[tablegen] Handle common load/store predicates inside tablegen. NFC.

Summary:
GlobalISel and SelectionDAG require different code for the common
load/store predicates due to differences in the representation.
For example:
   SelectionDAG: (load<signext,i8>:i32 GPR32:$addr) // The <> denote properties of the SDNode that are not printed in the DAG
   GlobalISel: (G_SEXT:s32 (G_LOAD:s8 GPR32:$addr))
Even without that, differences in the IR (SDNode vs MachineInstr) require
differences in the C++ predicate.

This patch moves the implementation of the common load/store predicates
into tablegen so that it can handle these differences.

It's NFC for SelectionDAG since it emits equivalent code and it's NFC for
GlobalISel since the rules involving the relevant predicates are still
rejected by the importer.

Depends on D36618

Reviewers: ab, qcolombet, t.p.northover, rovka, aditya_nandakumar

Subscribers: llvm-commits, igorb

Differential Revision: https://reviews.llvm.org/D37443

Includes a partial revert of r315826 since this patch makes it necessary for
getPredCode() to return a std::string and getImmCode() should have the same
interface as getPredCode().

llvm-svn: 315841

3 files changed, 276 insertions, 11 deletions

diff --git a/llvm/utils/TableGen/CodeGenDAGPatterns.cpp b/llvm/utils/TableGen/CodeGenDAGPatterns.cpp
index 8987091a162..163977f8e57 100644
--- a/llvm/utils/TableGen/CodeGenDAGPatterns.cpp
+++ b/llvm/utils/TableGen/CodeGenDAGPatterns.cpp
@@ -854,11 +854,129 @@ TreePredicateFn::TreePredicateFn(TreePattern *N) : PatFragRec(N) {
         ".td file corrupt: can't have a node predicate *and* an imm predicate");
 }
 
-StringRef TreePredicateFn::getPredCode() const {
-  return PatFragRec->getRecord()->getValueAsString("PredicateCode");
+std::string TreePredicateFn::getPredCode() const {
+  std::string Code = "";
+
+  if (!isLoad() && !isStore()) {
+    if (isUnindexed())
+      PrintFatalError(getOrigPatFragRecord()->getRecord()->getLoc(),
+                      "IsUnindexed requires IsLoad or IsStore");
+
+    Record *MemoryVT = getMemoryVT();
+    Record *ScalarMemoryVT = getScalarMemoryVT();
+
+    if (MemoryVT)
+      PrintFatalError(getOrigPatFragRecord()->getRecord()->getLoc(),
+                      "MemoryVT requires IsLoad or IsStore");
+    if (ScalarMemoryVT)
+      PrintFatalError(getOrigPatFragRecord()->getRecord()->getLoc(),
+                      "ScalarMemoryVT requires IsLoad or IsStore");
+  }
+
+  if (isLoad() && isStore())
+    PrintFatalError(getOrigPatFragRecord()->getRecord()->getLoc(),
+                    "IsLoad and IsStore are mutually exclusive");
+
+  if (isLoad()) {
+    if (!isUnindexed() && !isNonExtLoad() && !isAnyExtLoad() &&
+        !isSignExtLoad() && !isZeroExtLoad() && getMemoryVT() == nullptr &&
+        getScalarMemoryVT() == nullptr)
+      PrintFatalError(getOrigPatFragRecord()->getRecord()->getLoc(),
+                      "IsLoad cannot be used by itself");
+  } else {
+    if (isNonExtLoad())
+      PrintFatalError(getOrigPatFragRecord()->getRecord()->getLoc(),
+                      "IsNonExtLoad requires IsLoad");
+    if (isAnyExtLoad())
+      PrintFatalError(getOrigPatFragRecord()->getRecord()->getLoc(),
+                      "IsAnyExtLoad requires IsLoad");
+    if (isSignExtLoad())
+      PrintFatalError(getOrigPatFragRecord()->getRecord()->getLoc(),
+                      "IsSignExtLoad requires IsLoad");
+    if (isZeroExtLoad())
+      PrintFatalError(getOrigPatFragRecord()->getRecord()->getLoc(),
+                      "IsZeroExtLoad requires IsLoad");
+  }
+
+  if (isStore()) {
+    if (!isUnindexed() && !isTruncStore() && !isNonTruncStore() &&
+        getMemoryVT() == nullptr && getScalarMemoryVT() == nullptr)
+      PrintFatalError(getOrigPatFragRecord()->getRecord()->getLoc(),
+                      "IsStore cannot be used by itself");
+  } else {
+    if (isNonTruncStore())
+      PrintFatalError(getOrigPatFragRecord()->getRecord()->getLoc(),
+                      "IsNonTruncStore requires IsStore");
+    if (isTruncStore())
+      PrintFatalError(getOrigPatFragRecord()->getRecord()->getLoc(),
+                      "IsTruncStore requires IsStore");
+  }
+
+  if (isLoad() || isStore()) {
+    StringRef SDNodeName = isLoad() ? "LoadSDNode" : "StoreSDNode";
+
+    if (isUnindexed())
+      Code += ("if (cast<" + SDNodeName +
+               ">(N)->getAddressingMode() != ISD::UNINDEXED) "
+               "return false;\n")
+                  .str();
+
+    if (isLoad()) {
+      if ((isNonExtLoad() + isAnyExtLoad() + isSignExtLoad() +
+           isZeroExtLoad()) > 1)
+        PrintFatalError(getOrigPatFragRecord()->getRecord()->getLoc(),
+                        "IsNonExtLoad, IsAnyExtLoad, IsSignExtLoad, and "
+                        "IsZeroExtLoad are mutually exclusive");
+      if (isNonExtLoad())
+        Code += "if (cast<LoadSDNode>(N)->getExtensionType() != "
+                "ISD::NON_EXTLOAD) return false;\n";
+      if (isAnyExtLoad())
+        Code += "if (cast<LoadSDNode>(N)->getExtensionType() != ISD::EXTLOAD) "
+                "return false;\n";
+      if (isSignExtLoad())
+        Code += "if (cast<LoadSDNode>(N)->getExtensionType() != ISD::SEXTLOAD) "
+                "return false;\n";
+      if (isZeroExtLoad())
+        Code += "if (cast<LoadSDNode>(N)->getExtensionType() != ISD::ZEXTLOAD) "
+                "return false;\n";
+    } else {
+      if ((isNonTruncStore() + isTruncStore()) > 1)
+        PrintFatalError(
+            getOrigPatFragRecord()->getRecord()->getLoc(),
+            "IsNonTruncStore, and IsTruncStore are mutually exclusive");
+      if (isNonTruncStore())
+        Code +=
+            " if (cast<StoreSDNode>(N)->isTruncatingStore()) return false;\n";
+      if (isTruncStore())
+        Code +=
+            " if (!cast<StoreSDNode>(N)->isTruncatingStore()) return false;\n";
+    }
+
+    Record *MemoryVT = getMemoryVT();
+    Record *ScalarMemoryVT = getScalarMemoryVT();
+
+    if (MemoryVT)
+      Code += ("if (cast<" + SDNodeName + ">(N)->getMemoryVT() != MVT::" +
+               MemoryVT->getName() + ") return false;\n")
+                  .str();
+    if (ScalarMemoryVT)
+      Code += ("if (cast<" + SDNodeName +
+               ">(N)->getMemoryVT().getScalarType() != MVT::" +
+               ScalarMemoryVT->getName() + ") return false;\n")
+                  .str();
+  }
+
+  std::string PredicateCode = PatFragRec->getRecord()->getValueAsString("PredicateCode");
+
+  Code += PredicateCode;
+
+  if (PredicateCode.empty() && !Code.empty())
+    Code += "return true;\n";
+
+  return Code;
 }
 
-StringRef TreePredicateFn::getImmCode() const {
+std::string TreePredicateFn::getImmCode() const {
   return PatFragRec->getRecord()->getValueAsString("ImmediateCode");
 }
 
@@ -873,6 +991,55 @@ bool TreePredicateFn::immCodeUsesAPFloat() const {
                                                                    Unset);
 }
 
+bool TreePredicateFn::isPredefinedPredicateEqualTo(StringRef Field,
+                                                   bool Value) const {
+  bool Unset;
+  bool Result =
+      getOrigPatFragRecord()->getRecord()->getValueAsBitOrUnset(Field, Unset);
+  if (Unset)
+    return false;
+  return Result == Value;
+}
+bool TreePredicateFn::isLoad() const {
+  return isPredefinedPredicateEqualTo("IsLoad", true);
+}
+bool TreePredicateFn::isStore() const {
+  return isPredefinedPredicateEqualTo("IsStore", true);
+}
+bool TreePredicateFn::isUnindexed() const {
+  return isPredefinedPredicateEqualTo("IsUnindexed", true);
+}
+bool TreePredicateFn::isNonExtLoad() const {
+  return isPredefinedPredicateEqualTo("IsNonExtLoad", true);
+}
+bool TreePredicateFn::isAnyExtLoad() const {
+  return isPredefinedPredicateEqualTo("IsAnyExtLoad", true);
+}
+bool TreePredicateFn::isSignExtLoad() const {
+  return isPredefinedPredicateEqualTo("IsSignExtLoad", true);
+}
+bool TreePredicateFn::isZeroExtLoad() const {
+  return isPredefinedPredicateEqualTo("IsZeroExtLoad", true);
+}
+bool TreePredicateFn::isNonTruncStore() const {
+  return isPredefinedPredicateEqualTo("IsTruncStore", false);
+}
+bool TreePredicateFn::isTruncStore() const {
+  return isPredefinedPredicateEqualTo("IsTruncStore", true);
+}
+Record *TreePredicateFn::getMemoryVT() const {
+  Record *R = getOrigPatFragRecord()->getRecord();
+  if (R->isValueUnset("MemoryVT"))
+    return nullptr;
+  return R->getValueAsDef("MemoryVT");
+}
+Record *TreePredicateFn::getScalarMemoryVT() const {
+  Record *R = getOrigPatFragRecord()->getRecord();
+  if (R->isValueUnset("ScalarMemoryVT"))
+    return nullptr;
+  return R->getValueAsDef("ScalarMemoryVT");
+}
+
 StringRef TreePredicateFn::getImmType() const {
   if (immCodeUsesAPInt())
     return "const APInt &";
@@ -906,16 +1073,58 @@ std::string TreePredicateFn::getFnName() const {
 /// appropriate.
 std::string TreePredicateFn::getCodeToRunOnSDNode() const {
   // Handle immediate predicates first.
-  StringRef ImmCode = getImmCode();
+  std::string ImmCode = getImmCode();
   if (!ImmCode.empty()) {
-    std::string Result = "    " + getImmType().str() + " Imm = ";
+    if (isLoad())
+      PrintFatalError(getOrigPatFragRecord()->getRecord()->getLoc(),
+                      "IsLoad cannot be used with ImmLeaf or its subclasses");
+    if (isStore())
+      PrintFatalError(getOrigPatFragRecord()->getRecord()->getLoc(),
+                      "IsStore cannot be used with ImmLeaf or its subclasses");
+    if (isUnindexed())
+      PrintFatalError(
+          getOrigPatFragRecord()->getRecord()->getLoc(),
+          "IsUnindexed cannot be used with ImmLeaf or its subclasses");
+    if (isNonExtLoad())
+      PrintFatalError(
+          getOrigPatFragRecord()->getRecord()->getLoc(),
+          "IsNonExtLoad cannot be used with ImmLeaf or its subclasses");
+    if (isAnyExtLoad())
+      PrintFatalError(
+          getOrigPatFragRecord()->getRecord()->getLoc(),
+          "IsAnyExtLoad cannot be used with ImmLeaf or its subclasses");
+    if (isSignExtLoad())
+      PrintFatalError(
+          getOrigPatFragRecord()->getRecord()->getLoc(),
+          "IsSignExtLoad cannot be used with ImmLeaf or its subclasses");
+    if (isZeroExtLoad())
+      PrintFatalError(
+          getOrigPatFragRecord()->getRecord()->getLoc(),
+          "IsZeroExtLoad cannot be used with ImmLeaf or its subclasses");
+    if (isNonTruncStore())
+      PrintFatalError(
+          getOrigPatFragRecord()->getRecord()->getLoc(),
+          "IsNonTruncStore cannot be used with ImmLeaf or its subclasses");
+    if (isTruncStore())
+      PrintFatalError(
+          getOrigPatFragRecord()->getRecord()->getLoc(),
+          "IsTruncStore cannot be used with ImmLeaf or its subclasses");
+    if (getMemoryVT())
+      PrintFatalError(getOrigPatFragRecord()->getRecord()->getLoc(),
+                      "MemoryVT cannot be used with ImmLeaf or its subclasses");
+    if (getScalarMemoryVT())
+      PrintFatalError(
+          getOrigPatFragRecord()->getRecord()->getLoc(),
+          "ScalarMemoryVT cannot be used with ImmLeaf or its subclasses");
+
+    std::string Result = ("    " + getImmType() + " Imm = ").str();
     if (immCodeUsesAPFloat())
       Result += "cast<ConstantFPSDNode>(Node)->getValueAPF();\n";
     else if (immCodeUsesAPInt())
       Result += "cast<ConstantSDNode>(Node)->getAPIntValue();\n";
     else
       Result += "cast<ConstantSDNode>(Node)->getSExtValue();\n";
-    return Result + ImmCode.str();
+    return Result + ImmCode;
   }
 
   // Handle arbitrary node predicates.
@@ -933,7 +1142,7 @@ std::string TreePredicateFn::getCodeToRunOnSDNode() const {
   else
     Result = "    auto *N = cast<" + ClassName.str() + ">(Node);\n";
 
-  return Result + getPredCode().str();
+  return Result + getPredCode();
 }
 
 //===----------------------------------------------------------------------===//
diff --git a/llvm/utils/TableGen/CodeGenDAGPatterns.h b/llvm/utils/TableGen/CodeGenDAGPatterns.h
index 2103e154dad..5b047bc182d 100644
--- a/llvm/utils/TableGen/CodeGenDAGPatterns.h
+++ b/llvm/utils/TableGen/CodeGenDAGPatterns.h
@@ -452,8 +452,8 @@ public:
   /// getImmediatePredicateCode - Return the code that evaluates this pattern if
   /// this is an immediate predicate.  It is an error to call this on a
   /// non-immediate pattern.
-  StringRef getImmediatePredicateCode() const {
-    StringRef Result = getImmCode();
+  std::string getImmediatePredicateCode() const {
+    std::string Result = getImmCode();
     assert(!Result.empty() && "Isn't an immediate pattern!");
     return Result;
   }
@@ -481,11 +481,42 @@ public:
   /// usable as part of an identifier.
   StringRef getImmTypeIdentifier() const;
 
+  // Is the desired predefined predicate for a load?
+  bool isLoad() const;
+  // Is the desired predefined predicate for a store?
+  bool isStore() const;
+
+  /// Is this predicate the predefined unindexed load predicate?
+  /// Is this predicate the predefined unindexed store predicate?
+  bool isUnindexed() const;
+  /// Is this predicate the predefined non-extending load predicate?
+  bool isNonExtLoad() const;
+  /// Is this predicate the predefined any-extend load predicate?
+  bool isAnyExtLoad() const;
+  /// Is this predicate the predefined sign-extend load predicate?
+  bool isSignExtLoad() const;
+  /// Is this predicate the predefined zero-extend load predicate?
+  bool isZeroExtLoad() const;
+  /// Is this predicate the predefined non-truncating store predicate?
+  bool isNonTruncStore() const;
+  /// Is this predicate the predefined truncating store predicate?
+  bool isTruncStore() const;
+
+  /// If non-null, indicates that this predicate is a predefined memory VT
+  /// predicate for a load/store and returns the ValueType record for the memory VT.
+  Record *getMemoryVT() const;
+  /// If non-null, indicates that this predicate is a predefined memory VT
+  /// predicate (checking only the scalar type) for load/store and returns the
+  /// ValueType record for the memory VT.
+  Record *getScalarMemoryVT() const;
+
 private:
-  StringRef getPredCode() const;
-  StringRef getImmCode() const;
+  std::string getPredCode() const;
+  std::string getImmCode() const;
   bool immCodeUsesAPInt() const;
   bool immCodeUsesAPFloat() const;
+
+  bool isPredefinedPredicateEqualTo(StringRef Field, bool Value) const;
 };
 
 
diff --git a/llvm/utils/TableGen/GlobalISelEmitter.cpp b/llvm/utils/TableGen/GlobalISelEmitter.cpp
index b595143701a..467ae40e51d 100644
--- a/llvm/utils/TableGen/GlobalISelEmitter.cpp
+++ b/llvm/utils/TableGen/GlobalISelEmitter.cpp
@@ -170,6 +170,28 @@ static std::string explainPredicates(const TreePatternNode *N) {
       Explanation += " always-true";
     if (P.isImmediatePattern())
       Explanation += " immediate";
+
+    if (P.isUnindexed())
+      Explanation += " unindexed";
+
+    if (P.isNonExtLoad())
+      Explanation += " non-extload";
+    if (P.isAnyExtLoad())
+      Explanation += " extload";
+    if (P.isSignExtLoad())
+      Explanation += " sextload";
+    if (P.isZeroExtLoad())
+      Explanation += " zextload";
+
+    if (P.isNonTruncStore())
+      Explanation += " non-truncstore";
+    if (P.isTruncStore())
+      Explanation += " truncstore";
+
+    if (Record *VT = P.getMemoryVT())
+      Explanation += (" MemVT=" + VT->getName()).str();
+    if (Record *VT = P.getScalarMemoryVT())
+      Explanation += (" ScalarVT(MemVT)=" + VT->getName()).str();
   }
   return Explanation;
 }
@@ -204,6 +226,9 @@ static Error isTrivialOperatorNode(const TreePatternNode *N) {
     HasUnsupportedPredicate = true;
     Explanation = Separator + "Has a predicate (" + explainPredicates(N) + ")";
     Separator = ", ";
+    Explanation += (Separator + "first-failing:" +
+                    Predicate.getOrigPatFragRecord()->getRecord()->getName())
+                       .str();
     break;
   }