Fix an undetected Smi overflow on ARM.

runtime/vm/assembler_x64.cc

 // Copyright (c) 2013, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #include "vm/globals.h"
 #if defined(TARGET_ARCH_X64)
 
 #include "vm/assembler.h"
 #include "vm/cpu.h"
 #include "vm/heap.h"
@@ skipping 2345 matching lines @@
   }
 }
 
 
 void Assembler::PopRegister(Register r) {
   popq(r);
 }
 
 
 void Assembler::AddImmediate(Register reg, const Immediate& imm, Register pp) {
-  int64_t value = imm.value();
-  if (value > 0) {
+  const int64_t value = imm.value();
+  if (value == 0) {
+    return;
+  }
+  if ((value > 0) || (value == kMinInt64)) {
     if (value == 1) {
       incq(reg);
-    } else if (value != 0) {
+    } else {
       if (CanLoadImmediateFromPool(imm, pp)) {
         ASSERT(reg != TMP);
         LoadImmediate(TMP, imm, pp);
         addq(reg, TMP);
       } else {
         addq(reg, imm);
       }
     }
-  } else if (value < 0) {
-    value = -value;
-    if (value == 1) {
-      decq(reg);
-    } else if (value != 0) {
-      const Immediate& s = Immediate(value);
-      if (CanLoadImmediateFromPool(s, pp)) {
-        ASSERT(reg != TMP);
-        LoadImmediate(TMP, s, pp);
-        subq(reg, TMP);
-      } else {
-        subq(reg, Immediate(value));
-      }
-    }
+  } else {
+    SubImmediate(reg, Immediate(-value), pp);
   }
 }
 
 
 void Assembler::AddImmediate(const Address& address, const Immediate& imm,
                              Register pp) {
-  int64_t value = imm.value();
-  if (value > 0) {
+  const int64_t value = imm.value();
+  if (value == 0) {
+    return;
+  }
+  if ((value > 0) || (value == kMinInt64)) {
     if (value == 1) {
       incq(address);
-    } else if (value != 0) {
+    } else {
       if (CanLoadImmediateFromPool(imm, pp)) {
         LoadImmediate(TMP, imm, pp);
         addq(address, TMP);
       } else {
         addq(address, imm);
       }
     }
-  } else if (value < 0) {
-    value = -value;
-    if (value == 1) {
-      decq(address);
-    } else if (value != 0) {
-      const Immediate& s = Immediate(value);
-      if (CanLoadImmediateFromPool(s, pp)) {
-        LoadImmediate(TMP, s, pp);
-        subq(address, TMP);
-      } else {
-        subq(address, s);
-      }
-    }
+  } else {
+    SubImmediate(address, Immediate(-value), pp);
   }
 }
 
+
+void Assembler::SubImmediate(Register reg, const Immediate& imm, Register pp) {
+  const int64_t value = imm.value();
+  if (value == 0) {
+    return;
+  }
+  if ((value > 0) || (value == kMinInt64)) {
+    if (value == 1) {
+      decq(reg);
+    } else {
+      if (CanLoadImmediateFromPool(imm, pp)) {
+        ASSERT(reg != TMP);
+        LoadImmediate(TMP, imm, pp);
+        subq(reg, TMP);
+      } else {
+        subq(reg, imm);
+      }
+    }
+  } else {
+    AddImmediate(reg, Immediate(-value), pp);
+  }
+}
+
+
+void Assembler::SubImmediate(const Address& address, const Immediate& imm,
+                             Register pp) {
+  const int64_t value = imm.value();
+  if (value == 0) {
+    return;
+  }
+  if ((value > 0) || (value == kMinInt64)) {
+    if (value == 1) {
+      decq(address);
+    } else {
+      if (CanLoadImmediateFromPool(imm, pp)) {
+        LoadImmediate(TMP, imm, pp);
+        subq(address, TMP);
+      } else {
+        subq(address, imm);
+      }
+    }
+  } else {
+    AddImmediate(address, Immediate(-value), pp);
+  }
+}
+
 
 void Assembler::Drop(intptr_t stack_elements) {
   ASSERT(stack_elements >= 0);
   if (stack_elements <= 4) {
     for (intptr_t i = 0; i < stack_elements; i++) {
       popq(TMP);
     }
     return;
   }
   addq(RSP, Immediate(stack_elements * kWordSize));
@@ skipping 831 matching lines @@
 
 
 const char* Assembler::FpuRegisterName(FpuRegister reg) {
   ASSERT((0 <= reg) && (reg < kNumberOfXmmRegisters));
   return xmm_reg_names[reg];
 }
 
 }  // namespace dart
 
 #endif  // defined TARGET_ARCH_X64