[aarch64-port-dev ] Assert failure building Graal

[Andrew Haley]

On 06/07/2018 11:17 AM, Stuart Monteith wrote:
> I've retested with them removed, and the tests run to completion. It
> appears my suggestion for using r22/r23 instead of the scratch
> registers weren't quite sufficient to be error free.

That's right: everything is live.  This is a very tough nut to crack, but
I think this will do it:

diff -r b06f330492cd src/hotspot/cpu/aarch64/c1_CodeStubs_aarch64.cpp
--- a/src/hotspot/cpu/aarch64/c1_CodeStubs_aarch64.cpp	Wed Jun 06 13:06:21 2018 +0100
+++ b/src/hotspot/cpu/aarch64/c1_CodeStubs_aarch64.cpp	Thu Jun 07 12:15:42 2018 +0100
@@ -73,19 +73,20 @@
   }

   if (_index->is_cpu_register()) {
-    __ mov(r22, _index->as_register());
+    __ mov(rscratch1, _index->as_register());
   } else {
-    __ mov(r22, _index->as_jint());
+    __ mov(rscratch1, _index->as_jint());
   }
   Runtime1::StubID stub_id;
   if (_throw_index_out_of_bounds_exception) {
     stub_id = Runtime1::throw_index_exception_id;
   } else {
     assert(_array != NULL, "sanity");
-    __ mov(r23, _array->as_pointer_register());
+    __ mov(rscratch2, _array->as_pointer_register());
     stub_id = Runtime1::throw_range_check_failed_id;
   }
-  __ far_call(RuntimeAddress(Runtime1::entry_for(stub_id)), NULL, rscratch2);
+  __ lea(lr, RuntimeAddress(Runtime1::entry_for(stub_id)));
+  __ blr(lr);
   ce->add_call_info_here(_info);
   ce->verify_oop_map(_info);
   debug_only(__ should_not_reach_here());
diff -r b06f330492cd src/hotspot/cpu/aarch64/c1_Runtime1_aarch64.cpp
--- a/src/hotspot/cpu/aarch64/c1_Runtime1_aarch64.cpp	Wed Jun 06 13:06:21 2018 +0100
+++ b/src/hotspot/cpu/aarch64/c1_Runtime1_aarch64.cpp	Thu Jun 07 12:15:42 2018 +0100
@@ -323,7 +323,7 @@


 // target: the entry point of the method that creates and posts the exception oop
-// has_argument: true if the exception needs arguments (passed in r22 and r23)
+// has_argument: true if the exception needs arguments (passed in rscratch1 and rscratch2)

 OopMapSet* Runtime1::generate_exception_throw(StubAssembler* sasm, address target, bool has_argument) {
   // make a frame and preserve the caller's caller-save registers
@@ -332,7 +332,9 @@
   if (!has_argument) {
     call_offset = __ call_RT(noreg, noreg, target);
   } else {
-    call_offset = __ call_RT(noreg, noreg, target, r22, r23);
+    __ mov(c_rarg1, rscratch1);
+    __ mov(c_rarg2, rscratch2);
+    call_offset = __ call_RT(noreg, noreg, target);
   }
   OopMapSet* oop_maps = new OopMapSet();
   oop_maps->add_gc_map(call_offset, oop_map);

An alternative would be to push the array and the index onto the stack
and then write a custom version of save_live_registers() which saves
everything and pops the array and the index into r1 and r2, leaving
exactly the same stack layout.  That's more work, though, and not
obviously any better.

-- 
Andrew Haley
Java Platform Lead Engineer
Red Hat UK Ltd. <https://www.redhat.com>
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