[Bug target/52364] New: The unnecessary second form in *movabs<mode>_[12]

[Bug target/52364] New: The unnecessary second form in *movabs<mode>_[12]

[hjl.tools at gmail dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=52364

             Bug #: 52364
           Summary: The unnecessary second form in *movabs<mode>_[12]
    Classification: Unclassified
           Product: gcc
           Version: 4.7.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: target
        AssignedTo: unassigned@gcc.gnu.org
        ReportedBy: hjl.tools@gmail.com
                CC: hubicka@gcc.gnu.org, ubizjak@gmail.com
            Target: x86_64


i386.md has

;; Stores and loads of ax to arbitrary constant address.
;; We fake an second form of instruction to force reload to load address
;; into register when rax is not available
(define_insn "*movabs<mode>_1"
  [(set (mem:SWI1248x (match_operand:DI 0 "x86_64_movabs_operand" "i,r"))
        (match_operand:SWI1248x 1 "nonmemory_operand" "a,er"))]
  "TARGET_64BIT && ix86_check_movabs (insn, 0)"
  "@
   movabs{<imodesuffix>}\t{%1, %P0|%P0, %1}
   mov{<imodesuffix>}\t{%1, %a0|%a0, %1}"
  [(set_attr "type" "imov")
   (set_attr "modrm" "0,*")
   (set_attr "length_address" "8,0")
   (set_attr "length_immediate" "0,*")
   (set_attr "memory" "store")
   (set_attr "mode" "<MODE>")])

Isn't the second form redundant since it is just normal mov<mode>?

[Bug target/52364] The unnecessary second form in *movabs<mode>_[12]

[hjl.tools at gmail dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=52364

--- Comment #1 from H.J. Lu <hjl.tools at gmail dot com> 2012-02-24 05:00:55 UTC ---
A patch is posted at

http://gcc.gnu.org/ml/gcc-patches/2012-02/msg01222.html

[Bug target/52364] The unnecessary second form in *movabs<mode>_[12]

[hjl.tools at gmail dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=52364

H.J. Lu <hjl.tools at gmail dot com> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |RESOLVED
         Resolution|                            |INVALID

--- Comment #2 from H.J. Lu <hjl.tools at gmail dot com> 2012-02-24 19:15:08 UTC ---
The second form is needed for -ffixed-rax.