })
+
+(define_insn_and_split "*muluqihi3.sconst"
+  [(set (match_operand:HI 0 "register_operand"                         "=r")
+        (mult:HI (zero_extend:HI (match_operand:QI 1 "register_operand" "a"))
+                 (match_operand:HI 2 "s8_operand"                       "n")))
+   (clobber (match_scratch:QI 3                                       "=&a"))]
+  "AVR_HAVE_MUL"
+  "#"
+  "&& reload_completed"
+  [(set (match_dup 3)
+        (match_dup 2))
+   ; usmulqihi3
+   (set (match_dup 0)
+        (mult:HI (zero_extend:HI (match_dup 1))
+                 (sign_extend:HI (match_dup 3))))]
+  {
+    operands[2] = gen_int_mode (INTVAL (operands[2]), QImode);
+  })
+
+(define_insn_and_split "*mulsqihi3.sconst"
+  [(set (match_operand:HI 0 "register_operand"                         "=r")
+        (mult:HI (sign_extend:HI (match_operand:QI 1 "register_operand" "d"))
+                 (match_operand:HI 2 "s8_operand"                       "n")))
+   (clobber (match_scratch:QI 3                                       "=&d"))]
+  "AVR_HAVE_MUL"
+  "#"
+  "&& reload_completed"
+  [(set (match_dup 3)
+        (match_dup 2))
+   ; mulqihi3
+   (set (match_dup 0)
+        (mult:HI (sign_extend:HI (match_dup 1))
+                 (sign_extend:HI (match_dup 3))))]
+  {
+    operands[2] = gen_int_mode (INTVAL (operands[2]), QImode);
+  })
+
+(define_insn_and_split "*mulsqihi3.uconst"
+  [(set (match_operand:HI 0 "register_operand"                         "=r")
+        (mult:HI (sign_extend:HI (match_operand:QI 1 "register_operand" "a"))
+                 (match_operand:HI 2 "u8_operand"                       "M")))
+   (clobber (match_scratch:QI 3                                       "=&a"))]
+  "AVR_HAVE_MUL"
+  "#"
+  "&& reload_completed"
+  [(set (match_dup 3)
+        (match_dup 2))
+   ; usmulqihi3
+   (set (match_dup 0)
+        (mult:HI (zero_extend:HI (match_dup 3))
+                 (sign_extend:HI (match_dup 1))))]
+  {
+    operands[2] = gen_int_mode (INTVAL (operands[2]), QImode);
+  })
+
+(define_insn_and_split "*mulsqihi3.oconst"
+  [(set (match_operand:HI 0 "register_operand"                        "=&r")
+        (mult:HI (sign_extend:HI (match_operand:QI 1 "register_operand" "a"))
+                 (match_operand:HI 2 "o8_operand"                       "n")))
+   (clobber (match_scratch:QI 3                                       "=&a"))]
+  "AVR_HAVE_MUL"
+  "#"
+  "&& reload_completed"
+  [(set (match_dup 3)
+        (match_dup 2))
+   ; *osmulqihi3
+   (set (match_dup 0)
+        (mult:HI (not:HI (zero_extend:HI (not:QI (match_dup 3))))
+                 (sign_extend:HI (match_dup 1))))]
+  {
+    operands[2] = gen_int_mode (INTVAL (operands[2]), QImode);
+  })
+
+;; The EXTEND of $1 only appears in combine, we don't see it in expand so that
+;; expand decides to use ASHIFT instead of MUL because ASHIFT costs are cheaper
+;; at that time.  Fix that.
+
+(define_insn_and_split "*ashifthi3.signx.const"
+  [(set (match_operand:HI 0 "register_operand"                           "=r")
+        (ashift:HI (sign_extend:HI (match_operand:QI 1 "register_operand" "d"))
+                   (match_operand:HI 2 "const_2_to_6_operand"             "I")))
+   (clobber (match_scratch:QI 3                                         "=&d"))]
+  "AVR_HAVE_MUL"
+  "#"
+  "&& reload_completed"
+  [(set (match_dup 3)
+        (match_dup 2))
+   ; mulqihi3
+   (set (match_dup 0)
+        (mult:HI (sign_extend:HI (match_dup 1))
+                 (sign_extend:HI (match_dup 3))))]
+  {
+    operands[2] = GEN_INT (1 << INTVAL (operands[2]));
+  })
+
+(define_insn_and_split "*ashifthi3.signx.const7"
+  [(set (match_operand:HI 0 "register_operand"                           "=r")
+        (ashift:HI (sign_extend:HI (match_operand:QI 1 "register_operand" "a"))
+                   (const_int 7)))
+   (clobber (match_scratch:QI 2                                         "=&a"))]
+  "AVR_HAVE_MUL"
+  "#"
+  "&& reload_completed"
+  [(set (match_dup 2)
+        (match_dup 3))
+   ; usmulqihi3
+   (set (match_dup 0)
+        (mult:HI (zero_extend:HI (match_dup 2))
+                 (sign_extend:HI (match_dup 1))))]
+  {
+    operands[3] = gen_int_mode (1 << 7, QImode);
+  })
+
+(define_insn_and_split "*ashifthi3.zerox.const"
+  [(set (match_operand:HI 0 "register_operand"                           "=r")
+        (ashift:HI (zero_extend:HI (match_operand:QI 1 "register_operand" "r"))
+                   (match_operand:HI 2 "const_2_to_7_operand"             "I")))
+   (clobber (match_scratch:QI 3                                         "=&d"))]
+  "AVR_HAVE_MUL"
+  "#"
+  "&& reload_completed"
+  [(set (match_dup 3)
+        (match_dup 2))
+   ; umulqihi3
+   (set (match_dup 0)
+        (mult:HI (zero_extend:HI (match_dup 1))
+                 (zero_extend:HI (match_dup 3))))]
+  {
+    operands[2] = gen_int_mode (1 << INTVAL (operands[2]), QImode);
+  })
+
+;******************************************************************************
+; mul HI: $1 = sign-/zero-/one-extend, $2 = reg
+;******************************************************************************
+
+(define_insn "mulsqihi3"
+  [(set (match_operand:HI 0 "register_operand"                        "=&r")
+        (mult:HI (sign_extend:HI (match_operand:QI 1 "register_operand" "a"))
+                 (match_operand:HI 2 "register_operand"                 "a")))]
+  "AVR_HAVE_MUL"
+  "mulsu %1,%A2
+	movw %0,r0
+	mul %1,%B2
+	add %B0,r0
+	clr __zero_reg__"
+  [(set_attr "length" "5")
+   (set_attr "cc" "clobber")])
+
+(define_insn "muluqihi3"
+  [(set (match_operand:HI 0 "register_operand"                        "=&r")
+        (mult:HI (zero_extend:HI (match_operand:QI 1 "register_operand" "r"))
+                 (match_operand:HI 2 "register_operand"                 "r")))]
+  "AVR_HAVE_MUL"
+  "mul %1,%A2
+	movw %0,r0
+	mul %1,%B2
+	add %B0,r0
+	clr __zero_reg__"
+  [(set_attr "length" "5")
+   (set_attr "cc" "clobber")])
+
+;; one-extend operand 1
+
+(define_insn "muloqihi3"
+  [(set (match_operand:HI 0 "register_operand"                                        "=&r")
+        (mult:HI (not:HI (zero_extend:HI (not:QI (match_operand:QI 1 "register_operand" "r"))))
+                 (match_operand:HI 2 "register_operand"                                 "r")))]
+  "AVR_HAVE_MUL"
+  "mul %1,%A2
+	movw %0,r0
+	mul %1,%B2
+	add %B0,r0
+	sub %B0,%A2
+	clr __zero_reg__"
+  [(set_attr "length" "6")
+   (set_attr "cc" "clobber")])
+
+;******************************************************************************
+
 (define_expand "mulhi3"
   [(set (match_operand:HI 0 "register_operand" "")
-	(mult:HI (match_operand:HI 1 "register_operand" "")
-		 (match_operand:HI 2 "register_operand" "")))]
+        (mult:HI (match_operand:HI 1 "register_operand" "")
+                 (match_operand:HI 2 "register_or_s9_operand" "")))]
   ""
-  "
-{
-  if (!AVR_HAVE_MUL)
-    {
-      emit_insn (gen_mulhi3_call (operands[0], operands[1], operands[2]));
-      DONE;
-    }
-}")
+  {
+    if (!AVR_HAVE_MUL)
+      {
+        if (!register_operand (operands[2], HImode))
+          operands[2] = force_reg (HImode, operands[2]);
+
+        emit_insn (gen_mulhi3_call (operands[0], operands[1], operands[2]));
+        DONE;
+      }
+
+    /* For small constants we can do better by extending them on the fly.
+       The constant can be loaded in one instruction and the widening
+       multiplication is shorter.  First try the unsigned variant because it
+       allows constraint "d" instead of "a" for the signed version.  */
+
+    if (s9_operand (operands[2], HImode))
+      {
+        rtx reg = force_reg (QImode, gen_int_mode (INTVAL (operands[2]), QImode));
+
+        if (u8_operand (operands[2], HImode))
+          {
+            emit_insn (gen_muluqihi3 (operands[0], reg, operands[1]));
+          } 
+        else if (s8_operand (operands[2], HImode))
+          {
+            emit_insn (gen_mulsqihi3 (operands[0], reg, operands[1]));
+          }
+        else
+          {
+            emit_insn (gen_muloqihi3 (operands[0], reg, operands[1]));
+          }
+
+        DONE;
+      }
+
+    if (!register_operand (operands[2], HImode))
+      operands[2] = force_reg (HImode, operands[2]);
+  })
 
 (define_insn "*mulhi3_enh"
   [(set (match_operand:HI 0 "register_operand" "=&r")

gcc/config/avr/predicates.md

@@ -73,6 +73,16 @@
   (and (match_code "const_int")
        (match_test "IN_RANGE (INTVAL (op), 0, 7)")))
 
+;; Return 1 if OP is constant integer 2..7 for MODE.
+(define_predicate "const_2_to_7_operand"
+  (and (match_code "const_int")
+       (match_test "IN_RANGE (INTVAL (op), 2, 7)")))
+
+;; Return 1 if OP is constant integer 2..6 for MODE.
+(define_predicate "const_2_to_6_operand"
+  (and (match_code "const_int")
+       (match_test "IN_RANGE (INTVAL (op), 2, 6)")))
+
 ;; Returns true if OP is either the constant zero or a register.
 (define_predicate "reg_or_0_operand"
   (ior (match_operand 0 "register_operand")
@@ -156,3 +166,26 @@
   (and (match_code "const_int")
        (match_test "8 == INTVAL(op) || 16 == INTVAL(op) || 24 == INTVAL(op)")))
 
+;; Unsigned CONST_INT that fits in 8 bits, i.e. 0..255.
+(define_predicate "u8_operand"
+  (and (match_code "const_int")
+       (match_test "IN_RANGE (INTVAL (op), 0, 255)")))
+
+;; Signed CONST_INT that fits in 8 bits, i.e. -128..127.
+(define_predicate "s8_operand"
+  (and (match_code "const_int")
+       (match_test "IN_RANGE (INTVAL (op), -128, 127)")))
+
+;; One-extended CONST_INT that fits in 8 bits, i.e. -256..-1.
+(define_predicate "o8_operand"
+  (and (match_code "const_int")
+       (match_test "IN_RANGE (INTVAL (op), -256, -1)")))
+
+;; Signed CONST_INT that fits in 9 bits, i.e. -256..255.
+(define_predicate "s9_operand"
+  (and (match_code "const_int")
+       (match_test "IN_RANGE (INTVAL (op), -256, 255)")))
+
+(define_predicate "register_or_s9_operand"
+  (ior (match_operand 0 "register_operand")
+       (match_operand 0 "s9_operand")))