1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
|
; This is the test case taken from appel's book that illustrates a hard case
; that SCCP gets right. BB3 should be completely eliminated.
;
; RUN: opt %s -sccp -constprop -dce -simplifycfg | \
; RUN: llvm-dis | not grep BB3
define i32 @testfunction(i32 %i0, i32 %j0) {
BB1:
br label %BB2
BB2: ; preds = %BB7, %BB1
%j2 = phi i32 [ %j4, %BB7 ], [ 1, %BB1 ] ; <i32> [#uses=2]
%k2 = phi i32 [ %k4, %BB7 ], [ 0, %BB1 ] ; <i32> [#uses=4]
%kcond = icmp slt i32 %k2, 100 ; <i1> [#uses=1]
br i1 %kcond, label %BB3, label %BB4
BB3: ; preds = %BB2
%jcond = icmp slt i32 %j2, 20 ; <i1> [#uses=1]
br i1 %jcond, label %BB5, label %BB6
BB4: ; preds = %BB2
ret i32 %j2
BB5: ; preds = %BB3
%k3 = add i32 %k2, 1 ; <i32> [#uses=1]
br label %BB7
BB6: ; preds = %BB3
%k5 = add i32 %k2, 1 ; <i32> [#uses=1]
br label %BB7
BB7: ; preds = %BB6, %BB5
%j4 = phi i32 [ 1, %BB5 ], [ %k2, %BB6 ] ; <i32> [#uses=1]
%k4 = phi i32 [ %k3, %BB5 ], [ %k5, %BB6 ] ; <i32> [#uses=1]
br label %BB2
}
|
