[Bug target/48085] New: [x32] Unnecessary zero-extension

[Bug target/48085] New: [x32] Unnecessary zero-extension

[hjl.tools at gmail dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=48085

           Summary: [x32] Unnecessary zero-extension
           Product: gcc
           Version: 4.6.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: target
        AssignedTo: unassigned@gcc.gnu.org
        ReportedBy: hjl.tools@gmail.com


[hjl@gnu-6 ilp32-31]$ cat y.c 
int
foo (int *p)
{
  return *p;
}
[hjl@gnu-6 ilp32-31]$ make y.s
/export/build/gnu/gcc-x32/build-x86_64-linux/gcc/xgcc
-B/export/build/gnu/gcc-x32/build-x86_64-linux/gcc/ -S -o y.s -mx32
-funroll-all-loops -O3 -dp  y.c
[hjl@gnu-6 ilp32-31]$ cat y.s
    .file    "y.c"
    .text
    .p2align 4,,15
    .globl    foo
    .type    foo, @function
foo:
.LFB0:
    .cfi_startproc
    mov    %edi, %edi    # 2    *zero_extendsidi2_rex64/1    [length = 2]
    movl    (%rdi), %eax    # 6    *movsi_internal/1    [length = 2]
    ret    # 20    return_internal    [length = 1]
    .cfi_endproc
.LFE0:
    .size    foo, .-foo
    .ident    "GCC: (GNU) 4.6.0 20110311 (experimental)"
    .section    .note.GNU-stack,"",@progbits
[hjl@gnu-6 ilp32-31]$ 

We don't need to zero-extend 32bit pointer in EDI to RDI.

[Bug target/48085] [x32] Unnecessary zero-extension

[hjl.tools at gmail dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=48085

--- Comment #1 from H.J. Lu <hjl.tools at gmail dot com> 2011-03-19 15:03:05 UTC ---
The existing testcase is gcc.target/i386/pr32661-1.c.

[Bug target/48085] [x32] Unnecessary zero-extension

[hjl at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=48085

--- Comment #2 from hjl at gcc dot gnu.org <hjl at gcc dot gnu.org> 2011-04-02 06:05:06 UTC ---
Author: hjl
Date: Sat Apr  2 06:05:03 2011
New Revision: 171878

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=171878
Log:
Promote pointer function arguments and return values to Pmode.

2011-03-29  H.J. Lu  <hongjiu.lu@intel.com>

    PR middle-end/47725
    PR target/48085
    * calls.c (precompute_register_parameters): Convert pointer to
    TLS symbol if needed.

    * config/i386/i386.c (ix86_promote_function_mode): New.
    (TARGET_PROMOTE_FUNCTION_MODE): Likewise.

Modified:
    branches/x32/gcc/ChangeLog.x32
    branches/x32/gcc/calls.c
    branches/x32/gcc/config/i386/i386.c

[Bug target/48085] [x32] Unnecessary zero-extension

[ubizjak at gmail dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=48085

Uros Bizjak <ubizjak at gmail dot com> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Target|                            |x32
             Status|UNCONFIRMED                 |RESOLVED
         Resolution|                            |FIXED
   Target Milestone|---                         |4.7.0

--- Comment #3 from Uros Bizjak <ubizjak at gmail dot com> 2011-07-28 16:01:20 UTC ---
Current mainline gcc does not generate zero extensions anymore:

foo:
.LFB0:
    .cfi_startproc
    movl    (%rdi), %eax    # 6    *movsi_internal/1    [length = 2]
    ret    # 20    return_internal    [length = 1]
    .cfi_endproc
.LFE0:

Fixed.