[Inliner] Assert that the computed inline threshold is non-negative.

Reviewers: chandlerc

Subscribers: haicheng, llvm-commits

Differential Revision: https://reviews.llvm.org/D56409

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@350751 91177308-0d34-0410-b5e6-96231b3b80d8

lib/Analysis/InlineCost.cpp

@@ -1731,6 +1731,13 @@ InlineResult CallAnalyzer::analyzeCall(CallSite CS) {
   // Update the threshold based on callsite properties
   updateThreshold(CS, F);
 
+  // While Threshold depends on commandline options that can take negative
+  // values, we want to enforce the invariant that the computed threshold and
+  // bonuses are non-negative.
+  assert(Threshold >= 0);
+  assert(SingleBBBonus >= 0);
+  assert(VectorBonus >= 0);
+
   // Speculatively apply all possible bonuses to Threshold. If cost exceeds
   // this Threshold any time, and cost cannot decrease, we can stop processing
   // the rest of the function body.

test/Transforms/Inline/inline-remark.ll

@@ -1,7 +1,9 @@
-; RUN: opt < %s -inline -inline-remark-attribute --inline-threshold=-2 -S | FileCheck %s
+; RUN: opt < %s -inline -inline-remark-attribute --inline-threshold=0 -S | FileCheck %s
 
 ; Test that the inliner adds inline remark attributes to non-inlined callsites.
 
+declare void @ext();
+
 define void @foo() {
   call void @bar(i1 true)
   ret void
@@ -12,6 +14,7 @@ define void @bar(i1 %p) {
 
 bb1:
   call void @foo()
+  call void @ext()
   ret void
 
 bb2:
@@ -43,6 +46,6 @@ define void @test2(i8*) {
   ret void
 }
 
-; CHECK: attributes [[ATTR1]] = { "inline-remark"="(cost=-5, threshold=-6)" }
+; CHECK: attributes [[ATTR1]] = { "inline-remark"="(cost=25, threshold=0)" }
 ; CHECK: attributes [[ATTR2]] = { "inline-remark"="(cost=never): recursive" }
 ; CHECK: attributes [[ATTR3]] = { "inline-remark"="unsupported operand bundle; (cost={{.*}}, threshold={{.*}})" }