AArch64: Implement arm64cinterp.m4 and arm64helpers.m4

[knn-k]

This commit adds two asm files for aarch64, implementing c_cInterpreter.

Signed-off-by: knn-k konno@jp.ibm.com

[knn-k]

Should the file names be arm64* or aarch64*?

[pshipton]

@gacholio @DanHeidinga ^ do you have a preference?

[gacholio]

I'd prefer this not be in another file - will it not be 99% similar to the 32-bit implementation? I was hoping not to generate another branch of files for 64-bit (we haven't needed to do it on any other platforms).

I'd prefer to see ifdefs on our existing 64-bit flag (the poorly-name ENV_DATA64) in ARM files rather than calling out AARCH64 as an entirely different entity.

@knn-k See if you can fix/ifdef the existing m4 files.

[knn-k]

AArch64 instruction set is not an extension of existing 32-bit ARM instruction set. The implementation of those *.m4 files for AArch64 will be completely different from the 32-bit ARM version.
I believe it is natural to separate the 64-bit ARM code to another file from the 32-bit ARM code.

See #3502 for the case of unsafeHelper.s.

I have already wrote the full version of arm64cinterp.m4, which is not built nor tested yet.

[gacholio]

Can this difference be resolved by way of alias (in much the same way that _rbx on X is EBX or RBX on different bitness)? 99% of all of the instructions in the m4 files are fullword-sized.

[knn-k]

@gacholio It won't be simple instruction/register aliases. I guess I will have to define more macros to put both 32-bit and 64-bit ARM.

From the existing armcinterp.m4:

START_PROC(c_cInterpreter)
	sub r13,r13,{#}CINTERP_STACK_SIZE
	stmia r13,{{ r4,r5,r6,r7,r8,r9,r10,r11,r14 }}
	add r3,r13,{#}FPR_SAVE_OFFSET(0)
	vstmia.64 r3,{{ D8-D15 }}
	mov J9VMTHREAD,r0
	ldr r4,[J9VMTHREAD,{#}J9TR_VMThread_entryLocalStorage]	
	add r3,r13,{#}JIT_GPR_SAVE_OFFSET(0)
	str r3,[r4,{#}J9TR_ELS_jitGlobalStorageBase]

AArch64 version (in preparation):

START_PROC(c_cInterpreter)
	sub sp, sp, {#}CINTERP_STACK_SIZE
	stp x29, x30, [sp, GPR_SAVE_OFFSET(29)]
	stp x27, x28, [sp, GPR_SAVE_OFFSET(27)]
	stp x25, x26, [sp, GPR_SAVE_OFFSET(25)]
	stp x23, x24, [sp, GPR_SAVE_OFFSET(23)]
	stp x21, x22, [sp, GPR_SAVE_OFFSET(21)]
	stp x19, x20, [sp, GPR_SAVE_OFFSET(19)]
	stp d14, d15, [sp, FPR_SAVE_OFFSET(14)]
	stp d12, d13, [sp, FPR_SAVE_OFFSET(12)]
	stp d10, d11, [sp, FPR_SAVE_OFFSET(10)]
	stp d8, d9, [sp, FPR_SAVE_OFFSET(8)]
	mov J9VMTHREAD, x0
	ldr x27, [J9VMTHREAD,{#}J9TR_VMThread_entryLocalStorage]
	add x28, sp, {#}JIT_GPR_SAVE_OFFSET(0)
	str x28, [x27,{#}J9TR_ELS_jitGlobalStorageBase]

[gacholio]

Fair enough. Once the implementation is complete, we can look at commonizing things if it's worth it.

[gacholio]

jenkins compile xlinux jdk8

[gacholio]

Compile fails for the non-cmake xa64 build - I suspect it will fail elsewhere as well. I think you need to update the module.xml to exclude your new C interp file on non-AARCH64 platforms.

[knn-k]

Updated module.xml.

[gacholio]

jenkins compile xlinux jdk8

[gacholio]

spec.flags.arch_aarch64 is not defined. I suggest you use arch_arm and J9VM_ENV_DATA64.

[gacholio]

While you're at it, you may as well exclude the 32-bit file on 64-bit builds in preparation for having a build.

[knn-k]

How is the spec.flags determined during the OpenJ9 build process?

[knn-k]

I updated the files a little.
Not working yet, of course, but libj9vm29.so and vmtest are built successfully for aarch64 in my build environment.

[knn-k]

Updated the files adding actual code to c_cInterpreter.
It depends on the changes in oti/j9nonbuilder.h and jilgen/jilconsts.c in #4447.

[knn-k]

I can run HelloWorld on aarch64 Linux in the interpreter mode now.

[knn-k]

Removed unnecessary comments from the .m4 files.
Some macros in arm64helpers.m4, marked as "To be filled", are not implemented yet. I am going to write their code later in a separate PR along with the JIT work.

[DanHeidinga]

@gacholio can you give this another review?

[knn-k]

I would like this PR to be merged if the code is OK.
The aarch64 VM runs fine in the interpreter mode with the c_cInterpreter in this PR.

[gacholio]

Sorry, I will get to this soon.

[gacholio]

jenkins compile xlinux jdk8