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1; RUN: opt < %s -tailcallelim -S | FileCheck %s
2; RUN: opt < %s -passes=tailcallelim -S | FileCheck %s
3
4define i32 @test1_factorial(i32 %x) {
5entry:
6	%tmp.1 = icmp sgt i32 %x, 0		; <i1> [#uses=1]
7	br i1 %tmp.1, label %then, label %else
8then:		; preds = %entry
9	%tmp.6 = add i32 %x, -1		; <i32> [#uses=1]
10	%tmp.4 = call i32 @test1_factorial( i32 %tmp.6 )		; <i32> [#uses=1]
11	%tmp.7 = mul i32 %tmp.4, %x		; <i32> [#uses=1]
12	ret i32 %tmp.7
13else:		; preds = %entry
14	ret i32 1
15}
16
17; CHECK-LABEL: define i32 @test1_factorial(
18; CHECK: phi i32
19; CHECK-NOT: call i32
20; CHECK: else:
21
22; This is a more aggressive form of accumulator recursion insertion, which
23; requires noticing that X doesn't change as we perform the tailcall.
24
25define i32 @test2_mul(i32 %x, i32 %y) {
26entry:
27	%tmp.1 = icmp eq i32 %y, 0		; <i1> [#uses=1]
28	br i1 %tmp.1, label %return, label %endif
29endif:		; preds = %entry
30	%tmp.8 = add i32 %y, -1		; <i32> [#uses=1]
31	%tmp.5 = call i32 @test2_mul( i32 %x, i32 %tmp.8 )		; <i32> [#uses=1]
32	%tmp.9 = add i32 %tmp.5, %x		; <i32> [#uses=1]
33	ret i32 %tmp.9
34return:		; preds = %entry
35	ret i32 %x
36}
37
38; CHECK-LABEL: define i32 @test2_mul(
39; CHECK: phi i32
40; CHECK-NOT: call i32
41; CHECK: return:
42
43
44define i64 @test3_fib(i64 %n) nounwind readnone {
45; CHECK-LABEL: @test3_fib(
46entry:
47; CHECK: tailrecurse:
48; CHECK: %accumulator.tr = phi i64 [ %n, %entry ], [ %3, %bb1 ]
49; CHECK: %n.tr = phi i64 [ %n, %entry ], [ %2, %bb1 ]
50  switch i64 %n, label %bb1 [
51; CHECK: switch i64 %n.tr, label %bb1 [
52    i64 0, label %bb2
53    i64 1, label %bb2
54  ]
55
56bb1:
57; CHECK: bb1:
58  %0 = add i64 %n, -1
59; CHECK: %0 = add i64 %n.tr, -1
60  %1 = tail call i64 @test3_fib(i64 %0) nounwind
61; CHECK: %1 = tail call i64 @test3_fib(i64 %0)
62  %2 = add i64 %n, -2
63; CHECK: %2 = add i64 %n.tr, -2
64  %3 = tail call i64 @test3_fib(i64 %2) nounwind
65; CHECK-NOT: tail call i64 @test3_fib
66  %4 = add nsw i64 %3, %1
67; CHECK: add nsw i64 %accumulator.tr, %1
68  ret i64 %4
69; CHECK: br label %tailrecurse
70
71bb2:
72; CHECK: bb2:
73  ret i64 %n
74; CHECK: ret i64 %accumulator.tr
75}
76