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

["Carsey, Jaben" <jaben.carsey@intel.com>]

Reviewed-by: Jaben Carsey <jaben.carsey@intel.com>

> -----Original Message-----
> From: edk2-devel [mailto:edk2-devel-bounces@lists.01.org] On Behalf Of
> Michael Zimmermann
> Sent: Monday, August 08, 2016 4:24 AM
> To: Ard Biesheuvel <ard.biesheuvel@linaro.org>
> Cc: Carsey, Jaben <jaben.carsey@intel.com>; edk2-devel@lists.01.org; Leif
> Lindholm <leif.lindholm@linaro.org>; Daryl McDaniel <edk2-
> lists@mc2research.org>
> Subject: Re: [edk2] [PATCH 1/2] StdLib/LibC: avoid LTO code for compiler
> intrinsics
> Importance: High
> 
> 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
> >
> >
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