# HG changeset patch
# User smonteith
# Date 1561456259 -3600
# Node ID b7f68ddec66f996ae3aad03291d129ca9f02482d
# Parent  688f985f29c3b1c0cd794fbda6c4f9ff9df423a2
8226515: AArch64: float point register corruption in ZBarrierSetAssembler::load_at
Reviewed-by: aph

diff -r 688f985f29c3 -r b7f68ddec66f src/hotspot/cpu/aarch64/gc/z/zBarrierSetAssembler_aarch64.cpp
--- a/src/hotspot/cpu/aarch64/gc/z/zBarrierSetAssembler_aarch64.cpp	Wed Jun 26 01:15:51 2019 +0000
+++ b/src/hotspot/cpu/aarch64/gc/z/zBarrierSetAssembler_aarch64.cpp	Tue Jun 25 10:50:59 2019 +0100
@@ -63,27 +63,25 @@
     return;
   }
 
-  // rscratch1 can be passed as src or dst, so don't use it.
-  RegSet savedRegs = RegSet::of(rscratch2, rheapbase);
+  assert_different_registers(rscratch1, rscratch2, src.base());
+  assert_different_registers(rscratch1, rscratch2, dst);
+
+  RegSet savedRegs = RegSet::range(r0,r28) - RegSet::of(dst, rscratch1, rscratch2);
 
   Label done;
-  assert_different_registers(rheapbase, rscratch2, dst);
-  assert_different_registers(rheapbase, rscratch2, src.base());
-
-  __ push(savedRegs, sp);
 
   // Load bad mask into scratch register.
-  __ ldr(rheapbase, address_bad_mask_from_thread(rthread));
+  __ ldr(rscratch1, address_bad_mask_from_thread(rthread));
   __ lea(rscratch2, src);
   __ ldr(dst, src);
 
   // Test reference against bad mask. If mask bad, then we need to fix it up.
-  __ tst(dst, rheapbase);
+  __ tst(dst, rscratch1);
   __ br(Assembler::EQ, done);
 
   __ enter();
 
-  __ push(RegSet::range(r0,r28) - RegSet::of(dst), sp);
+  __ push(savedRegs, sp);
 
   if (c_rarg0 != dst) {
     __ mov(c_rarg0, dst);
@@ -91,13 +89,15 @@
   __ mov(c_rarg1, rscratch2);
 
   int step = 4 * wordSize;
-  __ mov(rscratch1, -step);
+  __ mov(rscratch2, -step);
   __ sub(sp, sp, step);
 
   for (int i = 28; i >= 4; i -= 4) {
     __ st1(as_FloatRegister(i), as_FloatRegister(i+1), as_FloatRegister(i+2),
-        as_FloatRegister(i+3), __ T1D, Address(__ post(sp, rscratch1)));
+        as_FloatRegister(i+3), __ T1D, Address(__ post(sp, rscratch2)));
   }
+  __ st1(as_FloatRegister(0), as_FloatRegister(1), as_FloatRegister(2),
+      as_FloatRegister(3), __ T1D, Address(sp));
 
   __ call_VM_leaf(ZBarrierSetRuntime::load_barrier_on_oop_field_preloaded_addr(decorators), 2);
 
@@ -111,13 +111,10 @@
     __ mov(dst, r0);
   }
 
-  __ pop(RegSet::range(r0,r28) - RegSet::of(dst), sp);
+  __ pop(savedRegs, sp);
   __ leave();
 
   __ bind(done);
-
-  // Restore tmps
-  __ pop(savedRegs, sp);
 }
 
 #ifdef ASSERT
diff -r 688f985f29c3 -r b7f68ddec66f src/hotspot/cpu/aarch64/templateInterpreterGenerator_aarch64.cpp
--- a/src/hotspot/cpu/aarch64/templateInterpreterGenerator_aarch64.cpp	Wed Jun 26 01:15:51 2019 +0000
+++ b/src/hotspot/cpu/aarch64/templateInterpreterGenerator_aarch64.cpp	Tue Jun 25 10:50:59 2019 +0100
@@ -886,8 +886,8 @@
   }
 
   // Get mirror and store it in the frame as GC root for this Method*
-  __ load_mirror(rscratch1, rmethod);
-  __ stp(rscratch1, zr, Address(sp, 4 * wordSize));
+  __ load_mirror(r10, rmethod);
+  __ stp(r10, zr, Address(sp, 4 * wordSize));
 
   __ ldr(rcpool, Address(rmethod, Method::const_offset()));
   __ ldr(rcpool, Address(rcpool, ConstMethod::constants_offset()));