diff options
Diffstat (limited to 'SConstruct')
| -rwxr-xr-x | SConstruct | 24 |
1 files changed, 24 insertions, 0 deletions
diff --git a/SConstruct b/SConstruct index ee53be196..d2e6b1233 100755 --- a/SConstruct +++ b/SConstruct @@ -165,6 +165,8 @@ AddLocalOption('--default', dest='default', type='string', action='store', help='Override which build_opts file to use for defaults') AddLocalOption('--ignore-style', dest='ignore_style', action='store_true', help='Disable style checking hooks') +AddLocalOption('--no-lto', dest='no_lto', action='store_true', + help='Disable Link-Time Optimization for fast') AddLocalOption('--update-ref', dest='update_ref', action='store_true', help='Update test reference outputs') AddLocalOption('--verbose', dest='verbose', action='store_true', @@ -477,6 +479,10 @@ else: main['SHCXXCOMSTR'] = Transform("SHCXX") Export('MakeAction') +# Initialize the Link-Time Optimization (LTO) flags +main['LTO_CCFLAGS'] = [] +main['LTO_LDFLAGS'] = [] + CXX_version = readCommand([main['CXX'],'--version'], exception=False) CXX_V = readCommand([main['CXX'],'-V'], exception=False) @@ -506,6 +512,24 @@ if main['GCC']: # http://gcc.gnu.org/projects/cxx0x.html for details if compareVersions(gcc_version, '4.4') >= 0: main.Append(CXXFLAGS=['-std=c++0x']) + + # LTO support is only really working properly from 4.6 and beyond + if compareVersions(gcc_version, '4.6') >= 0: + # Add the appropriate Link-Time Optimization (LTO) flags + # unless LTO is explicitly turned off. Note that these flags + # are only used by the fast target. + if not GetOption('no_lto'): + # Pass the LTO flag when compiling to produce GIMPLE + # output, we merely create the flags here and only append + # them later/ + main['LTO_CCFLAGS'] = ['-flto=%d' % GetOption('num_jobs')] + + # Use the same amount of jobs for LTO as we are running + # scons with, we hardcode the use of the linker plugin + # which requires either gold or GNU ld >= 2.21 + main['LTO_LDFLAGS'] = ['-flto=%d' % GetOption('num_jobs'), + '-fuse-linker-plugin'] + elif main['ICC']: pass #Fix me... add warning flags once we clean up icc warnings elif main['SUNCC']: |