MIPS: Support for DoubleToIStub (truncating).

src/mips/code-stubs-mips.cc

 // 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 503 matching lines @@
   // Compute lower part of fraction (last 12 bits).
   __ sll(mantissa, source_, HeapNumber::kMantissaBitsInTopWord);
   // And the top (top 20 bits).
   __ srl(source_, source_, 32 - HeapNumber::kMantissaBitsInTopWord);
 
   __ Ret(USE_DELAY_SLOT);
   __ or_(exponent, exponent, source_);
 }
 
 
+void DoubleToIStub::Generate(MacroAssembler* masm) {
+  Label out_of_range, only_low, negate, done;
+  Register input_reg = source();
+  Register result_reg = destination();
+
+  int double_offset = offset();
+  // Account for saved regs if input is sp.
+  if (input_reg.is(sp)) double_offset += 3 * kPointerSize;
+
+  Register scratch =
+      GetRegisterThatIsNotOneOf(input_reg, result_reg);
+  Register scratch2 =
+      GetRegisterThatIsNotOneOf(input_reg, result_reg, scratch);
+  Register scratch3 =
+      GetRegisterThatIsNotOneOf(input_reg, result_reg, scratch, scratch2);
+  DoubleRegister double_scratch = kLithiumScratchDouble.low();
+  DoubleRegister double_input = f12;
+
+  __ Push(scratch, scratch2, scratch3);
+
+  __ ldc1(double_input, MemOperand(input_reg, double_offset));
+
+  if (!skip_fastpath()) {
+    // Clear cumulative exception flags and save the FCSR.
+    __ cfc1(scratch2, FCSR);
+    __ ctc1(zero_reg, FCSR);
+    // Try a conversion to a signed integer.
+    __ trunc_w_d(double_scratch, double_input);
+    __ mfc1(result_reg, double_scratch);
+    // Retrieve and restore the FCSR.
+    __ cfc1(scratch, FCSR);
+    __ ctc1(scratch2, FCSR);
+    // Check for overflow and NaNs.
+    __ And(
+        scratch, scratch,
+        kFCSROverflowFlagMask | kFCSRUnderflowFlagMask
+           | kFCSRInvalidOpFlagMask);
+    // If we had no exceptions we are done.
+    __ Branch(&done, eq, scratch, Operand(zero_reg));
+  }
+
+  // Load the double value and perform a manual truncation.
+  Register input_high = scratch2;
+  Register input_low = scratch3;
+  __ Move(input_low, input_high, double_input);
+
+  __ EmitOutOfInt32RangeTruncate(result_reg,
+                                 input_high,
+                                 input_low,
+                                 scratch);
+
+  __ bind(&done);
+
+  __ Pop(scratch, scratch2, scratch3);
+  __ Ret();
+}
+
+
 bool WriteInt32ToHeapNumberStub::IsPregenerated() {
   // These variants are compiled ahead of time.  See next method.
   if (the_int_.is(a1) &&
       the_heap_number_.is(v0) &&
       scratch_.is(a2) &&
       sign_.is(a3)) {
     return true;
   }
   if (the_int_.is(a2) &&
       the_heap_number_.is(v0) &&
@@ skipping 991 matching lines @@
     case Token::BIT_XOR:
     case Token::BIT_AND:
     case Token::SAR:
     case Token::SHR:
     case Token::SHL: {
       if (smi_operands) {
         __ SmiUntag(a3, left);
         __ SmiUntag(a2, right);
       } else {
         // Convert operands to 32-bit integers. Right in a2 and left in a3.
-        __ ConvertNumberToInt32(
+        __ TruncateNumberToI(
             left, a3, heap_number_map,
-            scratch1, scratch2, scratch3, f0, not_numbers);
-        __ ConvertNumberToInt32(
+            scratch1, scratch2, scratch3, not_numbers);
+        __ TruncateNumberToI(
             right, a2, heap_number_map,
-            scratch1, scratch2, scratch3, f0, not_numbers);
+            scratch1, scratch2, scratch3, not_numbers);
       }
       Label result_not_a_smi;
       switch (op) {
         case Token::BIT_OR:
           __ Or(a2, a3, Operand(a2));
           break;
         case Token::BIT_XOR:
           __ Xor(a2, a3, Operand(a2));
           break;
         case Token::BIT_AND:
@@ skipping 5581 matching lines @@
   __ bind(&fast_elements_case);
   GenerateCase(masm, FAST_ELEMENTS);
 }
 
 
 #undef __
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_MIPS