[StructuralHash] Refactor (#112621)

This is largely NFC, and it prepares for #112638.
 - Use stable_hash instead of uint64_t
- Rename update* to hash* functions. They compute stable_hash locally and return it.
 
This is a patch for
https://discourse.llvm.org/t/rfc-global-function-merging/82608.

1 files changed, 3 insertions, 3 deletions

diff --git a/llvm/lib/Transforms/IPO/MergeFunctions.cpp b/llvm/lib/Transforms/IPO/MergeFunctions.cpp
index b50a700..ad16b0b 100644
--- a/llvm/lib/Transforms/IPO/MergeFunctions.cpp
+++ b/llvm/lib/Transforms/IPO/MergeFunctions.cpp
@@ -172,14 +172,14 @@ namespace {
 
 class FunctionNode {
   mutable AssertingVH<Function> F;
-  IRHash Hash;
+  stable_hash Hash;
 
 public:
   // Note the hash is recalculated potentially multiple times, but it is cheap.
   FunctionNode(Function *F) : F(F), Hash(StructuralHash(*F)) {}
 
   Function *getFunc() const { return F; }
-  IRHash getHash() const { return Hash; }
+  stable_hash getHash() const { return Hash; }
 
   /// Replace the reference to the function F by the function G, assuming their
   /// implementations are equal.
@@ -420,7 +420,7 @@ bool MergeFunctions::runOnModule(Module &M) {
 
   // All functions in the module, ordered by hash. Functions with a unique
   // hash value are easily eliminated.
-  std::vector<std::pair<IRHash, Function *>> HashedFuncs;
+  std::vector<std::pair<stable_hash, Function *>> HashedFuncs;
   for (Function &Func : M) {
     if (isEligibleForMerging(Func)) {
       HashedFuncs.push_back({StructuralHash(Func), &Func});