if (!E->IsCritical)
return canInstrument(DestBB);
+ // Some IndirectBr critical edges cannot be split by the previous
+ // SplitIndirectBrCriticalEdges call. Bail out.
unsigned SuccNum = GetSuccessorNumber(SrcBB, DestBB);
- BasicBlock *InstrBB = SplitCriticalEdge(TI, SuccNum);
+ BasicBlock *InstrBB =
+ isa<IndirectBrInst>(TI) ? nullptr : SplitCriticalEdge(TI, SuccNum);
if (!InstrBB) {
LLVM_DEBUG(
dbgs() << "Fail to split critical edge: not instrument this edge.\n");
indirectbr i8* %2, [label %for.cond2, label %if.end]
; CHECK: indirectbr i8* %2, [label %for.cond2, label %if.end]
}
+
+;; If an indirectbr critical edge cannot be split, ignore it.
+;; The edge will not be profiled.
+; CHECK-LABEL: @cannot_split(
+; CHECK-NEXT: entry:
+; CHECK-NEXT: call void @llvm.instrprof.increment
+; CHECK-NOT: call void @llvm.instrprof.increment
+define i32 @cannot_split(i8* nocapture readonly %p) {
+entry:
+ %targets = alloca <2 x i8*>, align 16
+ store <2 x i8*> <i8* blockaddress(@cannot_split, %indirect), i8* blockaddress(@cannot_split, %end)>, <2 x i8*>* %targets, align 16
+ %arrayidx2 = getelementptr inbounds i8, i8* %p, i64 1
+ %0 = load i8, i8* %arrayidx2
+ %idxprom = sext i8 %0 to i64
+ %arrayidx3 = getelementptr inbounds <2 x i8*>, <2 x i8*>* %targets, i64 0, i64 %idxprom
+ %1 = load i8*, i8** %arrayidx3, align 8
+ br label %indirect
+
+indirect: ; preds = %entry, %indirect
+ indirectbr i8* %1, [label %indirect, label %end]
+
+end: ; preds = %indirect
+ ret i32 0
+}