Ersek: I try O2 option. Compared to Ofast, there is a little different. I think it is acceptable. I will use O2 option. And, this warning message also exists without O2 enable. It is not introduced by this patch.
Tool Compression time Decompression time LzmaCompress (GCC O0) 3.476s 0.204s LzmaCompress (GCC Ofast) 1.655s 0.107s LzmaCompress (GCC O2) 1.687s 0.105s Thanks Liming From: edk2-devel [mailto:[email protected]] On Behalf Of Gao, Liming Sent: Friday, September 30, 2016 8:24 AM To: Laszlo Ersek <[email protected]> Cc: Justen, Jordan L <[email protected]>; [email protected]; Ard Biesheuvel <[email protected]> Subject: Re: [edk2] [Patch 4/4] BaseTools Makefile: Enable Ofast option for GCC tool chain Laszlo: Thanks for your suggestion. I will try O2 option and see the performance and warning. Thanks Liming From: Laszlo Ersek [mailto:[email protected]] Sent: Friday, September 30, 2016 2:30 AM To: Gao, Liming Cc: [email protected]<mailto:[email protected]>; Ard Biesheuvel ; Justen, Jordan L Subject: Re: [edk2] [Patch 4/4] BaseTools Makefile: Enable Ofast option for GCC tool chain Hi Liming, On 09/29/16 16:12, Liming Gao wrote: > Enable Ofast option to generate fast code for performance improvement. > > Contributed-under: TianoCore Contribution Agreement 1.0 > Signed-off-by: Liming Gao > --- > BaseTools/Source/C/Makefiles/header.makefile | 6 +++--- > 1 file changed, 3 insertions(+), 3 deletions(-) > > diff --git a/BaseTools/Source/C/Makefiles/header.makefile > b/BaseTools/Source/C/Makefiles/header.makefile > index f2041f8..ca2dc2e 100644 > --- a/BaseTools/Source/C/Makefiles/header.makefile > +++ b/BaseTools/Source/C/Makefiles/header.makefile > @@ -44,12 +44,12 @@ ARCH_INCLUDE = -I $(MAKEROOT)/Include/AArch64/ > endif > > INCLUDE = $(TOOL_INCLUDE) -I $(MAKEROOT) -I $(MAKEROOT)/Include/Common -I > $(MAKEROOT)/Include/ -I $(MAKEROOT)/Include/IndustryStandard -I > $(MAKEROOT)/Common/ -I .. -I . $(ARCH_INCLUDE) > -BUILD_CPPFLAGS = $(INCLUDE) > +BUILD_CPPFLAGS = $(INCLUDE) -Ofast > ifeq ($(DARWIN),Darwin) > # assume clang or clang compatible flags on OS X > -BUILD_CFLAGS = -MD -fshort-wchar -fno-strict-aliasing -Wall -Werror > -Wno-deprecated-declarations -Wno-self-assign -nostdlib -c -g > +BUILD_CFLAGS = -MD -fshort-wchar -fno-strict-aliasing -Wall -Werror > -Wno-deprecated-declarations -Wno-self-assign -Wno-unused-result -nostdlib -c > -g > else > -BUILD_CFLAGS = -MD -fshort-wchar -fno-strict-aliasing -Wall -Werror > -Wno-deprecated-declarations -nostdlib -c -g > +BUILD_CFLAGS = -MD -fshort-wchar -fno-strict-aliasing -Wall -Werror > -Wno-deprecated-declarations -Wno-unused-result -nostdlib -c -g > endif > BUILD_LFLAGS = > BUILD_CXXFLAGS = > are you sure -Ofast is a good idea? The gcc manual says, -Ofast Disregard strict standards compliance. -Ofast enables all -O3 optimizations. It also enables optimizations that are not valid for all standard-compliant programs. It turns on -ffast-math and the Fortran-specific -fno-protect-parens and -fstack-arrays. To me this sounds quite scary -- I'm worried it might break the base utilities in various obscure ways, which in turn could break the firmware built with these tools in obscure ways. Most upstream projects and GNU/Linux distributions use -O2 for performance-optimized builds. Can you try that please and see if the performance improvements (relative to the current status) are still acceptable? If so, I would strongly prefer -O2 over -Ofast. Also, while building BaseTools with your series applied (using gcc-4.8), I saw one warning issued: > g++ -c -I Pccts/h -I .. -I ../Include/Common -I ../Include/ -I > ../Include/IndustryStandard -I ../Common/ -I .. -I . -I ../Include/X64/ > -Ofast VfrFormPkg.cpp -o VfrFormPkg.o > VfrFormPkg.cpp: In member function 'void > CIfrRecordInfoDB::IfrUpdateRecordInfoForDynamicOpcode(BOOLEAN)': > VfrFormPkg.cpp:1360:91: warning: deprecated conversion from string constant > to 'CHAR8* {aka char*}' [-Wwrite-strings] > gCVfrErrorHandle.PrintMsg (0, "Error", "Can not find the adjust offset in the > record."); ^ Thanks! Laszlo _______________________________________________ edk2-devel mailing list [email protected]<mailto:[email protected]> https://lists.01.org/mailman/listinfo/edk2-devel _______________________________________________ edk2-devel mailing list [email protected] https://lists.01.org/mailman/listinfo/edk2-devel
