1 ; RUN: opt < %s -gvn -S | FileCheck %s 2 3 %struct.A = type { i32 (...)** } 4 @_ZTV1A = available_externally unnamed_addr constant [4 x i8*] [i8* null, i8* bitcast (i8** @_ZTI1A to i8*), i8* bitcast (i32 (%struct.A*)* @_ZN1A3fooEv to i8*), i8* bitcast (i32 (%struct.A*)* @_ZN1A3barEv to i8*)], align 8 5 @_ZTI1A = external constant i8* 6 7 ; Checks if indirect calls can be replaced with direct 8 ; assuming that %vtable == @_ZTV1A (with alignment). 9 ; Checking const propagation across other BBs 10 ; CHECK-LABEL: define void @_Z1gb( 11 12 define void @_Z1gb(i1 zeroext %p) { 13 entry: 14 %call = tail call noalias i8* @_Znwm(i64 8) #4 15 %0 = bitcast i8* %call to %struct.A* 16 tail call void @_ZN1AC1Ev(%struct.A* %0) #1 17 %1 = bitcast i8* %call to i8*** 18 %vtable = load i8**, i8*** %1, align 8 19 %cmp.vtables = icmp eq i8** %vtable, getelementptr inbounds ([4 x i8*], [4 x i8*]* @_ZTV1A, i64 0, i64 2) 20 tail call void @llvm.assume(i1 %cmp.vtables) 21 br i1 %p, label %if.then, label %if.else 22 23 if.then: ; preds = %entry 24 %vtable1.cast = bitcast i8** %vtable to i32 (%struct.A*)** 25 %2 = load i32 (%struct.A*)*, i32 (%struct.A*)** %vtable1.cast, align 8 26 27 ; CHECK: call i32 @_ZN1A3fooEv( 28 %call2 = tail call i32 %2(%struct.A* %0) #1 29 30 br label %if.end 31 32 if.else: ; preds = %entry 33 %vfn47 = getelementptr inbounds i8*, i8** %vtable, i64 1 34 %vfn4 = bitcast i8** %vfn47 to i32 (%struct.A*)** 35 36 ; CHECK: call i32 @_ZN1A3barEv( 37 %3 = load i32 (%struct.A*)*, i32 (%struct.A*)** %vfn4, align 8 38 39 %call5 = tail call i32 %3(%struct.A* %0) #1 40 br label %if.end 41 42 if.end: ; preds = %if.else, %if.then 43 ret void 44 } 45 46 ; Check integration with invariant.group handling 47 ; CHECK-LABEL: define void @invariantGroupHandling(i1 zeroext %p) { 48 define void @invariantGroupHandling(i1 zeroext %p) { 49 entry: 50 %call = tail call noalias i8* @_Znwm(i64 8) #4 51 %0 = bitcast i8* %call to %struct.A* 52 tail call void @_ZN1AC1Ev(%struct.A* %0) #1 53 %1 = bitcast i8* %call to i8*** 54 %vtable = load i8**, i8*** %1, align 8, !invariant.group !0 55 %cmp.vtables = icmp eq i8** %vtable, getelementptr inbounds ([4 x i8*], [4 x i8*]* @_ZTV1A, i64 0, i64 2) 56 tail call void @llvm.assume(i1 %cmp.vtables) 57 br i1 %p, label %if.then, label %if.else 58 59 if.then: ; preds = %entry 60 %vtable1.cast = bitcast i8** %vtable to i32 (%struct.A*)** 61 %2 = load i32 (%struct.A*)*, i32 (%struct.A*)** %vtable1.cast, align 8 62 63 ; CHECK: call i32 @_ZN1A3fooEv( 64 %call2 = tail call i32 %2(%struct.A* %0) #1 65 %vtable1 = load i8**, i8*** %1, align 8, !invariant.group !0 66 %vtable2.cast = bitcast i8** %vtable1 to i32 (%struct.A*)** 67 %call1 = load i32 (%struct.A*)*, i32 (%struct.A*)** %vtable2.cast, align 8 68 ; CHECK: call i32 @_ZN1A3fooEv( 69 %callx = tail call i32 %call1(%struct.A* %0) #1 70 71 %vtable2 = load i8**, i8*** %1, align 8, !invariant.group !0 72 %vtable3.cast = bitcast i8** %vtable2 to i32 (%struct.A*)** 73 %call4 = load i32 (%struct.A*)*, i32 (%struct.A*)** %vtable3.cast, align 8 74 ; CHECK: call i32 @_ZN1A3fooEv( 75 %cally = tail call i32 %call4(%struct.A* %0) #1 76 77 %b = bitcast i8* %call to %struct.A** 78 %vtable3 = load %struct.A*, %struct.A** %b, align 8, !invariant.group !0 79 %vtable4.cast = bitcast %struct.A* %vtable3 to i32 (%struct.A*)** 80 %vfun = load i32 (%struct.A*)*, i32 (%struct.A*)** %vtable4.cast, align 8 81 ; CHECK: call i32 @_ZN1A3fooEv( 82 %unknown = tail call i32 %vfun(%struct.A* %0) #1 83 84 br label %if.end 85 86 if.else: ; preds = %entry 87 %vfn47 = getelementptr inbounds i8*, i8** %vtable, i64 1 88 %vfn4 = bitcast i8** %vfn47 to i32 (%struct.A*)** 89 90 ; CHECK: call i32 @_ZN1A3barEv( 91 %3 = load i32 (%struct.A*)*, i32 (%struct.A*)** %vfn4, align 8 92 93 %call5 = tail call i32 %3(%struct.A* %0) #1 94 br label %if.end 95 96 if.end: ; preds = %if.else, %if.then 97 ret void 98 } 99 100 101 ; Checking const propagation in the same BB 102 ; CHECK-LABEL: define i32 @main() 103 104 define i32 @main() { 105 entry: 106 %call = tail call noalias i8* @_Znwm(i64 8) 107 %0 = bitcast i8* %call to %struct.A* 108 tail call void @_ZN1AC1Ev(%struct.A* %0) 109 %1 = bitcast i8* %call to i8*** 110 %vtable = load i8**, i8*** %1, align 8 111 %cmp.vtables = icmp eq i8** %vtable, getelementptr inbounds ([4 x i8*], [4 x i8*]* @_ZTV1A, i64 0, i64 2) 112 tail call void @llvm.assume(i1 %cmp.vtables) 113 %vtable1.cast = bitcast i8** %vtable to i32 (%struct.A*)** 114 115 ; CHECK: call i32 @_ZN1A3fooEv( 116 %2 = load i32 (%struct.A*)*, i32 (%struct.A*)** %vtable1.cast, align 8 117 118 %call2 = tail call i32 %2(%struct.A* %0) 119 ret i32 0 120 } 121 122 ; This tests checks const propatation with fcmp instruction. 123 ; CHECK-LABEL: define float @_Z1gf(float %p) 124 125 define float @_Z1gf(float %p) { 126 entry: 127 %p.addr = alloca float, align 4 128 %f = alloca float, align 4 129 store float %p, float* %p.addr, align 4 130 131 store float 3.000000e+00, float* %f, align 4 132 %0 = load float, float* %p.addr, align 4 133 %1 = load float, float* %f, align 4 134 %cmp = fcmp oeq float %1, %0 ; note const on lhs 135 call void @llvm.assume(i1 %cmp) 136 137 ; CHECK: ret float 3.000000e+00 138 ret float %0 139 } 140 141 ; CHECK-LABEL: define float @_Z1hf(float %p) 142 143 define float @_Z1hf(float %p) { 144 entry: 145 %p.addr = alloca float, align 4 146 store float %p, float* %p.addr, align 4 147 148 %0 = load float, float* %p.addr, align 4 149 %cmp = fcmp nnan ueq float %0, 3.000000e+00 150 call void @llvm.assume(i1 %cmp) 151 152 ; CHECK: ret float 3.000000e+00 153 ret float %0 154 } 155 156 ; CHECK-LABEL: define float @_Z1if(float %p) 157 define float @_Z1if(float %p) { 158 entry: 159 %p.addr = alloca float, align 4 160 store float %p, float* %p.addr, align 4 161 162 %0 = load float, float* %p.addr, align 4 163 %cmp = fcmp ueq float %0, 3.000000e+00 ; no nnan flag - can't propagate 164 call void @llvm.assume(i1 %cmp) 165 166 ; CHECK-NOT: ret float 3.000000e+00 167 ret float %0 168 } 169 170 ; This test checks if constant propagation works for multiple node edges 171 ; CHECK-LABEL: define i32 @_Z1ii(i32 %p) 172 define i32 @_Z1ii(i32 %p) { 173 entry: 174 %cmp = icmp eq i32 %p, 42 175 call void @llvm.assume(i1 %cmp) 176 177 ; CHECK: br i1 true, label %bb2, label %bb2 178 br i1 %cmp, label %bb2, label %bb2 179 bb2: 180 call void @llvm.assume(i1 true) 181 ; CHECK: br i1 true, label %bb2, label %bb2 182 br i1 %cmp, label %bb2, label %bb2 183 184 ; CHECK: ret i32 42 185 ret i32 %p 186 } 187 188 ; CHECK-LABEL: define i32 @_Z1ij(i32 %p) 189 define i32 @_Z1ij(i32 %p) { 190 entry: 191 %cmp = icmp eq i32 %p, 42 192 call void @llvm.assume(i1 %cmp) 193 194 ; CHECK: br i1 true, label %bb2, label %bb2 195 br i1 %cmp, label %bb2, label %bb2 196 bb2: 197 ; CHECK-NOT: %cmp2 = 198 %cmp2 = icmp eq i32 %p, 42 199 ; CHECK-NOT: call void @llvm.assume( 200 call void @llvm.assume(i1 %cmp2) 201 202 ; CHECK: br i1 true, label %bb2, label %bb2 203 br i1 %cmp, label %bb2, label %bb2 204 205 ; CHECK: ret i32 42 206 ret i32 %p 207 } 208 209 ; CHECK-LABEL: define i32 @_Z1ik(i32 %p) 210 define i32 @_Z1ik(i32 %p) { 211 entry: 212 %cmp = icmp eq i32 %p, 42 213 call void @llvm.assume(i1 %cmp) 214 215 ; CHECK: br i1 true, label %bb2, label %bb3 216 br i1 %cmp, label %bb2, label %bb3 217 bb2: 218 ; CHECK-NOT: %cmp3 = 219 %cmp3 = icmp eq i32 %p, 43 220 ; CHECK: store i8 undef, i8* null 221 call void @llvm.assume(i1 %cmp3) 222 ret i32 15 223 bb3: 224 ret i32 17 225 } 226 227 ; This test checks if GVN can do the constant propagation correctly 228 ; when there are multiple uses of the same assume value in the 229 ; basic block that has a loop back-edge pointing to itself. 230 ; 231 ; CHECK-LABEL: define i32 @_Z1il(i32 %val, i1 %k) 232 define i32 @_Z1il(i32 %val, i1 %k) { 233 br label %next 234 235 next: 236 ; CHECK: tail call void @llvm.assume(i1 %k) 237 ; CHECK-NEXT: %cmp = icmp eq i32 %val, 50 238 tail call void @llvm.assume(i1 %k) 239 tail call void @llvm.assume(i1 %k) 240 %cmp = icmp eq i32 %val, 50 241 br i1 %cmp, label %next, label %meh 242 243 meh: 244 ret i32 0 245 } 246 247 ; This test checks if GVN can prevent the constant propagation correctly 248 ; in the successor blocks that are not dominated by the basic block 249 ; with the assume instruction. 250 ; 251 ; CHECK-LABEL: define i1 @_z1im(i32 %val, i1 %k, i1 %j) 252 define i1 @_z1im(i32 %val, i1 %k, i1 %j) { 253 br i1 %j, label %next, label %meh 254 255 next: 256 ; CHECK: tail call void @llvm.assume(i1 %k) 257 ; CHECK-NEXT: br label %meh 258 tail call void @llvm.assume(i1 %k) 259 tail call void @llvm.assume(i1 %k) 260 br label %meh 261 262 meh: 263 ; CHECK: ret i1 %k 264 ret i1 %k 265 } 266 267 declare noalias i8* @_Znwm(i64) 268 declare void @_ZN1AC1Ev(%struct.A*) 269 declare void @llvm.assume(i1) 270 declare i32 @_ZN1A3fooEv(%struct.A*) 271 declare i32 @_ZN1A3barEv(%struct.A*) 272 273 !0 = !{!"struct A"} 274
