Change RelocInfo to write 64-bit data field on x64 architecture.

Review URL: http://codereview.chromium.org/115860

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@2081 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

src/assembler.cc

@@ -91,13 +91,13 @@ int Label::pos() const {
 //                     bits, the lowest 7 bits written first.
 //
 // data-jump + pos:    00 1110 11,
-//                     signed int, lowest byte written first
+//                     signed intptr_t, lowest byte written first
 //
 // data-jump + st.pos: 01 1110 11,
-//                     signed int, lowest byte written first
+//                     signed intptr_t, lowest byte written first
 //
 // data-jump + comm.:  10 1110 11,
-//                     signed int, lowest byte written first
+//                     signed intptr_t, lowest byte written first
 //
 const int kMaxRelocModes = 14;
 
@@ -159,7 +159,7 @@ void RelocInfoWriter::WriteTaggedPC(uint32_t pc_delta, int tag) {
 }
 
 
-void RelocInfoWriter::WriteTaggedData(int32_t data_delta, int tag) {
+void RelocInfoWriter::WriteTaggedData(intptr_t data_delta, int tag) {
   *--pos_ = data_delta << kPositionTypeTagBits | tag;
 }
 
@@ -179,11 +179,12 @@ void RelocInfoWriter::WriteExtraTaggedPC(uint32_t pc_delta, int extra_tag) {
 }
 
 
-void RelocInfoWriter::WriteExtraTaggedData(int32_t data_delta, int top_tag) {
+void RelocInfoWriter::WriteExtraTaggedData(intptr_t data_delta, int top_tag) {
   WriteExtraTag(kDataJumpTag, top_tag);
-  for (int i = 0; i < kIntSize; i++) {
+  for (int i = 0; i < kIntptrSize; i++) {
     *--pos_ = data_delta;
-    data_delta = ArithmeticShiftRight(data_delta, kBitsPerByte);
+  // Signed right shift is arithmetic shift.  Tested in test-utils.cc.
+    data_delta = data_delta >> kBitsPerByte;
   }
 }
 
@@ -206,11 +207,13 @@ void RelocInfoWriter::Write(const RelocInfo* rinfo) {
     WriteTaggedPC(pc_delta, kCodeTargetTag);
   } else if (RelocInfo::IsPosition(rmode)) {
     // Use signed delta-encoding for data.
-    int32_t data_delta = rinfo->data() - last_data_;
+    intptr_t data_delta = rinfo->data() - last_data_;
     int pos_type_tag = rmode == RelocInfo::POSITION ? kNonstatementPositionTag
                                                     : kStatementPositionTag;
     // Check if data is small enough to fit in a tagged byte.
-    if (is_intn(data_delta, kSmallDataBits)) {
+    // We cannot use is_intn because data_delta is not an int32_t.
+    if (data_delta >= -(1 << (kSmallDataBits-1)) &&
+        data_delta < 1 << (kSmallDataBits-1)) {
       WriteTaggedPC(pc_delta, kPositionTag);
       WriteTaggedData(data_delta, pos_type_tag);
       last_data_ = rinfo->data();
@@ -264,9 +267,9 @@ inline void RelocIterator::AdvanceReadPC() {
 
 
 void RelocIterator::AdvanceReadData() {
-  int32_t x = 0;
-  for (int i = 0; i < kIntSize; i++) {
-    x |= *--pos_ << i * kBitsPerByte;
+  intptr_t x = 0;
+  for (int i = 0; i < kIntptrSize; i++) {
+    x |= static_cast<intptr_t>(*--pos_) << i * kBitsPerByte;
   }
   rinfo_.data_ += x;
 }
@@ -295,7 +298,8 @@ inline int RelocIterator::GetPositionTypeTag() {
 
 inline void RelocIterator::ReadTaggedData() {
   int8_t signed_b = *pos_;
-  rinfo_.data_ += ArithmeticShiftRight(signed_b, kPositionTypeTagBits);
+  // Signed right shift is arithmetic shift.  Tested in test-utils.cc.
+  rinfo_.data_ += signed_b >> kPositionTypeTagBits;
 }
 
 

src/assembler.h

@@ -272,8 +272,8 @@ class RelocInfoWriter BASE_EMBEDDED {
   inline uint32_t WriteVariableLengthPCJump(uint32_t pc_delta);
   inline void WriteTaggedPC(uint32_t pc_delta, int tag);
   inline void WriteExtraTaggedPC(uint32_t pc_delta, int extra_tag);
-  inline void WriteExtraTaggedData(int32_t data_delta, int top_tag);
-  inline void WriteTaggedData(int32_t data_delta, int tag);
+  inline void WriteExtraTaggedData(intptr_t data_delta, int top_tag);
+  inline void WriteTaggedData(intptr_t data_delta, int tag);
   inline void WriteExtraTag(int extra_tag, int top_tag);
 
   byte* pos_;

src/globals.h

@@ -111,11 +111,12 @@ const int kMinInt = -kMaxInt - 1;
 
 const uint32_t kMaxUInt32 = 0xFFFFFFFFu;
 
-const int kCharSize     = sizeof(char);    // NOLINT
-const int kShortSize    = sizeof(short);   // NOLINT
-const int kIntSize      = sizeof(int);     // NOLINT
-const int kDoubleSize   = sizeof(double);  // NOLINT
-const int kPointerSize  = sizeof(void*);   // NOLINT
+const int kCharSize     = sizeof(char);      // NOLINT
+const int kShortSize    = sizeof(short);     // NOLINT
+const int kIntSize      = sizeof(int);       // NOLINT
+const int kDoubleSize   = sizeof(double);    // NOLINT
+const int kPointerSize  = sizeof(void*);     // NOLINT
+const int kIntptrSize   = sizeof(intptr_t);  // NOLINT
 
 #if V8_HOST_ARCH_64_BIT
 const int kPointerSizeLog2 = 3;

test/cctest/test-utils.cc

@@ -152,6 +152,13 @@ TEST(Utils1) {
   CHECK_EQ(0, FastD2I(0.345));
   CHECK_EQ(1, FastD2I(1.234));
   CHECK_EQ(1000000, FastD2I(1000000.123));
+  // Check that >> is implemented as arithmetic shift right.
+  // If this is not true, then ArithmeticShiftRight() must be changed,
+  // There are also documented right shifts in assembler.cc of
+  // int8_t and intptr_t signed integers.
+  CHECK_EQ(-2, -8 >> 2);
+  CHECK_EQ(-2, static_cast<int8_t>(-8) >> 2);
+  CHECK_EQ(-2, static_cast<intptr_t>(-8) >> 2);
 }
 
 
@@ -177,32 +184,3 @@ TEST(SNPrintF) {
     buffer.Dispose();
   }
 }
-
-
-// Issue 358: When copying EmbeddedVector, Vector::start_ must point
-// to the buffer in the copy, not in the source.
-TEST(EmbeddedVectorCopy) {
-  EmbeddedVector<int, 1> src;
-  src[0] = 100;
-  EmbeddedVector<int, 1> dst = src;
-  CHECK_NE(src.start(), dst.start());
-  CHECK_EQ(src[0], dst[0]);
-  src[0] = 200;
-  CHECK_NE(src[0], dst[0]);
-}
-
-
-// Also Issue 358, assignment case.
-TEST(EmbeddedVectorAssign) {
-  EmbeddedVector<int, 1> src;
-  src[0] = 100;
-  EmbeddedVector<int, 1> dst;
-  dst[0] = 200;
-  CHECK_NE(src.start(), dst.start());
-  CHECK_NE(src[0], dst[0]);
-  dst = src;
-  CHECK_NE(src.start(), dst.start());
-  CHECK_EQ(src[0], dst[0]);
-  src[0] = 200;
-  CHECK_NE(src[0], dst[0]);
-}