A64: Synchronize with r16756.

src/arm/lithium-codegen-arm.cc

Index: src/arm/lithium-codegen-arm.cc
diff --git a/src/arm/lithium-codegen-arm.cc b/src/arm/lithium-codegen-arm.cc
index cf76a086720a7282487f2d59ddd09f6938c79759..059aa13322adb4dde769c9be9cf594fac8133cb4 100644
--- a/src/arm/lithium-codegen-arm.cc
+++ b/src/arm/lithium-codegen-arm.cc
@@ -1383,7 +1383,8 @@ void LCodeGen::EmitSignedIntegerDivisionByConstant(
 
 void LCodeGen::DoDivI(LDivI* instr) {
   if (instr->hydrogen()->HasPowerOf2Divisor()) {
-    Register dividend = ToRegister(instr->left());
+    const Register dividend = ToRegister(instr->left());
+    const Register result = ToRegister(instr->result());
     int32_t divisor = instr->hydrogen()->right()->GetInteger32Constant();
     int32_t test_value = 0;
     int32_t power = 0;
@@ -1394,7 +1395,7 @@ void LCodeGen::DoDivI(LDivI* instr) {
     } else {
       // Check for (0 / -x) that will produce negative zero.
       if (instr->hydrogen()->CheckFlag(HValue::kBailoutOnMinusZero)) {
-        __ tst(dividend, Operand(dividend));
+        __ cmp(dividend, Operand::Zero());
         DeoptimizeIf(eq, instr->environment());
       }
       // Check for (kMinInt / -1).
@@ -1409,20 +1410,26 @@ void LCodeGen::DoDivI(LDivI* instr) {
     if (test_value != 0) {
       if (instr->hydrogen()->CheckFlag(
           HInstruction::kAllUsesTruncatingToInt32)) {
-        __ cmp(dividend, Operand(0));
-        __ rsb(dividend, dividend, Operand(0), LeaveCC, lt);
-        __ mov(dividend, Operand(dividend, ASR, power));
-        if (divisor > 0) __ rsb(dividend, dividend, Operand(0), LeaveCC, lt);
-        if (divisor < 0) __ rsb(dividend, dividend, Operand(0), LeaveCC, gt);
+        __ sub(result, dividend, Operand::Zero(), SetCC);
+        __ rsb(result, result, Operand::Zero(), LeaveCC, lt);
+        __ mov(result, Operand(result, ASR, power));
+        if (divisor > 0) __ rsb(result, result, Operand::Zero(), LeaveCC, lt);
+        if (divisor < 0) __ rsb(result, result, Operand::Zero(), LeaveCC, gt);
         return;  // Don't fall through to "__ rsb" below.
       } else {
         // Deoptimize if remainder is not 0.
         __ tst(dividend, Operand(test_value));
         DeoptimizeIf(ne, instr->environment());
-        __ mov(dividend, Operand(dividend, ASR, power));
+        __ mov(result, Operand(dividend, ASR, power));
+        if (divisor < 0) __ rsb(result, result, Operand(0));
+      }
+    } else {
+      if (divisor < 0) {
+        __ rsb(result, dividend, Operand(0));
+      } else {
+        __ Move(result, dividend);
       }
     }
-    if (divisor < 0) __ rsb(dividend, dividend, Operand(0));
 
     return;
   }
@@ -1439,12 +1446,15 @@ void LCodeGen::DoDivI(LDivI* instr) {
 
   // Check for (0 / -x) that will produce negative zero.
   if (instr->hydrogen()->CheckFlag(HValue::kBailoutOnMinusZero)) {
-    Label left_not_zero;
+    Label positive;
+    if (!instr->hydrogen()->CheckFlag(HValue::kCanBeDivByZero)) {
+      // Do the test only if it hadn't be done above.
+      __ cmp(right, Operand::Zero());
+    }
+    __ b(pl, &positive);
     __ cmp(left, Operand::Zero());
-    __ b(ne, &left_not_zero);
-    __ cmp(right, Operand::Zero());
-    DeoptimizeIf(mi, instr->environment());
-    __ bind(&left_not_zero);
+    DeoptimizeIf(eq, instr->environment());
+    __ bind(&positive);
   }
 
   // Check for (kMinInt / -1).
@@ -1975,32 +1985,42 @@ void LCodeGen::DoDateField(LDateField* instr) {
 
 void LCodeGen::DoSeqStringSetChar(LSeqStringSetChar* instr) {
   Register string = ToRegister(instr->string());
-  Register index = ToRegister(instr->index());
+  LOperand* index_op = instr->index();
   Register value = ToRegister(instr->value());
+  Register scratch = scratch0();
   String::Encoding encoding = instr->encoding();
 
   if (FLAG_debug_code) {
-    __ ldr(ip, FieldMemOperand(string, HeapObject::kMapOffset));
-    __ ldrb(ip, FieldMemOperand(ip, Map::kInstanceTypeOffset));
+    __ ldr(scratch, FieldMemOperand(string, HeapObject::kMapOffset));
+    __ ldrb(scratch, FieldMemOperand(scratch, Map::kInstanceTypeOffset));
 
-    __ and_(ip, ip, Operand(kStringRepresentationMask | kStringEncodingMask));
+    __ and_(scratch, scratch,
+            Operand(kStringRepresentationMask | kStringEncodingMask));
     static const uint32_t one_byte_seq_type = kSeqStringTag | kOneByteStringTag;
     static const uint32_t two_byte_seq_type = kSeqStringTag | kTwoByteStringTag;
-    __ cmp(ip, Operand(encoding == String::ONE_BYTE_ENCODING
-                           ? one_byte_seq_type : two_byte_seq_type));
+    __ cmp(scratch, Operand(encoding == String::ONE_BYTE_ENCODING
+                            ? one_byte_seq_type : two_byte_seq_type));
     __ Check(eq, kUnexpectedStringType);
   }
 
-  __ add(ip,
-         string,
-         Operand(SeqString::kHeaderSize - kHeapObjectTag));
-  if (encoding == String::ONE_BYTE_ENCODING) {
-    __ strb(value, MemOperand(ip, index));
+  if (index_op->IsConstantOperand()) {
+    int constant_index = ToInteger32(LConstantOperand::cast(index_op));
+    if (encoding == String::ONE_BYTE_ENCODING) {
+      __ strb(value,
+              FieldMemOperand(string, SeqString::kHeaderSize + constant_index));
+    } else {
+      __ strh(value,
+          FieldMemOperand(string, SeqString::kHeaderSize + constant_index * 2));
+    }
   } else {
-    // MemOperand with ip as the base register is not allowed for strh, so
-    // we do the address calculation explicitly.
-    __ add(ip, ip, Operand(index, LSL, 1));
-    __ strh(value, MemOperand(ip));
+    Register index = ToRegister(index_op);
+    if (encoding == String::ONE_BYTE_ENCODING) {
+      __ add(scratch, string, Operand(index));
+      __ strb(value, FieldMemOperand(scratch, SeqString::kHeaderSize));
+    } else {
+      __ add(scratch, string, Operand(index, LSL, 1));
+      __ strh(value, FieldMemOperand(scratch, SeqString::kHeaderSize));
+    }
   }
 }
 
@@ -3891,80 +3911,64 @@ void LCodeGen::DoPower(LPower* instr) {
 
 
 void LCodeGen::DoRandom(LRandom* instr) {
-  class DeferredDoRandom V8_FINAL : public LDeferredCode {
-   public:
-    DeferredDoRandom(LCodeGen* codegen, LRandom* instr)
-        : LDeferredCode(codegen), instr_(instr) { }
-    virtual void Generate() V8_OVERRIDE { codegen()->DoDeferredRandom(instr_); }
-    virtual LInstruction* instr() V8_OVERRIDE { return instr_; }
-   private:
-    LRandom* instr_;
-  };
-
-  DeferredDoRandom* deferred = new(zone()) DeferredDoRandom(this, instr);
-
-  // Having marked this instruction as a call we can use any
-  // registers.
-  ASSERT(ToDoubleRegister(instr->result()).is(d7));
-  ASSERT(ToRegister(instr->global_object()).is(r0));
-
+  // Assert that the register size is indeed the size of each seed.
   static const int kSeedSize = sizeof(uint32_t);
   STATIC_ASSERT(kPointerSize == kSeedSize);
 
-  __ ldr(r0, FieldMemOperand(r0, GlobalObject::kNativeContextOffset));
+  // Load native context
+  Register global_object = ToRegister(instr->global_object());
+  Register native_context = global_object;
+  __ ldr(native_context, FieldMemOperand(
+          global_object, GlobalObject::kNativeContextOffset));
+
+  // Load state (FixedArray of the native context's random seeds)
   static const int kRandomSeedOffset =
       FixedArray::kHeaderSize + Context::RANDOM_SEED_INDEX * kPointerSize;
-  __ ldr(r2, FieldMemOperand(r0, kRandomSeedOffset));
-  // r2: FixedArray of the native context's random seeds
+  Register state = native_context;
+  __ ldr(state, FieldMemOperand(native_context, kRandomSeedOffset));
 
   // Load state[0].
-  __ ldr(r1, FieldMemOperand(r2, ByteArray::kHeaderSize));
-  __ cmp(r1, Operand::Zero());
-  __ b(eq, deferred->entry());
+  Register state0 = ToRegister(instr->scratch());
+  __ ldr(state0, FieldMemOperand(state, ByteArray::kHeaderSize));
   // Load state[1].
-  __ ldr(r0, FieldMemOperand(r2, ByteArray::kHeaderSize + kSeedSize));
-  // r1: state[0].
-  // r0: state[1].
+  Register state1 = ToRegister(instr->scratch2());
+  __ ldr(state1, FieldMemOperand(state, ByteArray::kHeaderSize + kSeedSize));
 
   // state[0] = 18273 * (state[0] & 0xFFFF) + (state[0] >> 16)
-  __ and_(r3, r1, Operand(0xFFFF));
-  __ mov(r4, Operand(18273));
-  __ mul(r3, r3, r4);
-  __ add(r1, r3, Operand(r1, LSR, 16));
+  Register scratch3 = ToRegister(instr->scratch3());
+  Register scratch4 = scratch0();
+  __ and_(scratch3, state0, Operand(0xFFFF));
+  __ mov(scratch4, Operand(18273));
+  __ mul(scratch3, scratch3, scratch4);
+  __ add(state0, scratch3, Operand(state0, LSR, 16));
   // Save state[0].
-  __ str(r1, FieldMemOperand(r2, ByteArray::kHeaderSize));
+  __ str(state0, FieldMemOperand(state, ByteArray::kHeaderSize));
 
   // state[1] = 36969 * (state[1] & 0xFFFF) + (state[1] >> 16)
-  __ and_(r3, r0, Operand(0xFFFF));
-  __ mov(r4, Operand(36969));
-  __ mul(r3, r3, r4);
-  __ add(r0, r3, Operand(r0, LSR, 16));
+  __ and_(scratch3, state1, Operand(0xFFFF));
+  __ mov(scratch4, Operand(36969));
+  __ mul(scratch3, scratch3, scratch4);
+  __ add(state1, scratch3, Operand(state1, LSR, 16));
   // Save state[1].
-  __ str(r0, FieldMemOperand(r2, ByteArray::kHeaderSize + kSeedSize));
+  __ str(state1, FieldMemOperand(state, ByteArray::kHeaderSize + kSeedSize));
 
   // Random bit pattern = (state[0] << 14) + (state[1] & 0x3FFFF)
-  __ and_(r0, r0, Operand(0x3FFFF));
-  __ add(r0, r0, Operand(r1, LSL, 14));
+  Register random = scratch4;
+  __ and_(random, state1, Operand(0x3FFFF));
+  __ add(random, random, Operand(state0, LSL, 14));
 
-  __ bind(deferred->exit());
   // 0x41300000 is the top half of 1.0 x 2^20 as a double.
   // Create this constant using mov/orr to avoid PC relative load.
-  __ mov(r1, Operand(0x41000000));
-  __ orr(r1, r1, Operand(0x300000));
+  __ mov(scratch3, Operand(0x41000000));
+  __ orr(scratch3, scratch3, Operand(0x300000));
   // Move 0x41300000xxxxxxxx (x = random bits) to VFP.
-  __ vmov(d7, r0, r1);
+  DwVfpRegister result = ToDoubleRegister(instr->result());
+  __ vmov(result, random, scratch3);
   // Move 0x4130000000000000 to VFP.
-  __ mov(r0, Operand::Zero());
-  __ vmov(d8, r0, r1);
-  // Subtract and store the result in the heap number.
-  __ vsub(d7, d7, d8);
-}
-
-
-void LCodeGen::DoDeferredRandom(LRandom* instr) {
-  __ PrepareCallCFunction(1, scratch0());
-  __ CallCFunction(ExternalReference::random_uint32_function(isolate()), 1);
-  // Return value is in r0.
+  __ mov(scratch4, Operand::Zero());
+  DwVfpRegister scratch5 = double_scratch0();
+  __ vmov(scratch5, scratch4, scratch3);
+  __ vsub(result, result, scratch5);
 }
 
 
@@ -5003,15 +5007,19 @@ void LCodeGen::DoTaggedToI(LTaggedToI* instr) {
 
   Register input_reg = ToRegister(input);
 
-  DeferredTaggedToI* deferred = new(zone()) DeferredTaggedToI(this, instr);
+  if (instr->hydrogen()->value()->representation().IsSmi()) {
+    __ SmiUntag(input_reg);
+  } else {
+    DeferredTaggedToI* deferred = new(zone()) DeferredTaggedToI(this, instr);
 
-  // Optimistically untag the input.
-  // If the input is a HeapObject, SmiUntag will set the carry flag.
-  __ SmiUntag(input_reg, SetCC);
-  // Branch to deferred code if the input was tagged.
-  // The deferred code will take care of restoring the tag.
-  __ b(cs, deferred->entry());
-  __ bind(deferred->exit());
+    // Optimistically untag the input.
+    // If the input is a HeapObject, SmiUntag will set the carry flag.
+    __ SmiUntag(input_reg, SetCC);
+    // Branch to deferred code if the input was tagged.
+    // The deferred code will take care of restoring the tag.
+    __ b(cs, deferred->entry());
+    __ bind(deferred->exit());
+  }
 }