MIPS64: [turbofan] Add Int64(Add|Sub)WithOverflow support.

src/mips64/macro-assembler-mips64.cc

Index: src/mips64/macro-assembler-mips64.cc
diff --git a/src/mips64/macro-assembler-mips64.cc b/src/mips64/macro-assembler-mips64.cc
index 5aaf5269847067d3c9eedd0d084789810ecf63a3..596e2c44c43fb47a2199c6f1a1e3923ac12fa87f 100644
--- a/src/mips64/macro-assembler-mips64.cc
+++ b/src/mips64/macro-assembler-mips64.cc
@@ -4730,6 +4730,89 @@ void MacroAssembler::DadduAndCheckForOverflow(Register dst, Register left,
 }
 
 
+static inline void BranchOvfHelper(MacroAssembler* masm, Register overflow_dst,
+                                   Label* overflow_label,
+                                   Label* no_overflow_label) {
+  DCHECK(overflow_label || no_overflow_label);
+  if (!overflow_label) {
+    DCHECK(no_overflow_label);
+    masm->Branch(no_overflow_label, ge, overflow_dst, Operand(zero_reg));
+  } else {
+    masm->Branch(overflow_label, lt, overflow_dst, Operand(zero_reg));
+    if (no_overflow_label) masm->Branch(no_overflow_label);
+  }
+}
+
+
+void MacroAssembler::DaddBranchOvf(Register dst, Register left,
+                                   const Operand& right, Label* overflow_label,
+                                   Label* no_overflow_label, Register scratch) {
+  if (right.is_reg()) {
+    DaddBranchOvf(dst, left, right.rm(), overflow_label, no_overflow_label,
+                  scratch);
+  } else {
+    Register overflow_dst = t9;
+    DCHECK(!dst.is(scratch));
+    DCHECK(!dst.is(overflow_dst));
+    DCHECK(!scratch.is(overflow_dst));
+    DCHECK(!left.is(overflow_dst));
+    li(overflow_dst, right);  // Load right.
+    if (dst.is(left)) {
+      mov(scratch, left);              // Preserve left.
+      Daddu(dst, left, overflow_dst);  // Left is overwritten.
+      xor_(scratch, dst, scratch);     // Original left.
+      xor_(overflow_dst, dst, overflow_dst);
+      and_(overflow_dst, overflow_dst, scratch);
+    } else {
+      Daddu(dst, left, overflow_dst);
+      xor_(scratch, dst, overflow_dst);
+      xor_(overflow_dst, dst, left);
+      and_(overflow_dst, scratch, overflow_dst);
+    }
+    BranchOvfHelper(this, overflow_dst, overflow_label, no_overflow_label);
+  }
+}
+
+
+void MacroAssembler::DaddBranchOvf(Register dst, Register left, Register right,
+                                   Label* overflow_label,
+                                   Label* no_overflow_label, Register scratch) {
+  Register overflow_dst = t9;
+  DCHECK(!dst.is(scratch));
+  DCHECK(!dst.is(overflow_dst));
+  DCHECK(!scratch.is(overflow_dst));
+  DCHECK(!left.is(overflow_dst));
+  DCHECK(!right.is(overflow_dst));
+  DCHECK(!left.is(scratch));
+  DCHECK(!right.is(scratch));
+
+  if (left.is(right) && dst.is(left)) {
+    mov(overflow_dst, right);
+    right = overflow_dst;
+  }
+
+  if (dst.is(left)) {
+    mov(scratch, left);           // Preserve left.
+    daddu(dst, left, right);      // Left is overwritten.
+    xor_(scratch, dst, scratch);  // Original left.
+    xor_(overflow_dst, dst, right);
+    and_(overflow_dst, overflow_dst, scratch);
+  } else if (dst.is(right)) {
+    mov(scratch, right);          // Preserve right.
+    daddu(dst, left, right);      // Right is overwritten.
+    xor_(scratch, dst, scratch);  // Original right.
+    xor_(overflow_dst, dst, left);
+    and_(overflow_dst, overflow_dst, scratch);
+  } else {
+    daddu(dst, left, right);
+    xor_(overflow_dst, dst, left);
+    xor_(scratch, dst, right);
+    and_(overflow_dst, scratch, overflow_dst);
+  }
+  BranchOvfHelper(this, overflow_dst, overflow_label, no_overflow_label);
+}
+
+
 void MacroAssembler::SubuAndCheckForOverflow(Register dst, Register left,
                                              const Operand& right,
                                              Register overflow_dst,
@@ -4861,6 +4944,83 @@ void MacroAssembler::DsubuAndCheckForOverflow(Register dst, Register left,
   }
 }
 
+
+void MacroAssembler::DsubBranchOvf(Register dst, Register left,
+                                   const Operand& right, Label* overflow_label,
+                                   Label* no_overflow_label, Register scratch) {
+  DCHECK(overflow_label || no_overflow_label);
+  if (right.is_reg()) {
+    DsubBranchOvf(dst, left, right.rm(), overflow_label, no_overflow_label,
+                  scratch);
+  } else {
+    Register overflow_dst = t9;
+    DCHECK(!dst.is(scratch));
+    DCHECK(!dst.is(overflow_dst));
+    DCHECK(!scratch.is(overflow_dst));
+    DCHECK(!left.is(overflow_dst));
+    DCHECK(!left.is(scratch));
+    li(overflow_dst, right);  // Load right.
+    if (dst.is(left)) {
+      mov(scratch, left);                         // Preserve left.
+      Dsubu(dst, left, overflow_dst);             // Left is overwritten.
+      xor_(overflow_dst, scratch, overflow_dst);  // scratch is original left.
+      xor_(scratch, dst, scratch);                // scratch is original left.
+      and_(overflow_dst, scratch, overflow_dst);
+    } else {
+      Dsubu(dst, left, overflow_dst);
+      xor_(scratch, left, overflow_dst);
+      xor_(overflow_dst, dst, left);
+      and_(overflow_dst, scratch, overflow_dst);
+    }
+    BranchOvfHelper(this, overflow_dst, overflow_label, no_overflow_label);
+  }
+}
+
+
+void MacroAssembler::DsubBranchOvf(Register dst, Register left, Register right,
+                                   Label* overflow_label,
+                                   Label* no_overflow_label, Register scratch) {
+  DCHECK(overflow_label || no_overflow_label);
+  Register overflow_dst = t9;
+  DCHECK(!dst.is(scratch));
+  DCHECK(!dst.is(overflow_dst));
+  DCHECK(!scratch.is(overflow_dst));
+  DCHECK(!overflow_dst.is(left));
+  DCHECK(!overflow_dst.is(right));
+  DCHECK(!scratch.is(left));
+  DCHECK(!scratch.is(right));
+
+  // This happens with some crankshaft code. Since Subu works fine if
+  // left == right, let's not make that restriction here.
+  if (left.is(right)) {
+    mov(dst, zero_reg);
+    if (no_overflow_label) {
+      Branch(no_overflow_label);
+    }
+  }
+
+  if (dst.is(left)) {
+    mov(scratch, left);                // Preserve left.
+    dsubu(dst, left, right);           // Left is overwritten.
+    xor_(overflow_dst, dst, scratch);  // scratch is original left.
+    xor_(scratch, scratch, right);     // scratch is original left.
+    and_(overflow_dst, scratch, overflow_dst);
+  } else if (dst.is(right)) {
+    mov(scratch, right);      // Preserve right.
+    dsubu(dst, left, right);  // Right is overwritten.
+    xor_(overflow_dst, dst, left);
+    xor_(scratch, left, scratch);  // Original right.
+    and_(overflow_dst, scratch, overflow_dst);
+  } else {
+    dsubu(dst, left, right);
+    xor_(overflow_dst, dst, left);
+    xor_(scratch, left, right);
+    and_(overflow_dst, scratch, overflow_dst);
+  }
+  BranchOvfHelper(this, overflow_dst, overflow_label, no_overflow_label);
+}
+
+
 void MacroAssembler::CallRuntime(const Runtime::Function* f, int num_arguments,
                                  SaveFPRegsMode save_doubles,
                                  BranchDelaySlot bd) {