Re: PATCH: Properly generate X32 IE sequence

[Uros Bizjak <ubizjak at gmail dot com>]

On Sun, Mar 11, 2012 at 10:24 PM, H.J. Lu <hjl.tools@gmail.com> wrote:

> Here is the patch which is equivalent to clearing MASK_TLS_DIRECT_SEG_REFS
> when Pmode != word_mode. ?We need to keep
>
> ? ? ? ? ?else if (Pmode == SImode)
> ? ? ? ? ? ?{
> ? ? ? ? ? ? ?/* Always generate
> ? ? ? ? ? ? ? ? ? ? ? ?movl %fs:0, %reg32
> ? ? ? ? ? ? ? ? ? ? ? ?addl xgottpoff(%rip), %reg32
> ? ? ? ? ? ? ? ? to support linker IE->LE optimization and avoid
> ? ? ? ? ? ? ? ? fs:(%reg32) as memory operand. ?*/
> ? ? ? ? ? ? ?dest = gen_reg_rtx (Pmode);
> ? ? ? ? ? ? ?emit_insn (gen_tls_initial_exec_x32 (dest, x));
> ? ? ? ? ? ? ?return dest;
> ? ? ? ? ? ?}
>
> to support linker IE->LE optimization. ?TARGET_TLS_DIRECT_SEG_REFS only affects
> TLS LE access and fs:(%reg) is only generated by combine.
>
> So the main impact of disabling TARGET_TLS_DIRECT_SEG_REFS is to disable
> fs:immediate memory operand for TLS LE access, which doesn't have any problems
> to begin with.
>
> I would prefer to keep TARGET_TLS_DIRECT_SEG_REFS and disable only
> fs:(%reg), which is generated by combine.

Please try attached patch.  It introduces TARGET_TLS_INDIRECT_SEG_REFS
to block only indirect seg references.

Uros.

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