; RUN: opt < %s -basicaa -dse -S | FileCheck %s target datalayout = "E-p:64:64:64-a0:0:8-f32:32:32-f64:64:64-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:32:64-v64:64:64-v128:128:128" declare void @llvm.memset.p0i8.i64(i8* nocapture, i8, i64, i32, i1) nounwind declare void @llvm.memcpy.p0i8.p0i8.i64(i8* nocapture, i8* nocapture, i64, i32, i1) nounwind declare i8* @llvm.init.trampoline(i8*, i8*, i8*) define void @test1(i32* %Q, i32* %P) { %DEAD = load i32* %Q store i32 %DEAD, i32* %P store i32 0, i32* %P ret void ; CHECK: @test1 ; CHECK-NEXT: store i32 0, i32* %P ; CHECK-NEXT: ret void } ; PR8576 - Should delete store of 10 even though p/q are may aliases. define void @test2(i32 *%p, i32 *%q) { store i32 10, i32* %p, align 4 store i32 20, i32* %q, align 4 store i32 30, i32* %p, align 4 ret void ; CHECK: @test2 ; CHECK-NEXT: store i32 20 } ; PR8677 @g = global i32 1 define i32 @test3(i32* %g_addr) nounwind { ; CHECK: @test3 ; CHECK: load i32* %g_addr %g_value = load i32* %g_addr, align 4 store i32 -1, i32* @g, align 4 store i32 %g_value, i32* %g_addr, align 4 %tmp3 = load i32* @g, align 4 ret i32 %tmp3 } define void @test4(i32* %Q) { %a = load i32* %Q store volatile i32 %a, i32* %Q ret void ; CHECK: @test4 ; CHECK-NEXT: load i32 ; CHECK-NEXT: store volatile ; CHECK-NEXT: ret void } define void @test5(i32* %Q) { %a = load volatile i32* %Q store i32 %a, i32* %Q ret void ; CHECK: @test5 ; CHECK-NEXT: load volatile ; CHECK-NEXT: ret void } ; Should delete store of 10 even though memset is a may-store to P (P and Q may ; alias). define void @test6(i32 *%p, i8 *%q) { store i32 10, i32* %p, align 4 ;; dead. call void @llvm.memset.p0i8.i64(i8* %q, i8 42, i64 900, i32 1, i1 false) store i32 30, i32* %p, align 4 ret void ; CHECK: @test6 ; CHECK-NEXT: call void @llvm.memset } ; Should delete store of 10 even though memcpy is a may-store to P (P and Q may ; alias). define void @test7(i32 *%p, i8 *%q, i8* noalias %r) { store i32 10, i32* %p, align 4 ;; dead. call void @llvm.memcpy.p0i8.p0i8.i64(i8* %q, i8* %r, i64 900, i32 1, i1 false) store i32 30, i32* %p, align 4 ret void ; CHECK: @test7 ; CHECK-NEXT: call void @llvm.memcpy } ; Do not delete stores that are only partially killed. define i32 @test8() { %V = alloca i32 store i32 1234567, i32* %V %V2 = bitcast i32* %V to i8* store i8 0, i8* %V2 %X = load i32* %V ret i32 %X ; CHECK: @test8 ; CHECK: store i32 1234567 } ; Test for byval handling. %struct.x = type { i32, i32, i32, i32 } define void @test9(%struct.x* byval %a) nounwind { %tmp2 = getelementptr %struct.x* %a, i32 0, i32 0 store i32 1, i32* %tmp2, align 4 ret void ; CHECK: @test9 ; CHECK-NEXT: ret void } ; va_arg has fuzzy dependence, the store shouldn't be zapped. define double @test10(i8* %X) { %X_addr = alloca i8* store i8* %X, i8** %X_addr %tmp.0 = va_arg i8** %X_addr, double ret double %tmp.0 ; CHECK: @test10 ; CHECK: store } ; DSE should delete the dead trampoline. declare void @test11f() define void @test11() { ; CHECK: @test11 %storage = alloca [10 x i8], align 16 ; <[10 x i8]*> [#uses=1] ; CHECK-NOT: alloca %cast = getelementptr [10 x i8]* %storage, i32 0, i32 0 ; <i8*> [#uses=1] %tramp = call i8* @llvm.init.trampoline( i8* %cast, i8* bitcast (void ()* @test11f to i8*), i8* null ) ; <i8*> [#uses=1] ; CHECK-NOT: trampoline ret void ; CHECK: ret void } ; PR2599 - load -> store to same address. define void @test12({ i32, i32 }* %x) nounwind { %tmp4 = getelementptr { i32, i32 }* %x, i32 0, i32 0 %tmp5 = load i32* %tmp4, align 4 %tmp7 = getelementptr { i32, i32 }* %x, i32 0, i32 1 %tmp8 = load i32* %tmp7, align 4 %tmp17 = sub i32 0, %tmp8 store i32 %tmp5, i32* %tmp4, align 4 store i32 %tmp17, i32* %tmp7, align 4 ret void ; CHECK: @test12 ; CHECK-NOT: tmp5 ; CHECK: ret void } ; %P doesn't escape, the DEAD instructions should be removed. declare void @test13f() define i32* @test13() { %p = tail call i8* @malloc(i32 4) %P = bitcast i8* %p to i32* %DEAD = load i32* %P %DEAD2 = add i32 %DEAD, 1 store i32 %DEAD2, i32* %P call void @test13f( ) store i32 0, i32* %P ret i32* %P ; CHECK: @test13() ; CHECK-NEXT: malloc ; CHECK-NEXT: bitcast ; CHECK-NEXT: call void } declare noalias i8* @malloc(i32) declare noalias i8* @calloc(i32, i32) define void @test14(i32* %Q) { %P = alloca i32 %DEAD = load i32* %Q store i32 %DEAD, i32* %P ret void ; CHECK: @test14 ; CHECK-NEXT: ret void } ; PR8701 ;; Fully dead overwrite of memcpy. define void @test15(i8* %P, i8* %Q) nounwind ssp { tail call void @llvm.memcpy.p0i8.p0i8.i64(i8* %P, i8* %Q, i64 12, i32 1, i1 false) tail call void @llvm.memcpy.p0i8.p0i8.i64(i8* %P, i8* %Q, i64 12, i32 1, i1 false) ret void ; CHECK: @test15 ; CHECK-NEXT: call void @llvm.memcpy ; CHECK-NEXT: ret } ;; Full overwrite of smaller memcpy. define void @test16(i8* %P, i8* %Q) nounwind ssp { tail call void @llvm.memcpy.p0i8.p0i8.i64(i8* %P, i8* %Q, i64 8, i32 1, i1 false) tail call void @llvm.memcpy.p0i8.p0i8.i64(i8* %P, i8* %Q, i64 12, i32 1, i1 false) ret void ; CHECK: @test16 ; CHECK-NEXT: call void @llvm.memcpy ; CHECK-NEXT: ret } ;; Overwrite of memset by memcpy. define void @test17(i8* %P, i8* noalias %Q) nounwind ssp { tail call void @llvm.memset.p0i8.i64(i8* %P, i8 42, i64 8, i32 1, i1 false) tail call void @llvm.memcpy.p0i8.p0i8.i64(i8* %P, i8* %Q, i64 12, i32 1, i1 false) ret void ; CHECK: @test17 ; CHECK-NEXT: call void @llvm.memcpy ; CHECK-NEXT: ret } ; Should not delete the volatile memset. define void @test17v(i8* %P, i8* %Q) nounwind ssp { tail call void @llvm.memset.p0i8.i64(i8* %P, i8 42, i64 8, i32 1, i1 true) tail call void @llvm.memcpy.p0i8.p0i8.i64(i8* %P, i8* %Q, i64 12, i32 1, i1 false) ret void ; CHECK: @test17v ; CHECK-NEXT: call void @llvm.memset ; CHECK-NEXT: call void @llvm.memcpy ; CHECK-NEXT: ret } ; PR8728 ; Do not delete instruction where possible situation is: ; A = B ; A = A define void @test18(i8* %P, i8* %Q, i8* %R) nounwind ssp { tail call void @llvm.memcpy.p0i8.p0i8.i64(i8* %P, i8* %Q, i64 12, i32 1, i1 false) tail call void @llvm.memcpy.p0i8.p0i8.i64(i8* %P, i8* %R, i64 12, i32 1, i1 false) ret void ; CHECK: @test18 ; CHECK-NEXT: call void @llvm.memcpy ; CHECK-NEXT: call void @llvm.memcpy ; CHECK-NEXT: ret } ; The store here is not dead because the byval call reads it. declare void @test19f({i32}* byval align 4 %P) define void @test19({i32} * nocapture byval align 4 %arg5) nounwind ssp { bb: %tmp7 = getelementptr inbounds {i32}* %arg5, i32 0, i32 0 store i32 912, i32* %tmp7 call void @test19f({i32}* byval align 4 %arg5) ret void ; CHECK: @test19( ; CHECK: store i32 912 ; CHECK: call void @test19f } define void @test20() { %m = call i8* @malloc(i32 24) store i8 0, i8* %m ret void } ; CHECK: @test20 ; CHECK-NEXT: ret void ; CHECK: @test21 define void @test21() { %m = call i8* @calloc(i32 9, i32 7) store i8 0, i8* %m ; CHECK-NEXT: ret void ret void } ; CHECK: @test22( define void @test22(i1 %i, i32 %k, i32 %m) nounwind { %k.addr = alloca i32 %m.addr = alloca i32 %k.addr.m.addr = select i1 %i, i32* %k.addr, i32* %m.addr store i32 0, i32* %k.addr.m.addr, align 4 ; CHECK-NEXT: ret void ret void } ; PR13547 ; CHECK: @test23 ; CHECK: store i8 97 ; CHECK: store i8 0 declare noalias i8* @strdup(i8* nocapture) nounwind define noalias i8* @test23() nounwind uwtable ssp { %x = alloca [2 x i8], align 1 %arrayidx = getelementptr inbounds [2 x i8]* %x, i64 0, i64 0 store i8 97, i8* %arrayidx, align 1 %arrayidx1 = getelementptr inbounds [2 x i8]* %x, i64 0, i64 1 store i8 0, i8* %arrayidx1, align 1 %call = call i8* @strdup(i8* %arrayidx) nounwind ret i8* %call } ; Make sure same sized store to later element is deleted ; CHECK: @test24 ; CHECK-NOT: store i32 0 ; CHECK-NOT: store i32 0 ; CHECK: store i32 %b ; CHECK: store i32 %c ; CHECK: ret void define void @test24([2 x i32]* %a, i32 %b, i32 %c) nounwind { %1 = getelementptr inbounds [2 x i32]* %a, i64 0, i64 0 store i32 0, i32* %1, align 4 %2 = getelementptr inbounds [2 x i32]* %a, i64 0, i64 1 store i32 0, i32* %2, align 4 %3 = getelementptr inbounds [2 x i32]* %a, i64 0, i64 0 store i32 %b, i32* %3, align 4 %4 = getelementptr inbounds [2 x i32]* %a, i64 0, i64 1 store i32 %c, i32* %4, align 4 ret void } ; Check another case like PR13547 where strdup is not like malloc. ; CHECK: @test25 ; CHECK: load i8 ; CHECK: store i8 0 ; CHECK: store i8 %tmp define i8* @test25(i8* %p) nounwind { %p.4 = getelementptr i8* %p, i64 4 %tmp = load i8* %p.4, align 1 store i8 0, i8* %p.4, align 1 %q = call i8* @strdup(i8* %p) nounwind optsize store i8 %tmp, i8* %p.4, align 1 ret i8* %q }