Revert "Revert "Revert "Add implicit null and stack checks for x86"""

Broke the build.

This reverts commit 7fb36ded9cd5b1d254b63b3091f35c1e6471b90e.

Change-Id: I9df0e7446ff0913a0e1276a558b2ccf6c8f4c949
diff --git a/compiler/dex/quick/arm64/call_arm64.cc b/compiler/dex/quick/arm64/call_arm64.cc
index d319f53..56dcbe5 100644
--- a/compiler/dex/quick/arm64/call_arm64.cc
+++ b/compiler/dex/quick/arm64/call_arm64.cc
@@ -202,7 +202,7 @@
     null_check_branch = nullptr;  // No null check.
   } else {
     // If the null-check fails its handled by the slow-path to reduce exception related meta-data.
-    if (!cu_->compiler_driver->GetCompilerOptions().GetImplicitNullChecks()) {
+    if (cu_->compiler_driver->GetCompilerOptions().GetExplicitNullChecks()) {
       null_check_branch = OpCmpImmBranch(kCondEq, rs_x0, 0, NULL);
     }
   }
@@ -250,7 +250,7 @@
     null_check_branch = nullptr;  // No null check.
   } else {
     // If the null-check fails its handled by the slow-path to reduce exception related meta-data.
-    if (!cu_->compiler_driver->GetCompilerOptions().GetImplicitNullChecks()) {
+    if (cu_->compiler_driver->GetCompilerOptions().GetExplicitNullChecks()) {
       null_check_branch = OpCmpImmBranch(kCondEq, rs_x0, 0, NULL);
     }
   }
@@ -338,7 +338,7 @@
   const int frame_size_without_spills = frame_size_ - spill_size;
 
   if (!skip_overflow_check) {
-    if (!cu_->compiler_driver->GetCompilerOptions().GetImplicitStackOverflowChecks()) {
+    if (cu_->compiler_driver->GetCompilerOptions().GetExplicitStackOverflowChecks()) {
       if (!large_frame) {
         // Load stack limit
         LoadWordDisp(rs_xSELF, Thread::StackEndOffset<8>().Int32Value(), rs_x9);
@@ -371,7 +371,7 @@
   }
 
   if (!skip_overflow_check) {
-    if (!cu_->compiler_driver->GetCompilerOptions().GetImplicitStackOverflowChecks()) {
+    if (cu_->compiler_driver->GetCompilerOptions().GetExplicitStackOverflowChecks()) {
       class StackOverflowSlowPath: public LIRSlowPath {
       public:
         StackOverflowSlowPath(Mir2Lir* m2l, LIR* branch, size_t sp_displace) :
diff --git a/compiler/dex/quick/arm64/codegen_arm64.h b/compiler/dex/quick/arm64/codegen_arm64.h
index 01d6354..7d75da9 100644
--- a/compiler/dex/quick/arm64/codegen_arm64.h
+++ b/compiler/dex/quick/arm64/codegen_arm64.h
@@ -96,7 +96,7 @@
                               RegStorage r_src, OpSize size) OVERRIDE;
     void MarkGCCard(RegStorage val_reg, RegStorage tgt_addr_reg) OVERRIDE;
     LIR* OpCmpMemImmBranch(ConditionCode cond, RegStorage temp_reg, RegStorage base_reg,
-                           int offset, int check_value, LIR* target, LIR** compare) OVERRIDE;
+                           int offset, int check_value, LIR* target) OVERRIDE;
 
     // Required for target - register utilities.
     RegStorage TargetReg(SpecialTargetRegister reg) OVERRIDE;
diff --git a/compiler/dex/quick/arm64/int_arm64.cc b/compiler/dex/quick/arm64/int_arm64.cc
index 6be66a2..e8f5cb9 100644
--- a/compiler/dex/quick/arm64/int_arm64.cc
+++ b/compiler/dex/quick/arm64/int_arm64.cc
@@ -163,8 +163,7 @@
 
 LIR* Arm64Mir2Lir::OpCmpMemImmBranch(ConditionCode cond, RegStorage temp_reg,
                                      RegStorage base_reg, int offset, int check_value,
-                                     LIR* target, LIR** compare) {
-  DCHECK(compare == nullptr);
+                                     LIR* target) {
   // It is possible that temp register is 64-bit. (ArgReg or RefReg)
   // Always compare 32-bit value no matter what temp_reg is.
   if (temp_reg.Is64Bit()) {
diff --git a/compiler/dex/quick/arm64/target_arm64.cc b/compiler/dex/quick/arm64/target_arm64.cc
index 949295d..ef9dbdd 100644
--- a/compiler/dex/quick/arm64/target_arm64.cc
+++ b/compiler/dex/quick/arm64/target_arm64.cc
@@ -1190,7 +1190,7 @@
   call_state = next_call_insn(cu_, info, call_state, target_method, vtable_idx,
                            direct_code, direct_method, type);
   if (pcrLabel) {
-    if (!cu_->compiler_driver->GetCompilerOptions().GetImplicitNullChecks()) {
+    if (cu_->compiler_driver->GetCompilerOptions().GetExplicitNullChecks()) {
       *pcrLabel = GenExplicitNullCheck(TargetReg(kArg1), info->opt_flags);
     } else {
       *pcrLabel = nullptr;