From f72c9754301e2a2edfd122aeb96861ea2a62f49b Mon Sep 17 00:00:00 2001
From: Eric Schweitz <eschweitz@nvidia.com>
Date: Wed, 27 Oct 2021 11:22:22 -0700
Subject: [PATCH] Convert DenseMap to use value-based hashing and comparison.
 Add some more implementations. Second attempt to get rid of warning.

---
 flang/lib/Lower/IterationSpace.cpp | 39 ++++++++++++++++++++----------
 flang/lib/Lower/IterationSpace.h   | 28 +++++++++++++++++++--
 2 files changed, 52 insertions(+), 15 deletions(-)

diff --git a/flang/lib/Lower/IterationSpace.cpp b/flang/lib/Lower/IterationSpace.cpp
index 7739eb0fe7c5c8..b9bcbf1ece0ae0 100644
--- a/flang/lib/Lower/IterationSpace.cpp
+++ b/flang/lib/Lower/IterationSpace.cpp
@@ -208,7 +208,7 @@ class HashEvaluateExpr {
     unsigned args = 13u;
     for (const auto &v : x.arguments())
       args -= getHashValue(v);
-    return getHashValue(x.proc()) * 101u;
+    return getHashValue(x.proc()) * 101u - args;
   }
   template <typename A>
   static unsigned
@@ -217,16 +217,15 @@ class HashEvaluateExpr {
     return 127u;
   }
   static unsigned getHashValue(const Fortran::evaluate::ImpliedDoIndex &x) {
-    // FIXME: hash the contents.
-    return 131u;
+    return llvm::hash_value(toStringRef(x.name).str()) * 131u;
   }
   static unsigned getHashValue(const Fortran::evaluate::TypeParamInquiry &x) {
-    // FIXME: hash the contents.
-    return 137u;
+    return getHashValue(x.base()) * 137u - getHashValue(x.parameter()) * 3u;
   }
   static unsigned getHashValue(const Fortran::evaluate::DescriptorInquiry &x) {
-    // FIXME: hash the contents.
-    return 139u;
+    return getHashValue(x.base()) * 139u -
+           static_cast<unsigned>(x.field()) * 13u +
+           static_cast<unsigned>(x.dimension());
   }
   static unsigned
   getHashValue(const Fortran::evaluate::StructureConstructor &x) {
@@ -280,6 +279,10 @@ unsigned Fortran::lower::getHashValue(
       [&](const auto *p) { return HashEvaluateExpr::getHashValue(*p); }, x);
 }
 
+unsigned Fortran::lower::getHashValue(Fortran::lower::FrontEndExpr x) {
+  return HashEvaluateExpr::getHashValue(*x);
+}
+
 namespace {
 // Define the is equals test for using Fortran::evaluate::Expr values with
 // llvm::DenseMap.
@@ -464,9 +467,8 @@ class IsEqualEvaluateExpr {
         return isEqual(*xs, *ys);
       return false;
     }
-    if ([[maybe_unused]] const auto *ys = y.GetAssumedTypeDummy())
-      return false;
-    return isEqual(*x.UnwrapExpr(), *y.UnwrapExpr());
+    return !y.GetAssumedTypeDummy() &&
+           isEqual(*x.UnwrapExpr(), *y.UnwrapExpr());
   }
   static bool isEqual(const Fortran::evaluate::ProcedureDesignator &x,
                       const Fortran::evaluate::ProcedureDesignator &y) {
@@ -484,15 +486,16 @@ class IsEqualEvaluateExpr {
   }
   static bool isEqual(const Fortran::evaluate::ImpliedDoIndex &x,
                       const Fortran::evaluate::ImpliedDoIndex &y) {
-    llvm::report_fatal_error("not implemented");
+    return toStringRef(x.name) == toStringRef(y.name);
   }
   static bool isEqual(const Fortran::evaluate::TypeParamInquiry &x,
                       const Fortran::evaluate::TypeParamInquiry &y) {
-    llvm::report_fatal_error("not implemented");
+    return isEqual(x.base(), y.base()) && isEqual(x.parameter(), y.parameter());
   }
   static bool isEqual(const Fortran::evaluate::DescriptorInquiry &x,
                       const Fortran::evaluate::DescriptorInquiry &y) {
-    llvm::report_fatal_error("not implemented");
+    return isEqual(x.base(), y.base()) && x.field() == y.field() &&
+           x.dimension() == y.dimension();
   }
   static bool isEqual(const Fortran::evaluate::StructureConstructor &x,
                       const Fortran::evaluate::StructureConstructor &y) {
@@ -572,6 +575,16 @@ bool Fortran::lower::isEqual(
       x, y);
 }
 
+bool Fortran::lower::isEqual(Fortran::lower::FrontEndExpr x,
+                             Fortran::lower::FrontEndExpr y) {
+  auto empty = llvm::DenseMapInfo<Fortran::lower::FrontEndExpr>::getEmptyKey();
+  auto tombstone =
+      llvm::DenseMapInfo<Fortran::lower::FrontEndExpr>::getTombstoneKey();
+  if (x == empty || y == empty || x == tombstone || y == tombstone)
+    return x == y;
+  return x == y || IsEqualEvaluateExpr::isEqual(*x, *y);
+}
+
 namespace {
 
 /// This class can recover the base array in an expression that contains
diff --git a/flang/lib/Lower/IterationSpace.h b/flang/lib/Lower/IterationSpace.h
index befcbdb8c32340..eb3855f8a5445a 100644
--- a/flang/lib/Lower/IterationSpace.h
+++ b/flang/lib/Lower/IterationSpace.h
@@ -36,6 +36,31 @@ using FrontEndSymbol = const semantics::Symbol *;
 
 class AbstractConverter;
 
+unsigned getHashValue(FrontEndExpr x);
+bool isEqual(FrontEndExpr x, FrontEndExpr y);
+} // namespace lower
+} // namespace Fortran
+
+namespace llvm {
+template <>
+struct DenseMapInfo<Fortran::lower::FrontEndExpr> {
+  static inline Fortran::lower::FrontEndExpr getEmptyKey() {
+    return reinterpret_cast<Fortran::lower::FrontEndExpr>(~0);
+  }
+  static inline Fortran::lower::FrontEndExpr getTombstoneKey() {
+    return reinterpret_cast<Fortran::lower::FrontEndExpr>(~0 - 1);
+  }
+  static unsigned getHashValue(Fortran::lower::FrontEndExpr v) {
+    return Fortran::lower::getHashValue(v);
+  }
+  static bool isEqual(Fortran::lower::FrontEndExpr lhs,
+                      Fortran::lower::FrontEndExpr rhs) {
+    return Fortran::lower::isEqual(lhs, rhs);
+  }
+};
+} // namespace llvm
+
+namespace Fortran::lower {
 template <typename A>
 class StackableConstructExpr {
 public:
@@ -190,8 +215,7 @@ unsigned getHashValue(const ExplicitSpaceArrayBases &x);
 bool isEqual(const ExplicitSpaceArrayBases &x,
              const ExplicitSpaceArrayBases &y);
 
-} // namespace lower
-} // namespace Fortran
+} // namespace Fortran::lower
 
 namespace llvm {
 template <>