Re: [Qemu-devel] [RFC][PATCH v2 4/4] configure: add CONFIG_QEMU_LDST_OPTIMIZATION for TCG qemu_ld/st optimization

[Peter Maydell]

On 5 July 2012 14:23, Yeongkyoon Lee <address@hidden> wrote:
> Add an option "--enable-ldst-optimization" to enable 
> CONFIG_QEMU_LDST_OPTIMIZATION macro for TCG qemu_ld/st optimization. It only 
> works with CONFIG_SOFTMMU and doesn't work with CONFIG_TCG_PASS_AREG0.

This shouldn't be a user settable config option -- we should
just identify what the optimal setting is for the guest/target
combination and use it.

>  case "$target_arch2" in
>    alpha | sparc* | xtensa* | ppc*)
>      echo "CONFIG_TCG_PASS_AREG0=y" >> $config_target_mak
> +    # qemu_ld/st optimization is not available with CONFIG_TCG_PASS_AREG0
> +    target_ldst_optimization="no"

PASS_AREG0 is the way of the future -- you need to fix the ldst
optimization to work with it.

-- PMM