Reland of MIPS: Add FPXX support to MIPS32R2

src/mips/simulator-mips.cc

 // Copyright 2011 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include <limits.h>
 #include <stdarg.h>
 #include <stdlib.h>
 #include <cmath>
 
 #if V8_TARGET_ARCH_MIPS
@@ skipping 3388 matching lines @@
   switch (get_instr()->RsFieldRaw()) {
     case CFC1:
       // At the moment only FCSR is supported.
       DCHECK(fs_reg() == kFCSRRegister);
       set_register(rt_reg(), FCSR_);
       break;
     case MFC1:
       set_register(rt_reg(), get_fpu_register_word(fs_reg()));
       break;
     case MFHC1:
-      set_register(rt_reg(), get_fpu_register_hi_word(fs_reg()));
+      if (IsFp64Mode()) {
+        set_register(rt_reg(), get_fpu_register_hi_word(fs_reg()));
+      } else {
+        set_register(rt_reg(), get_fpu_register_word(fs_reg() + 1));
+      }
       break;
     case CTC1: {
       // At the moment only FCSR is supported.
       DCHECK(fs_reg() == kFCSRRegister);
       int32_t reg = registers_[rt_reg()];
       if (IsMipsArchVariant(kMips32r6)) {
         FCSR_ = reg | kFCSRNaN2008FlagMask;
       } else {
         DCHECK(IsMipsArchVariant(kMips32r1) || IsMipsArchVariant(kMips32r2));
         FCSR_ = reg & ~kFCSRNaN2008FlagMask;
       }
       break;
     }
     case MTC1:
       // Hardware writes upper 32-bits to zero on mtc1.
       set_fpu_register_hi_word(fs_reg(), 0);
       set_fpu_register_word(fs_reg(), registers_[rt_reg()]);
       break;
     case MTHC1:
-      set_fpu_register_hi_word(fs_reg(), registers_[rt_reg()]);
+      if (IsFp64Mode()) {
+        set_fpu_register_hi_word(fs_reg(), registers_[rt_reg()]);
+      } else {
+        set_fpu_register_word(fs_reg() + 1, registers_[rt_reg()]);
+      }
       break;
     case S: {
       DecodeTypeRegisterSRsType();
       break;
     }
     case D:
       DecodeTypeRegisterDRsType();
       break;
     case W:
       DecodeTypeRegisterWRsType();
@@ skipping 1175 matching lines @@
 
 
 #undef UNSUPPORTED
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // USE_SIMULATOR
 
 #endif  // V8_TARGET_ARCH_MIPS