llvm-project/llvm/test/Transforms/TailCallElim/ackermann.ll

26 lines
932 B
LLVM

; This function contains two tail calls, which should be eliminated
; RUN: opt < %s -tailcallelim -stats -disable-output |& grep {2 tailcallelim}
define i32 @Ack(i32 %M.1, i32 %N.1) {
entry:
%tmp.1 = icmp eq i32 %M.1, 0 ; <i1> [#uses=1]
br i1 %tmp.1, label %then.0, label %endif.0
then.0: ; preds = %entry
%tmp.4 = add i32 %N.1, 1 ; <i32> [#uses=1]
ret i32 %tmp.4
endif.0: ; preds = %entry
%tmp.6 = icmp eq i32 %N.1, 0 ; <i1> [#uses=1]
br i1 %tmp.6, label %then.1, label %endif.1
then.1: ; preds = %endif.0
%tmp.10 = add i32 %M.1, -1 ; <i32> [#uses=1]
%tmp.8 = call i32 @Ack( i32 %tmp.10, i32 1 ) ; <i32> [#uses=1]
ret i32 %tmp.8
endif.1: ; preds = %endif.0
%tmp.13 = add i32 %M.1, -1 ; <i32> [#uses=1]
%tmp.17 = add i32 %N.1, -1 ; <i32> [#uses=1]
%tmp.14 = call i32 @Ack( i32 %M.1, i32 %tmp.17 ) ; <i32> [#uses=1]
%tmp.11 = call i32 @Ack( i32 %tmp.13, i32 %tmp.14 ) ; <i32> [#uses=1]
ret i32 %tmp.11
}