Shenglei,
I was confused by the names of these patches. From a C point of view this is
inline assembly:
VOID
EFIAPI
CpuBreakpoint (
VOID
)
{
__asm__ __volatile__ ("int $3");
}
These patches seem to be removing GAS and MASM assembly files, but not the
inline assembly *.c files?
We don't want to remove the inline assembly from the BaseLib as that could have
size, performance, and compiler optimization impact.
For example CpuBreakpoint() for clang with LTO would end up inlining a single
byte. For i385 a call to assembler would be 5 bytes at each call location plus
the overhead of the function. So that is a size increase and a performance
overhead. For a C complier calling an assembly function is a serializing event
an that can restrict optimizations. Thus having some limited inline assembly
support is very useful.
Thanks,
Andrew Fish
> On Mar 4, 2019, at 5:40 PM, Shenglei Zhang <shenglei.zh...@intel.com> wrote:
>
> MdePkg BaseSynchronizationLib still uses the inline X86 assembly code
> in C code files.It should be updated to consume nasm only.
> https://bugzilla.tianocore.org/show_bug.cgi?id=1163
>
> Cc: Michael D Kinney <michael.d.kin...@intel.com>
> Cc: Liming Gao <liming....@intel.com>
> Contributed-under: TianoCore Contribution Agreement 1.1
> Signed-off-by: Shenglei Zhang <shenglei.zh...@intel.com>
> ---
> .../Library/BaseSynchronizationLib/BaseSynchronizationLib.inf | 2 --
> 1 file changed, 2 deletions(-)
>
> diff --git a/MdePkg/Library/BaseSynchronizationLib/BaseSynchronizationLib.inf
> b/MdePkg/Library/BaseSynchronizationLib/BaseSynchronizationLib.inf
> index 32414b29fa..719dc1938d 100755
> --- a/MdePkg/Library/BaseSynchronizationLib/BaseSynchronizationLib.inf
> +++ b/MdePkg/Library/BaseSynchronizationLib/BaseSynchronizationLib.inf
> @@ -75,13 +75,11 @@
>
> [Sources.ARM]
> Synchronization.c
> - Arm/Synchronization.asm | RVCT
> Arm/Synchronization.S | GCC
>
> [Sources.AARCH64]
> Synchronization.c
> AArch64/Synchronization.S | GCC
> - AArch64/Synchronization.asm | MSFT
>
> [Packages]
> MdePkg/MdePkg.dec
> --
> 2.18.0.windows.1
>
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