Use ankerl/unordered_dense as a hashmap implementation (#3036)

* Correct namespace for getClockFrequency

* missing const

* Add missing assignment operator

* Remove unused variables

* Return correct modified variable

* Use stable hash code for file system identity

* terse static_assert

* Structured binding for map iteration

* Make (==) and getHashCode const on many structs

* Add ConstIterator for LinkedList

* Replace uses of ItemProxy::getValue with Dictionary::at

* Extract list of loads from gradientsMap before updating it

* Const correctness in type layout

* Add unordered_dense hashmap submodule

* Use wyhash or getHashCode in slang-hash.h

* refactor slang-hash.h

* Use ankerl/unordered_dense as a hashmap implementation

Notable changes:
- The subscript operator returns a reference directly to the value,
  rather than a lazy ItemProxy (pair of dict pointer and key)

slang-profile time (95% over 10 runs):

- Before: 6.3913906 (±0.0746)
- After:  5.9276123 (±0.0964)

* 64 bit hash for strings

So they have the same hash as char buffers with the same contents

* Narrowing warnings for gcc to match msvc

* revert back to c++17

* Correct c++ version for msvc

* Use path to unordered_dense which keeps tests happy

* Do not assign to and read from map in same expression

* Remove redundant map operations in primal-hoist

* Split out stable hash functions into slang-stable-hash.h

* 64 bit hash by default

* regenerate vs projects

* Correct return type from HashSetBase::getCount()

* correct width for call to Dictionary::reserve

* Use stable hash for obfuscated module ids

* Signed int for reserve

* clearer variable naming

* Parameterize Dictionary on hash and equality functors

* Allow heterogenous lookup for Dictionary

* missing const

* Use set over operator[] in some places

* Remove unused function

* s/at/getValue

1 files changed, 6 insertions, 6 deletions

diff --git a/source/slang/slang-ir-specialize.cpp b/source/slang/slang-ir-specialize.cpp
index 83e2cad70..b2cd5edc4 100644
--- a/source/slang/slang-ir-specialize.cpp
+++ b/source/slang/slang-ir-specialize.cpp
@@ -632,7 +632,7 @@ struct SpecializationContext
         int childrenCount = 0;
         for (auto child = dictInst->getFirstChild(); child; child = child->next)
             childrenCount++;
-        dict.reserve(1 << Math::Log2Ceil(childrenCount * 2));
+        dict.reserve(Index{1} << Math::Log2Ceil(childrenCount * 2));
         for (auto child : dictInst->getChildren())
         {
             auto item = as<IRSpecializationDictionaryItem>(child);
@@ -698,18 +698,18 @@ struct SpecializationContext
         builder.setInsertInto(moduleInst);
         auto dictInst = builder.emitIntrinsicInst(nullptr, dictOp, 0, nullptr);
         builder.setInsertInto(dictInst);
-        for (auto kv : dict)
+        for (const auto& [key, value] : dict)
         {
-            if (!kv.value->parent)
+            if (!value->parent)
                 continue;
-            for (auto keyVal : kv.key.vals)
+            for (auto keyVal : key.vals)
             {
                 if (!keyVal->parent) goto next;
             }
             {
                 List<IRInst*> args;
-                args.add(kv.value);
-                args.addRange(kv.key.vals);
+                args.add(value);
+                args.addRange(key.vals);
                 builder.emitIntrinsicInst(nullptr, kIROp_SpecializationDictionaryItem, args.getCount(), args.getBuffer());
             }
         next:;