[Bug target/30778] [4.3 Regression] invalid code generation for memset() with -mtune=k8

["ubizjak at gmail dot com" <gcc-bugzilla at gcc dot gnu dot org>]

------- Comment #7 from ubizjak at gmail dot com  2007-02-25 07:54 -------
(In reply to comment #6)

> This patch however fixes one extra pasto and makes the prologue test
> unconditional - I was a bit overagressive minimizing amount of RTL produced
> that only leads to bugs in side corners.

This patch ICEs for "-O2 -march=nocona -m32" on the testcase above:

pr30778.c: In function ?init_reg_last?:
pr30778.c:21: internal compiler error: in predict_jump, at
config/i386/i386.c:13246

BTW: For -march=k8, we now generate:

        movq    reg_stat(%rip), %rax
        movq    $0, (%rax)
        addq    $8, %rax
        movq    $0, (%rax)
        addq    $8, %rax
        movq    $0, (%rax)
        addq    $8, %rax
        movl    $0, (%rax)
        addq    $4, %rax
        movw    $0, (%rax)
        movb    $0, 2(%rax)
        ret

and previously:

        movq    reg_stat(%rip), %rax
        movq    $0, (%rax)
        movq    $0, 8(%rax)
        movq    $0, 16(%rax)
        movl    $0, 24(%rax)
        movw    $0, 28(%rax)
        movb    $0, 30(%rax)
        ret

(I don't know if this is intentionally, just want to point it out.)


-- 

ubizjak at gmail dot com changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
         AssignedTo|ubizjak at gmail dot com    |unassigned at gcc dot gnu
                   |                            |dot org
             Status|ASSIGNED                    |NEW


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=30778