[Bug target/39942] Nonoptimal code - leaveq; xchg %ax,%ax; retq

[jakub at gcc dot gnu dot org]

------- Comment #47 from jakub at gcc dot gnu dot org  2009-05-16 07:12 -------
Subject: Bug 39942

Author: jakub
Date: Sat May 16 07:12:02 2009
New Revision: 147607

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=147607
Log:
        PR target/39942
        * final.c (label_to_max_skip): New function.
        (label_to_alignment): Only use LABEL_TO_ALIGNMENT if
        CODE_LABEL_NUMBER <= max_labelno.
        * output.h (label_to_max_skip): New prototype.
        * config/i386/i386.c (ix86_avoid_jump_misspredicts): Renamed to...
        (ix86_avoid_jump_mispredicts): ... this.  Don't define if
        ASM_OUTPUT_MAX_SKIP_ALIGN isn't defined.  Update comment.
        Handle CODE_LABELs with >= 16 byte alignment or with
        max_skip == (1 << align) - 1.
        (ix86_reorg): Don't call ix86_avoid_jump_mispredicts if
        ASM_OUTPUT_MAX_SKIP_ALIGN isn't defined.

Modified:
    trunk/gcc/ChangeLog
    trunk/gcc/config/i386/i386.c
    trunk/gcc/final.c
    trunk/gcc/output.h


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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=39942