MIPS: Use SmiTst and TrySmiTag MacroAssembler instructions.

src/mips/macro-assembler-mips.h

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 1353 matching lines @@
   }
 
   // Test for overflow < 0: use BranchOnOverflow() or BranchOnNoOverflow().
   void SmiTagCheckOverflow(Register reg, Register overflow);
   void SmiTagCheckOverflow(Register dst, Register src, Register overflow);
 
   void SmiTag(Register dst, Register src) {
     Addu(dst, src, src);
   }
 
+  // Try to convert int32 to smi. If the value is to large, preserve
+  // the original value and jump to not_a_smi. Destroys scratch and
+  // sets flags.
+  void TrySmiTag(Register reg, Register scratch, Label* not_a_smi) {
+    TrySmiTag(reg, reg, scratch, not_a_smi);
+  }
+  void TrySmiTag(Register dst,
+                 Register src,
+                 Register scratch,
+                 Label* not_a_smi) {
+    SmiTagCheckOverflow(at, src, scratch);
+    BranchOnOverflow(not_a_smi, scratch);
+    mov(dst, at);
+  }
+
   void SmiUntag(Register reg) {
     sra(reg, reg, kSmiTagSize);
   }
 
   void SmiUntag(Register dst, Register src) {
     sra(dst, src, kSmiTagSize);
   }
 
+  // Test if the register contains a smi.
+  inline void SmiTst(Register value, Register scratch) {
+    And(scratch, value, Operand(kSmiTagMask));
+  }
+  inline void NonNegativeSmiTst(Register value, Register scratch) {
+    And(scratch, value, Operand(kSmiTagMask | kSmiSignMask));
+  }
+
   // Untag the source value into destination and jump if source is a smi.
   // Souce and destination can be the same register.
   void UntagAndJumpIfSmi(Register dst, Register src, Label* smi_case);
 
   // Untag the source value into destination and jump if source is not a smi.
   // Souce and destination can be the same register.
   void UntagAndJumpIfNotSmi(Register dst, Register src, Label* non_smi_case);
 
   // Jump the register contains a smi.
   void JumpIfSmi(Register value,
@@ skipping 269 matching lines @@
 #define CODE_COVERAGE_TOSTRING(x) CODE_COVERAGE_STRINGIFY(x)
 #define __FILE_LINE__ __FILE__ ":" CODE_COVERAGE_TOSTRING(__LINE__)
 #define ACCESS_MASM(masm) masm->stop(__FILE_LINE__); masm->
 #else
 #define ACCESS_MASM(masm) masm->
 #endif
 
 } }  // namespace v8::internal
 
 #endif  // V8_MIPS_MACRO_ASSEMBLER_MIPS_H_