commit 6ce3eba0f2e6e505ed408cdc40d213c8a512238d
author Vladimir Marko <vmarko@google.com> Mon Feb 16 13:05:59 2015 +0000
committer Vladimir Marko <vmarko@google.com> Thu Feb 19 17:08:25 2015 +0000
tree 5f7ced5c710ada776fa2e2624a05a0d414ed8b39
parent 1b472546657d31d38883373d8340d1441281a6a5

Add suspend checks to special methods.

Generate suspend checks at the beginning of special methods.
If we need to call to runtime, go to the slow path where we
create a simplified but valid frame, spill all arguments,
call art_quick_test_suspend, restore necessary arguments and
return back to the fast path. This keeps the fast path
overhead to a minimum.

Bug: 19245639
Change-Id: I3de5aee783943941322a49c4cf2c4c94411dbaa2

compiler/dex/quick/arm/call_arm.cc

diff --git a/compiler/dex/quick/arm/call_arm.cc b/compiler/dex/quick/arm/call_arm.cc
index 1b5dde2..9cf005b 100644
--- a/compiler/dex/quick/arm/call_arm.cc
+++ b/compiler/dex/quick/arm/call_arm.cc
@@ -484,6 +484,28 @@
   NewLIR1(kThumbBx, rs_rARM_LR.GetReg());
 }
 
+void ArmMir2Lir::GenSpecialEntryForSuspend() {
+  // Keep 16-byte stack alignment - push r0, i.e. ArtMethod*, r5, r6, lr.
+  DCHECK(!IsTemp(rs_r5));
+  DCHECK(!IsTemp(rs_r6));
+  core_spill_mask_ =
+      (1u << rs_r5.GetRegNum()) | (1u << rs_r6.GetRegNum()) | (1u << rs_rARM_LR.GetRegNum());
+  num_core_spills_ = 3u;
+  fp_spill_mask_ = 0u;
+  num_fp_spills_ = 0u;
+  frame_size_ = 16u;
+  core_vmap_table_.clear();
+  fp_vmap_table_.clear();
+  NewLIR1(kThumbPush, (1u << rs_r0.GetRegNum()) |                 // ArtMethod*
+          (core_spill_mask_ & ~(1u << rs_rARM_LR.GetRegNum())) |  // Spills other than LR.
+          (1u << 8));                                             // LR encoded for 16-bit push.
+}
+
+void ArmMir2Lir::GenSpecialExitForSuspend() {
+  // Pop the frame. (ArtMethod* no longer needed but restore it anyway.)
+  NewLIR1(kThumb2Pop, (1u << rs_r0.GetRegNum()) | core_spill_mask_);  // 32-bit because of LR.
+}
+
 static bool ArmUseRelativeCall(CompilationUnit* cu, const MethodReference& target_method) {
   // Emit relative calls only within a dex file due to the limited range of the BL insn.
   return cu->dex_file == target_method.dex_file;

compiler/dex/quick/arm/codegen_arm.h

diff --git a/compiler/dex/quick/arm/codegen_arm.h b/compiler/dex/quick/arm/codegen_arm.h
index 025e69f..a62e597 100644
--- a/compiler/dex/quick/arm/codegen_arm.h
+++ b/compiler/dex/quick/arm/codegen_arm.h
@@ -167,7 +167,9 @@
     void GenDivZeroCheckWide(RegStorage reg);
     void GenEntrySequence(RegLocation* ArgLocs, RegLocation rl_method);
     void GenExitSequence();
-    void GenSpecialExitSequence();
+    void GenSpecialExitSequence() OVERRIDE;
+    void GenSpecialEntryForSuspend() OVERRIDE;
+    void GenSpecialExitForSuspend() OVERRIDE;
     void GenFusedFPCmpBranch(BasicBlock* bb, MIR* mir, bool gt_bias, bool is_double);
     void GenFusedLongCmpBranch(BasicBlock* bb, MIR* mir);
     void GenSelect(BasicBlock* bb, MIR* mir);