答复: 答复: [RFR] Re: jdk9 builds status

[yangyongyong]

"What happens if a future compiler pushes something different?"
This makes sense. " compile -O0" does not push other things for now, that's what the comment " This is a leaf method " means.

All the best.

>> -----邮件原件-----
>> 发件人: Edward Nevill [mailto:edward.nevill at gmail.com]
>> 发送时间: 2016年6月2日 22:08
>> 收件人: yangyongyong
>> 抄送: Anton Kozlov; andrey.petushkov at gmail.com; akashche at redhat.com;
>> aarch32-port-dev at openjdk.java.net
>> 主题: Re: 答复: [RFR] Re: jdk9 builds status
>> 
>> Hi,
>> 
>> This solution makes me nervous. It relies on the fact that the compiler only
>> pushes RFP, hence it adds 'BytesPerWord'. What happens if a future compiler pushes
>> something different? Or if we compile -O0 as in a slowdebug build.
>> 
>> I think the asm version is more shock proof.
>> 
>> All the best,
>> Ed.
>> 
>> On Thu, 2016-06-02 at 13:12 +0000, yangyongyong wrote:
>> > Hi, all,
>> >
>> > Has someone tried the following patch:
>> >
>> > === Patch begin ===
>> > diff -r 79bf1547b28d src/os_cpu/linux_aarch32/vm/os_linux_aarch32.cpp
>> > --- a/src/os_cpu/linux_aarch32/vm/os_linux_aarch32.cpp	Sat May 14
>> 17:34:57 2016 +0100
>> > +++ b/src/os_cpu/linux_aarch32/vm/os_linux_aarch32.cpp	Wed Jun 01
>> 10:08:09 2016 +0800
>> > @@ -81,7 +81,7 @@
>> >  #define SPELL_REG_SP "sp"
>> >  #define SPELL_REG_FP "fp"
>> >
>> > -address os::current_stack_pointer() {
>> > +__attribute__ ((noinline)) address os::current_stack_pointer() {
>> >    register void* sp __asm__ (SPELL_REG_SP);
>> >    // This is a leaf method. Only rfp has been pushed.
>> >    return (address) sp + BytesPerWord; === Patch end ===
>> >
>> > it fixes a crash caused by fastdebug version build with with gcc 4.7.1
>> >
>> > All the best.
>> >
>>