[i386] : Handle otential partial reg stall alternatives with preferred_for_speed attribute

Index: i386.md
===================================================================
--- i386.md	(revision 235995)
+++ i386.md	(working copy)
@@ -2699,34 +2699,31 @@ 
    (set_attr "amdfam10_decode" "double")
    (set_attr "bdver1_decode" "double")])
 
-(define_insn "*swap<mode>_1"
-  [(set (match_operand:SWI12 0 "register_operand" "+r")
-	(match_operand:SWI12 1 "register_operand" "+r"))
+(define_insn "*swap<mode>"
+  [(set (match_operand:SWI12 0 "register_operand" "+<r>,r")
+	(match_operand:SWI12 1 "register_operand" "+<r>,r"))
    (set (match_dup 1)
 	(match_dup 0))]
-  "!TARGET_PARTIAL_REG_STALL || optimize_function_for_size_p (cfun)"
-  "xchg{l}\t%k1, %k0"
+  ""
+  "@
+   xchg{<imodesuffix>}\t%1, %0
+   xchg{l}\t%k1, %k0"
   [(set_attr "type" "imov")
-   (set_attr "mode" "SI")
+   (set_attr "mode" "<MODE>,SI")
+   (set (attr "preferred_for_size")
+     (cond [(eq_attr "alternative" "0")
+	      (symbol_ref "false")]
+	   (symbol_ref "true")))
+   ;; Potential partial reg stall on alternative 1.
+   (set (attr "preferred_for_speed")
+     (cond [(eq_attr "alternative" "1")
+	      (symbol_ref "!TARGET_PARTIAL_REG_STALL")]
+	   (symbol_ref "true")))
    (set_attr "pent_pair" "np")
    (set_attr "athlon_decode" "vector")
    (set_attr "amdfam10_decode" "double")
    (set_attr "bdver1_decode" "double")])
 
-;; Not added amdfam10_decode since TARGET_PARTIAL_REG_STALL
-;; is disabled for AMDFAM10
-(define_insn "*swap<mode>_2"
-  [(set (match_operand:SWI12 0 "register_operand" "+<r>")
-	(match_operand:SWI12 1 "register_operand" "+<r>"))
-   (set (match_dup 1)
-	(match_dup 0))]
-  "TARGET_PARTIAL_REG_STALL"
-  "xchg{<imodesuffix>}\t%1, %0"
-  [(set_attr "type" "imov")
-   (set_attr "mode" "<MODE>")
-   (set_attr "pent_pair" "np")
-   (set_attr "athlon_decode" "vector")])
-
 (define_expand "movstrict<mode>"
   [(set (strict_low_part (match_operand:SWI12 0 "nonimmediate_operand"))
 	(match_operand:SWI12 1 "general_operand"))]
@@ -5607,7 +5604,6 @@ 
 	(const_string "*")))
    (set_attr "mode" "HI,HI,HI,SI")])
 
-;; %%% Potential partial reg stall on alternatives 3 and 4.  What to do?
 (define_insn "*addqi_1"
   [(set (match_operand:QI 0 "nonimmediate_operand" "=qm,q,q,r,r,Yp")
 	(plus:QI (match_operand:QI 1 "nonimmediate_operand" "%0,0,q,0,r,Yp")
@@ -5615,7 +5611,7 @@ 
    (clobber (reg:CC FLAGS_REG))]
   "ix86_binary_operator_ok (PLUS, QImode, operands)"
 {
-  bool widen = (which_alternative == 3 || which_alternative == 4);
+  bool widen = (get_attr_mode (insn) != MODE_QI);
 
   switch (get_attr_type (insn))
     {
@@ -5664,7 +5660,12 @@ 
 	(and (eq_attr "type" "alu") (match_operand 2 "const128_operand"))
 	(const_string "1")
 	(const_string "*")))
-   (set_attr "mode" "QI,QI,QI,SI,SI,SI")])
+   (set_attr "mode" "QI,QI,QI,SI,SI,SI")
+   ;; Potential partial reg stall on alternatives 3 and 4.
+   (set (attr "preferred_for_speed")
+     (cond [(eq_attr "alternative" "3,4")
+	      (symbol_ref "!TARGET_PARTIAL_REG_STALL")]
+	   (symbol_ref "true")))])
 
 (define_insn "*addqi_1_slp"
   [(set (strict_low_part (match_operand:QI 0 "nonimmediate_operand" "+qm,q"))
@@ -8215,7 +8216,6 @@ 
        (const_string "*")))
    (set_attr "mode" "HI,HI,SI,HI")])
 
-;; %%% Potential partial reg stall on alternative 2.  What to do?
 (define_insn "*andqi_1"
   [(set (match_operand:QI 0 "nonimmediate_operand" "=qm,q,r,!k")
 	(and:QI (match_operand:QI 1 "nonimmediate_operand" "%0,0,0,k")
@@ -8238,7 +8238,12 @@ 
     }
 }
   [(set_attr "type" "alu,alu,alu,msklog")
-   (set_attr "mode" "QI,QI,SI,HI")])
+   (set_attr "mode" "QI,QI,SI,HI")
+   ;; Potential partial reg stall on alternative 2.
+   (set (attr "preferred_for_speed")
+     (cond [(eq_attr "alternative" "2")
+	      (symbol_ref "!TARGET_PARTIAL_REG_STALL")]
+	   (symbol_ref "true")))])
 
 (define_insn "*andqi_1_slp"
   [(set (strict_low_part (match_operand:QI 0 "nonimmediate_operand" "+qm,q"))
@@ -8723,7 +8728,6 @@ 
   [(set_attr "type" "alu,alu,msklog")
    (set_attr "mode" "HI")])
 
-;; %%% Potential partial reg stall on alternative 2.  What to do?
 (define_insn "*<code>qi_1"
   [(set (match_operand:QI 0 "nonimmediate_operand" "=q,m,r,!k")
 	(any_or:QI (match_operand:QI 1 "nonimmediate_operand" "%0,0,0,k")
@@ -8736,7 +8740,12 @@ 
    <logic>{l}\t{%k2, %k0|%k0, %k2}
    k<logic>w\t{%2, %1, %0|%0, %1, %2}"
   [(set_attr "type" "alu,alu,alu,msklog")
-   (set_attr "mode" "QI,QI,SI,HI")])
+   (set_attr "mode" "QI,QI,SI,HI")
+   ;; Potential partial reg stall on alternative 2.
+   (set (attr "preferred_for_speed")
+     (cond [(eq_attr "alternative" "2")
+	      (symbol_ref "!TARGET_PARTIAL_REG_STALL")]
+	   (symbol_ref "true")))])
 
 ;; See comment for addsi_1_zext why we do use nonimmediate_operand
 (define_insn "*<code>si_1_zext"
@@ -9513,7 +9522,6 @@ 
    (set_attr "prefix" "*,vex")
    (set_attr "mode" "HI")])
 
-;; %%% Potential partial reg stall on alternative 1.  What to do?
 (define_insn "*one_cmplqi2_1"
   [(set (match_operand:QI 0 "nonimmediate_operand" "=qm,r,!k")
 	(not:QI (match_operand:QI 1 "nonimmediate_operand" "0,0,k")))]
@@ -9536,7 +9544,12 @@ 
   [(set_attr "isa" "*,*,avx512f")
    (set_attr "type" "negnot,negnot,msklog")
    (set_attr "prefix" "*,*,vex")
-   (set_attr "mode" "QI,SI,QI")])
+   (set_attr "mode" "QI,SI,QI")
+   ;; Potential partial reg stall on alternative 1.
+   (set (attr "preferred_for_speed")
+     (cond [(eq_attr "alternative" "1")
+	      (symbol_ref "!TARGET_PARTIAL_REG_STALL")]
+	   (symbol_ref "true")))])
 
 ;; ??? Currently never generated - xor is used instead.
 (define_insn "*one_cmplsi2_1_zext"
@@ -9955,7 +9968,6 @@ 
        (const_string "*")))
    (set_attr "mode" "HI,SI")])
 
-;; %%% Potential partial reg stall on alternative 1.  What to do?
 (define_insn "*ashlqi3_1"
   [(set (match_operand:QI 0 "nonimmediate_operand" "=qm,r,Yp")
 	(ashift:QI (match_operand:QI 1 "nonimmediate_operand" "0,0,l")
@@ -10011,7 +10023,12 @@ 
 			   (match_test "optimize_function_for_size_p (cfun)")))))
        (const_string "0")
        (const_string "*")))
-   (set_attr "mode" "QI,SI,SI")])
+   (set_attr "mode" "QI,SI,SI")
+   ;; Potential partial reg stall on alternative 1.
+   (set (attr "preferred_for_speed")
+     (cond [(eq_attr "alternative" "1")
+	      (symbol_ref "!TARGET_PARTIAL_REG_STALL")]
+	   (symbol_ref "true")))])
 
 (define_insn "*ashlqi3_1_slp"
   [(set (strict_low_part (match_operand:QI 0 "nonimmediate_operand" "+qm"))