[cfe-commits] r64882 - /cfe/trunk/Driver/Makefile
Chris Lattner
sabre at nondot.org
Tue Feb 17 20:02:00 PST 2009
Author: lattner
Date: Tue Feb 17 22:02:00 2009
New Revision: 64882
URL: http://llvm.org/viewvc/llvm-project?rev=64882&view=rev
Log:
Optimize dyld startup time by specifying a trivial export map
(only export main) on the mac.
This improves DYLD_PRINT_STATISTICS from:
total time: 6.0 milliseconds (100.0%)
total images loaded: 5 (4 from dyld shared cache, 3 needed no fixups)
total segments mapped: 0, into 0 pages with 0 pages pre-fetched
total images loading time: 0.0 milliseconds (1.4%)
total rebase fixups: 0
total rebase fixups time: 0.0 milliseconds (0.0%)
total binding fixups: 7,928
total binding symbol lookups: 4,087, average images searched per symbol: 1.9
total binding fixups time: 4.7 milliseconds (79.2%)
total bindings lazily fixed up: 170 of 4,372
total init time time: 1.1 milliseconds (19.2%)
total images with weak exports: 2
to:
total time: 1.4 milliseconds (100.0%)
total images loaded: 5 (4 from dyld shared cache, 4 needed no fixups)
total segments mapped: 0, into 0 pages with 0 pages pre-fetched
total images loading time: 0.0 milliseconds (5.7%)
total rebase fixups: 0
total rebase fixups time: 0.0 milliseconds (0.2%)
total binding fixups: 1,079
total binding symbol lookups: 75, average images searched per symbol: 1.0
total binding fixups time: 0.5 milliseconds (33.9%)
total bindings lazily fixed up: 14 of 216
total init time time: 0.8 milliseconds (60.0%)
total images with weak exports: 1
This reduces the time to -fsyntax-only cocoa.h with PTH from 0.192s to 0.184 (4.3%)
rdar://6505315
Modified:
cfe/trunk/Driver/Makefile
Modified: cfe/trunk/Driver/Makefile
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/Driver/Makefile?rev=64882&r1=64881&r2=64882&view=diff
==============================================================================
--- cfe/trunk/Driver/Makefile (original)
+++ cfe/trunk/Driver/Makefile Tue Feb 17 22:02:00 2009
@@ -8,6 +8,12 @@
# early so we can set up LINK_COMPONENTS before including Makefile.rules
include $(LEVEL)/Makefile.config
+# Optimize startup time of the app by not exporting all of the weak symbols
+# from the binary. This reduces dyld startup time by 4x.
+ifeq ($(OS),Darwin)
+LD.Flags += -Wl,-exported_symbol -Wl,_main
+endif
+
LINK_COMPONENTS := $(TARGETS_TO_BUILD) bitreader bitwriter codegen ipo selectiondag
USEDLIBS = clangCodeGen.a clangAnalysis.a clangRewrite.a clangSema.a \
clangDriver.a clangAST.a clangParse.a clangLex.a \
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