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