[llvm] [InlineCost] Cache collectEphemeralValues() to save compile time (PR #130210)

[Nikita Popov via llvm-commits]

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@@ -273,14 +274,14 @@ int getCallsiteCost(const TargetTransformInfo &TTI, const CallBase &Call,
 ///
 /// Also note that calling this function *dynamically* computes the cost of
 /// inlining the callsite. It is an expensive, heavyweight call.
-InlineCost
-getInlineCost(CallBase &Call, const InlineParams &Params,
-              TargetTransformInfo &CalleeTTI,
-              function_ref<AssumptionCache &(Function &)> GetAssumptionCache,
-              function_ref<const TargetLibraryInfo &(Function &)> GetTLI,
-              function_ref<BlockFrequencyInfo &(Function &)> GetBFI = nullptr,
-              ProfileSummaryInfo *PSI = nullptr,
-              OptimizationRemarkEmitter *ORE = nullptr);
+InlineCost getInlineCost(
+    CallBase &Call, const InlineParams &Params, TargetTransformInfo &CalleeTTI,
+    function_ref<AssumptionCache &(Function &)> GetAssumptionCache,
+    function_ref<const TargetLibraryInfo &(Function &)> GetTLI,
+    function_ref<BlockFrequencyInfo &(Function &)> GetBFI = nullptr,
+    ProfileSummaryInfo *PSI = nullptr, OptimizationRemarkEmitter *ORE = nullptr,
+    std::optional<function_ref<EphemeralValuesCache &(Function &)>>
+        GetEphValuesCache = std::nullopt);
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nikic wrote:

function_ref accepts nullptr, so I think it would be better to use `function_ref<EphemeralValuesCache &(Function &)> GetEphValuesCache = nullptr` here, to save the std::optional wrapper. See GetBFI above.

https://github.com/llvm/llvm-project/pull/130210