X87: [turbofan] Support subtraction displacements in BaseWithIndexAndDisplacementMatcher.

  port 574f6fe1 (r37701)

  original commit message:
  Previously, the following schedule fragment:

   1: Parameter[0](0)
   2: Parameter[1](0)
   7: Int32Constant[1]
   8: Int32Sub(2, 7)
   9: Load[kRepTagged|kTypeAny](1, 8)

  would generate the following code (on ia32):

   mov eax,[ebp+0x8]
   mov ecx,[ebp+0xc]
   sub eax,0x1
   mov eax,[eax+ecx*1]

  Now it generates:

   mov eax,[ebp+0x8]
   mov ecx,[ebp+0xc]
   mov eax,[eax+ecx*1-1]

  Similar pattern matching also now works on x64.

BUG=

Review-Url: https://codereview.chromium.org/2151753002
Cr-Commit-Position: refs/heads/master@{#37738}

src/compiler/x87/instruction-selector-x87.cc

@@ -86,12 +86,16 @@ class X87OperandGenerator final : public OperandGenerator {
 
   AddressingMode GenerateMemoryOperandInputs(Node* index, int scale, Node* base,
                                              Node* displacement_node,
+                                             DisplacementMode displacement_mode,
                                              InstructionOperand inputs[],
                                              size_t* input_count) {
     AddressingMode mode = kMode_MRI;
     int32_t displacement = (displacement_node == nullptr)
                                ? 0
                                : OpParameter<int32_t>(displacement_node);
+    if (displacement_mode == kNegativeDisplacement) {
+      displacement = -displacement;
+    }
     if (base != nullptr) {
       if (base->opcode() == IrOpcode::kInt32Constant) {
         displacement += OpParameter<int32_t>(base);
@@ -149,8 +153,9 @@ class X87OperandGenerator final : public OperandGenerator {
     BaseWithIndexAndDisplacement32Matcher m(node, true);
     DCHECK(m.matches());
     if ((m.displacement() == nullptr || CanBeImmediate(m.displacement()))) {
-      return GenerateMemoryOperandInputs(m.index(), m.scale(), m.base(),
-                                         m.displacement(), inputs, input_count);
+      return GenerateMemoryOperandInputs(
+          m.index(), m.scale(), m.base(), m.displacement(),
+          m.displacement_mode(), inputs, input_count);
     } else {
       inputs[(*input_count)++] = UseRegister(node->InputAt(0));
       inputs[(*input_count)++] = UseRegister(node->InputAt(1));
@@ -538,12 +543,14 @@ void VisitMod(InstructionSelector* selector, Node* node, ArchOpcode opcode) {
 }
 
 void EmitLea(InstructionSelector* selector, Node* result, Node* index,
-             int scale, Node* base, Node* displacement) {
+             int scale, Node* base, Node* displacement,
+             DisplacementMode displacement_mode) {
   X87OperandGenerator g(selector);
   InstructionOperand inputs[4];
   size_t input_count = 0;
-  AddressingMode mode = g.GenerateMemoryOperandInputs(
-      index, scale, base, displacement, inputs, &input_count);
+  AddressingMode mode =
+      g.GenerateMemoryOperandInputs(index, scale, base, displacement,
+                                    displacement_mode, inputs, &input_count);
 
   DCHECK_NE(0u, input_count);
   DCHECK_GE(arraysize(inputs), input_count);
@@ -564,7 +571,7 @@ void InstructionSelector::VisitWord32Shl(Node* node) {
   if (m.matches()) {
     Node* index = node->InputAt(0);
     Node* base = m.power_of_two_plus_one() ? index : nullptr;
-    EmitLea(this, node, index, m.scale(), base, nullptr);
+    EmitLea(this, node, index, m.scale(), base, nullptr, kPositiveDisplacement);
     return;
   }
   VisitShift(this, node, kX87Shl);
@@ -701,7 +708,8 @@ void InstructionSelector::VisitInt32Add(Node* node) {
     InstructionOperand inputs[4];
     size_t input_count = 0;
     AddressingMode mode = g.GenerateMemoryOperandInputs(
-        m.index(), m.scale(), m.base(), m.displacement(), inputs, &input_count);
+        m.index(), m.scale(), m.base(), m.displacement(), m.displacement_mode(),
+        inputs, &input_count);
 
     DCHECK_NE(0u, input_count);
     DCHECK_GE(arraysize(inputs), input_count);
@@ -735,7 +743,7 @@ void InstructionSelector::VisitInt32Mul(Node* node) {
   if (m.matches()) {
     Node* index = node->InputAt(0);
     Node* base = m.power_of_two_plus_one() ? index : nullptr;
-    EmitLea(this, node, index, m.scale(), base, nullptr);
+    EmitLea(this, node, index, m.scale(), base, nullptr, kPositiveDisplacement);
     return;
   }
   X87OperandGenerator g(this);