Implements DoubleToI on ARM. Refactor some VFP code at the same time and...

src/arm/lithium-codegen-arm.cc

 // Copyright 2011 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 2648 matching lines @@
     Register input = ToRegister(instr->InputAt(0));
     // Smi check.
     __ JumpIfNotSmi(input, deferred->entry());
     // If smi, handle it directly.
     EmitIntegerMathAbs(instr);
     __ bind(deferred->exit());
   }
 }
 
 
+// Truncates a double using a specific rounding mode.
+// Clears the z flag (ne condition) if an overflow occurs.
+void LCodeGen::EmitVFPTruncate(VFPRoundingMode rounding_mode,
+                               SwVfpRegister result,
+                               DwVfpRegister double_input,
+                               Register scratch1,
+                               Register scratch2) {
+  Register prev_fpscr = scratch1;
+  Register scratch = scratch2;
+
+  // Set custom FPCSR:
+  //  - Set rounding mode.
+  //  - Clear vfp cumulative exception flags.
+  //  - Make sure Flush-to-zero mode control bit is unset.
+  __ vmrs(prev_fpscr);
+  __ bic(scratch, prev_fpscr, Operand(kVFPExceptionMask |
+                                      kVFPRoundingModeMask |
+                                      kVFPFlushToZeroMask));
+  __ orr(scratch, scratch, Operand(rounding_mode));
+  __ vmsr(scratch);
+
+  // Convert the argument to an integer.
+  __ vcvt_s32_f64(result,
+                  double_input,
+                  kFPSCRRounding);
+
+  // Retrieve FPSCR.
+  __ vmrs(scratch);
+  // Restore FPSCR.
+  __ vmsr(prev_fpscr);
+  // Check for vfp exceptions.
+  __ tst(scratch, Operand(kVFPExceptionMask));
+}
+
+
 void LCodeGen::DoMathFloor(LUnaryMathOperation* instr) {
   DoubleRegister input = ToDoubleRegister(instr->InputAt(0));
   Register result = ToRegister(instr->result());
-  Register prev_fpscr = ToRegister(instr->TempAt(0));
   SwVfpRegister single_scratch = double_scratch0().low();
-  Register scratch = scratch0();
+  Register scratch1 = scratch0();
+  Register scratch2 = ToRegister(instr->TempAt(0));
 
-  // Set custom FPCSR:
-  //  - Set rounding mode to "Round towards Minus Infinity".
-  //  - Clear vfp cumulative exception flags.
-  //  - Make sure Flush-to-zero mode control bit is unset.
-  __ vmrs(prev_fpscr);
-  __ bic(scratch, prev_fpscr,
-      Operand(kVFPExceptionMask | kVFPRoundingModeMask | kVFPFlushToZeroMask));
-  __ orr(scratch, scratch, Operand(kVFPRoundToMinusInfinityBits));
-  __ vmsr(scratch);
-
-  // Convert the argument to an integer.
-  __ vcvt_s32_f64(single_scratch,
+  EmitVFPTruncate(kRoundToMinusInf,
+                  single_scratch,
                   input,
-                  Assembler::FPSCRRounding,
-                  al);
-
-  // Retrieve FPSCR and check for vfp exceptions.
-  __ vmrs(scratch);
-  // Restore FPSCR
-  __ vmsr(prev_fpscr);
-  __ tst(scratch, Operand(kVFPExceptionMask));
+                  scratch1,
+                  scratch2);
   DeoptimizeIf(ne, instr->environment());
 
   // Move the result back to general purpose register r0.
   __ vmov(result, single_scratch);
 
   // Test for -0.
   Label done;
   __ cmp(result, Operand(0));
   __ b(ne, &done);
-  __ vmov(scratch, input.high());
-  __ tst(scratch, Operand(HeapNumber::kSignMask));
+  __ vmov(scratch1, input.high());
+  __ tst(scratch1, Operand(HeapNumber::kSignMask));
   DeoptimizeIf(ne, instr->environment());
   __ bind(&done);
 }
 
 
 void LCodeGen::DoMathSqrt(LUnaryMathOperation* instr) {
   DoubleRegister input = ToDoubleRegister(instr->InputAt(0));
   ASSERT(ToDoubleRegister(instr->result()).is(input));
   __ vsqrt(input, input);
 }
@@ skipping 613 matching lines @@
   ASSERT(result->IsDoubleRegister());
 
   Register input_reg = ToRegister(input);
   DoubleRegister result_reg = ToDoubleRegister(result);
 
   EmitNumberUntagD(input_reg, result_reg, instr->environment());
 }
 
 
 void LCodeGen::DoDoubleToI(LDoubleToI* instr) {
-  Abort("DoDoubleToI unimplemented.");
+  LOperand* input = instr->InputAt(0);
+  ASSERT(input->IsDoubleRegister());
+  LOperand* result = instr->result();
+  ASSERT(result->IsRegister());
+
+  DoubleRegister double_input = ToDoubleRegister(input);
+  Register result_reg = ToRegister(result);
+  SwVfpRegister single_scratch = double_scratch0().low();
+  Register scratch1 = scratch0();
+  Register scratch2 = ToRegister(instr->TempAt(0));
+
+  VFPRoundingMode rounding_mode = instr->truncating() ? kRoundToMinusInf
+                                                      : kRoundToNearest;
+
+
+  EmitVFPTruncate(rounding_mode,
+                  single_scratch,
+                  double_input,
+                  scratch1,
+                  scratch2);
+  // Deoptimize if we had a vfp invalid exception.
+  DeoptimizeIf(ne, instr->environment());
+  // Retrieve the result.
+  __ vmov(result_reg, single_scratch);
+
+  if (instr->truncating() &&
+      instr->hydrogen()->CheckFlag(HValue::kBailoutOnMinusZero)) {
+    Label done;
+    __ cmp(result_reg, Operand(0));
+    __ b(ne, &done);
+    // Check for -0.
+    __ vmov(scratch1, double_input.high());
+    __ tst(scratch1, Operand(HeapNumber::kSignMask));
+    DeoptimizeIf(ne, instr->environment());
+
+    __ bind(&done);
+  }
 }
 
 
 void LCodeGen::DoCheckSmi(LCheckSmi* instr) {
   LOperand* input = instr->InputAt(0);
   ASSERT(input->IsRegister());
   __ tst(ToRegister(input), Operand(kSmiTagMask));
   DeoptimizeIf(instr->condition(), instr->environment());
 }
 
@@ skipping 371 matching lines @@
 
 
 void LCodeGen::DoOsrEntry(LOsrEntry* instr) {
   Abort("DoOsrEntry unimplemented.");
 }
 
 
 #undef __
 
 } }  // namespace v8::internal