xref: /llvm-project/llvm/test/Transforms/AggressiveInstCombine/trunc_phi.ll (revision 8f527e08a576ceec09b6e8fbd9ccd8e1e62bc31b) 
1; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
2; RUN: opt < %s -passes=aggressive-instcombine -S | FileCheck %s
3
4define i16 @trunc_phi(i8 %x) {
5; CHECK-LABEL: @trunc_phi(
6; CHECK-NEXT:  LoopHeader:
7; CHECK-NEXT:    [[ZEXT:%.*]] = zext i8 [[X:%.*]] to i16
8; CHECK-NEXT:    br label [[LOOP:%.*]]
9; CHECK:       Loop:
10; CHECK-NEXT:    [[ZEXT2:%.*]] = phi i16 [ [[ZEXT]], [[LOOPHEADER:%.*]] ], [ [[SHL:%.*]], [[LOOP]] ]
11; CHECK-NEXT:    [[J:%.*]] = phi i32 [ 0, [[LOOPHEADER]] ], [ [[I:%.*]], [[LOOP]] ]
12; CHECK-NEXT:    [[SHL]] = shl i16 [[ZEXT2]], 1
13; CHECK-NEXT:    [[I]] = add i32 [[J]], 1
14; CHECK-NEXT:    [[CMP:%.*]] = icmp eq i32 [[I]], 10
15; CHECK-NEXT:    br i1 [[CMP]], label [[LOOPEND:%.*]], label [[LOOP]]
16; CHECK:       LoopEnd:
17; CHECK-NEXT:    ret i16 [[SHL]]
18;
19LoopHeader:
20  %zext = zext i8 %x to i32
21  br label %Loop
22
23Loop:
24  %zext2 = phi i32 [%zext, %LoopHeader], [%shl, %Loop]
25  %j = phi i32 [0, %LoopHeader], [%i, %Loop]
26  %shl = shl i32 %zext2, 1
27  %trunc = trunc i32 %shl to i16
28  %i = add i32 %j, 1
29  %cmp = icmp eq i32 %i, 10
30  br i1 %cmp, label %LoopEnd, label %Loop
31
32LoopEnd:
33  ret i16 %trunc
34}
35
36define i16 @trunc_phi2(i8 %x, i32 %sw) {
37; CHECK-LABEL: @trunc_phi2(
38; CHECK-NEXT:  LoopHeader:
39; CHECK-NEXT:    [[ZEXT:%.*]] = zext i8 [[X:%.*]] to i16
40; CHECK-NEXT:    switch i32 [[SW:%.*]], label [[LOOPEND:%.*]] [
41; CHECK-NEXT:    i32 0, label [[LOOP:%.*]]
42; CHECK-NEXT:    i32 1, label [[LOOP]]
43; CHECK-NEXT:    ]
44; CHECK:       Loop:
45; CHECK-NEXT:    [[ZEXT2:%.*]] = phi i16 [ [[ZEXT]], [[LOOPHEADER:%.*]] ], [ [[ZEXT]], [[LOOPHEADER]] ], [ [[SHL:%.*]], [[LOOP]] ]
46; CHECK-NEXT:    [[J:%.*]] = phi i32 [ 0, [[LOOPHEADER]] ], [ 0, [[LOOPHEADER]] ], [ [[I:%.*]], [[LOOP]] ]
47; CHECK-NEXT:    [[SHL]] = shl i16 [[ZEXT2]], 1
48; CHECK-NEXT:    [[I]] = add i32 [[J]], 1
49; CHECK-NEXT:    [[CMP:%.*]] = icmp eq i32 [[I]], 10
50; CHECK-NEXT:    br i1 [[CMP]], label [[LOOPEND]], label [[LOOP]]
51; CHECK:       LoopEnd:
52; CHECK-NEXT:    [[ZEXT3:%.*]] = phi i16 [ [[ZEXT]], [[LOOPHEADER]] ], [ [[ZEXT2]], [[LOOP]] ]
53; CHECK-NEXT:    ret i16 [[ZEXT3]]
54;
55LoopHeader:
56  %zext = zext i8 %x to i32
57  switch i32 %sw, label %LoopEnd [ i32 0, label %Loop
58  i32 1, label %Loop ]
59
60Loop:
61  %zext2 = phi i32 [%zext, %LoopHeader], [%zext, %LoopHeader], [%shl, %Loop]
62  %j = phi i32 [0, %LoopHeader], [0, %LoopHeader], [%i, %Loop]
63  %shl = shl i32 %zext2, 1
64  %i = add i32 %j, 1
65  %cmp = icmp eq i32 %i, 10
66  br i1 %cmp, label %LoopEnd, label %Loop
67
68LoopEnd:
69  %zext3 = phi i32 [%zext, %LoopHeader], [%zext2, %Loop]
70  %trunc = trunc i32 %zext3 to i16
71  ret i16 %trunc
72}
73