Beta Branch Testing GCC 8, GCC 9 & Clang 5/6/7 compiler for Centmin Mod Nginx & PHP-FPM

Like GCC 7 and Clang 4/5 testing previously, I am also starting to test optional support for using GCC 8 compiler for compiling Nginx and PHP-FPM with eventually. Currently, there's no YUM packages for GCC 8 as it's still in development. But I am testing GCC 8 snapshot releases. Updated: Clang 5.0.1 and Clang 6.0.0 coming along nicely too.

Example of Binutils 2.29.1 and GCC 8 snapshot installed

Code (Text):

*************************************************
* Setup /opt/gcc-8-20180107/enable
*************************************************

*************************************************
* Setup /opt/gcc-8-20180107/enable completed
*************************************************

/opt/gcc-8-20180107/bin/ld -v
GNU ld (GNU Binutils) 2.29.1

/opt/gcc-8-20180107/bin/ld.gold -v
GNU gold (GNU Binutils 2.29.1) 1.14

/opt/gcc-8-20180107/bin/ld.bfd -v
GNU ld (GNU Binutils) 2.29.1

/opt/gcc-8-20180107/bin/gcc --version
gcc (GCC) 8.0.0 20180107 (experimental)
Copyright (C) 2018 Free Software Foundation, Inc.
This is free software; see the source for copying conditions.  There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.

/opt/gcc-8-20180107/bin/g++ --version
g++ (GCC) 8.0.0 20180107 (experimental)
Copyright (C) 2018 Free Software Foundation, Inc.
This is free software; see the source for copying conditions.  There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.

*************************************************
* Compile GCC Completed
*************************************************

symlink to make it easier to detect for Nginx and PHP-FPM compiles

Code (Text):

ls -lah /opt/gcc8
lrwxrwxrwx 1 root root 19 Jan 14 02:22 /opt/gcc8 -> /opt/gcc-8-20180107

Code (Text):

/opt/gcc8/bin/gcc -v
Using built-in specs.
COLLECT_GCC=/opt/gcc8/bin/gcc
COLLECT_LTO_WRAPPER=/opt/gcc-8-20180107/libexec/gcc/x86_64-redhat-linux/8.0.0/lto-wrapper
Target: x86_64-redhat-linux
Configured with: ../configure --prefix=/opt/gcc-8-20180107 --disable-multilib --disable-nls --enable-threads=posix --enable-checking=release --with-system-zlib --enable-__cxa_atexit --disable-libunwind-exceptions --enable-gnu-unique-object --enable-linker-build-id --with-linker-hash-style=gnu --enable-languages=c,c++ --enable-initfini-array --disable-libgcj --enable-gnu-indirect-function --with-tune=generic --build=x86_64-redhat-linux
Thread model: posix
gcc version 8.0.0 20180107 (experimental) (GCC)

Though right now Nginx fails to compile with GCC 8 installed - so some ways to go before we will see it working. So more private testing

Code (Text):

./configure --with-ld-opt="-lrt -ljemalloc -Wl,-z,relro -Wl,-rpath,/usr/local/lib" --with-cc-opt="-m64 -march=native -g -O3 -fstack-protector-strong -flto -fuse-ld=gold --param=ssp-buffer-size=4 -Wformat -Werror=format-security  -Wp,-D_FORTIFY_SOURCE=2 -gsplit-dwarf" --sbin-path=/usr/local/sbin/nginx --conf-path=/usr/local/nginx/conf/nginx.conf --with-compat --with-http_stub_status_module --with-http_secure_link_module --with-libatomic --with-http_gzip_static_module --with-http_sub_module --with-http_addition_module --with-http_image_filter_module=dynamic --with-http_geoip_module --with-stream_geoip_module --with-stream_realip_module --with-stream_ssl_preread_module --with-threads --with-stream=dynamic --with-stream_ssl_module --with-http_realip_module --add-dynamic-module=../ngx-fancyindex-0.4.2 --add-module=../ngx_cache_purge-2.4.2 --add-module=../ngx_devel_kit-0.3.0 --add-dynamic-module=../set-misc-nginx-module-0.31 --add-dynamic-module=../echo-nginx-module-0.61 --add-module=../redis2-nginx-module-0.14 --add-module=../ngx_http_redis-0.3.7 --add-module=../memc-nginx-module-0.18 --add-module=../srcache-nginx-module-0.31 --add-dynamic-module=../headers-more-nginx-module-0.33 --with-pcre=../pcre-8.41 --with-pcre-jit --with-zlib=../zlib-1.2.11 --with-http_ssl_module --with-http_v2_module --with-openssl=../libressl-2.6.4
checking for OS
 + Linux 2.6.32-042stab120.19 x86_64
checking for C compiler ... found
 + using GNU C compiler
 + gcc version: 8.0.0 20180107 (experimental) (GCC)
checking for gcc -pipe switch ... found
checking for --with-ld-opt="-lrt -ljemalloc -Wl,-z,relro -Wl,-rpath,/usr/local/lib" ... not found
./configure: error: the invalid value in --with-ld-opt="-lrt -ljemalloc -Wl,-z,relro -Wl,-rpath,/usr/local/lib"

nginx error log

Code (Text):

cat /svr-setup/nginx-1.13.8/objs/autoconf.err

----------------------------------------
checking for C compiler

----------------------------------------
checking for gcc -pipe switch

----------------------------------------
checking for --with-ld-opt="-lrt -ljemalloc -Wl,-z,relro -Wl,-rpath,/usr/local/lib"

objs/autotest.c:9:1: internal compiler error: Segmentation fault
 }
 ^
0xb0eadf crash_signal
        ../../gcc/toplev.c:325
0x873f6b hash_table<indirect_string_hasher, xcallocator>::elements() const
        ../../gcc/hash-table.h:388
0x873f6b void hash_table<indirect_string_hasher, xcallocator>::traverse<dwarf_form, &(output_indirect_string(indirect_string_node**, dwarf_form))>(dwarf_form)
        ../../gcc/hash-table.h:987
0x841748 output_indirect_strings
        ../../gcc/dwarf2out.c:27799
0x8725d2 dwarf2out_early_finish
        ../../gcc/dwarf2out.c:30894
0x7f4fe8 symbol_table::finalize_compilation_unit()
        ../../gcc/cgraphunit.c:2713
Please submit a full bug report,
with preprocessed source if appropriate.
Please include the complete backtrace with any bug report.
See <https://gcc.gnu.org/bugs/> for instructions.
----------
#include <sys/types.h>

int main(void) {
    ;
    return 0;
}

----------
ccache gcc -m64 -march=native -g -O3 -fstack-protector-strong -flto -fuse-ld=gold --param=ssp-buffer-size=4 -Wformat -Werror=format-security -Wp,-D_FORTIFY_SOURCE=2 -gsplit-dwarf -o objs/autotest objs/autotest.c -lrt -ljemalloc -Wl,-z,relro -Wl,-rpath,/usr/local/lib
----------

no problems with GCC 7.2.1 though

---

 

Looks like Nginx doesn't like to be compiled with GCC 8 when -gsplit-dwarf parameter was set. Could be a GCC 8 regression bug since it's stilll in development. That got me past the internal compiler error segmentation fault above. But ran into more errors hanging up on -Werror=cast-function-type related warnings so need to add another compile flag to Nginx compile routines when GCC 8 is used for -Wno-cast-function-type

Code (Text):

ccache gcc -c -pipe  -O -W -Wall -Wpointer-arith -Wno-unused-parameter -Werror -g -m64 -march=x86-64 -g -O3 -fstack-protector-strong -flto -fuse-ld=gold --param=ssp-buffer-size=4 -Wformat -Werror=format-security  -Wp,-D_FORTIFY_SOURCE=2 -DNDK_SET_VAR -DNDK_UPSTREAM_LIST -I src/core -I src/event -I src/event/modules -I src/os/unix -I ../ngx_devel_kit-0.3.0/objs -I objs/addon/ndk -I ../pcre-8.41 -I ../libressl-2.6.4/.openssl/include -I ../zlib-1.2.11 -I objs -I src/http -I src/http/modules -I src/http/v2 -I ../ngx_devel_kit-0.3.0/src -I ../ngx_devel_kit-0.3.0/src -I ../ngx_devel_kit-0.3.0/objs -I objs/addon/ndk \
        -o objs/src/http/ngx_http_upstream.o \
        src/http/ngx_http_upstream.c
src/http/ngx_http_script.c: In function 'ngx_http_script_add_copy_code':
src/http/ngx_http_script.c:698:18: error: cast between incompatible function types from 'size_t (*)(ngx_http_script_engine_t *)' {aka 'long unsigned int (*)(struct <anonymous> *)'} to 'void (*)(ngx_http_script_engine_t *)' {aka 'void (*)(struct <anonymous> *)'} [-Werror=cast-function-type]
     code->code = (ngx_http_script_code_pt) ngx_http_script_copy_len_code;
                  ^
src/http/ngx_http_script.c: In function 'ngx_http_script_add_var_code':
src/http/ngx_http_script.c:787:18: error: cast between incompatible function types from 'size_t (*)(ngx_http_script_engine_t *)' {aka 'long unsigned int (*)(struct <anonymous> *)'} to 'void (*)(ngx_http_script_engine_t *)' {aka 'void (*)(struct <anonymous> *)'} [-Werror=cast-function-type]
     code->code = (ngx_http_script_code_pt) ngx_http_script_copy_var_len_code;
                  ^
src/http/ngx_http_script.c: In function 'ngx_http_script_add_capture_code':
src/http/ngx_http_script.c:1181:18: error: cast between incompatible function types from 'size_t (*)(ngx_http_script_engine_t *)' {aka 'long unsigned int (*)(struct <anonymous> *)'} to 'void (*)(ngx_http_script_engine_t *)' {aka 'void (*)(struct <anonymous> *)'} [-Werror=cast-function-type]
     code->code = (ngx_http_script_code_pt)
                  ^
src/http/ngx_http_script.c: In function 'ngx_http_script_add_full_name_code':
src/http/ngx_http_script.c:1296:18: error: cast between incompatible function types from 'size_t (*)(ngx_http_script_engine_t *)' {aka 'long unsigned int (*)(struct <anonymous> *)'} to 'void (*)(ngx_http_script_engine_t *)' {aka 'void (*)(struct <anonymous> *)'} [-Werror=cast-function-type]
     code->code = (ngx_http_script_code_pt) ngx_http_script_full_name_len_code;
                  ^
cc1: all warnings being treated as errors
make[1]: *** [objs/src/http/ngx_http_script.o] Error 1
make[1]: *** Waiting for unfinished jobs....
make[1]: Leaving directory `/svr-setup/nginx-1.13.8'
make: *** [build] Error 2

Looking much better with workaround for GCC 8 compiled Nginx. First successful Nginx + GCC 8 compilation

with LibreSSL 2.6.4

with OpenSSL 1.1.0g and setting variable LIBRESSL_SWITCH='n' in persistent config file /etc/centminmod/custom_config.inc prior to Nginx compile via centmin.sh menu option 4

 

Guide To GCC & Clang Compiler Selection For Nginx Installs

Centmin Mod 123.09beta01 LEMP stack can allow users to optionally select their own choice of compilers for Nginx and PHP-FPM. Below is example for Nginx where you can choose between native CentOS GCC version, GCC 5.3.1, GCC 6.3.1, GCC 7.2.1, Clang 3.4.2, Clang 4.0.1 and soon GCC 8.0 and Clang 5.0. As discussed here, depending on pairing of compiler and specific cpu model, you can get better Nginx or PHP-FPM performance usually between 5-10%. Which may offset some of the performance loss due to Linux Kernel Page Table Isolation updates to fix Meltdown/Spectre vulnerabilities

Blow is a list of persisent config file /etc/centminmod/custom_config.inc variables controlling which compiler and version is used for GCC or Clang compilers with Nginx + switching from default LibreSSL 2.6.4 to OpenSSL 1.1.0g. You set these variables BEFORE you run centmin.sh menu option 4 to recompile your Nginx versions.

You can check nginx -V output's built by line for details.

For GCC 8.0 - note experimental and not enabled in public Centmin Mod 123.09beta01 code yet and undergoing private testing right now.

Code (Text):

LIBRESSL_SWITCH='n'
CLANG='n'
DEVTOOLSETSIX='n'
DEVTOOLSETSEVEN='n'
DEVTOOLSETEIGHT='y'
NGINX_DEVTOOLSETGCC='y'

For GCC 7.2.1

Code (Text):

LIBRESSL_SWITCH='n'
CLANG='n'
DEVTOOLSETSIX='n'
DEVTOOLSETSEVEN='y'
DEVTOOLSETEIGHT='n'
NGINX_DEVTOOLSETGCC='y'

For GCC 6.3.1

Code (Text):

LIBRESSL_SWITCH='n'
CLANG='n'
DEVTOOLSETSIX='y'
DEVTOOLSETSEVEN='n'
DEVTOOLSETEIGHT='n'
NGINX_DEVTOOLSETGCC='y'

For GCC 5.3.1

Code (Text):

LIBRESSL_SWITCH='n'
CLANG='n'
DEVTOOLSETSIX='n'
DEVTOOLSETSEVEN='n'
DEVTOOLSETEIGHT='n'
NGINX_DEVTOOLSETGCC='y'

For GCC 4.8.5 native CentOS 7.4 OS provided

Code (Text):

LIBRESSL_SWITCH='n'
CLANG='n'
DEVTOOLSETSIX='n'
DEVTOOLSETSEVEN='n'
DEVTOOLSETEIGHT='n'
NGINX_DEVTOOLSETGCC='n'

For Clang 3.4.2

Code (Text):

LIBRESSL_SWITCH='n'
CLANG='y'
DEVTOOLSETSIX='n'
DEVTOOLSETSEVEN='n'
DEVTOOLSETEIGHT='n'
NGINX_DEVTOOLSETGCC='n'

For Clang 4.0.1 add CLANG_FOUR='y'

Code (Text):

LIBRESSL_SWITCH='n'
CLANG_FOUR='y'
CLANG='y'
DEVTOOLSETSIX='n'
DEVTOOLSETSEVEN='n'
DEVTOOLSETEIGHT='n'
NGINX_DEVTOOLSETGCC='y'

For Clang 5.0.1 add CLANG_FIVE='y'

Code (Text):

LIBRESSL_SWITCH='n'
CLANG_FIVE='y'
CLANG='y'
DEVTOOLSETSIX='n'
DEVTOOLSETSEVEN='n'
DEVTOOLSETEIGHT='n'
NGINX_DEVTOOLSETGCC='y'

 

Doing some quick Siege static web serving benchmarks on 2 cpu thread OpenVZ VPS server which sports an Intel E5-1650v3 @3.50Ghz processor running Centmin Mod 123.09beta01 on CentOS 7.4 64bit.

Siege test paramaters and changing comment marker for each respective GCC version tested

Code (Text):

comment='gcc8'
siege -b -d1s -c100 -r500 -m $comment http://localhost | tee "siege-${comment}-$(date +"%d%m%y-%H%M%S").log"

Results running each Nginx + GCC pairing through 3x runs of Siege benchmarking and average of 3 runs shown.

Notes:

• These are just quick tests as the results aren't entirely accurate as you probably need to do more than 3x runs and being on OpenVZ virtualized server means you're subject to noisy neighbours and resource contention still.
• Do not take these results as gospel as performance depends on your compiler + cpu model pairing. You may have a different cpu model and that may perform differently to below results. Finding the right compiler + cpu pairing is part of the fun

 

New January 14th, 2018 snapshot of GCC 8 has been released so started building that for testing including building a custom RPM. Moved build testing to my OVH MC-32 i7 4790K 4C/8T dedicated server for faster compile times.

Just the GCC 8 build task ~1534 seconds - it was this fast as Centmin Mod uses compiler caching via ccache, so subsequent recompiles are faster.

Code (Text):

*************************************************
Setup /opt/gcc-8-20180114/enable
*************************************************

*************************************************
Setup /opt/gcc-8-20180114/enable completed
*************************************************

/opt/gcc-8-20180114/bin/ld -v
GNU ld (GNU Binutils) 2.29.1

/opt/gcc-8-20180114/bin/ld.gold -v
GNU gold (GNU Binutils 2.29.1) 1.14

/opt/gcc-8-20180114/bin/ld.bfd -v
GNU ld (GNU Binutils) 2.29.1

/opt/gcc-8-20180114/bin/gcc --version
gcc (GCC) 8.0.0 20180114 (experimental)
Copyright (C) 2018 Free Software Foundation, Inc.
This is free software; see the source for copying conditions.  There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.


/opt/gcc-8-20180114/bin/g++ --version
g++ (GCC) 8.0.0 20180114 (experimental)
Copyright (C) 2018 Free Software Foundation, Inc.
This is free software; see the source for copying conditions.  There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.


RPMs Built

/svr-setup/gcc-8-20180114/test/gcc-all-8.0-1.x86_64.rpm

*************************************************
Compile GCC Completed
log: /root/centminlogs/tools-gcc-install_160118-181920.log
*************************************************

Total GCC Install Time: 1534.884407254 seconds

Code (Text):

/opt/gcc8/bin/gcc -v
Using built-in specs.
COLLECT_GCC=/opt/gcc8/bin/gcc
COLLECT_LTO_WRAPPER=/opt/gcc-8-20180114/libexec/gcc/x86_64-redhat-linux/8.0.0/lto-wrapper
Target: x86_64-redhat-linux
Configured with: ../configure --prefix=/opt/gcc-8-20180114 --disable-multilib --enable-shared --disable-nls --enable-threads=posix --enable-checking=release --with-system-zlib --enable-__cxa_atexit --disable-install-libiberty --disable-libunwind-exceptions --enable-gnu-unique-object --enable-linker-build-id --with-linker-hash-style=gnu --enable-languages=c,c++ --enable-initfini-array --disable-libgcj --enable-gnu-indirect-function --with-tune=generic --build=x86_64-redhat-linux --enable-lto --enable-gold
Thread model: posix
gcc version 8.0.0 20180114 (experimental) (GCC)

ccache compiler caching stats - had to bump up cache allocation from default 2GB to 8GB

Code (Text):

ccache -s
cache directory                     /home/.ccache
primary config                      /home/.ccache/ccache.conf
secondary config      (readonly)    /usr/local/etc/ccache.conf
cache hit (direct)                418866
cache hit (preprocessed)           71518
cache miss                        199055
cache hit rate                     71.13 %
called for link                    60404
called for preprocessing           24744
multiple source files                 16
compiler produced empty output         3
compile failed                      7202
ccache internal error               3932
preprocessor error                  4233
bad compiler arguments              7022
unsupported source language           30
autoconf compile/link              70493
unsupported compiler option          428
unsupported code directive             6
no input file                      17476
cleanups performed                   238
files in cache                    168818
cache size                           2.4 GB
max cache size                       8.0 GB

Resulting Centmin Mod Nginx compiled with GCC 8 Jan 14, 2018 snapshot

GCC Retpoline Patches For Spectre Variant 2

The Jan 14th, 2018 GCC 8 snapshot adds the new GCC Retpoline patches to address Spectre variant 2 vulnerabilities. I confirmed they exist in my custom build GCC 8 RPM binary installations.

For Intel i7 4790K native supported options now show the 3 new options for -mindirect-branch, -mindirect-return and -mindirect-branch-register

Code (Text):

/opt/gcc8/bin/gcc -c -Q -march=native --help=target
The following options are target specific:
  -m128bit-long-double                  [enabled]
  -m16                                  [disabled]
  -m32                                  [disabled]
  -m3dnow                               [disabled]
  -m3dnowa                              [disabled]
  -m64                                  [enabled]
  -m80387                               [enabled]
  -m8bit-idiv                           [disabled]
  -m96bit-long-double                   [disabled]
  -mabi=                                sysv
  -mabm                                 [enabled]
  -maccumulate-outgoing-args            [disabled]
  -maddress-mode=                       long
  -madx                                 [disabled]
  -maes                                 [enabled]
  -malign-data=                         compat
  -malign-double                        [disabled]
  -malign-functions=                    0
  -malign-jumps=                        0
  -malign-loops=                        0
  -malign-stringops                     [enabled]
  -mandroid                             [disabled]
  -march=                               haswell
  -masm=                                att
  -mavx                                 [enabled]
  -mavx2                                [enabled]
  -mavx256-split-unaligned-load         [disabled]
  -mavx256-split-unaligned-store        [disabled]
  -mavx5124fmaps                        [disabled]
  -mavx5124vnniw                        [disabled]
  -mavx512bitalg                        [disabled]
  -mavx512bw                            [disabled]
  -mavx512cd                            [disabled]
  -mavx512dq                            [disabled]
  -mavx512er                            [disabled]
  -mavx512f                             [disabled]
  -mavx512ifma                          [disabled]
  -mavx512pf                            [disabled]
  -mavx512vbmi                          [disabled]
  -mavx512vbmi2                         [disabled]
  -mavx512vl                            [disabled]
  -mavx512vnni                          [disabled]
  -mavx512vpopcntdq                     [disabled]
  -mbionic                              [disabled]
  -mbmi                                 [enabled]
  -mbmi2                                [enabled]
  -mbranch-cost=<0,5>                   3
  -mcall-ms2sysv-xlogues                [disabled]
  -mcet                                 [disabled]
  -mcet-switch                          [disabled]
  -mcld                                 [disabled]
  -mclflushopt                          [disabled]
  -mclwb                                [disabled]
  -mclzero                              [disabled]
  -mcmodel=                             [default]
  -mcpu=                         
  -mcrc32                               [disabled]
  -mcx16                                [enabled]
  -mdispatch-scheduler                  [disabled]
  -mdump-tune-features                  [disabled]
  -mf16c                                [enabled]
  -mfancy-math-387                      [enabled]
  -mfentry                              [disabled]
  -mfma                                 [enabled]
  -mfma4                                [disabled]
  -mforce-drap                          [disabled]
  -mforce-indirect-call                 [disabled]
  -mfp-ret-in-387                       [enabled]
  -mfpmath=                             sse
  -mfsgsbase                            [enabled]
  -mfunction-return=                    keep
  -mfused-madd                   
  -mfxsr                                [enabled]
  -mgeneral-regs-only                   [disabled]
  -mgfni                                [disabled]
  -mglibc                               [enabled]
  -mhard-float                          [enabled]
  -mhle                                 [enabled]
  -miamcu                               [disabled]
  -mibt                                 [disabled]
  -mieee-fp                             [enabled]
  -mincoming-stack-boundary=            0
  -mindirect-branch-register            [disabled]
  -mindirect-branch=                    keep
  -minline-all-stringops                [disabled]
  -minline-stringops-dynamically        [disabled]
  -mintel-syntax                 
  -mlarge-data-threshold=<number>       65536
  -mlong-double-128                     [disabled]
  -mlong-double-64                      [disabled]
  -mlong-double-80                      [enabled]
  -mlwp                                 [disabled]
  -mlzcnt                               [enabled]
  -mmemcpy-strategy=             
  -mmemset-strategy=             
  -mmitigate-rop                        [disabled]
  -mmmx                                 [enabled]
  -mmovbe                               [enabled]
  -mmpx                                 [disabled]
  -mms-bitfields                        [disabled]
  -mmusl                                [disabled]
  -mmwaitx                              [disabled]
  -mno-align-stringops                  [disabled]
  -mno-default                          [disabled]
  -mno-fancy-math-387                   [disabled]
  -mno-push-args                        [disabled]
  -mno-red-zone                         [disabled]
  -mno-sse4                             [disabled]
  -mnop-mcount                          [disabled]
  -momit-leaf-frame-pointer             [disabled]
  -mpc32                                [disabled]
  -mpc64                                [disabled]
  -mpc80                                [disabled]
  -mpclmul                              [enabled]
  -mpcommit                             [disabled]
  -mpku                                 [disabled]
  -mpopcnt                              [enabled]
  -mprefer-avx128                 
  -mprefer-vector-width=                none
  -mpreferred-stack-boundary=           0
  -mprefetchwt1                         [disabled]
  -mprfchw                              [disabled]
  -mpush-args                           [enabled]
  -mrdpid                               [disabled]
  -mrdrnd                               [enabled]
  -mrdseed                              [disabled]
  -mrecip                               [disabled]
  -mrecip=                       
  -mrecord-mcount                       [disabled]
  -mred-zone                            [enabled]
  -mregparm=                            6
  -mrtd                                 [disabled]
  -mrtm                                 [disabled]
  -msahf                                [enabled]
  -msgx                                 [disabled]
  -msha                                 [disabled]
  -mshstk                               [disabled]
  -mskip-rax-setup                      [disabled]
  -msoft-float                          [disabled]
  -msse                                 [enabled]
  -msse2                                [enabled]
  -msse2avx                             [disabled]
  -msse3                                [enabled]
  -msse4                                [enabled]
  -msse4.1                              [enabled]
  -msse4.2                              [enabled]
  -msse4a                               [disabled]
  -msse5                         
  -msseregparm                          [disabled]
  -mssse3                               [enabled]
  -mstack-arg-probe                     [disabled]
  -mstack-protector-guard-offset= 
  -mstack-protector-guard-reg=   
  -mstack-protector-guard-symbol= 
  -mstack-protector-guard=              tls
  -mstackrealign                        [disabled]
  -mstringop-strategy=                  [default]
  -mstv                                 [enabled]
  -mtbm                                 [disabled]
  -mtls-dialect=                        gnu
  -mtls-direct-seg-refs                 [enabled]
  -mtune-ctrl=                   
  -mtune=                               haswell
  -muclibc                              [disabled]
  -mvaes                                [disabled]
  -mveclibabi=                          [default]
  -mvect8-ret-in-mem                    [disabled]
  -mvpclmulqdq                          [disabled]
  -mvzeroupper                          [enabled]
  -mx32                                 [disabled]
  -mxop                                 [disabled]
  -mxsave                               [enabled]
  -mxsavec                              [disabled]
  -mxsaveopt                            [enabled]
  -mxsaves                              [disabled]

  Known assembler dialects (for use with the -masm= option):
    att intel

  Known ABIs (for use with the -mabi= option):
    ms sysv

  Known code models (for use with the -mcmodel= option):
    32 kernel large medium small

  Valid arguments to -mfpmath=:
    387 387+sse 387,sse both sse sse+387 sse,387

  Known indirect branch choices (for use with the -mindirect-branch=/-mfunction-return= options):
    keep thunk thunk-extern thunk-inline

  Known data alignment choices (for use with the -malign-data= option):
    abi cacheline compat

  Known vectorization library ABIs (for use with the -mveclibabi= option):
    acml svml

  Known address mode (for use with the -maddress-mode= option):
    long short

  Known preferred register vector length (to use with the -mprefer-vector-width= option)
    128 256 512 none

  Known stack protector guard (for use with the -mstack-protector-guard= option):
    global tls

  Valid arguments to -mstringop-strategy=:
    byte_loop libcall loop rep_4byte rep_8byte rep_byte unrolled_loop
    vector_loop

  Known TLS dialects (for use with the -mtls-dialect= option):
    gnu gnu2

note the output for

Code (Text):

/opt/gcc8/bin/gcc -c -Q -march=native --help=target | egrep 'indirect|function-return'
  -mforce-indirect-call                    [disabled]
  -mfunction-return=                       keep
  -mindirect-branch-register               [disabled]
  -mindirect-branch=                       keep
  Known indirect branch choices (for use with the -mindirect-branch=/-mfunction-return= options):

Code (Text):

  Known indirect branch choices (for use with the -mindirect-branch=/-mfunction-return= options):
    keep thunk thunk-extern thunk-inline

From Benchmarking Linux With The Retpoline Patches For Spectre - Phoronix

GCC 8 Patches Posted For Spectre Mitigation - Phoronix

Benchmarks from Phoronix for GCC 8 new patches Benchmarking Retpoline-Enabled GCC 8 With -mindirect-branch=thunk - Phoronix

 

Test Building GCC 7.2.1 & GCC 8.0 RPMs

Been busy perfecting my GCC 7/8 + Binutils compilation configurations and custom RPM builds specifically for CentOS 7 64bit OS for now. Just like PHP 7 which supports Profile Guided Optimizations (PGO) to boost PHP 7 performance, GCC can be built with PGO as well for better than stock build performance. GCC can also be built with Link Time Optimization (LTO).

So I have scripted building both GCC 7 and GCC 8 with RPMs with PGO + LTO and RPMs without PGO + LTO. Building GCC with PGO + LTO increases compilation times by ~20-25% on Intel Core i7 4790K but result in better performing GCC binaries which in turn if used to build apps i.e. using resulting GCC binary to build Centmin Mod Nginx binary, can in theory result in better Nginx performance. Haven't benchmark tested the improvements yet but from what I have seen it's between ~7-10% improvement

Build both GCC 7 & GCC 8 RPMs (both PGO + non-PGO) and accompanying Binutils RPMs all at once

Code (Text):

-rw-r--r--   1 root  root  5.2M Jan 20 13:24 binutils-gcc7-2.29.1-1.el7.x86_64.rpm
-rw-r--r--   1 root  root  5.2M Jan 20 12:17 binutils-gcc8-2.29.1-1.el7.x86_64.rpm
-rw-r--r--   1 root  root   33M Jan 20 16:41 gcc7-7.2.1-1.el7.x86_64.rpm
-rw-r--r--   1 root  root   37M Jan 20 17:09 gcc7-pgo-7.2.1-1.el7.x86_64.rpm
-rw-r--r--   1 root  root   36M Jan 20 16:09 gcc8-8.0-1.el7.x86_64.rpm
-rw-r--r--   1 root  root   41M Jan 20 17:46 gcc8-pgo-8.0-1.el7.x86_64.rpm

GCC 7

Code (Text):

/opt/gcc7/bin/gcc -v
Using built-in specs.
COLLECT_GCC=/opt/gcc7/bin/gcc
COLLECT_LTO_WRAPPER=/opt/gcc-7-20180111/libexec/gcc/x86_64-redhat-linux/7/lto-wrapper
Target: x86_64-redhat-linux
Configured with: ../configure --prefix=/opt/gcc-7-20180111 --disable-multilib --enable-bootstrap --enable-plugin --with-gcc-major-version-only --enable-shared --disable-nls --enable-threads=posix --enable-checking=release --with-system-zlib --enable-__cxa_atexit --disable-install-libiberty --disable-libunwind-exceptions --enable-gnu-unique-object --enable-linker-build-id --with-linker-hash-style=gnu --enable-languages=c,c++ --enable-initfini-array --disable-libgcj --enable-gnu-indirect-function --with-tune=generic --build=x86_64-redhat-linux --enable-lto --enable-gold
Thread model: posix
gcc version 7.2.1 20180111 (GCC)

Code (Text):

/opt/gcc7/bin/ld.gold -v
GNU gold (GNU Binutils 2.29.1) 1.14

GCC 8

Code (Text):

/opt/gcc8/bin/gcc -v 
Using built-in specs.
COLLECT_GCC=/opt/gcc8/bin/gcc
COLLECT_LTO_WRAPPER=/opt/gcc-8-20180114/libexec/gcc/x86_64-redhat-linux/8/lto-wrapper
Target: x86_64-redhat-linux
Configured with: ../configure --prefix=/opt/gcc-8-20180114 --disable-multilib --enable-bootstrap --enable-plugin --with-gcc-major-version-only --enable-shared --disable-nls --enable-threads=posix --enable-checking=release --with-system-zlib --enable-__cxa_atexit --disable-install-libiberty --disable-libunwind-exceptions --enable-gnu-unique-object --enable-linker-build-id --with-linker-hash-style=gnu --enable-languages=c,c++ --enable-initfini-array --disable-libgcj --enable-gnu-indirect-function --with-tune=generic --build=x86_64-redhat-linux --enable-lto --enable-gold
Thread model: posix
gcc version 8.0.0 20180114 (experimental) (GCC)

Code (Text):

/opt/gcc8/bin/ld.gold -v
GNU gold (GNU Binutils 2.29.1) 1.14

Compiling GCC is very time consuming though not as complicated and as time consuming as compiling for Clang 4/5 compilers. My OVH i7 4790K was kept quite busy from below stats

 

Latest GCC 8.0.1 20180304 built RPMs with Profile Guided Optimizations + LTO + Gold Linker

Code (Text):

/opt/gcc-8-20180304/bin/gcc -v
Using built-in specs.
COLLECT_GCC=/opt/gcc-8-20180304/bin/gcc
COLLECT_LTO_WRAPPER=/opt/gcc-8-20180304/libexec/gcc/x86_64-redhat-linux/8/lto-wrapper
Target: x86_64-redhat-linux
Configured with: ../configure --prefix=/opt/gcc-8-20180304 --disable-multilib --enable-bootstrap --enable-plugin --with-gcc-major-version-only --enable-shared --disable-nls --enable-threads=posix --enable-checking=release --with-system-zlib --enable-__cxa_atexit --disable-install-libiberty --disable-libunwind-exceptions --enable-gnu-unique-object --enable-linker-build-id --with-linker-hash-style=gnu --enable-languages=c,c++ --enable-initfini-array --disable-libgcj --enable-gnu-indirect-function --with-tune=generic --build=x86_64-redhat-linux --enable-lto --enable-gold
Thread model: posix
gcc version 8.0.1 20180304 (experimental) (GCC)

Code (Text):

RPMs Built
/svr-setup/binutils-gcc8-2.30-1.el7.x86_64.rpm
/svr-setup/gcc8-pgo-8.0-1.el7.x86_64.rpm

ls -lah /svr-setup | egrep 'gcc8-pgo-8.0|binutils-gcc8-2.30'
-rw-r--r--    1 root      root       5.3M Mar  7 21:48 binutils-gcc8-2.30-1.el7.x86_64.rpm
-rw-r--r--    1 root      root        38M Mar  7 22:27 gcc8-pgo-8.0-1.el7.x86_64.rpm

Installed Packages
Name        : binutils-gcc8
Arch        : x86_64
Version     : 2.30
Release     : 1.el7
Size        : 48 M
Repo        : installed
Summary     : binutils-gcc8 for centminmod.com LEMP stack installs
URL         : https://centminmod.com
License     : unknown
Description : binutils-gcc8 for centminmod.com LEMP stacks


* Wed Mar 07 2018 George Liu <centminmod.com> 2.30
- Binutils 2.30 for centminmod.com LEMP stack installs

Code (Text):

Installed Packages
Name        : gcc8-pgo
Arch        : x86_64
Version     : 8.0
Release     : 1.el7
Size        : 287 M
Repo        : installed
Summary     : gcc8-pgo for centminmod.com LEMP stack installs
URL         : https://centminmod.com
License     : unknown
Description : gcc8-pgo for centminmod.com LEMP stacks


* Wed Mar 07 2018 George Liu <centminmod.com> 8
- GCC 8 for centminmod.com LEMP stack installs

Test compile Nginx 1.13.9 with GCC 8.0.1 20180304 date snapshot + OpenSSL 1.1.1-pre2 beta for TLSv1.3 support

 

Latest source compiled Clang 4.0.1, 5.0.1 and 6.0.0 compilers builds

Clang 6.0.0 compiler built Centmin Mod Nginx 1.13.9 web server Unfortunately, some compatibility issues with Clang 6.0.0 and Cloudflare zlib forked library so have to switch back to standard zlib 1.2.11 library and Clang 6.0.0 throws up an error with OpenSSL 1.1.1-pre2 beta crypto library so using OpenSSL 1.1.0g stable

Code (Text):

/opt/sbin/llvm-release_60/bin/clang -v
clang version 6.0.0 (branches/release_60 326962)
Target: x86_64-unknown-linux-gnu
Thread model: posix
InstalledDir: /opt/sbin/llvm-release_60/bin
Found candidate GCC installation: /opt/rh/devtoolset-4/root/usr/lib/gcc/x86_64-redhat-linux/5.3.1
Found candidate GCC installation: /opt/rh/devtoolset-6/root/usr/lib/gcc/x86_64-redhat-linux/6.3.1
Found candidate GCC installation: /usr/lib/gcc/x86_64-redhat-linux/4.8.2
Found candidate GCC installation: /usr/lib/gcc/x86_64-redhat-linux/4.8.5
Selected GCC installation: /opt/rh/devtoolset-6/root/usr/lib/gcc/x86_64-redhat-linux/6.3.1
Candidate multilib: .;@m64
Candidate multilib: 32;@m32
Selected multilib: .;@m64

Code (Text):

/opt/sbin/llvm-release_50/bin/clang -v
clang version 5.0.1 (branches/release_50 326959)
Target: x86_64-unknown-linux-gnu
Thread model: posix
InstalledDir: /opt/sbin/llvm-release_50/bin
Found candidate GCC installation: /opt/rh/devtoolset-4/root/usr/lib/gcc/x86_64-redhat-linux/5.3.1
Found candidate GCC installation: /opt/rh/devtoolset-6/root/usr/lib/gcc/x86_64-redhat-linux/6.3.1
Found candidate GCC installation: /usr/lib/gcc/x86_64-redhat-linux/4.8.2
Found candidate GCC installation: /usr/lib/gcc/x86_64-redhat-linux/4.8.5
Selected GCC installation: /opt/rh/devtoolset-6/root/usr/lib/gcc/x86_64-redhat-linux/6.3.1
Candidate multilib: .;@m64
Candidate multilib: 32;@m32
Selected multilib: .;@m64

Code (Text):

/opt/sbin/llvm-release_40/bin/clang -v
clang version 4.0.1 (branches/release_40 326956)
Target: x86_64-unknown-linux-gnu
Thread model: posix
InstalledDir: /opt/sbin/llvm-release_40/bin
Found candidate GCC installation: /opt/rh/devtoolset-4/root/usr/lib/gcc/x86_64-redhat-linux/5.3.1
Found candidate GCC installation: /usr/lib/gcc/x86_64-redhat-linux/4.8.2
Found candidate GCC installation: /usr/lib/gcc/x86_64-redhat-linux/4.8.5
Selected GCC installation: /opt/rh/devtoolset-4/root/usr/lib/gcc/x86_64-redhat-linux/5.3.1
Candidate multilib: .;@m64
Candidate multilib: 32;@m32
Selected multilib: .;@m64

 

Good news GCC 8.1 coming soon GCC 8.1 RC1 Released, The Big Compiler Update Could Officially Debut Next Week - Phoronix

Test Nginx 1.15.0 master branch + GCC 8.0.1 RC1 20180425 snapshot built custom RPMs with Profile Guided Optimizations (PGO) + LTO + Gold linker enabled.

Code (Text):

/opt/gcc-8.0.1-RC-20180425/bin/gcc -v
Using built-in specs.
COLLECT_GCC=/opt/gcc-8.0.1-RC-20180425/bin/gcc
COLLECT_LTO_WRAPPER=/opt/gcc-8.0.1-RC-20180425/libexec/gcc/x86_64-redhat-linux/8/lto-wrapper
Target: x86_64-redhat-linux
Configured with: ../configure --prefix=/opt/gcc-8.0.1-RC-20180425 --disable-multilib --enable-bootstrap --enable-plugin --with-gcc-major-version-only --enable-shared --disable-nls --enable-threads=posix --enable-checking=release --with-system-zlib --enable-__cxa_atexit --disable-install-libiberty --disable-libunwind-exceptions --enable-gnu-unique-object --enable-linker-build-id --with-linker-hash-style=gnu --enable-languages=c,c++ --enable-initfini-array --disable-libgcj --enable-gnu-indirect-function --with-tune=generic --build=x86_64-redhat-linux --enable-lto --enable-gold
Thread model: posix
gcc version 8.0.1 20180425 (prerelease) (GCC)

Code (Text):

RPMs Built
/svr-setup/binutils-gcc8-2.30-1.el7.x86_64.rpm
/svr-setup/gcc8-pgo-8.0-1.el7.x86_64.rpm

ls -lah /svr-setup | egrep 'gcc8-pgo-8.0|binutils-gcc8-2.30'
-rw-r--r--   1 root      root     5.3M Apr 25 21:52 binutils-gcc8-2.30-1.el7.x86_64.rpm
-rw-r--r--   1 root      root      40M Apr 25 22:32 gcc8-pgo-8.0-1.el7.x86_64.rpm

Installed Packages
Name        : binutils-gcc8
Arch        : x86_64
Version     : 2.30
Release     : 1.el7
Size        : 48 M
Repo        : installed
Summary     : binutils-gcc8 for centminmod.com LEMP stack installs
URL         : https://centminmod.com
License     : unknown
Description : binutils-gcc8 for centminmod.com LEMP stacks

* Wed Apr 25 2018 George Liu <centminmod.com> 2.30
- Binutils 2.30 for centminmod.com LEMP stack installs

Code (Text):

Installed Packages
Name        : gcc8-pgo
Arch        : x86_64
Version     : 8.0
Release     : 1.el7
Size        : 301 M
Repo        : installed
Summary     : gcc8-pgo for centminmod.com LEMP stack installs
URL         : https://centminmod.com
License     : unknown
Description : gcc8-pgo for centminmod.com LEMP stacks

* Wed Apr 25 2018 George Liu <centminmod.com> 8
- GCC 8 for centminmod.com LEMP stack installs

 

GCC 8.1.0 final tests

Nginx 1.15.0 master branch + GCC 8.1.0 built custom RPMs with Profile Guided Optimizations (PGO) + LTO + Gold linker enabled.

Code (Text):

yum -q info gcc8-pgo   
Installed Packages
Name        : gcc8-pgo
Arch        : x86_64
Version     : 8.1
Release     : 1.el7
Size        : 301 M
Repo        : installed
Summary     : gcc8-pgo for centminmod.com LEMP stack installs
URL         : https://centminmod.com
License     : unknown
Description : gcc8-pgo for centminmod.com LEMP stacks

Code (Text):

/opt/gcc8/bin/gcc -v
Using built-in specs.
COLLECT_GCC=/opt/gcc8/bin/gcc
COLLECT_LTO_WRAPPER=/opt/gcc-8.1.0/libexec/gcc/x86_64-redhat-linux/8/lto-wrapper
Target: x86_64-redhat-linux
Configured with: ../configure --prefix=/opt/gcc-8.1.0 --disable-multilib --enable-bootstrap --enable-plugin --with-gcc-major-version-only --enable-shared --disable-nls --enable-threads=posix --enable-checking=release --with-system-zlib --enable-__cxa_atexit --disable-install-libiberty --disable-libunwind-exceptions --enable-gnu-unique-object --enable-linker-build-id --with-linker-hash-style=gnu --enable-languages=c,c++ --enable-initfini-array --disable-libgcj --enable-gnu-indirect-function --with-tune=generic --build=x86_64-redhat-linux --enable-lto --enable-gold
Thread model: posix
gcc version 8.1.0 (GCC) 

 

Building GCC 8.1.1 RPMs with Profile Guided Optimisations

Code (Text):

ld -v
GNU ld (GNU Binutils) 2.30

ld.gold -v
GNU gold (GNU Binutils 2.30) 1.15

Code (Text):

gcc -v
Using built-in specs.
COLLECT_GCC=gcc
COLLECT_LTO_WRAPPER=/opt/gcc-8-20180608/libexec/gcc/x86_64-redhat-linux/8/lto-wrapper
Target: x86_64-redhat-linux
Configured with: ../configure --prefix=/opt/gcc-8-20180608 --disable-multilib --enable-bootstrap --enable-plugin --with-gcc-major-version-only --enable-shared --disable-nls --enable-threads=posix --enable-checking=release --with-system-zlib --enable-__cxa_atexit --disable-install-libiberty --disable-libunwind-exceptions --enable-gnu-unique-object --enable-linker-build-id --with-linker-hash-style=gnu --enable-languages=c,c++ --enable-initfini-array --disable-libgcj --enable-gnu-indirect-function --with-tune=generic --build=x86_64-redhat-linux --enable-lto --enable-gold
Thread model: posix
gcc version 8.1.1 20180608 (GCC)

Code (Text):

yum info binutils-gcc8 -q
IInstalled Packages
Name        : binutils-gcc8
Arch        : x86_64
Version     : 2.30
Release     : 1.el7
Size        : 48 M
Repo        : installed
Summary     : binutils-gcc8 for centminmod.com LEMP stack installs
URL         : https://centminmod.com
License     : unknown
Description : binutils-gcc8 for centminmod.com LEMP stacks

* Fri Jun 15 2018 George Liu <centminmod.com> 2.30
- Binutils 2.30 for centminmod.com LEMP stack installs

Code (Text):

yum info gcc8-pgo -q
Installed Packages
Name        : gcc8-pgo
Arch        : x86_64
Version     : 8.1.1
Release     : 1.el7
Size        : 301 M
Repo        : installed
Summary     : gcc8-pgo for centminmod.com LEMP stack installs
URL         : https://centminmod.com
License     : unknown
Description : gcc8-pgo for centminmod.com LEMP stacks

* Fri Jun 15 2018 George Liu <centminmod.com> 8
- GCC 8 for centminmod.com LEMP stack installs

 

Facebook has open sourced a new compilation optimisation tool, BOLT which requires Clang compiler Accelerate large-scale applications with BOLT and Facebook floats BOLT to jolt code out of bit bloat

So testing Centmin Mod latest experimental Clang 6.0.1 compiler install first before looking at adding BOLT support

Code (Text):

/opt/sbin/llvm-release_60/bin/clang -v
clang version 6.0.1 (branches/release_60 335101)
Target: x86_64-unknown-linux-gnu
Thread model: posix
InstalledDir: /opt/sbin/llvm-release_60/bin
Found candidate GCC installation: /opt/rh/devtoolset-4/root/usr/lib/gcc/x86_64-redhat-linux/5.3.1
Found candidate GCC installation: /opt/rh/devtoolset-6/root/usr/lib/gcc/x86_64-redhat-linux/6.3.1
Found candidate GCC installation: /usr/lib/gcc/x86_64-redhat-linux/4.8.2
Found candidate GCC installation: /usr/lib/gcc/x86_64-redhat-linux/4.8.5
Selected GCC installation: /opt/rh/devtoolset-6/root/usr/lib/gcc/x86_64-redhat-linux/6.3.1
Candidate multilib: .;@m64
Candidate multilib: 32;@m32
Selected multilib: .;@m64

 

Just started testing Clang 7 master branch too

Code (Text):

/opt/sbin/llvm-release_master/bin/clang -v
clang version 7.0.0 (https://github.com/llvm-mirror/clang 5e8547baedb21953ae64b6eb2830dcf1ff0d8768) (https://github.com/llvm-mirror/llvm 737553be0c9c25c497b45a241689994f177d5a5d)
Target: x86_64-unknown-linux-gnu
Thread model: posix
InstalledDir: /opt/sbin/llvm-release_master/bin
Found candidate GCC installation: /opt/rh/devtoolset-4/root/usr/lib/gcc/x86_64-redhat-linux/5.3.1
Found candidate GCC installation: /opt/rh/devtoolset-6/root/usr/lib/gcc/x86_64-redhat-linux/6.3.1
Found candidate GCC installation: /opt/rh/devtoolset-7/root/usr/lib/gcc/x86_64-redhat-linux/7
Found candidate GCC installation: /usr/lib/gcc/x86_64-redhat-linux/4.8.2
Found candidate GCC installation: /usr/lib/gcc/x86_64-redhat-linux/4.8.5
Selected GCC installation: /opt/rh/devtoolset-7/root/usr/lib/gcc/x86_64-redhat-linux/7
Candidate multilib: .;@m64
Candidate multilib: 32;@m32
Selected multilib: .;@m64

 

Spun up a 8 cpu Upcloud KVM with Intel Xeon E5-2687w v4 @ 3.0Ghz for some compiler testing and timings

for Clang 6.0.1 compile time + binutils 2.30

Code (Text):

/opt/sbin/llvm-release_60/bin/clang -v
clang version 6.0.1 (branches/release_60 335343)
Target: x86_64-unknown-linux-gnu
Thread model: posix
InstalledDir: /opt/sbin/llvm-release_60/bin
Found candidate GCC installation: /opt/rh/devtoolset-6/root/usr/lib/gcc/x86_64-redhat-linux/6.3.1
Found candidate GCC installation: /usr/lib/gcc/x86_64-redhat-linux/4.8.2
Found candidate GCC installation: /usr/lib/gcc/x86_64-redhat-linux/4.8.5
Selected GCC installation: /opt/rh/devtoolset-6/root/usr/lib/gcc/x86_64-redhat-linux/6.3.1
Candidate multilib: .;@m64
Candidate multilib: 32;@m32
Selected multilib: .;@m64

ls -lah /opt/sbin/llvm-release_60/lib/LLVMgold.so
-rwxr-xr-x 1 root root 29M Jun 22 13:27 /opt/sbin/llvm-release_60/lib/LLVMgold.so
-------------------------------------------------------------------

tail -1 /root/centminlogs/centminmod_llvm_220618-130008.log

real    28m41.542s
user    163m50.060s
sys     13m50.991s

for Clang 7.0.0 master branch compile time + binutils 2.30

Code (Text):

/opt/sbin/llvm-release_master/bin/clang -v
clang version 7.0.0 (https://github.com/llvm-mirror/clang 84dae0555379696bff8fe6472ba402223ef04608) (https://github.com/llvm-mirror/llvm a054f92cdc4d1101988fcc3fac0673bc3ce794c5)
Target: x86_64-unknown-linux-gnu
Thread model: posix
InstalledDir: /opt/sbin/llvm-release_master/bin
Found candidate GCC installation: /opt/rh/devtoolset-6/root/usr/lib/gcc/x86_64-redhat-linux/6.3.1
Found candidate GCC installation: /opt/rh/devtoolset-7/root/usr/lib/gcc/x86_64-redhat-linux/7
Found candidate GCC installation: /usr/lib/gcc/x86_64-redhat-linux/4.8.2
Found candidate GCC installation: /usr/lib/gcc/x86_64-redhat-linux/4.8.5
Selected GCC installation: /opt/rh/devtoolset-7/root/usr/lib/gcc/x86_64-redhat-linux/7
Candidate multilib: .;@m64
Candidate multilib: 32;@m32
Selected multilib: .;@m64

ls -lah /opt/sbin/llvm-release_master/lib/LLVMgold.so
-rwxr-xr-x 1 root root 29M Jun 22 13:43 /opt/sbin/llvm-release_master/lib/LLVMgold.so
-------------------------------------------------------------------

tail -1 /root/centminlogs/centminmod_llvm_220618-133337.log

real    24m39.367s
user    171m51.821s
sys     13m37.691s

for Profile Guided Optimized GCC 8.1.1 + binutils 2.30 + custom GCC and binutil RPM builds

Code (Text):

/opt/gcc-8-20180615/bin/gcc -v
Using built-in specs.
COLLECT_GCC=/opt/gcc-8-20180615/bin/gcc
COLLECT_LTO_WRAPPER=/opt/gcc-8-20180615/libexec/gcc/x86_64-redhat-linux/8/lto-wrapper
Target: x86_64-redhat-linux
Configured with: ../configure --prefix=/opt/gcc-8-20180615 --disable-multilib --enable-bootstrap --enable-plugin --with-gcc-major-version-only --enable-shared --disable-nls --enable-threads=posix --enable-checking=release --with-system-zlib --enable-__cxa_atexit --disable-install-libiberty --disable-libunwind-exceptions --enable-gnu-unique-object --enable-linker-build-id --with-linker-hash-style=gnu --enable-languages=c,c++ --enable-initfini-array --disable-libgcj --enable-gnu-indirect-function --with-tune=generic --build=x86_64-redhat-linux --enable-lto --enable-gold
Thread model: posix
gcc version 8.1.1 20180615 (GCC)

Code (Text):

RPMs Built
/svr-setup/binutils-gcc8-2.30-1.el7.x86_64.rpm
/svr-setup/gcc8-pgo-8.1.1-1.el7.x86_64.rpm

ls -lah /svr-setup | egrep 'gcc8-pgo-8.1.1|binutils-gcc8-2.30'
-rw-r--r--   1 root      root       5.2M Jun 22 14:37 binutils-gcc8-2.30-1.el7.x86_64.rpm
-rw-r--r--   1 root      root        40M Jun 22 15:18 gcc8-pgo-8.1.1-1.el7.x86_64.rpm

Code (Text):

Installed Packages
Name        : binutils-gcc8
Arch        : x86_64
Version     : 2.30
Release     : 1.el7
Size        : 48 M
Repo        : installed
Summary     : binutils-gcc8 for centminmod.com LEMP stack installs
URL         : https://centminmod.com
License     : unknown
Description : binutils-gcc8 for centminmod.com LEMP stacks


* Fri Jun 22 2018 George Liu <centminmod.com> 2.30
- Binutils 2.30 for centminmod.com LEMP stack installs

Code (Text):

Installed Packages
Name        : gcc8-pgo
Arch        : x86_64
Version     : 8.1.1
Release     : 1.el7
Size        : 301 M
Repo        : installed
Summary     : gcc8-pgo for centminmod.com LEMP stack installs
URL         : https://centminmod.com
License     : unknown
Description : gcc8-pgo for centminmod.com LEMP stacks

* Fri Jun 22 2018 George Liu <centminmod.com> 8
- GCC 8 for centminmod.com LEMP stack installs

Code (Text):

*************************************************
Compile GCC Completed
log: /root/centminlogs/tools-gcc-install-pgo_220618-143449.log
*************************************************

Total Binutils + GCC Install Time: 2632.168653765 seconds

real    43m52.190s
user    191m12.389s
sys     16m45.287s

 

Wow upcoming GCC 8 patch for Intel Skylake based cpus can improve performance by up to 60% GCC 8 Hasn't Been Performing As Fast As It Should For Skylake With "-march=native" - Phoronix !

Looking forward to this

 

GCC 8.2 stable release is out and up to 60% improvements for Intel Skylake cpus GCC 8.2 Released, GCC 8.3 Coming Around Year's End - Phoronix so ran updated testing for Centmin Mod Nginx compatibility

Code (Text):

/opt/gcc-8.2.0/bin/gcc -v
Using built-in specs.
COLLECT_GCC=/opt/gcc-8.2.0/bin/gcc
COLLECT_LTO_WRAPPER=/opt/gcc-8.2.0/libexec/gcc/x86_64-redhat-linux/8/lto-wrapper
Target: x86_64-redhat-linux
Configured with: ../configure --prefix=/opt/gcc-8.2.0 --disable-multilib --enable-bootstrap --enable-plugin --with-gcc-major-version-only --enable-shared --disable-nls --enable-threads=posix --enable-checking=release --with-system-zlib --enable-__cxa_atexit --disable-install-libiberty --disable-libunwind-exceptions --enable-gnu-unique-object --enable-linker-build-id --with-linker-hash-style=gnu --enable-languages=c,c++ --enable-initfini-array --disable-libgcj --enable-gnu-indirect-function --with-tune=generic --build=x86_64-redhat-linux --enable-lto --enable-gold
Thread model: posix
gcc version 8.2.0 (GCC) 

Code (Text):

RPMs Built
/svr-setup/binutils-gcc8-2.31-1.el7.x86_64.rpm
/svr-setup/gcc8-pgo-8.2.0-1.el7.x86_64.rpm

ls -lah /svr-setup | egrep 'gcc8-pgo-8.2.0|binutils-gcc8-2.31'
-rw-r--r--   1 root      root       5.2M Jul 26 22:50 binutils-gcc8-2.31-1.el7.x86_64.rpm
-rw-r--r--   1 root      root        40M Jul 26 23:31 gcc8-pgo-8.2.0-1.el7.x86_64.rpm

Code (Text):

Installed Packages
Name        : binutils-gcc8
Arch        : x86_64
Version     : 2.31
Release     : 1.el7
Size        : 47 M
Repo        : installed
Summary     : binutils-gcc8 for centminmod.com LEMP stack installs
URL         : https://centminmod.com
License     : unknown
Description : binutils-gcc8 for centminmod.com LEMP stacks


* Thu Jul 26 2018 George Liu <centminmod.com> 2.31
- Binutils 2.31 for centminmod.com LEMP stack installs

Code (Text):

Installed Packages
Name        : gcc8-pgo
Arch        : x86_64
Version     : 8.2.0
Release     : 1.el7
Size        : 301 M
Repo        : installed
Summary     : gcc8-pgo for centminmod.com LEMP stack installs
URL         : https://centminmod.com
License     : unknown
Description : gcc8-pgo for centminmod.com LEMP stacks


* Thu Jul 26 2018 George Liu <centminmod.com> 8
- GCC 8 for centminmod.com LEMP stack installs

 

Updated Centmin Mod 123.09beta01 for updated llvm-toolset-clang-7 version. Clang was updated from Clang 4.0.1 to Clang 5.0.1 so updated Centmin Mod CLANG_FIVE persistent config support for it.

Code (Text):

yum list updates -q
Updated                            Packages
llvm-toolset-7-clang.x86_64        5.0.1-4.el7  centos-sclo-rh
llvm-toolset-7-clang-libs.x86_64   5.0.1-4.el7  centos-sclo-rh
llvm-toolset-7-compiler-rt.x86_64  5.0.1-2.el7  centos-sclo-rh
llvm-toolset-7-libomp.x86_64       5.0.1-2.el7  centos-sclo-rh
llvm-toolset-7-llvm-libs.x86_64    5.0.1-8.el7  centos-sclo-rh
llvm-toolset-7-llvm-static.x86_64  5.0.1-8.el7  centos-sclo-rh
llvm-toolset-7-runtime.x86_64      5.0.1-4.el7  centos-sclo-rh

For Clang 5.0.1 add CLANG_FIVE='y'

Code (Text):

LIBRESSL_SWITCH='n'
CLANG_FIVE='y'
CLANG='y'
DEVTOOLSETSIX='n'
DEVTOOLSETSEVEN='n'
DEVTOOLSETEIGHT='n'
NGINX_DEVTOOLSETGCC='y'

 

devtoolset-8 GCC 8.2.1 compiler testing

First test in Centmin Mod 123.09beta01 and higher for devtoolset-8 support in CentOS. When DEVTOOLSETEIGHT='y' set in persistent config file /etc/centminmod/custom_config.inc, Nginx will be built with GCC 8.2.1 compiler instead of GCC 7.3.1 compiler when running centmin.sh menu option 4

Code (Text):

log files saved at /root/centminlogs
-rw-r--r-- 1 root root    0 Feb  1 01:55 patch_opensslpatches_010219-015533.log
-rw-r--r-- 1 root root   44 Feb  1 01:56 centminmod_opensslinstalltime_010219-015533.log
-rw-r--r-- 1 root root  158 Feb  1 01:56 patch_patchnginx_010219-015533.log
-rw-r--r-- 1 root root 8.0K Feb  1 01:57 nginx-configure-010219-015533.log
-rw-r--r-- 1 root root  28K Feb  1 02:01 nginx_autoconf.err.010219-015533.log
-rw-r--r-- 1 root root 1.5M Feb  1 02:01 centminmod_123.09beta01.b094_010219-015533_nginx_upgrade.log

Code (Text):

gcc --version
gcc (GCC) 8.2.1 20180905 (Red Hat 8.2.1-3)
Copyright (C) 2018 Free Software Foundation, Inc.
This is free software; see the source for copying conditions.  There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.

Using nginx-binary-backup.sh tool to backup Centmin Mod Nginx binary compiled with GCC 7.3.1 and 8.2.1 so can switch between them for comparative testing

backup Nginx with GCC 7.3.1

Code (Text):

tools/nginx-binary-backup.sh backup
--------------------------------------------------------
backup current Nginx binary and dynamic modules
--------------------------------------------------------
backup started...
--------------------------------------------------------
/home/backup-nginxbin/1.15.8-gcc-7.3.1-20180303-openssl-1.1.1a-010219-022359-cfzlib
+-- bin
|   +-- nginx
+-- dynamic-modules.conf
+-- dynamic-modules-includes.conf
+-- modules
    +-- ndk_http_module.so
    +-- ngx_http_brotli_filter_module.so
    +-- ngx_http_brotli_static_module.so
    +-- ngx_http_echo_module.so
    +-- ngx_http_fancyindex_module.so
    +-- ngx_http_headers_more_filter_module.so
    +-- ngx_http_image_filter_module.so
    +-- ngx_http_set_misc_module.so

2 directories, 11 files
backup finished...
--------------------------------------------------------
backup created at /home/backup-nginxbin/1.15.8-gcc-7.3.1-20180303-openssl-1.1.1a-010219-022359-cfzlib
--------------------------------------------------------

backup Nginx with GCC 8.2.1

Code (Text):

tools/nginx-binary-backup.sh backup
--------------------------------------------------------
backup current Nginx binary and dynamic modules
--------------------------------------------------------
backup started...
--------------------------------------------------------
/home/backup-nginxbin/1.15.8-gcc-8.2.1-20180905-openssl-1.1.1a-010219-022005-cfzlib
+-- bin
|   +-- nginx
+-- dynamic-modules.conf
+-- dynamic-modules-includes.conf
+-- modules
    +-- ndk_http_module.so
    +-- ngx_http_brotli_filter_module.so
    +-- ngx_http_brotli_static_module.so
    +-- ngx_http_echo_module.so
    +-- ngx_http_fancyindex_module.so
    +-- ngx_http_headers_more_filter_module.so
    +-- ngx_http_image_filter_module.so
    +-- ngx_http_set_misc_module.so

2 directories, 11 files
backup finished...
--------------------------------------------------------
backup created at /home/backup-nginxbin/1.15.8-gcc-8.2.1-20180905-openssl-1.1.1a-010219-022005-cfzlib

list all backed up nginx binaries

Code (Text):

tools/nginx-binary-backup.sh list
--------------------------------------------------------
Listing of available Nginx binary/module backups
--------------------------------------------------------
/home/backup-nginxbin/1.15.8-gcc-8.2.1-20180905-openssl-1.1.1a-010219-022005-cfzlib
/home/backup-nginxbin/1.15.8-gcc-7.3.1-20180303-openssl-1.1.1a-010219-022359-cfzlib
--------------------------------------------------------

Nginx HTTP/2 HTTPS h2load Benchmarks

Next up comparing Centmin Mod Nginx 1.15.8 built with GCC 8.2.1 vs GCC 7.3.1 vs GCC 4.8.5 vs Clang 5.0.1 where GCC 4.8.5 is CentOS 7 default compiler and others are provided by SCL Yum repo via devtoolset.

Using nginx-binary-backup.sh allows me to compile each Nginx binary once and switch between them for comparison testing without needing to source compile them again.

Code (Text):

tools/nginx-binary-backup.sh list
--------------------------------------------------------
Listing of available Nginx binary/module backups
--------------------------------------------------------
/home/backup-nginxbin/1.15.8-gcc-7.3.1-20180303-openssl-1.1.1a-010219-022359-cfzlib
/home/backup-nginxbin/1.15.8-gcc-8.2.1-20180905-openssl-1.1.1a-010219-122942-cfzlib
/home/backup-nginxbin/1.15.8-gcc-4.8.5-20150623-openssl-1.1.1a-010219-125105-cfzlib
/home/backup-nginxbin/1.15.8-clang-5.0.1-tags-RELEASE_501-final-openssl-1.1.1a-010219-131850-cfzlib
--------------------------------------------------------

System:

• ImpactVPS 2cpu 4GB Ram KVM VPS
• Intel Xeon Silver 4114 @ 2.20Ghz Skylake 4GB RAM with 2 cpu threads
• CentOS 7.6 64bit
• Centmin Mod 123.09beta01
• Nginx 1.15.8 HTTP/2 HTTPS benchmarks via https_bench.sh

I ran https_bench.sh benchmark which will test both standard RSA 2048bit SSL certificate Nginx HTTP/2 HTTPS as well as more performant ECC 256bit ECDSA SSL certificate configurations which you will see perform much better especially with Intel Skylake cpus and when using Nginx Brotli HTTP compression instead of default Gzip HTTP compression. Updated February 21, 2019 - the assumption was flawed that Intel Skylake cpus accelerated brotli compression when it fact it was an incorrect ngx_brotli setting set in Centmin Mod Nginx default settings as explained here.

Centmin Mod 123.09beta01 beta optionally supports Nginx Brotli compression as outlined here. And was enabled for below benchmarks.

Nginx HTTP/2 HTTPS with RSA 2048bit SSL certificates

Centmin Mod HTTP/2 HTTPS configurations default to AES128 variant of each SSL ciphers, so you'd want to be reading those results rather than AES256 variant. Note, results are highly dependent on the cpu model/family being used to compile Nginx. The results are for Intel Xeon Silver 4114 Skylake based processor.

• For RSA 2048bit SSL certificates with gzip compression and AES128 fastest was GCC 7.3.1, then GCC 8.2.1, then Clang 5.0.1 and last place GCC 4.8.5.
• For RSA 2048bit SSL certificates with brotli compression and AES128 fastest was GCC 4.8.5, then GCC 7.3.1, then Clang 5.0.1 and last place GCC 8.2.1.
• So for all round performance with specific Intel Xeon Silver 4114 Skylake, GCC 7.3.1 would have best balance for gzip and brotli compression based Nginx HTTP/2 HTTPS performance.

Nginx HTTP/2 HTTPS with ECC 256bit ECDSA SSL certificates

Centmin Mod HTTP/2 HTTPS configurations default to AES128 variant of each SSL ciphers, so you'd want to be reading those results rather than AES256 variant. Note, results are highly dependent on the cpu model/family being used to compile Nginx. The results are for Intel Xeon Silver 4114 Skylake based processor. Updated February 21, 2019 - the assumption was flawed that Intel Skylake cpus accelerated brotli compression when it fact it was an incorrect ngx_brotli setting set in Centmin Mod Nginx default settings as explained here.

• For ECC 256bit ECDSA SSL certificates with gzip compression and AES128 fastest was GCC 8.2.1, then Clang 5.0.1, then GCC 7.3.1 and last place GCC 4.8.5.
• For ECC 256bit ECDSA SSL certificates with brotli compression and AES128 fastest was GCC 7.3.1, then GCC 4.8.5, then GCC 8.2.1 and last place Clang 5.0.1.
• So for all round performance with specific Intel Xeon Silver 4114 Skylake, GCC 7.3.1 or GCC 8.2.1 would have best balance for gzip and brotli compression based Nginx HTTP/2 HTTPS performance depending on whether you're using brotli compression. Updated February 21, 2019 - the assumption was flawed that Intel Skylake cpus accelerated brotli compression when it fact it was an incorrect ngx_brotli setting set in Centmin Mod Nginx default settings as explained here.

nginx + GCC 8.2.1

nginx + GCC 7.3.1

nginx + GCC 4.8.5

nginx + Clang 5.0.1

 

Custom GCC 8.3.1 & GCC 9.0.1 RPM Builds

Private testing for custom GCC 8.3.1 and GCC 9.0.1 RPM builds

Code (Text):

yum info gcc9 -q         
Installed Packages
Name        : gcc9
Arch        : x86_64
Version     : 9.0.1
Release     : 1.el7
Size        : 320 M
Repo        : installed
Summary     : gcc9 for centminmod.com LEMP stack installs
URL         : https://centminmod.com
License     : unknown
Description : gcc9 for centminmod.com LEMP stacks

Code (Text):

yum info gcc8-pgo -q
Installed Packages
Name        : gcc8-pgo
Arch        : x86_64
Version     : 8.2.1
Release     : 1.el7
Size        : 302 M
Repo        : installed
Summary     : gcc8-pgo for centminmod.com LEMP stack installs
URL         : https://centminmod.com
License     : unknown
Description : gcc8-pgo for centminmod.com LEMP stacks

Code (Text):

/opt/gcc-9-20190224/bin/gcc -v
Using built-in specs.
COLLECT_GCC=/opt/gcc-9-20190224/bin/gcc
COLLECT_LTO_WRAPPER=/opt/gcc-9-20190224/libexec/gcc/x86_64-redhat-linux/9/lto-wrapper
Target: x86_64-redhat-linux
Configured with: ../configure --prefix=/opt/gcc-9-20190224 --disable-multilib --enable-bootstrap --enable-plugin --with-gcc-major-version-only --enable-shared --disable-nls --enable-threads=posix --enable-checking=release --with-system-zlib --enable-__cxa_atexit --disable-install-libiberty --disable-libunwind-exceptions --enable-gnu-unique-object --enable-linker-build-id --with-linker-hash-style=gnu --enable-languages=c,c++ --enable-initfini-array --disable-libgcj --enable-gnu-indirect-function --with-tune=generic --build=x86_64-redhat-linux --enable-lto --enable-gold
Thread model: posix
gcc version 9.0.1 20190224 (experimental) (GCC)

Code (Text):

/opt/gcc-8-20190222/bin/gcc -v
Using built-in specs.
COLLECT_GCC=/opt/gcc-8-20190222/bin/gcc
COLLECT_LTO_WRAPPER=/opt/gcc-8-20190222/libexec/gcc/x86_64-redhat-linux/8/lto-wrapper
Target: x86_64-redhat-linux
Configured with: ../configure --prefix=/opt/gcc-8-20190222 --disable-multilib --enable-bootstrap --enable-plugin --with-gcc-major-version-only --enable-shared --disable-nls --enable-threads=posix --enable-checking=release --with-system-zlib --enable-__cxa_atexit --disable-install-libiberty --disable-libunwind-exceptions --enable-gnu-unique-object --enable-linker-build-id --with-linker-hash-style=gnu --enable-languages=c,c++ --enable-initfini-array --disable-libgcj --enable-gnu-indirect-function --with-tune=generic --build=x86_64-redhat-linux --enable-lto --enable-gold
Thread model: posix
gcc version 8.3.1 20190222 (GCC)

 

Clang 7.1.0 & Clang 8.0.0 Builds

More compiler testing on CentOS 7 for Clang 7.1.0 and Clang 8.0.0 which is about to be released. So eventually Centmin Mod will support building Nginx and PHP-FPM with GCC 4.4/4.8 native, GCC 7.3.1, GCC 8.2.1, GCC 8.3.1, GCC 9.0.1 and Clang 3.4, 4.01, 5.0.1, 6.0.1, 7.1.0 and 8.0.0

These Clang 7.1 and Clang 8.0 binaries were build with GCC 7.3.1 via devtoolset-7.

Code (Text):

/opt/sbin/llvm-release_70/bin/clang -v
clang version 7.1.0 (branches/release_70 354890)
Target: x86_64-unknown-linux-gnu
Thread model: posix
InstalledDir: /opt/sbin/llvm-release_70/bin
Found candidate GCC installation: /opt/rh/devtoolset-4/root/usr/lib/gcc/x86_64-redhat-linux/5.3.1
Found candidate GCC installation: /opt/rh/devtoolset-6/root/usr/lib/gcc/x86_64-redhat-linux/6.3.1
Found candidate GCC installation: /opt/rh/devtoolset-7/root/usr/lib/gcc/x86_64-redhat-linux/7
Found candidate GCC installation: /usr/lib/gcc/x86_64-redhat-linux/4.8.2
Found candidate GCC installation: /usr/lib/gcc/x86_64-redhat-linux/4.8.5
Selected GCC installation: /opt/rh/devtoolset-7/root/usr/lib/gcc/x86_64-redhat-linux/7
Candidate multilib: .;@m64
Candidate multilib: 32;@m32
Selected multilib: .;@m64

ls -lah /opt/sbin/llvm-release_70/lib/LLVMgold.so
-rwxr-xr-x 1 root root 29M Feb 26 16:31 /opt/sbin/llvm-release_70/lib/LLVMgold.so

Code (Text):

/opt/sbin/llvm-release_80/bin/clang -v
clang version 8.0.0 (branches/release_80 354893)
Target: x86_64-unknown-linux-gnu
Thread model: posix
InstalledDir: /opt/sbin/llvm-release_80/bin
Found candidate GCC installation: /opt/rh/devtoolset-4/root/usr/lib/gcc/x86_64-redhat-linux/5.3.1
Found candidate GCC installation: /opt/rh/devtoolset-6/root/usr/lib/gcc/x86_64-redhat-linux/6.3.1
Found candidate GCC installation: /opt/rh/devtoolset-7/root/usr/lib/gcc/x86_64-redhat-linux/7
Found candidate GCC installation: /usr/lib/gcc/x86_64-redhat-linux/4.8.2
Found candidate GCC installation: /usr/lib/gcc/x86_64-redhat-linux/4.8.5
Selected GCC installation: /opt/rh/devtoolset-7/root/usr/lib/gcc/x86_64-redhat-linux/7
Candidate multilib: .;@m64
Candidate multilib: 32;@m32
Selected multilib: .;@m64

ls -lah /opt/sbin/llvm-release_80/lib/LLVMgold.so
-rwxr-xr-x 1 root root 31M Feb 26 17:10 /opt/sbin/llvm-release_80/lib/LLVMgold.so

Nginx built with Clang 8.0.0

Nginx built with Clang 7.1.0