Hi Volker, Do you have any idea about the modification considering David Holmes' comments ?
On Fri, Dec 21, 2012 at 6:48 PM, Volker Simonis <volker.simo...@gmail.com>wrote: > Hi Sean, > > honestly speaking, I wasn't aware of this problem until now and I just > checked that we currently don't use this option, neither internally nor in > our port. > I found the following nice explanation of the issue: > http://www.network-theory.co.uk/docs/gccintro/gccintro_71.html > > It seems that you only get problems if your programs relies on the fact > that 'char' is either unsigned or signed. I suppose that the current > OpenJDK doesn't rely on such assumptions (which is good) because we didn't > saw any of them until now. > > If I understand you right, you add some closed code the the JDK which has > problems because it makes such assumptions. Is that right? If yes, you > should probably first fix that code in the way described in the referenced > document. Wouldn't that be possible? > > Regarding your patch: I suppose you took it against an original JDK and > not our port, because in our port we already have the following lines (at > least in http://hg.openjdk.java.net/ppc-aix-port/jdk7u//jdk because we > haven't started to work on jdk8 until now) > > CFLAGS_REQUIRED_arm += -fsigned-char -D_LITTLE_ENDIAN > CFLAGS_REQUIRED_ppc += -fsigned-char -D_BIG_ENDIAN > CFLAGS_REQUIRED_ppc64 += -m64 > LDFLAGS_COMMON_ppc64 += -m64 -L/lib64 -Wl,-melf64ppc > > Notice that we don't set '-D_BIG_ENDIAN' because it is the default. > > Didn't you observed your problems with jdk7 on Linux/PPC? I think we > should patch JDK7 first if this is really necessary. > > Regards, > Volker > > > > On Fri, Dec 21, 2012 at 10:40 AM, Sean Chou <zho...@linux.vnet.ibm.com>wrote: > >> Hello, >> >> We found -fsigned-char is added to ppc platform, but not added to ppc64 >> platform. As they are different platforms, I think it is needed for ppc64 >> as well. Currently I just added one line modification as follow, but there >> may be more places to modify. If some one can give some comments, I can >> make a complete webrev. >> >> The buggy scenario we found needs closed code to reproduce, so it is not >> reproduced with current openjdk build on ppc linux from AIX porting >> project. I tested with ibmjdk, the patch works. >> >> I found CFLAGS_REQUIRED_ppc is from changeset >> http://hg.openjdk.java.net/jdk8/jdk8/jdk/rev/54d8193f177b . Is it >> enough to add ppc64 option for places ppc appears in that patch? >> >> ///////////////////////// the patch //////////////////////// >> >> diff --git a/make/common/Defs-linux.gmk b/make/common/Defs-linux.gmk >> --- a/make/common/Defs-linux.gmk >> +++ b/make/common/Defs-linux.gmk >> @@ -196,6 +196,7 @@ >> LDFLAGS_COMMON_sparc += -m32 -mcpu=v9 >> CFLAGS_REQUIRED_arm += -fsigned-char -D_LITTLE_ENDIAN >> CFLAGS_REQUIRED_ppc += -fsigned-char -D_BIG_ENDIAN >> +CFLAGS_REQUIRED_ppc64 += -fsigned-char -D_BIG_ENDIAN >> ifeq ($(ZERO_BUILD), true) >> CFLAGS_REQUIRED = $(ZERO_ARCHFLAG) >> ifeq ($(ZERO_ENDIANNESS), little) >> >> >> -- >> >> Best Regards, >> Sean Chou >> > > -- Best Regards, Sean Chou
