# HG changeset patch
# User zgu
# Date 1573224678 18000
# Node ID 66b1db608c12b735b9c1eafbd21bf04b5637a5ca
# Parent  5606867a5e6e8d06270f26dc5fb4b53a18feee17
8233337: Shenandoah: Cleanup AArch64 SBSA::load_reference_barrier_not_null()
Reviewed-by: rkennke

diff -r 5606867a5e6e -r 66b1db608c12 src/hotspot/cpu/aarch64/gc/shenandoah/shenandoahBarrierSetAssembler_aarch64.cpp
--- a/src/hotspot/cpu/aarch64/gc/shenandoah/shenandoahBarrierSetAssembler_aarch64.cpp	Fri Nov 08 09:50:07 2019 -0500
+++ b/src/hotspot/cpu/aarch64/gc/shenandoah/shenandoahBarrierSetAssembler_aarch64.cpp	Fri Nov 08 09:51:18 2019 -0500
@@ -254,32 +254,16 @@
     dst = rscratch1;
   }
 
-  RegSet to_save_r1 = RegSet::of(r1);
-  // If outgoing register is r1, we can clobber it
-  if (result_dst != r1) {
-    __ push(to_save_r1, sp);
-  }
+  // Save r0 and r1, unless it is an output register
+  RegSet to_save = RegSet::of(r0, r1) - result_dst;
+  __ push(to_save, sp);
   __ lea(r1, load_addr);
-
-  RegSet to_save_r0 = RegSet::of(r0);
-  if (dst != r0) {
-    __ push(to_save_r0, sp);
-    __ mov(r0, dst);
-  }
+  __ mov(r0, dst);
 
   __ far_call(RuntimeAddress(CAST_FROM_FN_PTR(address, ShenandoahBarrierSetAssembler::shenandoah_lrb())));
 
-  if (result_dst != r0) {
-    __ mov(result_dst, r0);
-  }
-
-  if (dst != r0) {
-    __ pop(to_save_r0, sp);
-  }
-
-  if (result_dst != r1) {
-    __ pop(to_save_r1, sp);
-  }
+  __ mov(result_dst, r0);
+  __ pop(to_save, sp);
 
   __ bind(done);
   __ leave();