Implement truncated d-to-i with a stub on x86

test/cctest/test-code-stubs-ia32.cc

+// Copyright 2013 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
+//       with the distribution.
+//     * Neither the name of Google Inc. nor the names of its
+//       contributors may be used to endorse or promote products derived
+//       from this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+#include <stdlib.h>
+
+#include "v8.h"
+
+#include "cctest.h"
+#include "code-stubs.h"
+#include "factory.h"
+#include "macro-assembler.h"
+#include "platform.h"
+
+#if __GNUC__
+#define STDCALL  __attribute__((stdcall))
+#else
+#define STDCALL  __stdcall
+#endif
+
+using namespace v8::internal;
+
+
+typedef int32_t STDCALL (*ConvertDToIFunc)(double input);
+
+
+int STDCALL ConvertDToICVersion(double d) {
+  Address double_ptr = reinterpret_cast<Address>(&d);
+  uint32_t exponent_bits = Memory::uint32_at(double_ptr + kDoubleSize / 2);
+  int32_t shifted_mask = static_cast<int32_t>(Double::kExponentMask >> 32);
+  int32_t exponent = (((exponent_bits & shifted_mask) >>
+                       (Double::kPhysicalSignificandSize - 32)) -
+                      HeapNumber::kExponentBias);
+  uint32_t unsigned_exponent = static_cast<uint32_t>(exponent);
+  int result = 0;
+  uint32_t max_exponent =
+    static_cast<uint32_t>(Double::kPhysicalSignificandSize);
+  if (unsigned_exponent >= max_exponent) {
+    if ((exponent - Double::kPhysicalSignificandSize) < 32) {
+      result = Memory::uint32_at(double_ptr) <<
+        (exponent - Double::kPhysicalSignificandSize);
+    }
+  } else {
+    uint64_t big_result =
+        (BitCast<uint64_t>(d) & Double::kSignificandMask) | Double::kHiddenBit;
+    big_result = big_result >> (Double::kPhysicalSignificandSize - exponent);
+    result = static_cast<uint32_t>(big_result);
+  }
+  if (static_cast<int32_t>(exponent_bits) < 0) {
+    return (0 - result);
+  } else {
+    return result;
+  }
+}
+
+
+void RunOneTruncationTestWithTest(ConvertDToIFunc func,
+                                  double from,
+                                  int64_t to) {
+  int result = (*func)(from);
+  CHECK_EQ(static_cast<int>(to), result);
+}
+
+
+// #define NaN and Infinity so that it's possible to cut-and-paste these tests
+// directly to a .js file and run them.
+#define NaN NAN
+#define Infinity INFINITY
+#define RunOneTruncationTest(p1, p2) RunOneTruncationTestWithTest(func, p1, p2)
+
+void RunAllTruncationTests(ConvertDToIFunc func) {
+  RunOneTruncationTest(0, 0);
+  RunOneTruncationTest(0.5, 0);
+  RunOneTruncationTest(-0.5, 0);
+  RunOneTruncationTest(1.5, 1);
+  RunOneTruncationTest(-1.5, -1);
+  RunOneTruncationTest(5.5, 5);
+  RunOneTruncationTest(-5.0, -5);
+  RunOneTruncationTest(NaN, 0);
+  RunOneTruncationTest(Infinity, 0);
+  RunOneTruncationTest(-NaN, 0);
+  RunOneTruncationTest(-Infinity, 0);
+
+  RunOneTruncationTest(4.5036e+15, 0x1635E000);
+  RunOneTruncationTest(-4.5036e+15, -372629504);
+
+  RunOneTruncationTest(4503603922337791.0, -1);
+  RunOneTruncationTest(-4503603922337791.0, 1);
+  RunOneTruncationTest(4503601774854143.0, 2147483647);
+  RunOneTruncationTest(-4503601774854143.0, -2147483647);
+  RunOneTruncationTest(9007207844675582.0, -2);
+  RunOneTruncationTest(-9007207844675582.0, 2);
+  RunOneTruncationTest(2.4178527921507624e+24, -536870912);
+  RunOneTruncationTest(-2.4178527921507624e+24, 536870912);
+  RunOneTruncationTest(2.417853945072267e+24, -536870912);
+  RunOneTruncationTest(-2.417853945072267e+24, 536870912);
+
+  RunOneTruncationTest(4.8357055843015248e+24, -1073741824);
+  RunOneTruncationTest(-4.8357055843015248e+24, 1073741824);
+  RunOneTruncationTest(4.8357078901445341e+24, -1073741824);
+  RunOneTruncationTest(-4.8357078901445341e+24, 1073741824);
+
+  RunOneTruncationTest(9.6714111686030497e+24, -2147483648.0);
+  RunOneTruncationTest(-9.6714111686030497e+24, -2147483648.0);
+  RunOneTruncationTest(9.6714157802890681e+24, -2147483648.0);
+  RunOneTruncationTest(-9.6714157802890681e+24, -2147483648.0);
+}
+
+#undef NaN
+#undef Infinity
+#undef RunOneTruncationTest
+
+#define __ assm.
+
+ConvertDToIFunc MakeConvertDToIFuncTrampoline(Isolate* isolate,
+                                              Register source_reg,
+                                              Register destination_reg) {
+  // Allocate an executable page of memory.
+  size_t actual_size;
+  byte* buffer = static_cast<byte*>(OS::Allocate(Assembler::kMinimalBufferSize,
+                                                   &actual_size,
+                                                   true));
+  CHECK(buffer);
+  HandleScope handles(isolate);
+  MacroAssembler assm(isolate, buffer, static_cast<int>(actual_size));
+  assm.set_allow_stub_calls(false);
+  int offset =
+    source_reg.is(esp) ? 0 : (HeapNumber::kValueOffset - kSmiTagSize);
+  DoubleToIStub stub(source_reg, destination_reg, offset, true);
+  byte* start = stub.GetCode(isolate)->instruction_start();
+
+  __ push(ebx);
+  __ push(ecx);
+  __ push(edx);
+  __ push(esi);
+  __ push(edi);
+
+  if (!source_reg.is(esp)) {
+    __ lea(source_reg, MemOperand(esp, 6 * kPointerSize - offset));
+  }
+
+  int param_offset = 7 * kPointerSize;
+  // Save registers make sure they don't get clobbered.
+  int reg_num = 0;
+  for (;reg_num < Register::NumAllocatableRegisters(); ++reg_num) {
+    Register reg = Register::from_code(reg_num);
+    if (!reg.is(esp) && !reg.is(ebp) && !reg.is(destination_reg)) {
+      __ push(reg);
+      param_offset += kPointerSize;
+    }
+  }
+
+  // Re-push the double argument
+  __ push(MemOperand(esp, param_offset));
+  __ push(MemOperand(esp, param_offset));
+
+  // Call through to the actual stub
+  __ call(start, RelocInfo::EXTERNAL_REFERENCE);
+
+  __ add(esp, Immediate(kDoubleSize));
+
+  // Make sure no registers have been unexpectedly clobbered
+  for (--reg_num; reg_num >= 0; --reg_num) {
+    Register reg = Register::from_code(reg_num);
+    if (!reg.is(esp) && !reg.is(ebp) && !reg.is(destination_reg)) {
+      __ cmp(reg, MemOperand(esp, 0));
+      __ Assert(equal, "register was clobbered");
+      __ add(esp, Immediate(kPointerSize));
+    }
+  }
+
+  __ mov(eax, destination_reg);
+
+  __ pop(edi);
+  __ pop(esi);
+  __ pop(edx);
+  __ pop(ecx);
+  __ pop(ebx);
+
+  __ ret(kDoubleSize);
+
+  CodeDesc desc;
+  assm.GetCode(&desc);
+  return reinterpret_cast<ConvertDToIFunc>(
+      reinterpret_cast<intptr_t>(buffer));
+}
+
+#undef __
+
+
+static Isolate* GetIsolateFrom(LocalContext* context) {
+  return reinterpret_cast<Isolate*>((*context)->GetIsolate());
+}
+
+
+TEST(ConvertDToI) {
+  CcTest::InitializeVM();
+  LocalContext context;
+  Isolate* isolate = GetIsolateFrom(&context);
+  HandleScope scope(isolate);
+
+#if DEBUG
+  // Verify that the tests actually work with the C version. In the release
+  // code, the compiler optimizes it away because it's all constant, but does it
+  // wrong, triggering an assert on gcc.
+  RunAllTruncationTests(&ConvertDToICVersion);
+#endif
+
+  RunAllTruncationTests(MakeConvertDToIFuncTrampoline(isolate, esp, eax));
+  RunAllTruncationTests(MakeConvertDToIFuncTrampoline(isolate, esp, ebx));
+  RunAllTruncationTests(MakeConvertDToIFuncTrampoline(isolate, esp, ecx));
+  RunAllTruncationTests(MakeConvertDToIFuncTrampoline(isolate, esp, edx));
+  RunAllTruncationTests(MakeConvertDToIFuncTrampoline(isolate, esp, edi));
+  RunAllTruncationTests(MakeConvertDToIFuncTrampoline(isolate, esp, esi));
+  RunAllTruncationTests(MakeConvertDToIFuncTrampoline(isolate, eax, eax));
+  RunAllTruncationTests(MakeConvertDToIFuncTrampoline(isolate, eax, ebx));
+  RunAllTruncationTests(MakeConvertDToIFuncTrampoline(isolate, eax, ecx));
+  RunAllTruncationTests(MakeConvertDToIFuncTrampoline(isolate, eax, edx));
+  RunAllTruncationTests(MakeConvertDToIFuncTrampoline(isolate, eax, edi));
+  RunAllTruncationTests(MakeConvertDToIFuncTrampoline(isolate, eax, esi));
+  RunAllTruncationTests(MakeConvertDToIFuncTrampoline(isolate, ebx, eax));
+  RunAllTruncationTests(MakeConvertDToIFuncTrampoline(isolate, ebx, ebx));
+  RunAllTruncationTests(MakeConvertDToIFuncTrampoline(isolate, ebx, ecx));
+  RunAllTruncationTests(MakeConvertDToIFuncTrampoline(isolate, ebx, edx));
+  RunAllTruncationTests(MakeConvertDToIFuncTrampoline(isolate, ebx, edi));
+  RunAllTruncationTests(MakeConvertDToIFuncTrampoline(isolate, ebx, esi));
+  RunAllTruncationTests(MakeConvertDToIFuncTrampoline(isolate, ecx, eax));
+  RunAllTruncationTests(MakeConvertDToIFuncTrampoline(isolate, ecx, ebx));
+  RunAllTruncationTests(MakeConvertDToIFuncTrampoline(isolate, ecx, ecx));
+  RunAllTruncationTests(MakeConvertDToIFuncTrampoline(isolate, ecx, edx));
+  RunAllTruncationTests(MakeConvertDToIFuncTrampoline(isolate, ecx, edi));
+  RunAllTruncationTests(MakeConvertDToIFuncTrampoline(isolate, ecx, esi));
+  RunAllTruncationTests(MakeConvertDToIFuncTrampoline(isolate, edx, eax));
+  RunAllTruncationTests(MakeConvertDToIFuncTrampoline(isolate, edx, ebx));
+  RunAllTruncationTests(MakeConvertDToIFuncTrampoline(isolate, edx, ecx));
+  RunAllTruncationTests(MakeConvertDToIFuncTrampoline(isolate, edx, edx));
+  RunAllTruncationTests(MakeConvertDToIFuncTrampoline(isolate, edx, edi));
+  RunAllTruncationTests(MakeConvertDToIFuncTrampoline(isolate, edx, esi));
+  RunAllTruncationTests(MakeConvertDToIFuncTrampoline(isolate, esi, eax));
+  RunAllTruncationTests(MakeConvertDToIFuncTrampoline(isolate, esi, ebx));
+  RunAllTruncationTests(MakeConvertDToIFuncTrampoline(isolate, esi, ecx));
+  RunAllTruncationTests(MakeConvertDToIFuncTrampoline(isolate, esi, edx));
+  RunAllTruncationTests(MakeConvertDToIFuncTrampoline(isolate, esi, edi));
+  RunAllTruncationTests(MakeConvertDToIFuncTrampoline(isolate, esi, esi));
+  RunAllTruncationTests(MakeConvertDToIFuncTrampoline(isolate, edi, eax));
+  RunAllTruncationTests(MakeConvertDToIFuncTrampoline(isolate, edi, ebx));
+  RunAllTruncationTests(MakeConvertDToIFuncTrampoline(isolate, edi, ecx));
+  RunAllTruncationTests(MakeConvertDToIFuncTrampoline(isolate, edi, edx));
+  RunAllTruncationTests(MakeConvertDToIFuncTrampoline(isolate, edi, edi));
+  RunAllTruncationTests(MakeConvertDToIFuncTrampoline(isolate, edi, esi));
+}