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, 4 insertions, 3 deletions

diff --git a/source/slang/slang-emit-c-like.cpp b/source/slang/slang-emit-c-like.cpp
index 95c691d8b..337860771 100644
--- a/source/slang/slang-emit-c-like.cpp
+++ b/source/slang/slang-emit-c-like.cpp
@@ -3,6 +3,7 @@
 
 #include "../core/slang-writer.h"
 #include "../compiler-core/slang-name.h"
+#include "../core/slang-stable-hash.h"
 
 #include "slang-ir-bind-existentials.h"
 #include "slang-ir-dce.h"
@@ -833,7 +834,7 @@ void CLikeSourceEmitter::appendScrubbedName(const UnownedStringSlice& name, Stri
         if (length > maxTokenLength)
         {
             // We are going to output with a prefix and a hash of the full name
-            const HashCode64 hash = getStableHashCode64(out.getBuffer(), length);
+            const auto hash = getStableHashCode64(out.getBuffer(), length);
             // Two hex chars per byte
             const Index hashSize = sizeof(hash) * 2; 
 
@@ -848,7 +849,7 @@ void CLikeSourceEmitter::appendScrubbedName(const UnownedStringSlice& name, Stri
             // Let's add a _ to separate from the rest of the name
             out.appendChar('_');
             // Append the hash in hex
-            out.append(uint64_t(hash), 16);
+            out.append(hash);
 
             SLANG_ASSERT(out.getLength() <= maxTokenLength);
         }
@@ -2497,7 +2498,7 @@ void CLikeSourceEmitter::defaultEmitInstExpr(IRInst* inst, const EmitOpInfo& inO
         if (stringLit)
         {
             auto slice = stringLit->getStringSlice();
-            m_writer->emit(static_cast<int32_t>(getStableHashCode32(slice.begin(), slice.getLength())));
+            m_writer->emit(getStableHashCode32(slice.begin(), slice.getLength()).hash);
         }
         else
         {