CS.isNoInline())
return llvm::InlineCost::getNever();
+ // Don't inline directly recursive calls, for now. Inlining a directly
+ // recursive call is effectively unrolling a loop, so it calls for different
+ // heuristics, which aren't implemented yet. Until then, err on the
+ // conservative side.
+ if (Callee == Caller)
+ return llvm::InlineCost::getNever();
+
// InlineCost - This value measures how good of an inline candidate this call
// site is to inline. A lower inline cost make is more likely for the call to
// be inlined. This value may go negative.
--- /dev/null
+; RUN: opt -inline -tailcallelim -indvars -loop-deletion -S < %s | FileCheck %s
+
+; Inline shouldn't inline foo into itself because it's a tailcallelim
+; candidate. Tailcallelim should convert the call into a loop. Indvars
+; should calculate the exit value, making the loop dead. Loop deletion
+; should delete the loop.
+; PR6842
+
+; CHECK: define i32 @bar() nounwind {
+; CHECK-NEXT: ret i32 10000
+; CHECK-NEXT: }
+
+define internal i32 @foo(i32 %x) nounwind {
+ %i = add i32 %x, 1 ; <i32> [#uses=3]
+ %a = icmp slt i32 %i, 10000 ; <i1> [#uses=1]
+ br i1 %a, label %more, label %done
+
+done: ; preds = %0
+ ret i32 %i
+
+more: ; preds = %0
+ %z = tail call i32 @foo(i32 %i) ; <i32> [#uses=1]
+ ret i32 %z
+}
+
+define i32 @bar() nounwind {
+ %z = call i32 @foo(i32 0) ; <i32> [#uses=1]
+ ret i32 %z
+}