Re: [PATCH] MdePkg/DebugLib; swap if conditions in ASSERT_[EFI|RETURN]_ERROR

[Ard Biesheuvel <ard.biesheuvel@linaro.org>]

On 7 December 2017 at 17:36, Kinney, Michael D
<michael.d.kinney@intel.com> wrote:
> Ard,
>
> With link time optimization, the current order produces
> smaller code.
>

I don't think it does. You are essentially saying that
DebugAssertEnabled() may resolve to a link time constant FALSE under
LTO.

In that case, why would the following two statement not be equivalent?

if (FALSE && EFI_ERROR (StatusParameter)) {}

if (EFI_ERROR (StatusParameter) && FALSE) {}

(which is essentially what a nested if () resolves to)

In other words, the compiler is smart enough to drop the status check
in the second case, because it can see there are no side effects, and
the condition can never be made true anyway.

> Without link time optimization, your patch will produce
> smaller code, but not as small as link time optimized code.
>