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Bail out jump threading on indirect branches only (#117778)
Remove check for PHI in pred as pointed out in #103688 Reduced the testcase to remove redundant phi in pred Fixes: #102351
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2 files changed

+60
-84
lines changed

2 files changed

+60
-84
lines changed

‎llvm/lib/Transforms/Utils/Local.cpp

Lines changed: 1 addition & 2 deletions
Original file line numberDiff line numberDiff line change
@@ -1034,8 +1034,7 @@ CanRedirectPredsOfEmptyBBToSucc(BasicBlock *BB, BasicBlock *Succ,
10341034
return false;
10351035

10361036
if (any_of(BBPreds, [](const BasicBlock *Pred) {
1037-
return isa<PHINode>(Pred->begin()) &&
1038-
isa<IndirectBrInst>(Pred->getTerminator());
1037+
return isa<IndirectBrInst>(Pred->getTerminator());
10391038
}))
10401039
return false;
10411040

‎llvm/test/Transforms/SimplifyCFG/switch-branch-fold-indirectbr-102351.ll

Lines changed: 59 additions & 82 deletions
Original file line numberDiff line numberDiff line change
@@ -1,104 +1,81 @@
1-
; NOTE: Assertions have been autogenerated by utils/update_test_checks.py UTC_ARGS: --version 5
1+
; NOTE: Assertions have been autogenerated by utils/update_test_checks.py UTC_ARGS: --prefix-filecheck-ir-name pref --version 5
22
; RUN: opt < %s -passes=simplifycfg -S | FileCheck %s
33

4-
target datalayout = "e-m:e-p270:32:32-p271:32:32-p272:64:64-i64:64-i128:128-f80:128-n8:16:32:64-S128"
5-
target triple = "x86_64-unknown-linux-gnu"
6-
7-
define dso_local noundef i32 @main() {
8-
; CHECK-LABEL: define dso_local noundef i32 @main() {
4+
define i32 @foo.1(i32 %arg, ptr %arg1) {
5+
; CHECK-LABEL: define i32 @foo.1(
6+
; CHECK-SAME: i32 [[ARG:%.*]], ptr [[ARG1:%.*]]) {
97
; CHECK-NEXT: [[BB:.*]]:
108
; CHECK-NEXT: [[ALLOCA:%.*]] = alloca [2 x ptr], align 16
11-
; CHECK-NEXT: store ptr blockaddress(@main, %[[BB4:.*]]), ptr [[ALLOCA]], align 16, !tbaa [[TBAA0:![0-9]+]]
9+
; CHECK-NEXT: store ptr blockaddress(@foo.1, %[[BB8:.*]]), ptr [[ALLOCA]], align 16
1210
; CHECK-NEXT: [[GETELEMENTPTR:%.*]] = getelementptr inbounds [2 x ptr], ptr [[ALLOCA]], i64 0, i64 1
13-
; CHECK-NEXT: store ptr blockaddress(@main, %[[BB10:.*]]), ptr [[GETELEMENTPTR]], align 8, !tbaa [[TBAA0]]
14-
; CHECK-NEXT: br label %[[BB1:.*]]
15-
; CHECK: [[BB1]]:
16-
; CHECK-NEXT: [[PHI:%.*]] = phi i32 [ 0, %[[BB]] ], [ [[PHI8:%.*]], %[[BB7:.*]] ]
17-
; CHECK-NEXT: [[PHI2:%.*]] = phi i32 [ 0, %[[BB]] ], [ [[PHI9:%.*]], %[[BB7]] ]
18-
; CHECK-NEXT: switch i32 [[PHI]], label %[[BB7]] [
19-
; CHECK-NEXT: i32 0, label %[[BB12:.*]]
20-
; CHECK-NEXT: i32 1, label %[[BB4]]
21-
; CHECK-NEXT: i32 2, label %[[BB6:.*]]
11+
; CHECK-NEXT: store ptr blockaddress(@foo.1, %[[BB16:.*]]), ptr [[GETELEMENTPTR]], align 8
12+
; CHECK-NEXT: br label %[[PREFBB2:.*]]
13+
; CHECK: [[PREFBB2]]:
14+
; CHECK-NEXT: [[PHI:%.*]] = phi i32 [ 0, %[[BB]] ], [ [[PHI14:%.*]], %[[BB13:.*]] ]
15+
; CHECK-NEXT: [[PHI3:%.*]] = phi i32 [ 0, %[[BB]] ], [ [[PHI15:%.*]], %[[BB13]] ]
16+
; CHECK-NEXT: switch i32 [[PHI]], label %[[BB13]] [
17+
; CHECK-NEXT: i32 0, label %[[PREFBB18:.*]]
18+
; CHECK-NEXT: i32 1, label %[[BB8]]
19+
; CHECK-NEXT: i32 2, label %[[PREFBB11:.*]]
2220
; CHECK-NEXT: ]
23-
; CHECK: [[BB4]]:
24-
; CHECK-NEXT: [[PHI5:%.*]] = phi i32 [ [[PHI13:%.*]], %[[BB12]] ], [ [[PHI2]], %[[BB1]] ]
25-
; CHECK-NEXT: br label %[[BB7]]
26-
; CHECK: [[BB6]]:
27-
; CHECK-NEXT: [[CALL:%.*]] = call i32 @foo(i32 noundef [[PHI2]])
28-
; CHECK-NEXT: [[ADD:%.*]] = add nsw i32 [[PHI2]], 1
29-
; CHECK-NEXT: br label %[[BB12]]
30-
; CHECK: [[BB7]]:
31-
; CHECK-NEXT: [[PHI8]] = phi i32 [ [[PHI]], %[[BB1]] ], [ 2, %[[BB4]] ]
32-
; CHECK-NEXT: [[PHI9]] = phi i32 [ [[PHI2]], %[[BB1]] ], [ [[PHI5]], %[[BB4]] ]
33-
; CHECK-NEXT: br label %[[BB1]], !llvm.loop [[LOOP4:![0-9]+]]
34-
; CHECK: [[BB10]]:
35-
; CHECK-NEXT: [[CALL11:%.*]] = call i32 @foo(i32 noundef [[PHI13]])
21+
; CHECK: [[BB8]]:
22+
; CHECK-NEXT: [[PHI10:%.*]] = phi i32 [ [[ARG]], %[[PREFBB18]] ], [ [[PHI3]], %[[PREFBB2]] ]
23+
; CHECK-NEXT: br label %[[BB13]]
24+
; CHECK: [[PREFBB11]]:
25+
; CHECK-NEXT: [[CALL:%.*]] = call i32 @wombat(i32 noundef [[PHI3]])
26+
; CHECK-NEXT: [[ADD:%.*]] = add nsw i32 [[PHI3]], 1
27+
; CHECK-NEXT: br label %[[PREFBB18]]
28+
; CHECK: [[BB13]]:
29+
; CHECK-NEXT: [[PHI14]] = phi i32 [ [[PHI]], %[[PREFBB2]] ], [ 2, %[[BB8]] ]
30+
; CHECK-NEXT: [[PHI15]] = phi i32 [ [[PHI3]], %[[PREFBB2]] ], [ [[PHI10]], %[[BB8]] ]
31+
; CHECK-NEXT: br label %[[PREFBB2]]
32+
; CHECK: [[BB16]]:
33+
; CHECK-NEXT: [[CALL17:%.*]] = call i32 @wombat(i32 noundef [[ARG]])
3634
; CHECK-NEXT: ret i32 0
37-
; CHECK: [[BB12]]:
38-
; CHECK-NEXT: [[PHI13]] = phi i32 [ [[ADD]], %[[BB6]] ], [ [[PHI2]], %[[BB1]] ]
39-
; CHECK-NEXT: [[SEXT:%.*]] = sext i32 [[PHI13]] to i64
40-
; CHECK-NEXT: [[GETELEMENTPTR14:%.*]] = getelementptr inbounds [2 x ptr], ptr [[ALLOCA]], i64 0, i64 [[SEXT]]
41-
; CHECK-NEXT: [[LOAD:%.*]] = load ptr, ptr [[GETELEMENTPTR14]], align 8, !tbaa [[TBAA0]]
42-
; CHECK-NEXT: indirectbr ptr [[LOAD]], [label %[[BB4]], label %bb10]
35+
; CHECK: [[PREFBB18]]:
36+
; CHECK-NEXT: [[LOAD:%.*]] = load ptr, ptr [[ARG1]], align 8
37+
; CHECK-NEXT: indirectbr ptr [[LOAD]], [label %[[BB8]], label %bb16]
4338
;
4439
bb:
4540
%alloca = alloca [2 x ptr], align 16
46-
store ptr blockaddress(@main, %bb4), ptr %alloca, align 16, !tbaa !0
41+
store ptr blockaddress(@foo.1, %bb8), ptr %alloca, align 16
4742
%getelementptr = getelementptr inbounds [2 x ptr], ptr %alloca, i64 0, i64 1
48-
store ptr blockaddress(@main, %bb10), ptr %getelementptr, align 8, !tbaa !0
49-
br label %bb1
43+
store ptr blockaddress(@foo.1, %bb16), ptr %getelementptr, align 8
44+
br label %bb2
5045

51-
bb1: ; preds = %bb7, %bb
52-
%phi = phi i32 [ 0, %bb ], [ %phi8, %bb7 ]
53-
%phi2 = phi i32 [ 0, %bb ], [ %phi9, %bb7 ]
54-
switch i32 %phi, label %bb7 [
55-
i32 0, label %bb3
56-
i32 1, label %bb4
57-
i32 2, label %bb6
46+
bb2: ; preds = %bb13, %bb
47+
%phi = phi i32 [ 0, %bb ], [ %phi14, %bb13 ]
48+
%phi3 = phi i32 [ 0, %bb ], [ %phi15, %bb13 ]
49+
switch i32 %phi, label %bb13 [
50+
i32 0, label %bb5
51+
i32 1, label %bb8
52+
i32 2, label %bb11
5853
]
5954

60-
bb3: ; preds = %bb1
61-
br label %bb12
55+
bb5: ; preds = %bb2
56+
br label %bb18
6257

63-
bb4: ; preds = %bb12, %bb1
64-
%phi5 = phi i32 [ %phi13, %bb12 ], [ %phi2, %bb1 ]
65-
br label %bb7
58+
bb8: ; preds = %bb18, %bb2
59+
%phi10 = phi i32 [ %arg, %bb18 ], [ %phi3, %bb2 ]
60+
br label %bb13
6661

67-
bb6: ; preds = %bb1
68-
%call = call i32 @foo(i32 noundef %phi2)
69-
%add = add nsw i32 %phi2, 1
70-
br label %bb12
62+
bb11: ; preds = %bb2
63+
%call = call i32 @wombat(i32 noundef %phi3)
64+
%add = add nsw i32 %phi3, 1
65+
br label %bb18
7166

72-
bb7: ; preds = %bb4, %bb1
73-
%phi8 = phi i32 [ %phi, %bb1 ], [ 2, %bb4 ]
74-
%phi9 = phi i32 [ %phi2, %bb1 ], [ %phi5, %bb4 ]
75-
br label %bb1, !llvm.loop !4
67+
bb13: ; preds = %bb8, %bb2
68+
%phi14 = phi i32 [ %phi, %bb2 ], [ 2, %bb8 ]
69+
%phi15 = phi i32 [ %phi3, %bb2 ], [ %phi10, %bb8 ]
70+
br label %bb2
7671

77-
bb10: ; preds = %bb12
78-
%call11 = call i32 @foo(i32 noundef %phi13)
72+
bb16: ; preds = %bb18
73+
%call17 = call i32 @wombat(i32 noundef %arg)
7974
ret i32 0
8075

81-
bb12: ; preds = %bb6, %bb3
82-
%phi13 = phi i32 [ %add, %bb6 ], [ %phi2, %bb3 ]
83-
%sext = sext i32 %phi13 to i64
84-
%getelementptr14 = getelementptr inbounds [2 x ptr], ptr %alloca, i64 0, i64 %sext
85-
%load = load ptr, ptr %getelementptr14, align 8, !tbaa !0
86-
indirectbr ptr %load, [label %bb4, label %bb10]
76+
bb18: ; preds = %bb11, %bb5
77+
%load = load ptr, ptr %arg1, align 8
78+
indirectbr ptr %load, [label %bb8, label %bb16]
8779
}
8880

89-
declare i32 @foo(i32)
90-
91-
!0 = !{!1, !1, i64 0}
92-
!1 = !{!"any pointer", !2, i64 0}
93-
!2 = !{!"omnipotent char", !3, i64 0}
94-
!3 = !{!"Simple C++ TBAA"}
95-
!4 = !{!5, !5, i64 0}
96-
!5 = !{!"int", !2, i64 0}
97-
;.
98-
; CHECK: [[TBAA0]] = !{[[META1:![0-9]+]], [[META1]], i64 0}
99-
; CHECK: [[META1]] = !{!"any pointer", [[META2:![0-9]+]], i64 0}
100-
; CHECK: [[META2]] = !{!"omnipotent char", [[META3:![0-9]+]], i64 0}
101-
; CHECK: [[META3]] = !{!"Simple C++ TBAA"}
102-
; CHECK: [[LOOP4]] = !{[[META5:![0-9]+]], [[META5]], i64 0}
103-
; CHECK: [[META5]] = !{!"int", [[META2]], i64 0}
104-
;.
81+
declare i32 @wombat(i32)

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