Re: [PATCH 1/2] StdLib/LibC: avoid LTO code for compiler intrinsics

[Michael Zimmermann <sigmaepsilon92@gmail.com>]

Reviewed-by: Michael Zimmermann <sigmaepsilon92@gmail.com>

On Mon, Aug 8, 2016 at 1:12 PM, Ard Biesheuvel <ard.biesheuvel@linaro.org>
wrote:

> The softfloat routines and some other routines supplied by LibC
> will satisfy references to compiler intrinsics that are emitted
> by the compiler backend, which under LTO means that the link-time
> code generation may emit references to symbols that have been
> optimized away already.
>
> Work around this by building the ARM and AARCH64 versions of LibC
> and the softfloat library without LTO.
>
> Contributed-under: TianoCore Contribution Agreement 1.0
> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
> ---
>  StdLib/LibC/LibC.inf                | 1 +
>  StdLib/LibC/Softfloat/Softfloat.inf | 2 +-
>  2 files changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/StdLib/LibC/LibC.inf b/StdLib/LibC/LibC.inf
> index f13630648555..6039bb81c7dd 100644
> --- a/StdLib/LibC/LibC.inf
> +++ b/StdLib/LibC/LibC.inf
> @@ -120,3 +120,4 @@ [LibraryClasses]
>  #
>  [BuildOptions]
>    MSFT:*_*_IA32_CC_FLAGS = /GL-
> +  GCC:*_*_ARM_CC_FLAGS = -fno-lto
> diff --git a/StdLib/LibC/Softfloat/Softfloat.inf b/StdLib/LibC/Softfloat/
> Softfloat.inf
> index 99763bcb57ba..460406c38fa4 100644
> --- a/StdLib/LibC/Softfloat/Softfloat.inf
> +++ b/StdLib/LibC/Softfloat/Softfloat.inf
> @@ -71,4 +71,4 @@ [Packages]
>  # Nasty things could happen if you do.
>
>  [BuildOptions]
> -  GCC:*_*_*_CC_FLAGS  = -DSOFTFLOAT_FOR_GCC -Wno-enum-compare
> -fno-tree-vrp
> +  GCC:*_*_*_CC_FLAGS  = -DSOFTFLOAT_FOR_GCC -Wno-enum-compare
> -fno-tree-vrp -fno-lto
> --
> 2.7.4
>
>