[PATCH, i386]: Allow memory operand for BT with immediate bitcount operand

[PATCH, i386]: Allow memory operand for BT with immediate bitcount operand

[Uros Bizjak]

Hello!

The BT instruction is slow only when memory operand is used with
nonimmediate bitcount operand.

2017-09-03  Uros Bizjak  <ubizjak@gmail.com>

    * config/i386/i386.md (*bt<mode>): Use nonimmediate_operand
    predicate for operand 1.  Add (m,<S>) constraint.
    (*jcc_bt<mode>): Use nonimmediate_operand predicate for operand 1.
    Prevent memory operand 1 with register operand 2.

Bootstrapped and regression tested on x86_64-linux-gnu {,-m32}.

Committed to mainline SVN.

Uros.

Index: config/i386/i386.md
===================================================================
--- config/i386/i386.md (revision 251566)
+++ config/i386/i386.md (working copy)
@@ -11217,9 +11217,9 @@
   [(set (reg:CCC FLAGS_REG)
        (compare:CCC
          (zero_extract:SWI48
-           (match_operand:SWI48 0 "register_operand" "r")
+           (match_operand:SWI48 0 "nonimmediate_operand" "r,m")
            (const_int 1)
-           (match_operand:SI 1 "nonmemory_operand" "r<S>"))
+           (match_operand:SI 1 "nonmemory_operand" "r<S>,<S>"))
          (const_int 0)))]
   ""
 {
@@ -11248,7 +11248,7 @@
   [(set (pc)
        (if_then_else (match_operator 0 "bt_comparison_operator"
                        [(zero_extract:SWI48
-                          (match_operand:SWI48 1 "register_operand")
+                          (match_operand:SWI48 1 "nonimmediate_operand")
                           (const_int 1)
                           (match_operand:SI 2 "nonmemory_operand"))
                         (const_int 0)])
@@ -11260,7 +11260,7 @@
        ? (INTVAL (operands[2]) < GET_MODE_BITSIZE (<MODE>mode)
          && INTVAL (operands[2])
               >= (optimize_function_for_size_p (cfun) ? 8 : 32))
-       : register_operand (operands[2], SImode))
+       : !memory_operand (operands[1], <MODE>mode))
    && can_create_pseudo_p ()"
   "#"
   "&& 1"