1 ; This test makes sure that these instructions are properly eliminated.
3 ; RUN: llvm-as < %s | opt -instcombine | llvm-dis | not grep sh
5 define i32 @test1(i32 %A) {
6 %B = shl i32 %A, 0 ; <i32> [#uses=1]
10 define i32 @test2(i8 %A) {
11 %shift.upgrd.1 = zext i8 %A to i32 ; <i32> [#uses=1]
12 %B = shl i32 0, %shift.upgrd.1 ; <i32> [#uses=1]
16 define i32 @test3(i32 %A) {
17 %B = ashr i32 %A, 0 ; <i32> [#uses=1]
21 define i32 @test4(i8 %A) {
22 %shift.upgrd.2 = zext i8 %A to i32 ; <i32> [#uses=1]
23 %B = ashr i32 0, %shift.upgrd.2 ; <i32> [#uses=1]
28 define i32 @test5(i32 %A) {
29 %B = lshr i32 %A, 32 ;; shift all bits out
33 define i32 @test5a(i32 %A) {
34 %B = shl i32 %A, 32 ;; shift all bits out
38 define i32 @test6(i32 %A) {
39 %B = shl i32 %A, 1 ;; convert to an mul instruction
44 define i32 @test7(i8 %A) {
45 %shift.upgrd.3 = zext i8 %A to i32
46 %B = ashr i32 -1, %shift.upgrd.3 ;; Always equal to -1
50 ;; (A << 5) << 3 === A << 8 == 0
51 define i8 @test8(i8 %A) {
52 %B = shl i8 %A, 5 ; <i8> [#uses=1]
53 %C = shl i8 %B, 3 ; <i8> [#uses=1]
57 ;; (A << 7) >> 7 === A & 1
58 define i8 @test9(i8 %A) {
59 %B = shl i8 %A, 7 ; <i8> [#uses=1]
60 %C = lshr i8 %B, 7 ; <i8> [#uses=1]
64 ;; (A >> 7) << 7 === A & 128
65 define i8 @test10(i8 %A) {
66 %B = lshr i8 %A, 7 ; <i8> [#uses=1]
67 %C = shl i8 %B, 7 ; <i8> [#uses=1]
71 ;; (A >> 3) << 4 === (A & 0x1F) << 1
72 define i8 @test11(i8 %A) {
73 %a = mul i8 %A, 3 ; <i8> [#uses=1]
74 %B = lshr i8 %a, 3 ; <i8> [#uses=1]
75 %C = shl i8 %B, 4 ; <i8> [#uses=1]
79 ;; (A >> 8) << 8 === A & -256
80 define i32 @test12(i32 %A) {
81 %B = ashr i32 %A, 8 ; <i32> [#uses=1]
82 %C = shl i32 %B, 8 ; <i32> [#uses=1]
86 ;; (A >> 3) << 4 === (A & -8) * 2
87 define i8 @test13(i8 %A) {
88 %a = mul i8 %A, 3 ; <i8> [#uses=1]
89 %B = ashr i8 %a, 3 ; <i8> [#uses=1]
90 %C = shl i8 %B, 4 ; <i8> [#uses=1]
94 ;; D = ((B | 1234) << 4) === ((B << 4)|(1234 << 4)
95 define i32 @test14(i32 %A) {
96 %B = lshr i32 %A, 4 ; <i32> [#uses=1]
97 %C = or i32 %B, 1234 ; <i32> [#uses=1]
98 %D = shl i32 %C, 4 ; <i32> [#uses=1]
102 ;; D = ((B | 1234) << 4) === ((B << 4)|(1234 << 4)
103 define i32 @test14a(i32 %A) {
104 %B = shl i32 %A, 4 ; <i32> [#uses=1]
105 %C = and i32 %B, 1234 ; <i32> [#uses=1]
106 %D = lshr i32 %C, 4 ; <i32> [#uses=1]
110 define i32 @test15(i1 %C) {
111 %A = select i1 %C, i32 3, i32 1 ; <i32> [#uses=1]
112 %V = shl i32 %A, 2 ; <i32> [#uses=1]
116 define i32 @test15a(i1 %C) {
117 %A = select i1 %C, i8 3, i8 1 ; <i8> [#uses=1]
118 %shift.upgrd.4 = zext i8 %A to i32 ; <i32> [#uses=1]
119 %V = shl i32 64, %shift.upgrd.4 ; <i32> [#uses=1]
123 define i1 @test16(i32 %X) {
124 %tmp.3 = ashr i32 %X, 4 ; <i32> [#uses=1]
125 %tmp.6 = and i32 %tmp.3, 1 ; <i32> [#uses=1]
126 %tmp.7 = icmp ne i32 %tmp.6, 0 ; <i1> [#uses=1]
130 define i1 @test17(i32 %A) {
131 %B = lshr i32 %A, 3 ; <i32> [#uses=1]
132 %C = icmp eq i32 %B, 1234 ; <i1> [#uses=1]
137 define i1 @test18(i8 %A) {
138 %B = lshr i8 %A, 7 ; <i8> [#uses=1]
140 %C = icmp eq i8 %B, 123 ; <i1> [#uses=1]
144 define i1 @test19(i32 %A) {
145 %B = ashr i32 %A, 2 ; <i32> [#uses=1]
147 %C = icmp eq i32 %B, 0 ; <i1> [#uses=1]
152 define i1 @test19a(i32 %A) {
153 %B = ashr i32 %A, 2 ; <i32> [#uses=1]
155 %C = icmp eq i32 %B, -1 ; <i1> [#uses=1]
159 define i1 @test20(i8 %A) {
160 %B = ashr i8 %A, 7 ; <i8> [#uses=1]
162 %C = icmp eq i8 %B, 123 ; <i1> [#uses=1]
166 define i1 @test21(i8 %A) {
167 %B = shl i8 %A, 4 ; <i8> [#uses=1]
168 %C = icmp eq i8 %B, -128 ; <i1> [#uses=1]
172 define i1 @test22(i8 %A) {
173 %B = shl i8 %A, 4 ; <i8> [#uses=1]
174 %C = icmp eq i8 %B, 0 ; <i1> [#uses=1]
178 define i8 @test23(i32 %A) {
180 %B = shl i32 %A, 24 ; <i32> [#uses=1]
181 %C = ashr i32 %B, 24 ; <i32> [#uses=1]
182 %D = trunc i32 %C to i8 ; <i8> [#uses=1]
186 define i8 @test24(i8 %X) {
187 %Y = and i8 %X, -5 ; <i8> [#uses=1]
188 %Z = shl i8 %Y, 5 ; <i8> [#uses=1]
189 %Q = ashr i8 %Z, 5 ; <i8> [#uses=1]
193 define i32 @test25(i32 %tmp.2, i32 %AA) {
194 %x = lshr i32 %AA, 17 ; <i32> [#uses=1]
195 %tmp.3 = lshr i32 %tmp.2, 17 ; <i32> [#uses=1]
196 %tmp.5 = add i32 %tmp.3, %x ; <i32> [#uses=1]
197 %tmp.6 = shl i32 %tmp.5, 17 ; <i32> [#uses=1]
201 ;; handle casts between shifts.
202 define i32 @test26(i32 %A) {
203 %B = lshr i32 %A, 1 ; <i32> [#uses=1]
204 %C = bitcast i32 %B to i32 ; <i32> [#uses=1]
205 %D = shl i32 %C, 1 ; <i32> [#uses=1]