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我正在開發嵌入式ARM平臺上運行的軟件。在更新我們的平臺的過程中，我們正在從基於OpenEmbedded的系統切換到Linaro。Linaro編譯速度
在我的機器上，使用OpenEmbedded爲我們構建的32位gcc 4.6.4，我們需要大約9分鐘的時間來交叉編譯我們的ARM軟件。對於新系統，我們現在正在嘗試使用Linaro的gcc 4.7二進制文件 - 令人驚訝的結果是編譯突然需要大約兩倍的時間（18分鐘）。 Linaro gcc 4.6二進制文件具有相同的問題，因此它不是gcc版本特定的。
使用Linaro的crosstool-ng創建其編譯器的調整版本（例如嘗試儘可能接近配置選項）沒有加快速度。
- 舊使用softfp，Linaro的硬並指定FPU
- 舊目標沒有特別的ARM處理器/架構（ARM-無：
我們的舊gcc編譯和Linaro的一個之間的主要區別-linux-gnueabi），Linaro的GCC（ARM-Linux的gnueabihf）具有
with-target=armv7-a和with-tune=cortex-a9明確地設置
更改配置的gcc選項，如啓用的SSP，拇指/臂模式，採用的multilib，目標CPU（cortex- a8訴s a9）沒有產生改善。
對於一個簡單的test.cpp，性能速度已經有所不同了，它只有一個主要功能vector<int>，所以它與鏈接無關，我懷疑STL頭文件造成了很大的差別。
我想出了什麼來調整。有人有想法嗎？
EDIT4：我也嘗試了手臂交叉編譯器的Ubuntu 12.04（gcc版本4.6.3（Ubuntu的/ Linaro的4.6.3-1ubuntu5）），它具有相當的編譯時間到我的4.6.4版本。所以在Linaro的版本中似乎有些特別的不同，我可能無法關閉或者是他們應用的一些特殊補丁？
EDIT3：-ftime-report從Linaro的GCC 4.7從項目的實際源文件：
Execution times (seconds)
phase setup : 0.00 (0%) usr 0.00 (0%) sys 0.02 (1%) wall 2076 kB (2%) ggc
phase parsing : 1.72 (74%) usr 0.34 (85%) sys 2.04 (75%) wall 66732 kB (79%) ggc
phase lang. deferred : 0.28 (12%) usr 0.04 (10%) sys 0.33 (12%) wall 10215 kB (12%) ggc
phase cgraph : 0.32 (14%) usr 0.02 (5%) sys 0.33 (12%) wall 5481 kB (6%) ggc
phase generate : 0.60 (26%) usr 0.06 (15%) sys 0.66 (24%) wall 15700 kB (19%) ggc
|name lookup : 0.28 (12%) usr 0.02 (5%) sys 0.24 (9%) wall 8058 kB (10%) ggc
|overload resolution : 0.32 (14%) usr 0.06 (15%) sys 0.36 (13%) wall 10042 kB (12%) ggc
callgraph construction : 0.06 (3%) usr 0.00 (0%) sys 0.02 (1%) wall 551 kB (1%) ggc
callgraph optimization : 0.02 (1%) usr 0.00 (0%) sys 0.01 (0%) wall 224 kB (0%) ggc
varpool construction : 0.00 (0%) usr 0.00 (0%) sys 0.01 (0%) wall 94 kB (0%) ggc
df scan insns : 0.06 (3%) usr 0.00 (0%) sys 0.02 (1%) wall 5 kB (0%) ggc
df reg dead/unused notes: 0.00 (0%) usr 0.00 (0%) sys 0.01 (0%) wall 22 kB (0%) ggc
alias analysis : 0.00 (0%) usr 0.02 (5%) sys 0.00 (0%) wall 11 kB (0%) ggc
preprocessing : 0.08 (3%) usr 0.10 (25%) sys 0.29 (11%) wall 1069 kB (1%) ggc
parser (global) : 0.58 (25%) usr 0.08 (20%) sys 0.43 (16%) wall 25145 kB (30%) ggc
parser struct body : 0.28 (12%) usr 0.02 (5%) sys 0.34 (12%) wall 12400 kB (15%) ggc
parser enumerator list : 0.00 (0%) usr 0.00 (0%) sys 0.01 (0%) wall 121 kB (0%) ggc
parser function body : 0.14 (6%) usr 0.00 (0%) sys 0.15 (6%) wall 2435 kB (3%) ggc
parser inl. func. body : 0.10 (4%) usr 0.02 (5%) sys 0.18 (7%) wall 3682 kB (4%) ggc
parser inl. meth. body : 0.24 (10%) usr 0.02 (5%) sys 0.20 (7%) wall 5298 kB (6%) ggc
template instantiation : 0.58 (25%) usr 0.14 (35%) sys 0.75 (28%) wall 26588 kB (31%) ggc
tree gimplify : 0.02 (1%) usr 0.00 (0%) sys 0.03 (1%) wall 785 kB (1%) ggc
tree CFG construction : 0.00 (0%) usr 0.00 (0%) sys 0.01 (0%) wall 543 kB (1%) ggc
tree SSA other : 0.00 (0%) usr 0.00 (0%) sys 0.02 (1%) wall 32 kB (0%) ggc
out of ssa : 0.00 (0%) usr 0.00 (0%) sys 0.01 (0%) wall 0 kB (0%) ggc
expand : 0.00 (0%) usr 0.00 (0%) sys 0.01 (0%) wall 438 kB (1%) ggc
varconst : 0.00 (0%) usr 0.00 (0%) sys 0.01 (0%) wall 6 kB (0%) ggc
integrated RA : 0.04 (2%) usr 0.00 (0%) sys 0.09 (3%) wall 1313 kB (2%) ggc
reload : 0.06 (3%) usr 0.00 (0%) sys 0.02 (1%) wall 60 kB (0%) ggc
thread pro- & epilogue : 0.00 (0%) usr 0.00 (0%) sys 0.02 (1%) wall 92 kB (0%) ggc
final : 0.02 (1%) usr 0.00 (0%) sys 0.02 (1%) wall 4 kB (0%) ggc
rest of compilation : 0.02 (1%) usr 0.00 (0%) sys 0.02 (1%) wall 133 kB (0%) ggc
unaccounted todo : 0.02 (1%) usr 0.00 (0%) sys 0.01 (0%) wall 0 kB (0%) ggc
TOTAL : 2.32 0.40 2.72 84519 kB
與同爲我的gcc-4.6：
Execution times (seconds)
callgraph construction: 0.00 (0%) usr 0.00 (0%) sys 0.02 (1%) wall 527 kB (1%) ggc
trivially dead code : 0.00 (0%) usr 0.00 (0%) sys 0.01 (1%) wall 0 kB (0%) ggc
df scan insns : 0.02 (2%) usr 0.00 (0%) sys 0.01 (1%) wall 5 kB (0%) ggc
df reg dead/unused notes: 0.00 (0%) usr 0.00 (0%) sys 0.01 (1%) wall 22 kB (0%) ggc
preprocessing : 0.08 (7%) usr 0.10 (26%) sys 0.14 (9%) wall 1016 kB (1%) ggc
parser : 0.68 (58%) usr 0.24 (63%) sys 0.83 (52%) wall 52215 kB (76%) ggc
name lookup : 0.28 (24%) usr 0.02 (5%) sys 0.41 (26%) wall 10211 kB (15%) ggc
inline heuristics : 0.00 (0%) usr 0.02 (5%) sys 0.00 (0%) wall 0 kB (0%) ggc
tree gimplify : 0.00 (0%) usr 0.00 (0%) sys 0.01 (1%) wall 637 kB (1%) ggc
tree CFG construction : 0.02 (2%) usr 0.00 (0%) sys 0.00 (0%) wall 463 kB (1%) ggc
expand : 0.02 (2%) usr 0.00 (0%) sys 0.01 (1%) wall 426 kB (1%) ggc
varconst : 0.00 (0%) usr 0.00 (0%) sys 0.02 (1%) wall 132 kB (0%) ggc
integrated RA : 0.02 (2%) usr 0.00 (0%) sys 0.03 (2%) wall 304 kB (0%) ggc
reload : 0.00 (0%) usr 0.00 (0%) sys 0.01 (1%) wall 58 kB (0%) ggc
machine dep reorg : 0.02 (2%) usr 0.00 (0%) sys 0.00 (0%) wall 3 kB (0%) ggc
final : 0.00 (0%) usr 0.00 (0%) sys 0.02 (1%) wall 4 kB (0%) ggc
rest of compilation : 0.02 (2%) usr 0.00 (0%) sys 0.01 (1%) wall 133 kB (0%) ggc
unaccounted todo : 0.02 (2%) usr 0.00 (0%) sys 0.03 (2%) wall 0 kB (0%) ggc
TOTAL : 1.18 0.38 1.59 68315 kB
EDIT2： Linaro gc ç4.6.3的-ftime-report輸出一個非常簡單的TEST.CPP（包括期權-fno-graphite-identity -fno-graphite）：
Execution times (seconds)
preprocessing : 0.00 (0%) usr 0.02 (50%) sys 0.02 (10%) wall 121 kB (2%) ggc
parser : 0.10 (62%) usr 0.02 (50%) sys 0.11 (55%) wall 4022 kB (65%) ggc
name lookup : 0.02 (12%) usr 0.00 (0%) sys 0.04 (20%) wall 879 kB (14%) ggc
tree gimplify : 0.02 (13%) usr 0.00 (0%) sys 0.00 (0%) wall 20 kB (0%) ggc
expand : 0.00 (0%) usr 0.00 (0%) sys 0.01 (5%) wall 34 kB (1%) ggc
integrated RA : 0.02 (12%) usr 0.00 (0%) sys 0.01 (5%) wall 59 kB (1%) ggc
TOTAL : 0.16 0.04 0.20 6207 kB
，並用我的舊的gcc 4.6.4在同一個文件：
Execution times (seconds)
preprocessing : 0.02 (25%) usr 0.00 (0%) sys 0.02 (14%) wall 119 kB (2%) ggc
parser : 0.00 (0%) usr 0.04 (100%) sys 0.06 (43%) wall 4021 kB (65%) ggc
name lookup : 0.04 (50%) usr 0.00 (0%) sys 0.03 (21%) wall 879 kB (14%) ggc
expand : 0.02 (25%) usr 0.00 (0%) sys 0.01 (7%) wall 34 kB (1%) ggc
unaccounted todo : 0.00 (0%) usr 0.00 (0%) sys 0.01 (7%) wall 0 kB (0%) ggc
TOTAL : 0.08 0.04 0.14 6204 kB
生成預處理文件兩個編譯器都沒有產生顯着差異（Linaro的gcc的輸出只有3行更長）。
EDIT1： GCC -v用於縮短或除去舊的（路徑（例如--sbindir）
# arm-none-linux-gnueabi-g++ -v
Using built-in specs.
COLLECT_GCC=..sysroots/i686-linux/usr/bin/arm-none-linux-gnueabi-g++
COLLECT_LTO_WRAPPER=../libexec/gcc/arm-none-linux-gnueabi/4.6.4/lto-wrapper
Target: arm-none-linux-gnueabi
Configured with: ..tmp/work/armv7a-none-linux-gnueabi/gcc-cross-4.6.3+svnr184847-r27/gcc-4_6-branch/configure --build=i686-linux --host=i686-linux --target=arm-none-linux-gnueabi --with-gnu-ld --enable-shared --enable-languages=c,c++ --enable-threads=posix --disable-multilib --enable-c99 --enable-long-long --enable-symvers=gnu --enable-libstdcxx-pch --program-prefix=arm-none-linux-gnueabi- --without-local-prefix --enable-lto --enable-libssp --disable-bootstrap --disable-libgomp --disable-libmudflap --with-system-zlib --with-linker-hash-style=gnu --with-ppl=no --with-cloog=no --enable-cheaders=c_global --enable-languages=c,c++,fortran --disable-libunwind-exceptions --with-mpfr=..sysroots/i686-linux/usr --with-system-zlib --enable-__cxa_atexit
Thread model: posix
gcc version 4.6.4 20120303 (prerelease) (GCC)
和Linaro的GCC -v
# arm-linux-gnueabihf-g++ -v
Using built-in specs.
COLLECT_GCC=..compiler/bin/arm-linux-gnueabihf-g++
COLLECT_LTO_WRAPPER=../libexec/gcc/arm-linux-gnueabihf/4.7.2/lto-wrapper
Target: arm-linux-gnueabihf
Configured with: .build/src/gcc-linaro-4.7-2012.08/configure --build=i686-build_pc-linux-gnu --host=i686-build_pc-linux-gnu --target=arm-linux-gnueabihf --enable-languages=c,c++,fortran --enable-multilib --with-arch=armv7-a --with-tune=cortex-a9 --with-fpu=vfpv3-d16 --with-float=hard --with-pkgversion='crosstool-NG linaro-1.13.1-2012.08-20120827 - Linaro GCC 2012.08' --with-bugurl=https://bugs.launchpad.net/gcc-linaro --enable-__cxa_atexit --enable-libmudflap --enable-libgomp --enable-libssp --with-gmp=.. --with-mpfr=.. --with-mpc=.. --with-ppl=.. --with-cloog=.. --with-libelf=.. --with-host-libstdcxx='-L.. -lpwl' --enable-threads=posix --disable-libstdcxx-pch --enable-linker-build-id --enable-gold --with-local-prefix=.. --enable-c99 --enable-long-long --with-mode=thumb
Thread model: posix
gcc version 4.7.2 20120731 (prerelease) (crosstool-NG linaro-1.13.1-2012.08-20120827 - Linaro GCC 2012.08)
對於後者我也做了調整，讓--disable-multilib --disable-libmudflap --disable-libgomp --disable-multilib。
而這裏的Ubuntu 12.04的ARM編譯器：
> arm-linux-gnueabihf-g++-4.6 -v
Using built-in specs.
COLLECT_GCC=arm-linux-gnueabihf-g++-4.6
COLLECT_LTO_WRAPPER=/usr/lib/gcc/arm-linux-gnueabihf/4.6/lto-wrapper
Target: arm-linux-gnueabihf
Configured with: ../src/configure -v --with-pkgversion='Ubuntu/Linaro 4.6.3-1ubuntu5' --enable-languages=c,c++,fortran,objc,obj-c++ --prefix=/usr --program-suffix=-4.6 --enable-shared --enable-linker-build-id --with-system-zlib --libexecdir=/usr/lib --without-included-gettext --enable-threads=posix --with-gxx-include-dir=/usr/arm-linux-gnueabihf/include/c++/4.6.3 --libdir=/usr/lib --enable-nls --enable-clocale=gnu --enable-libstdcxx-debug --enable-libstdcxx-time=yes --enable-gnu-unique-object --enable-plugin --enable-objc-gc --enable-multilib --disable-sjlj-exceptions --with-arch=armv7-a --with-float=hard --with-fpu=vfpv3-d16 --with-mode=thumb --disable-werror --enable-checking=release --build=x86_64-linux-gnu --host=x86_64-linux-gnu --target=arm-linux-gnueabihf
Linaro的GCC使用cloog及PPL所以提供了石墨的循環優化。 –
@BasileStarynkevitch：我在'-fno-graphite-identity -fno-graphite'的編譯過程中嘗試禁用它，但它在編譯時間上完全沒有區別。 – Frankie