Rewrite stackmap encoding code.

Remove most of the code related to handling of bit encodings.
The design is still same; the encodings are just more implicit.
Most of the complexity is replaced with a single BitTable class,
which is a generic purpose table of tightly bit-packed integers.
It has its own header which stores the bit-encoding of columns,
and that removes the need to handle the encodings explicitly.

Other classes, like StackMap, are accessors into the BitTable,
with named getter methods for the individual columns.

This CL saves ~1% of .oat file size (~4% of stackmap size).

Test: test-art-host-gtest
Change-Id: I7e92683753b0cc376300e3b23d892feac3670890

1 files changed, 20 insertions, 27 deletions

diff --git a/runtime/quick_exception_handler.cc b/runtime/quick_exception_handler.cc
index 077aa33925..c555fca23c 100644
--- a/runtime/quick_exception_handler.cc
+++ b/runtime/quick_exception_handler.cc
@@ -224,30 +224,29 @@ void QuickExceptionHandler::SetCatchEnvironmentForOptimizedHandler(StackVisitor*
 
   CodeItemDataAccessor accessor(handler_method_->DexInstructionData());
   const size_t number_of_vregs = accessor.RegistersSize();
-  CodeInfo code_info = handler_method_header_->GetOptimizedCodeInfo();
-  CodeInfoEncoding encoding = code_info.ExtractEncoding();
+  CodeInfo code_info(handler_method_header_);
 
   // Find stack map of the catch block.
-  StackMap catch_stack_map = code_info.GetCatchStackMapForDexPc(GetHandlerDexPc(), encoding);
+  StackMap catch_stack_map = code_info.GetCatchStackMapForDexPc(GetHandlerDexPc());
   DCHECK(catch_stack_map.IsValid());
   DexRegisterMap catch_vreg_map =
-      code_info.GetDexRegisterMapOf(catch_stack_map, encoding, number_of_vregs);
+      code_info.GetDexRegisterMapOf(catch_stack_map, number_of_vregs);
   if (!catch_vreg_map.IsValid()) {
     return;
   }
 
   // Find stack map of the throwing instruction.
   StackMap throw_stack_map =
-      code_info.GetStackMapForNativePcOffset(stack_visitor->GetNativePcOffset(), encoding);
+      code_info.GetStackMapForNativePcOffset(stack_visitor->GetNativePcOffset());
   DCHECK(throw_stack_map.IsValid());
   DexRegisterMap throw_vreg_map =
-      code_info.GetDexRegisterMapOf(throw_stack_map, encoding, number_of_vregs);
+      code_info.GetDexRegisterMapOf(throw_stack_map, number_of_vregs);
   DCHECK(throw_vreg_map.IsValid());
 
   // Copy values between them.
   for (uint16_t vreg = 0; vreg < number_of_vregs; ++vreg) {
     DexRegisterLocation::Kind catch_location =
-        catch_vreg_map.GetLocationKind(vreg, number_of_vregs, code_info, encoding);
+        catch_vreg_map.GetLocationKind(vreg, number_of_vregs, code_info);
     if (catch_location == DexRegisterLocation::Kind::kNone) {
       continue;
     }
@@ -257,8 +256,7 @@ void QuickExceptionHandler::SetCatchEnvironmentForOptimizedHandler(StackVisitor*
     uint32_t vreg_value;
     VRegKind vreg_kind = ToVRegKind(throw_vreg_map.GetLocationKind(vreg,
                                                                    number_of_vregs,
-                                                                   code_info,
-                                                                   encoding));
+                                                                   code_info));
     bool get_vreg_success = stack_visitor->GetVReg(stack_visitor->GetMethod(),
                                                    vreg,
                                                    vreg_kind,
@@ -271,8 +269,7 @@ void QuickExceptionHandler::SetCatchEnvironmentForOptimizedHandler(StackVisitor*
     // Copy value to the catch phi's stack slot.
     int32_t slot_offset = catch_vreg_map.GetStackOffsetInBytes(vreg,
                                                                number_of_vregs,
-                                                               code_info,
-                                                               encoding);
+                                                               code_info);
     ArtMethod** frame_top = stack_visitor->GetCurrentQuickFrame();
     uint8_t* slot_address = reinterpret_cast<uint8_t*>(frame_top) + slot_offset;
     uint32_t* slot_ptr = reinterpret_cast<uint32_t*>(slot_address);
@@ -404,20 +401,18 @@ class DeoptimizeStackVisitor FINAL : public StackVisitor {
                                       const bool* updated_vregs)
       REQUIRES_SHARED(Locks::mutator_lock_) {
     const OatQuickMethodHeader* method_header = GetCurrentOatQuickMethodHeader();
-    CodeInfo code_info = method_header->GetOptimizedCodeInfo();
+    CodeInfo code_info(method_header);
     uintptr_t native_pc_offset = method_header->NativeQuickPcOffset(GetCurrentQuickFramePc());
-    CodeInfoEncoding encoding = code_info.ExtractEncoding();
-    StackMap stack_map = code_info.GetStackMapForNativePcOffset(native_pc_offset, encoding);
+    StackMap stack_map = code_info.GetStackMapForNativePcOffset(native_pc_offset);
     CodeItemDataAccessor accessor(m->DexInstructionData());
     const size_t number_of_vregs = accessor.RegistersSize();
-    uint32_t register_mask = code_info.GetRegisterMaskOf(encoding, stack_map);
-    BitMemoryRegion stack_mask = code_info.GetStackMaskOf(encoding, stack_map);
+    uint32_t register_mask = code_info.GetRegisterMaskOf(stack_map);
+    BitMemoryRegion stack_mask = code_info.GetStackMaskOf(stack_map);
     DexRegisterMap vreg_map = IsInInlinedFrame()
         ? code_info.GetDexRegisterMapAtDepth(GetCurrentInliningDepth() - 1,
-                                             code_info.GetInlineInfoOf(stack_map, encoding),
-                                             encoding,
+                                             code_info.GetInlineInfoOf(stack_map),
                                              number_of_vregs)
-        : code_info.GetDexRegisterMapOf(stack_map, encoding, number_of_vregs);
+        : code_info.GetDexRegisterMapOf(stack_map, number_of_vregs);
 
     if (!vreg_map.IsValid()) {
       return;
@@ -430,7 +425,7 @@ class DeoptimizeStackVisitor FINAL : public StackVisitor {
       }
 
       DexRegisterLocation::Kind location =
-          vreg_map.GetLocationKind(vreg, number_of_vregs, code_info, encoding);
+          vreg_map.GetLocationKind(vreg, number_of_vregs, code_info);
       static constexpr uint32_t kDeadValue = 0xEBADDE09;
       uint32_t value = kDeadValue;
       bool is_reference = false;
@@ -439,12 +434,11 @@ class DeoptimizeStackVisitor FINAL : public StackVisitor {
         case DexRegisterLocation::Kind::kInStack: {
           const int32_t offset = vreg_map.GetStackOffsetInBytes(vreg,
                                                                 number_of_vregs,
-                                                                code_info,
-                                                                encoding);
+                                                                code_info);
           const uint8_t* addr = reinterpret_cast<const uint8_t*>(GetCurrentQuickFrame()) + offset;
           value = *reinterpret_cast<const uint32_t*>(addr);
           uint32_t bit = (offset >> 2);
-          if (bit < encoding.stack_mask.encoding.BitSize() && stack_mask.LoadBit(bit)) {
+          if (bit < code_info.GetNumberOfStackMaskBits() && stack_mask.LoadBit(bit)) {
             is_reference = true;
           }
           break;
@@ -453,7 +447,7 @@ class DeoptimizeStackVisitor FINAL : public StackVisitor {
         case DexRegisterLocation::Kind::kInRegisterHigh:
         case DexRegisterLocation::Kind::kInFpuRegister:
         case DexRegisterLocation::Kind::kInFpuRegisterHigh: {
-          uint32_t reg = vreg_map.GetMachineRegister(vreg, number_of_vregs, code_info, encoding);
+          uint32_t reg = vreg_map.GetMachineRegister(vreg, number_of_vregs, code_info);
           bool result = GetRegisterIfAccessible(reg, ToVRegKind(location), &value);
           CHECK(result);
           if (location == DexRegisterLocation::Kind::kInRegister) {
@@ -464,7 +458,7 @@ class DeoptimizeStackVisitor FINAL : public StackVisitor {
           break;
         }
         case DexRegisterLocation::Kind::kConstant: {
-          value = vreg_map.GetConstant(vreg, number_of_vregs, code_info, encoding);
+          value = vreg_map.GetConstant(vreg, number_of_vregs, code_info);
           if (value == 0) {
             // Make it a reference for extra safety.
             is_reference = true;
@@ -479,8 +473,7 @@ class DeoptimizeStackVisitor FINAL : public StackVisitor {
               << "Unexpected location kind "
               << vreg_map.GetLocationInternalKind(vreg,
                                                   number_of_vregs,
-                                                  code_info,
-                                                  encoding);
+                                                  code_info);
           UNREACHABLE();
         }
       }