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1; RUN: opt -instcombine -S < %s | FileCheck %s
2; RUN: opt -passes=instcombine -S < %s | FileCheck %s
3
4; This test makes sure that these instructions are properly eliminated.
5
6target datalayout = "e-m:e-p:64:64:64-i64:64-f80:128-n8:16:32:64-S128"
7
8@X = constant i32 42		; <i32*> [#uses=2]
9@X2 = constant i32 47		; <i32*> [#uses=1]
10@Y = constant [2 x { i32, float }] [ { i32, float } { i32 12, float 1.000000e+00 }, { i32, float } { i32 37, float 0x3FF3B2FEC0000000 } ]		; <[2 x { i32, float }]*> [#uses=2]
11@Z = constant [2 x { i32, float }] zeroinitializer		; <[2 x { i32, float }]*> [#uses=1]
12
13@GLOBAL = internal constant [4 x i32] zeroinitializer
14
15
16; CHECK-LABEL: @test1(
17; CHECK-NOT: load
18define i32 @test1() {
19	%B = load i32, i32* @X		; <i32> [#uses=1]
20	ret i32 %B
21}
22
23; CHECK-LABEL: @test2(
24; CHECK-NOT: load
25define float @test2() {
26	%A = getelementptr [2 x { i32, float }], [2 x { i32, float }]* @Y, i64 0, i64 1, i32 1		; <float*> [#uses=1]
27	%B = load float, float* %A		; <float> [#uses=1]
28	ret float %B
29}
30
31; CHECK-LABEL: @test3(
32; CHECK-NOT: load
33define i32 @test3() {
34	%A = getelementptr [2 x { i32, float }], [2 x { i32, float }]* @Y, i64 0, i64 0, i32 0		; <i32*> [#uses=1]
35	%B = load i32, i32* %A		; <i32> [#uses=1]
36	ret i32 %B
37}
38
39; CHECK-LABEL: @test4(
40; CHECK-NOT: load
41define i32 @test4() {
42	%A = getelementptr [2 x { i32, float }], [2 x { i32, float }]* @Z, i64 0, i64 1, i32 0		; <i32*> [#uses=1]
43	%B = load i32, i32* %A		; <i32> [#uses=1]
44	ret i32 %B
45}
46
47; CHECK-LABEL: @test5(
48; CHECK-NOT: load
49define i32 @test5(i1 %C) {
50	%Y = select i1 %C, i32* @X, i32* @X2		; <i32*> [#uses=1]
51	%Z = load i32, i32* %Y		; <i32> [#uses=1]
52	ret i32 %Z
53}
54
55; CHECK-LABEL: @test7(
56; CHECK-NOT: load
57define i32 @test7(i32 %X) {
58	%V = getelementptr i32, i32* null, i32 %X		; <i32*> [#uses=1]
59	%R = load i32, i32* %V		; <i32> [#uses=1]
60	ret i32 %R
61}
62
63; CHECK-LABEL: @test8(
64; CHECK-NOT: load
65define i32 @test8(i32* %P) {
66	store i32 1, i32* %P
67	%X = load i32, i32* %P		; <i32> [#uses=1]
68	ret i32 %X
69}
70
71; CHECK-LABEL: @test9(
72; CHECK-NOT: load
73define i32 @test9(i32* %P) {
74	%X = load i32, i32* %P		; <i32> [#uses=1]
75	%Y = load i32, i32* %P		; <i32> [#uses=1]
76	%Z = sub i32 %X, %Y		; <i32> [#uses=1]
77	ret i32 %Z
78}
79
80; CHECK-LABEL: @test10(
81; CHECK-NOT: load
82define i32 @test10(i1 %C.upgrd.1, i32* %P, i32* %Q) {
83	br i1 %C.upgrd.1, label %T, label %F
84T:		; preds = %0
85	store i32 1, i32* %Q
86	store i32 0, i32* %P
87	br label %C
88F:		; preds = %0
89	store i32 0, i32* %P
90	br label %C
91C:		; preds = %F, %T
92	%V = load i32, i32* %P		; <i32> [#uses=1]
93	ret i32 %V
94}
95
96; CHECK-LABEL: @test11(
97; CHECK-NOT: load
98define double @test11(double* %p) {
99  %t0 = getelementptr double, double* %p, i32 1
100  store double 2.0, double* %t0
101  %t1 = getelementptr double, double* %p, i32 1
102  %x = load double, double* %t1
103  ret double %x
104}
105
106; CHECK-LABEL: @test12(
107; CHECK-NOT: load
108define i32 @test12(i32* %P) {
109  %A = alloca i32
110  store i32 123, i32* %A
111  ; Cast the result of the load not the source
112  %Q = bitcast i32* %A to i32*
113  %V = load i32, i32* %Q
114  ret i32 %V
115}
116
117; CHECK-LABEL: @test13(
118; CHECK-NOT: load
119define <16 x i8> @test13(<2 x i64> %x) {
120  %tmp = load <16 x i8>, <16 x i8>* bitcast ([4 x i32]* @GLOBAL to <16 x i8>*)
121  ret <16 x i8> %tmp
122}
123
124define i8 @test14(i8 %x, i32 %y) {
125; This test must not have the store of %x forwarded to the load -- there is an
126; intervening store if %y. However, the intervening store occurs with a different
127; type and size and to a different pointer value. This is ensuring that none of
128; those confuse the analysis into thinking that the second store does not alias
129; the first.
130; CHECK-LABEL: @test14(
131; CHECK:         %[[R:.*]] = load i8, i8*
132; CHECK-NEXT:    ret i8 %[[R]]
133  %a = alloca i32
134  %a.i8 = bitcast i32* %a to i8*
135  store i8 %x, i8* %a.i8
136  store i32 %y, i32* %a
137  %r = load i8, i8* %a.i8
138  ret i8 %r
139}
140
141@test15_global = external global i32
142
143define i8 @test15(i8 %x, i32 %y) {
144; Same test as @test14 essentially, but using a global instead of an alloca.
145; CHECK-LABEL: @test15(
146; CHECK:         %[[R:.*]] = load i8, i8*
147; CHECK-NEXT:    ret i8 %[[R]]
148  %g.i8 = bitcast i32* @test15_global to i8*
149  store i8 %x, i8* %g.i8
150  store i32 %y, i32* @test15_global
151  %r = load i8, i8* %g.i8
152  ret i8 %r
153}
154
155define void @test16(i8* %x, i8* %a, i8* %b, i8* %c) {
156; Check that we canonicalize loads which are only stored to use integer types
157; when there is a valid integer type.
158; CHECK-LABEL: @test16(
159; CHECK: %[[L1:.*]] = load i32, i32*
160; CHECK-NOT: load
161; CHECK: store i32 %[[L1]], i32*
162; CHECK: store i32 %[[L1]], i32*
163; CHECK-NOT: store
164; CHECK: %[[L1:.*]] = load i32, i32*
165; CHECK-NOT: load
166; CHECK: store i32 %[[L1]], i32*
167; CHECK: store i32 %[[L1]], i32*
168; CHECK-NOT: store
169; CHECK: ret
170
171entry:
172  %x.cast = bitcast i8* %x to float*
173  %a.cast = bitcast i8* %a to float*
174  %b.cast = bitcast i8* %b to float*
175  %c.cast = bitcast i8* %c to i32*
176
177  %x1 = load float, float* %x.cast
178  store float %x1, float* %a.cast
179  store float %x1, float* %b.cast
180
181  %x2 = load float, float* %x.cast
182  store float %x2, float* %b.cast
183  %x2.cast = bitcast float %x2 to i32
184  store i32 %x2.cast, i32* %c.cast
185
186  ret void
187}
188
189define void @test17(i8** %x, i8 %y) {
190; Check that in cases similar to @test16 we don't try to rewrite a load when
191; its only use is a store but it is used as the pointer to that store rather
192; than the value.
193;
194; CHECK-LABEL: @test17(
195; CHECK: %[[L:.*]] = load i8*, i8**
196; CHECK: store i8 %y, i8* %[[L]]
197
198entry:
199  %x.load = load i8*, i8** %x
200  store i8 %y, i8* %x.load
201
202  ret void
203}
204