Use TRUNC.W instead of CVT.W on mips to convert from double to int as to not

runtime/vm/simulator_mips.cc

Index: runtime/vm/simulator_mips.cc
diff --git a/runtime/vm/simulator_mips.cc b/runtime/vm/simulator_mips.cc
index 074fc8c7eb08767fc0c15e7e28f2cb713887b23d..4f00cad57d3678287147a9839dcbcd3e5636f876 100644
--- a/runtime/vm/simulator_mips.cc
+++ b/runtime/vm/simulator_mips.cc
@@ -1888,24 +1888,18 @@ void Simulator::DecodeCop1(Instr* instr) {
             (fs_val <= ft_val) || isnan(fs_val) || isnan(ft_val));
         break;
       }
-      case COP1_CVT_D: {
+      case COP1_TRUNC_W: {
         switch (instr->FormatField()) {
-          case FMT_W: {
-            int32_t fs_int = get_fregister(instr->FsField());
-            double fs_dbl = static_cast<double>(fs_int);
-            set_fregister_double(instr->FdField(), fs_dbl);
-            break;
-          }
-          case FMT_S: {
-            float fs_flt = get_fregister_float(instr->FsField());
-            double fs_dbl = static_cast<double>(fs_flt);
-            set_fregister_double(instr->FdField(), fs_dbl);
-            break;
-          }
-          case FMT_L: {
-            int64_t fs_int = get_fregister_long(instr->FsField());
-            double fs_dbl = static_cast<double>(fs_int);
-            set_fregister_double(instr->FdField(), fs_dbl);
+          case FMT_D: {
+            double fs_dbl = get_fregister_double(instr->FsField());
+            int32_t fs_int;
+            if (isnan(fs_dbl) || isinf(fs_dbl) || (fs_dbl > INT_MAX) ||

[rmacnak, 2016/03/03 22:12:03]

INT_MAX isn't necessarily kInt32Max (although ILP64 systems are rare)

[regis, 2016/03/03 23:14:48]

OK, changed to kMaxInt32 and kMinInt32. But note that we will have many other
locations to fix if we use an ILP64 platform one day.

+                (fs_dbl < INT_MIN)) {
+              fs_int = INT_MIN;

[rmacnak, 2016/03/03 22:12:02]

kMaxInt32

"Otherwise, the default result, 2^31–1, is written to fd"

[regis, 2016/03/03 23:14:48]

Good catch. Fixed. I had simply recycled the existing code for CVT.W, which was
also wrong.

+            } else {
+              fs_int = static_cast<int32_t>(fs_dbl);
+            }
+            set_fregister(instr->FdField(), fs_int);
             break;
           }
           default: {
@@ -1916,18 +1910,18 @@ void Simulator::DecodeCop1(Instr* instr) {
         }
         break;
       }
-      case COP1_CVT_W: {
+      case COP1_CVT_D: {
         switch (instr->FormatField()) {
-          case FMT_D: {
-            double fs_dbl = get_fregister_double(instr->FsField());
-            int32_t fs_int;
-            if (isnan(fs_dbl) || isinf(fs_dbl) || (fs_dbl > INT_MAX) ||
-                (fs_dbl < INT_MIN)) {
-              fs_int = INT_MIN;
-            } else {
-              fs_int = static_cast<int32_t>(fs_dbl);
-            }
-            set_fregister(instr->FdField(), fs_int);
+          case FMT_W: {
+            int32_t fs_int = get_fregister(instr->FsField());
+            double fs_dbl = static_cast<double>(fs_int);
+            set_fregister_double(instr->FdField(), fs_dbl);
+            break;
+          }
+          case FMT_S: {
+            float fs_flt = get_fregister_float(instr->FsField());
+            double fs_dbl = static_cast<double>(fs_flt);
+            set_fregister_double(instr->FdField(), fs_dbl);
             break;
           }
           default: {