1 files changed, 262 insertions, 0 deletions
diff --git a/js/src/jsapi-tests/testJitFoldsTo.cpp b/js/src/jsapi-tests/testJitFoldsTo.cpp
new file mode 100644
index 0000000000..9537e1dcf7
--- /dev/null
+++ b/js/src/jsapi-tests/testJitFoldsTo.cpp
@@ -0,0 +1,262 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*-
+ * vim: set ts=8 sts=2 et sw=2 tw=80:
+ */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "jit/IonAnalysis.h"
+#include "jit/MIRGenerator.h"
+#include "jit/MIRGraph.h"
+#include "jit/ValueNumbering.h"
+
+#include "jsapi-tests/testJitMinimalFunc.h"
+#include "jsapi-tests/tests.h"
+
+using namespace js;
+using namespace js::jit;
+
+BEGIN_TEST(testJitFoldsTo_DivReciprocal) {
+  MinimalFunc func;
+  MBasicBlock* block = func.createEntryBlock();
+
+  // return p / 4.0
+  MParameter* p = func.createParameter();
+  block->add(p);
+  MConstant* c = MConstant::New(func.alloc, DoubleValue(4.0));
+  block->add(c);
+  MDiv* div = MDiv::New(func.alloc, p, c, MIRType::Double);
+  block->add(div);
+  if (!div->typePolicy()->adjustInputs(func.alloc, div)) {
+    return false;
+  }
+  MDefinition* left = div->getOperand(0);
+  MReturn* ret = MReturn::New(func.alloc, div);
+  block->end(ret);
+
+  if (!func.runGVN()) {
+    return false;
+  }
+
+  // Test that the div got folded to p * 0.25.
+  MDefinition* op = ret->getOperand(0);
+  CHECK(op->isMul());
+  CHECK(op->getOperand(0) == left);
+  CHECK(op->getOperand(1)->isConstant());
+  CHECK(op->getOperand(1)->toConstant()->numberToDouble() == 0.25);
+  return true;
+}
+END_TEST(testJitFoldsTo_DivReciprocal)
+
+BEGIN_TEST(testJitFoldsTo_NoDivReciprocal) {
+  MinimalFunc func;
+  MBasicBlock* block = func.createEntryBlock();
+
+  // return p / 5.0
+  MParameter* p = func.createParameter();
+  block->add(p);
+  MConstant* c = MConstant::New(func.alloc, DoubleValue(5.0));
+  block->add(c);
+  MDiv* div = MDiv::New(func.alloc, p, c, MIRType::Double);
+  block->add(div);
+  if (!div->typePolicy()->adjustInputs(func.alloc, div)) {
+    return false;
+  }
+  MDefinition* left = div->getOperand(0);
+  MDefinition* right = div->getOperand(1);
+  MReturn* ret = MReturn::New(func.alloc, div);
+  block->end(ret);
+
+  if (!func.runGVN()) {
+    return false;
+  }
+
+  // Test that the div didn't get folded.
+  MDefinition* op = ret->getOperand(0);
+  CHECK(op->isDiv());
+  CHECK(op->getOperand(0) == left);
+  CHECK(op->getOperand(1) == right);
+  return true;
+}
+END_TEST(testJitFoldsTo_NoDivReciprocal)
+
+BEGIN_TEST(testJitNotNot) {
+  MinimalFunc func;
+  MBasicBlock* block = func.createEntryBlock();
+
+  // return Not(Not(p))
+  MParameter* p = func.createParameter();
+  block->add(p);
+  MNot* not0 = MNot::New(func.alloc, p);
+  block->add(not0);
+  MNot* not1 = MNot::New(func.alloc, not0);
+  block->add(not1);
+  MReturn* ret = MReturn::New(func.alloc, not1);
+  block->end(ret);
+
+  if (!func.runGVN()) {
+    return false;
+  }
+
+  // Test that the nots did not get folded.
+  MDefinition* op = ret->getOperand(0);
+  CHECK(op->isNot());
+  CHECK(op->getOperand(0)->isNot());
+  CHECK(op->getOperand(0)->getOperand(0) == p);
+  return true;
+}
+END_TEST(testJitNotNot)
+
+BEGIN_TEST(testJitNotNotNot) {
+  MinimalFunc func;
+  MBasicBlock* block = func.createEntryBlock();
+
+  // return Not(Not(Not(p)))
+  MParameter* p = func.createParameter();
+  block->add(p);
+  MNot* not0 = MNot::New(func.alloc, p);
+  block->add(not0);
+  MNot* not1 = MNot::New(func.alloc, not0);
+  block->add(not1);
+  MNot* not2 = MNot::New(func.alloc, not1);
+  block->add(not2);
+  MReturn* ret = MReturn::New(func.alloc, not2);
+  block->end(ret);
+
+  if (!func.runGVN()) {
+    return false;
+  }
+
+  // Test that the nots got folded.
+  MDefinition* op = ret->getOperand(0);
+  CHECK(op->isNot());
+  CHECK(op->getOperand(0) == p);
+  return true;
+}
+END_TEST(testJitNotNotNot)
+
+BEGIN_TEST(testJitNotTest) {
+  MinimalFunc func;
+  MBasicBlock* block = func.createEntryBlock();
+  MBasicBlock* then = func.createBlock(block);
+  MBasicBlock* else_ = func.createBlock(block);
+  MBasicBlock* exit = func.createBlock(block);
+
+  // MTest(Not(p))
+  MParameter* p = func.createParameter();
+  block->add(p);
+  MNot* not0 = MNot::New(func.alloc, p);
+  block->add(not0);
+  MTest* test = MTest::New(func.alloc, not0, then, else_);
+  block->end(test);
+
+  then->end(MGoto::New(func.alloc, exit));
+
+  else_->end(MGoto::New(func.alloc, exit));
+
+  MReturn* ret = MReturn::New(func.alloc, p);
+  exit->end(ret);
+
+  MOZ_ALWAYS_TRUE(exit->addPredecessorWithoutPhis(then));
+
+  if (!func.runGVN()) {
+    return false;
+  }
+
+  // Test that the not got folded.
+  test = block->lastIns()->toTest();
+  CHECK(test->getOperand(0) == p);
+  CHECK(test->getSuccessor(0) == else_);
+  CHECK(test->getSuccessor(1) == then);
+  return true;
+}
+END_TEST(testJitNotTest)
+
+BEGIN_TEST(testJitNotNotTest) {
+  MinimalFunc func;
+  MBasicBlock* block = func.createEntryBlock();
+  MBasicBlock* then = func.createBlock(block);
+  MBasicBlock* else_ = func.createBlock(block);
+  MBasicBlock* exit = func.createBlock(block);
+
+  // MTest(Not(Not(p)))
+  MParameter* p = func.createParameter();
+  block->add(p);
+  MNot* not0 = MNot::New(func.alloc, p);
+  block->add(not0);
+  MNot* not1 = MNot::New(func.alloc, not0);
+  block->add(not1);
+  MTest* test = MTest::New(func.alloc, not1, then, else_);
+  block->end(test);
+
+  then->end(MGoto::New(func.alloc, exit));
+
+  else_->end(MGoto::New(func.alloc, exit));
+
+  MReturn* ret = MReturn::New(func.alloc, p);
+  exit->end(ret);
+
+  MOZ_ALWAYS_TRUE(exit->addPredecessorWithoutPhis(then));
+
+  if (!func.runGVN()) {
+    return false;
+  }
+
+  // Test that the nots got folded.
+  test = block->lastIns()->toTest();
+  CHECK(test->getOperand(0) == p);
+  CHECK(test->getSuccessor(0) == then);
+  CHECK(test->getSuccessor(1) == else_);
+  return true;
+}
+END_TEST(testJitNotNotTest)
+
+BEGIN_TEST(testJitFoldsTo_UnsignedDiv) {
+  MinimalFunc func;
+  MBasicBlock* block = func.createEntryBlock();
+
+  // return 1.0 / 0xffffffff
+  MConstant* c0 = MConstant::New(func.alloc, Int32Value(1));
+  block->add(c0);
+  MConstant* c1 = MConstant::New(func.alloc, Int32Value(0xffffffff));
+  block->add(c1);
+  MDiv* div = MDiv::New(func.alloc, c0, c1, MIRType::Int32, /*unsignd=*/true);
+  block->add(div);
+  MReturn* ret = MReturn::New(func.alloc, div);
+  block->end(ret);
+
+  if (!func.runGVN()) {
+    return false;
+  }
+
+  // Test that the div got folded to 0.
+  MConstant* op = ret->getOperand(0)->toConstant();
+  CHECK(mozilla::NumbersAreIdentical(op->numberToDouble(), 0.0));
+  return true;
+}
+END_TEST(testJitFoldsTo_UnsignedDiv)
+
+BEGIN_TEST(testJitFoldsTo_UnsignedMod) {
+  MinimalFunc func;
+  MBasicBlock* block = func.createEntryBlock();
+
+  // return 1.0 % 0xffffffff
+  MConstant* c0 = MConstant::New(func.alloc, Int32Value(1));
+  block->add(c0);
+  MConstant* c1 = MConstant::New(func.alloc, Int32Value(0xffffffff));
+  block->add(c1);
+  MMod* mod = MMod::New(func.alloc, c0, c1, MIRType::Int32, /*unsignd=*/true);
+  block->add(mod);
+  MReturn* ret = MReturn::New(func.alloc, mod);
+  block->end(ret);
+
+  if (!func.runGVN()) {
+    return false;
+  }
+
+  // Test that the mod got folded to 1.
+  MConstant* op = ret->getOperand(0)->toConstant();
+  CHECK(mozilla::NumbersAreIdentical(op->numberToDouble(), 1.0));
+  return true;
+}
+END_TEST(testJitFoldsTo_UnsignedMod)