8204935: [aix] TOC overflow in libjvm.so (release build)
Reviewed-by: goetz, mbaesken, ihse
--- a/make/autoconf/flags-cflags.m4 Wed Jun 13 20:11:18 2018 +0200
+++ b/make/autoconf/flags-cflags.m4 Wed Jun 13 07:53:27 2018 +0200
@@ -573,22 +573,24 @@
# '-qpic' defaults to 'qpic=small'. This means that the compiler generates only
# one instruction for accessing the TOC. If the TOC grows larger than 64K, the linker
# will have to patch this single instruction with a call to some out-of-order code which
- # does the load from the TOC. This is of course slow. But in that case we also would have
+ # does the load from the TOC. This is of course slower, and we also would have
# to use '-bbigtoc' for linking anyway so we could also change the PICFLAG to 'qpic=large'.
# With 'qpic=large' the compiler will by default generate a two-instruction sequence which
# can be patched directly by the linker and does not require a jump to out-of-order code.
- # Another alternative instead of using 'qpic=large -bbigtoc' may be to use '-qminimaltoc'
- # instead. This creates a distinct TOC for every compilation unit (and thus requires two
- # loads for accessing a global variable). But there are rumors that this may be seen as a
- # 'performance feature' because of improved code locality of the symbols used in a
- # compilation unit.
- PICFLAG="-qpic"
+ #
+ # Since large TOC causes perf. overhead, only pay it where we must. Currently this is
+ # for all libjvm variants (both gtest and normal) but no other binaries. So, build
+ # libjvm with -qpic=large and link with -bbigtoc.
+ JVM_PICFLAG="-qpic=large"
+ JDK_PICFLAG="-qpic"
elif test "x$TOOLCHAIN_TYPE" = xmicrosoft; then
PICFLAG=""
fi
- JVM_PICFLAG="$PICFLAG"
- JDK_PICFLAG="$PICFLAG"
+ if test "x$TOOLCHAIN_TYPE" != xxlc; then
+ JVM_PICFLAG="$PICFLAG"
+ JDK_PICFLAG="$PICFLAG"
+ fi
if test "x$OPENJDK_TARGET_OS" = xmacosx; then
# Linking is different on MacOSX
--- a/make/autoconf/flags-ldflags.m4 Wed Jun 13 20:11:18 2018 +0200
+++ b/make/autoconf/flags-ldflags.m4 Wed Jun 13 07:53:27 2018 +0200
@@ -94,7 +94,8 @@
elif test "x$TOOLCHAIN_TYPE" = xxlc; then
BASIC_LDFLAGS="-b64 -brtl -bnolibpath -bexpall -bernotok -btextpsize:64K \
-bdatapsize:64K -bstackpsize:64K"
- BASIC_LDFLAGS_JVM_ONLY="-Wl,-lC_r"
+ # libjvm.so has gotten too large for normal TOC size; compile with qpic=large and link with bigtoc
+ BASIC_LDFLAGS_JVM_ONLY="-Wl,-lC_r -bbigtoc"
elif test "x$TOOLCHAIN_TYPE" = xmicrosoft; then
BASIC_LDFLAGS="-nologo -opt:ref"
--- a/make/hotspot/lib/CompileGtest.gmk Wed Jun 13 20:11:18 2018 +0200
+++ b/make/hotspot/lib/CompileGtest.gmk Wed Jun 13 07:53:27 2018 +0200
@@ -55,13 +55,6 @@
# Disabling undef, switch, format-nonliteral and tautological-undefined-compare
# warnings for clang because of test source.
-# Note: On AIX, the gtest test classes linked into the libjvm.so push the TOC
-# size beyond 64k, so we need to link with bigtoc. However, this means that
-# -qpic=large would be advisable to lessen the performance effect of bigtoc.
-# But we want to avoid imposing -qpic=large onto the regular libjvm.so, which
-# has no problem with its TOC, so do this only for object files which are
-# exclusive to the gtest libjvm.so.
-
$(eval $(call SetupNativeCompilation, BUILD_GTEST_LIBJVM, \
NAME := jvm, \
TOOLCHAIN := TOOLCHAIN_LINK_CXX, \
@@ -80,7 +73,6 @@
CFLAGS_windows := -EHsc, \
CFLAGS_solaris := -DGTEST_HAS_EXCEPTIONS=0 -library=stlport4, \
CFLAGS_macosx := -DGTEST_OS_MAC=1, \
- CFLAGS_aix := -qpic=large, \
DISABLED_WARNINGS_gcc := undef, \
DISABLED_WARNINGS_clang := undef switch format-nonliteral \
tautological-undefined-compare $(BUILD_LIBJVM_DISABLED_WARNINGS_clang), \
@@ -88,7 +80,6 @@
DISABLED_WARNINGS_CXX_microsoft := 4996, \
LDFLAGS := $(JVM_LDFLAGS), \
LDFLAGS_solaris := -library=stlport4 $(call SET_SHARED_LIBRARY_ORIGIN), \
- LDFLAGS_aix := -bbigtoc, \
LIBS := $(JVM_LIBS), \
OPTIMIZATION := $(JVM_OPTIMIZATION), \
MAPFILE := $(GTEST_JVM_MAPFILE), \