> On May 11, 2016, at 5:08 AM, Shi, Steven <steven....@intel.com> wrote:
>
> Hi Andrew,
> From your data, it looks the XCode LTO is not enabled correctly for IA32, but
> correct for X64. Attachment has my build map files, and below are my build
> commands. FYI.
>
Sorry had a typo in the tools_def.txt, here are the numbers with -flto
correctly added to the CC_FLAGS:
> build -a IA32 -t XCODE5 -p OvmfPkg/OvmfPkgIa32.dsc -n 5 -m
> MdeModulePkg/Core/Pei/PeiMain.inf -b RELEASE
25K
> build -a IA32 -t XCODE5 -p OvmfPkg/OvmfPkgIa32.dsc -n 5 -m
> MdeModulePkg/Core/Pei/PeiMain.inf -b DEBUG -DDEBUG_ON_SERIAL_PORT
45K
> build -a X64 -t XCODE5 -p OvmfPkg/OvmfPkgX64.dsc -n 5 -m
> MdeModulePkg/Core/Dxe/DxeMain.inf -b RELEASE
103K
> build -a X64 -t XCODE5 -p OvmfPkg/OvmfPkgX64.dsc -n 5 -m
> MdeModulePkg/Core/Dxe/DxeMain.inf -b DEBUG -DDEBUG_ON_SERIAL_PORT
133K
When doing size optimizations it is often easier to start with smaller drivers.
Can you send the sizes/map files for:
> build -a IA32 -t XCODE5 -p OvmfPkg/OvmfPkgIa32.dsc -n 5 -m
> IntelFrameworkModulePkg/Universal/StatusCode/Pei/StatusCodePei.inf -b RELEASE
1220
> build -a IA32 -t XCODE5 -p OvmfPkg/OvmfPkgIa32.dsc -n 5 -m
> IntelFrameworkModulePkg/Universal/StatusCode/Pei/StatusCodePei.inf -b DEBUG
> -DDEBUG_ON_SERIAL_PORT
8228
> build -a X64 -t XCODE5 -p OvmfPkg/OvmfPkgX64.dsc -n 5 -m
> PcAtChipsetPkg/8254TimerDxe/8254Timer.inf -b RELEASE
2464
> build -a X64 -t XCODE5 -p OvmfPkg/OvmfPkgX64.dsc -n 5 -m
> PcAtChipsetPkg/8254TimerDxe/8254Timer.inf -b DEBUG -DDEBUG_ON_SERIAL_PORT
9088
I forgot to mention that X64 XCODE5/clang has a 5 byte overhead per function
vs.VS2013x86 due to supporting stack unwind. The upside is the unexpected
exception handler can print out a stack trace. VS2013x86 requires the debugger
with symbols to unwind the stack.
~/work/Compiler>cat call.c
int main ()
{
return 0;
}
~/work/Compiler>clang -Os call.c
~/work/Compiler>lldb a.out
(lldb) target create "a.out"
Current executable set to 'a.out' (x86_64).
(lldb) dis -m -b -n main
a.out`main
a.out`main:
a.out[0x100000f98] <+0>: 55 pushq %rbp
a.out[0x100000f99] <+1>: 48 89 e5 movq %rsp, %rbp
a.out[0x100000f9c] <+4>: 31 c0 xorl %eax, %eax
a.out[0x100000f9e] <+6>: 5d popq %rbp
a.out[0x100000f9f] <+7>: c3 retq
Thanks,
Andrew Fish
> VS2013x86:
> build -a IA32 -t VS2013x86 -p OvmfPkg\OvmfPkgIa32.dsc -n 5 -m
> MdeModulePkg\Core\Pei\PeiMain.inf -b RELEASE
> build -a IA32 -t VS2013x86 -p OvmfPkg\OvmfPkgIa32.dsc -n 5 -m
> MdeModulePkg\Core\Pei\PeiMain.inf -b DEBUG -DDEBUG_ON_SERIAL_PORT
> build -a X64 -t VS2013x86 -p OvmfPkg\OvmfPkgX64.dsc -n 5 -m
> MdeModulePkg\Core\Dxe\DxeMain.inf -b RELEASE
> build -a X64 -t VS2013x86 -p OvmfPkg\OvmfPkgX64.dsc -n 5 -m
> MdeModulePkg\Core\Dxe\DxeMain.inf -b DEBUG -DDEBUG_ON_SERIAL_PORT
>
> CLANGLTO38:
> build -a IA32 -t CLANGLTO38 -p OvmfPkg/OvmfPkgIa32.dsc -n 5 -m
> MdeModulePkg/Core/Pei/PeiMain.inf -b RELEASE
> build -a IA32 -t CLANGLTO38 -p OvmfPkg/OvmfPkgIa32.dsc -n 5 -m
> MdeModulePkg/Core/Pei/PeiMain.inf -b DEBUG -DDEBUG_ON_SERIAL_PORT
> build -a X64 -t CLANGLTO38 -p OvmfPkg/OvmfPkgX64.dsc -n 5 -m
> MdeModulePkg/Core/Dxe/DxeMain.inf -b RELEASE
> build -a X64 -t CLANGLTO38 -p OvmfPkg/OvmfPkgX64.dsc -n 5 -m
> MdeModulePkg/Core/Dxe/DxeMain.inf -b DEBUG -DDEBUG_ON_SERIAL_PORT
>
>
>
> Steven Shi
> Intel\SSG\STO\UEFI Firmware
>
> Tel: +86 021-61166522
> iNet: 821-6522
>
> From: af...@apple.com [mailto:af...@apple.com]
> Sent: Wednesday, May 11, 2016 2:03 AM
> To: Shi, Steven <steven....@intel.com>
> Cc: edk2-devel@lists.01.org
> Subject: Re: [edk2] edk2 llvm branch
>
>
> On May 10, 2016, at 8:05 AM, Shi, Steven
> <steven....@intel.com<mailto:steven....@intel.com>> wrote:
>
> Hi Andrew,
> Thank you for the suggestion. I will try your suggestion and response other
> questions in your email later. I don't have XCODE5 environment, but could do
> me a favor and let me know what current XCODE5 code size for PeiCore.efi and
> DxeCore.efi in your side? In my side, as below data show, I see the LTO can
> bring big code size improvement which is quite important for firmware in many
> scenarios.
>
> I forgot to mention. LTO or not it is good to check to make sure the assembly
> files are getting dead stripped. For example check to make sure you are not
> getting all the assembly functions in the BaseLib included in your
> executable. Some of the assembly is .S and some is .nasm so you may see
> different behavior depending on which assembler was used.
>
> It is also useful to start looking at the smallest PEIM/DXE drivers 1st as it
> may be easier to spot what is different.
>
>
> Maybe it is also a good idea to enable LTO in XCODE.
>
> For Xcode you add -object_path_lto $(DEST_DIR_DEBUG)/$(BASE_NAME).lto to
> *_XCODE5_*_DLINK_FLAGS. This places the intermediate link code gen in the
> Build/ director vs. a temp director and is important for source level
> debugging. To turn LTO on and off you add -flto to *_XCODE5_*_CC_FLAGS .
>
> We ended up making LTO a configurable build option, so we control it in the
> DSC file. git
>
> [BuildOptions]
> !if $(PEI_LTO_ENABLE)
> XCODE:*_*_IA32_PLATFORM_FLAGS = -flto
> !endif
>
> !if $(DXE_LTO_ENABLE)
> XCODE:*_*_X64_PLATFORM_FLAGS = -flto
> !endif
>
> I included the Xcode 6.3.2 Numbers:
>
>
>
>
> IA32 DEBUG PeiCore.efi on Ovmf build code size example:
> ToolChainName PeiCore.efi file size
> VS2013x86: 40KB
> CLANGLTO38: 42KB
> Xcode 61K
>
>
> GCCLTO53: 44KB
> GCC49: 55KB
> CLANG38: 60KB
>
>
> IA32 RELEASE PeiCore.efi on Ovmf build code size example:
> ToolChainName PeiCore.efi file size
> VS2013x86: 20KB
> GCCLTO53: 23KB
> CLANGLTO38: 24KB
> Xcode 31K
>
>
>
> GCC49: 27KB
> Clang38: 29KB
>
>
> X64 DEBUG DxeCore.efi on Ovmf build code size example:
> ToolChainName .efi file size LZMA
> Compressed size
> VS2013x86: 137KB
> 57KB
> CLANGLTO38: 145KB
> 61KB
> Xcode 157K 68K
>
>
> GCCLTO53: 161KB
> 63KB
> GCC49: 273KB 69KB
> CLANG38: 205KB
> 72KB
>
>
>
> X64 RELEASE DxeCore.efi on Ovmf build code size example:
> ToolChainName .efi file size LZMA
> Compressed size
> VS2013x86: 95KB
> 44KB
> GCCLTO53: 101KB
> 46KB
> CLANGLTO38: 107KB
> 48KB
> Xcode 104K 49K
>
>
> GCC49: 184KB 52KB
> CLANG38: 133KB
> 53KB
>
>
> Can you send my linker map files for VS2013 & CLANGLTO38 off list.
>
> Thanks,
>
> Andrew Fish
>
>
> Steven Shi
> Intel\SSG\STO\UEFI Firmware
>
> Tel: +86 021-61166522
> iNet: 821-6522
>
>> -----Original Message-----
>> From: af...@apple.com<mailto:af...@apple.com> [mailto:af...@apple.com]
>> Sent: Tuesday, May 10, 2016 1:12 PM
>> To: Shi, Steven <steven....@intel.com<mailto:steven....@intel.com>>
>> Cc: edk2-devel@lists.01.org<mailto:edk2-devel@lists.01.org>
>> Subject: Re: [edk2] edk2 llvm branch
>>
>>
>
> _______________________________________________
> edk2-devel mailing list
> edk2-devel@lists.01.org
> https://lists.01.org/mailman/listinfo/edk2-devel
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