[InlineOrder] fix the calculation of Cost for CostBenefitPriority

[helloguo]

getCost() expects that isVariable() is true. https://github.com/llvm/llvm-project/blob/main/llvm/include/llvm/Analysis/InlineCost.h#L146

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[llvmbot]

@llvm/pr-subscribers-llvm-analysis

Author: Xiangyang (Mark) Guo (helloguo)

Changes

---

Full diff: https://github.com/llvm/llvm-project/pull/86630.diff

1 Files Affected:

• (modified) llvm/lib/Analysis/InlineOrder.cpp (+4-1)

diff --git a/llvm/lib/Analysis/InlineOrder.cpp b/llvm/lib/Analysis/InlineOrder.cpp
index 09fc4f9a00f49c..f156daa2f126fb 100644
--- a/llvm/lib/Analysis/InlineOrder.cpp
+++ b/llvm/lib/Analysis/InlineOrder.cpp
@@ -114,7 +114,10 @@ class CostBenefitPriority {
   CostBenefitPriority(const CallBase *CB, FunctionAnalysisManager &FAM,
                       const InlineParams &Params) {
     auto IC = getInlineCostWrapper(const_cast<CallBase &>(*CB), FAM, Params);
-    Cost = IC.getCost();
+    if (IC.isVariable())
+      Cost = IC.getCost();
+    else
+      Cost = IC.isNever() ? INT_MAX : INT_MIN;
     StaticBonusApplied = IC.getStaticBonusApplied();
     CostBenefit = IC.getCostBenefit();
   }

[kazutakahirata]

The patch looks good. Do you happen to have a test case that tripped on assert(isVariable() ... in getCost()? If so, we should incorporate that into this PR.

[helloguo]

I don't have a specific test case. I do see the assertion happens when building some workloads though.

[kazutakahirata]

LGTM. Thanks!

[wlei-llvm]

Does it always need to check isVariable for the return of getInlineCostWrapper? As far as I can see, there are three usages of getInlineCostWrapper and all needs those checks, maybe we can just move it into getInlineCostWrapper?

[wlei-llvm]

Oh, I think it needs to use the IC not only the cost, (I was just thinking to avoid those three duplicated code), no better idea so far, feel free to ignore.

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