PPC/s390: [wasm] Trim graph before scheduling.

src/compiler/s390/instruction-selector-s390.cc

Index: src/compiler/s390/instruction-selector-s390.cc
diff --git a/src/compiler/s390/instruction-selector-s390.cc b/src/compiler/s390/instruction-selector-s390.cc
index f1aa332a493ce44e0fc8aaa4d9598ec3cc8e26b6..84938dfd9f2a7fd8ddca383b69f61f2575848ef1 100644
--- a/src/compiler/s390/instruction-selector-s390.cc
+++ b/src/compiler/s390/instruction-selector-s390.cc
@@ -835,48 +835,69 @@ void InstructionSelector::VisitWord32Sar(Node* node) {
 }
 
 #if !V8_TARGET_ARCH_S390X
-void VisitPairBinop(InstructionSelector* selector, ArchOpcode opcode,
-                    Node* node) {
+void VisitPairBinop(InstructionSelector* selector, InstructionCode opcode,
+                    InstructionCode opcode2, Node* node) {
   S390OperandGenerator g(selector);
 
-  // We use UseUniqueRegister here to avoid register sharing with the output
-  // registers.
-  InstructionOperand inputs[] = {
-      g.UseRegister(node->InputAt(0)), g.UseUniqueRegister(node->InputAt(1)),
-      g.UseRegister(node->InputAt(2)), g.UseUniqueRegister(node->InputAt(3))};
+  Node* projection1 = NodeProperties::FindProjection(node, 1);
+  if (projection1) {
+    // We use UseUniqueRegister here to avoid register sharing with the output
+    // registers.
+    InstructionOperand inputs[] = {
+        g.UseRegister(node->InputAt(0)), g.UseUniqueRegister(node->InputAt(1)),
+        g.UseRegister(node->InputAt(2)), g.UseUniqueRegister(node->InputAt(3))};
 
-  InstructionOperand outputs[] = {
-      g.DefineAsRegister(node),
-      g.DefineAsRegister(NodeProperties::FindProjection(node, 1))};
+    InstructionOperand outputs[] = {
+        g.DefineAsRegister(node),
+        g.DefineAsRegister(NodeProperties::FindProjection(node, 1))};
 
-  selector->Emit(opcode, 2, outputs, 4, inputs);
+    selector->Emit(opcode, 2, outputs, 4, inputs);
+  } else {
+    // The high word of the result is not used, so we emit the standard 32 bit
+    // instruction.
+    selector->Emit(opcode2, g.DefineSameAsFirst(node),
+                   g.UseRegister(node->InputAt(0)),
+                   g.UseRegister(node->InputAt(2)));
+  }
 }
 
 void InstructionSelector::VisitInt32PairAdd(Node* node) {
-  VisitPairBinop(this, kS390_AddPair, node);
+  VisitPairBinop(this, kS390_AddPair, kS390_Add32, node);
 }
 
 void InstructionSelector::VisitInt32PairSub(Node* node) {
-  VisitPairBinop(this, kS390_SubPair, node);
+  VisitPairBinop(this, kS390_SubPair, kS390_Sub32, node);
 }
 
 void InstructionSelector::VisitInt32PairMul(Node* node) {
   S390OperandGenerator g(this);
-  InstructionOperand inputs[] = {g.UseUniqueRegister(node->InputAt(0)),
-                                 g.UseUniqueRegister(node->InputAt(1)),
-                                 g.UseUniqueRegister(node->InputAt(2)),
-                                 g.UseUniqueRegister(node->InputAt(3))};
-
-  InstructionOperand outputs[] = {
-      g.DefineAsRegister(node),
-      g.DefineAsRegister(NodeProperties::FindProjection(node, 1))};
-
-  Emit(kS390_MulPair, 2, outputs, 4, inputs);
+  Node* projection1 = NodeProperties::FindProjection(node, 1);
+  if (projection1) {
+    InstructionOperand inputs[] = {g.UseUniqueRegister(node->InputAt(0)),
+                                   g.UseUniqueRegister(node->InputAt(1)),
+                                   g.UseUniqueRegister(node->InputAt(2)),
+                                   g.UseUniqueRegister(node->InputAt(3))};
+
+    InstructionOperand outputs[] = {
+        g.DefineAsRegister(node),
+        g.DefineAsRegister(NodeProperties::FindProjection(node, 1))};
+
+    Emit(kS390_MulPair, 2, outputs, 4, inputs);
+  } else {
+    // The high word of the result is not used, so we emit the standard 32 bit
+    // instruction.
+    Emit(kS390_Mul32, g.DefineSameAsFirst(node),
+         g.UseRegister(node->InputAt(0)), g.UseRegister(node->InputAt(2)));
+  }
 }
 
-void VisitPairShift(InstructionSelector* selector, ArchOpcode opcode,
+namespace {
+// Shared routine for multiple shift operations.
+void VisitPairShift(InstructionSelector* selector, InstructionCode opcode,
                     Node* node) {
   S390OperandGenerator g(selector);
+  // We use g.UseUniqueRegister here to guarantee that there is
+  // no register aliasing of input registers with output registers.
   Int32Matcher m(node->InputAt(2));
   InstructionOperand shift_operand;
   if (m.HasValue()) {
@@ -885,16 +906,27 @@ void VisitPairShift(InstructionSelector* selector, ArchOpcode opcode,
     shift_operand = g.UseUniqueRegister(m.node());
   }
 
-  InstructionOperand inputs[] = {g.UseRegister(node->InputAt(0)),
-                                 g.UseRegister(node->InputAt(1)),
+  InstructionOperand inputs[] = {g.UseUniqueRegister(node->InputAt(0)),
+                                 g.UseUniqueRegister(node->InputAt(1)),
                                  shift_operand};
 
-  InstructionOperand outputs[] = {
-      g.DefineSameAsFirst(node),
-      g.DefineAsRegister(NodeProperties::FindProjection(node, 1))};
+  Node* projection1 = NodeProperties::FindProjection(node, 1);
 
-  selector->Emit(opcode, 2, outputs, 3, inputs);
+  InstructionOperand outputs[2];
+  InstructionOperand temps[1];
+  int32_t output_count = 0;
+  int32_t temp_count = 0;
+
+  outputs[output_count++] = g.DefineAsRegister(node);
+  if (projection1) {
+    outputs[output_count++] = g.DefineAsRegister(projection1);
+  } else {
+    temps[temp_count++] = g.TempRegister();
+  }
+
+  selector->Emit(opcode, output_count, outputs, 3, inputs, temp_count, temps);
 }
+}  // namespace
 
 void InstructionSelector::VisitWord32PairShl(Node* node) {
   VisitPairShift(this, kS390_ShiftLeftPair, node);