xref: /aosp_15_r20/external/llvm/test/Transforms/EarlyCSE/invariant-loads.ll (revision 9880d6810fe72a1726cb53787c6711e909410d58) 
1*9880d681SAndroid Build Coastguard Worker; RUN: opt -S -early-cse < %s | FileCheck %s
2*9880d681SAndroid Build Coastguard Worker
3*9880d681SAndroid Build Coastguard Workerdeclare void @clobber_and_use(i32)
4*9880d681SAndroid Build Coastguard Worker
5*9880d681SAndroid Build Coastguard Workerdefine void @f_0(i32* %ptr) {
6*9880d681SAndroid Build Coastguard Worker; CHECK-LABEL: @f_0(
7*9880d681SAndroid Build Coastguard Worker; CHECK:   %val0 = load i32, i32* %ptr, !invariant.load !0
8*9880d681SAndroid Build Coastguard Worker; CHECK:   call void @clobber_and_use(i32 %val0)
9*9880d681SAndroid Build Coastguard Worker; CHECK:   call void @clobber_and_use(i32 %val0)
10*9880d681SAndroid Build Coastguard Worker; CHECK:   call void @clobber_and_use(i32 %val0)
11*9880d681SAndroid Build Coastguard Worker; CHECK:   ret void
12*9880d681SAndroid Build Coastguard Worker
13*9880d681SAndroid Build Coastguard Worker  %val0 = load i32, i32* %ptr, !invariant.load !{}
14*9880d681SAndroid Build Coastguard Worker  call void @clobber_and_use(i32 %val0)
15*9880d681SAndroid Build Coastguard Worker  %val1 = load i32, i32* %ptr, !invariant.load !{}
16*9880d681SAndroid Build Coastguard Worker  call void @clobber_and_use(i32 %val1)
17*9880d681SAndroid Build Coastguard Worker  %val2 = load i32, i32* %ptr, !invariant.load !{}
18*9880d681SAndroid Build Coastguard Worker  call void @clobber_and_use(i32 %val2)
19*9880d681SAndroid Build Coastguard Worker  ret void
20*9880d681SAndroid Build Coastguard Worker}
21*9880d681SAndroid Build Coastguard Worker
22*9880d681SAndroid Build Coastguard Workerdefine void @f_1(i32* %ptr) {
23*9880d681SAndroid Build Coastguard Worker; We can forward invariant loads to non-invariant loads, since once an
24*9880d681SAndroid Build Coastguard Worker; invariant load has executed, the location loaded from is known to be
25*9880d681SAndroid Build Coastguard Worker; unchanging.
26*9880d681SAndroid Build Coastguard Worker
27*9880d681SAndroid Build Coastguard Worker; CHECK-LABEL: @f_1(
28*9880d681SAndroid Build Coastguard Worker; CHECK:   %val0 = load i32, i32* %ptr, !invariant.load !0
29*9880d681SAndroid Build Coastguard Worker; CHECK:   call void @clobber_and_use(i32 %val0)
30*9880d681SAndroid Build Coastguard Worker; CHECK:   call void @clobber_and_use(i32 %val0)
31*9880d681SAndroid Build Coastguard Worker
32*9880d681SAndroid Build Coastguard Worker  %val0 = load i32, i32* %ptr, !invariant.load !{}
33*9880d681SAndroid Build Coastguard Worker  call void @clobber_and_use(i32 %val0)
34*9880d681SAndroid Build Coastguard Worker  %val1 = load i32, i32* %ptr
35*9880d681SAndroid Build Coastguard Worker  call void @clobber_and_use(i32 %val1)
36*9880d681SAndroid Build Coastguard Worker  ret void
37*9880d681SAndroid Build Coastguard Worker}
38*9880d681SAndroid Build Coastguard Worker
39*9880d681SAndroid Build Coastguard Workerdefine void @f_2(i32* %ptr) {
40*9880d681SAndroid Build Coastguard Worker; Negative test -- we can't forward a non-invariant load into an
41*9880d681SAndroid Build Coastguard Worker; invariant load.
42*9880d681SAndroid Build Coastguard Worker
43*9880d681SAndroid Build Coastguard Worker; CHECK-LABEL: @f_2(
44*9880d681SAndroid Build Coastguard Worker; CHECK:   %val0 = load i32, i32* %ptr
45*9880d681SAndroid Build Coastguard Worker; CHECK:   call void @clobber_and_use(i32 %val0)
46*9880d681SAndroid Build Coastguard Worker; CHECK:   %val1 = load i32, i32* %ptr, !invariant.load !0
47*9880d681SAndroid Build Coastguard Worker; CHECK:   call void @clobber_and_use(i32 %val1)
48*9880d681SAndroid Build Coastguard Worker
49*9880d681SAndroid Build Coastguard Worker  %val0 = load i32, i32* %ptr
50*9880d681SAndroid Build Coastguard Worker  call void @clobber_and_use(i32 %val0)
51*9880d681SAndroid Build Coastguard Worker  %val1 = load i32, i32* %ptr, !invariant.load !{}
52*9880d681SAndroid Build Coastguard Worker  call void @clobber_and_use(i32 %val1)
53*9880d681SAndroid Build Coastguard Worker  ret void
54*9880d681SAndroid Build Coastguard Worker}
55*9880d681SAndroid Build Coastguard Worker
56*9880d681SAndroid Build Coastguard Workerdefine void @f_3(i1 %cond, i32* %ptr) {
57*9880d681SAndroid Build Coastguard Worker; CHECK-LABEL: @f_3(
58*9880d681SAndroid Build Coastguard Worker  %val0 = load i32, i32* %ptr, !invariant.load !{}
59*9880d681SAndroid Build Coastguard Worker  call void @clobber_and_use(i32 %val0)
60*9880d681SAndroid Build Coastguard Worker  br i1 %cond, label %left, label %right
61*9880d681SAndroid Build Coastguard Worker
62*9880d681SAndroid Build Coastguard Worker; CHECK:  %val0 = load i32, i32* %ptr, !invariant.load !0
63*9880d681SAndroid Build Coastguard Worker; CHECK: left:
64*9880d681SAndroid Build Coastguard Worker; CHECK-NEXT:  call void @clobber_and_use(i32 %val0)
65*9880d681SAndroid Build Coastguard Worker
66*9880d681SAndroid Build Coastguard Workerleft:
67*9880d681SAndroid Build Coastguard Worker  %val1 = load i32, i32* %ptr
68*9880d681SAndroid Build Coastguard Worker  call void @clobber_and_use(i32 %val1)
69*9880d681SAndroid Build Coastguard Worker  ret void
70*9880d681SAndroid Build Coastguard Worker
71*9880d681SAndroid Build Coastguard Workerright:
72*9880d681SAndroid Build Coastguard Worker  ret void
73*9880d681SAndroid Build Coastguard Worker}
74*9880d681SAndroid Build Coastguard Worker
75*9880d681SAndroid Build Coastguard Workerdefine void @f_4(i1 %cond, i32* %ptr) {
76*9880d681SAndroid Build Coastguard Worker; Negative test -- can't forward %val0 to %va1 because that'll break
77*9880d681SAndroid Build Coastguard Worker; def-dominates-use.
78*9880d681SAndroid Build Coastguard Worker
79*9880d681SAndroid Build Coastguard Worker; CHECK-LABEL: @f_4(
80*9880d681SAndroid Build Coastguard Worker  br i1 %cond, label %left, label %merge
81*9880d681SAndroid Build Coastguard Worker
82*9880d681SAndroid Build Coastguard Workerleft:
83*9880d681SAndroid Build Coastguard Worker; CHECK: left:
84*9880d681SAndroid Build Coastguard Worker; CHECK-NEXT:  %val0 = load i32, i32* %ptr, !invariant.load !
85*9880d681SAndroid Build Coastguard Worker; CHECK-NEXT:  call void @clobber_and_use(i32 %val0)
86*9880d681SAndroid Build Coastguard Worker
87*9880d681SAndroid Build Coastguard Worker  %val0 = load i32, i32* %ptr, !invariant.load !{}
88*9880d681SAndroid Build Coastguard Worker  call void @clobber_and_use(i32 %val0)
89*9880d681SAndroid Build Coastguard Worker  br label %merge
90*9880d681SAndroid Build Coastguard Worker
91*9880d681SAndroid Build Coastguard Workermerge:
92*9880d681SAndroid Build Coastguard Worker; CHECK: merge:
93*9880d681SAndroid Build Coastguard Worker; CHECK-NEXT:   %val1 = load i32, i32* %ptr
94*9880d681SAndroid Build Coastguard Worker; CHECK-NEXT:   call void @clobber_and_use(i32 %val1)
95*9880d681SAndroid Build Coastguard Worker
96*9880d681SAndroid Build Coastguard Worker  %val1 = load i32, i32* %ptr
97*9880d681SAndroid Build Coastguard Worker  call void @clobber_and_use(i32 %val1)
98*9880d681SAndroid Build Coastguard Worker  ret void
99*9880d681SAndroid Build Coastguard Worker}
100