hfinkel
commented
10 years ago Reverted in r213023. Please fix and reapply!
Reapplied (hopefully in a strictly-better state this time) in r213219. Thanks!
Closed llvmbot closed 10 years ago
hfinkel
commented
10 years ago Reverted in r213023. Please fix and reapply!
Reapplied (hopefully in a strictly-better state this time) in r213219. Thanks!
llvmbot
commented
10 years ago Reverted in r213023. Please fix and reapply!
llvmbot
commented
10 years ago assigned to @hfinkel
Extended Description
Testcase with opt -basicaa -dse:
; ModuleID = 'z4.ll' target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128" target triple = "x86_64-unknown-linux-gnu"
%class.basic_string = type { %"class.gnu_cxx::__versa_string" } %"class.gnu_cxx::versa_string" = type { %"class.__gnu_cxx::sso_string_base" } %"class.gnu_cxx::sso_string_base" = type { %"struct.gnu_cxx::vstring_utility<char, std::char_traits, std::allocator >::_Alloc_hider", i64, %union.anon }
%"struct.__gnu_cxx::__vstring_utility<char, std::char_traits, std::allocator >::_Alloc_hider" = type { i8* }
%union.anon = type { i64, [8 x i8] }
; Function Attrs: nounwind declare void @llvm.memset.p0i8.i64(i8* nocapture, i8, i64, i32, i1) #0
; Function Attrs: noinline nounwind readonly uwtable declare zeroext i1 @callee_takes_string(%class.basic_string* nonnull) #1 align 2
; Function Attrs: nounwind uwtable define weak_odr zeroext i1 @test() #2 align 2 { bb: %tmp = alloca %class.basic_string, align 8 %tmp1 = alloca %class.basic_string, align 8 %tmp3 = getelementptr inbounds %class.basic_string %tmp, i64 0, i32 0, i32 0, i32 2 %tmp4 = bitcast %union.anon %tmp3 to i8 %tmp5 = getelementptr inbounds %class.basic_string %tmp, i64 0, i32 0, i32 0, i32 0, i32 0 %tmp6 = getelementptr inbounds %class.basic_string %tmp, i64 0, i32 0, i32 0, i32 1 %tmp7 = getelementptr inbounds i8 %tmp4, i64 1 %tmp8 = bitcast %class.basic_string %tmp to i8 %tmp9 = bitcast i64 0 to i64 %tmp10 = getelementptr inbounds %class.basic_string %tmp1, i64 0, i32 0, i32 0, i32 2 %tmp11 = bitcast %union.anon %tmp10 to i8 %tmp12 = getelementptr inbounds %class.basic_string %tmp1, i64 0, i32 0, i32 0, i32 0, i32 0 %tmp13 = getelementptr inbounds %class.basic_string %tmp1, i64 0, i32 0, i32 0, i32 1 %tmp14 = getelementptr inbounds i8 %tmp11, i64 1 %tmp15 = bitcast %class.basic_string %tmp1 to i8 br label %_ZN12basic_stringIcSt11chartraitsIcESaIcEEC2EPKcRKS2.exit
_ZN12basic_stringIcSt11chartraitsIcESaIcEEC2EPKcRKS2.exit: ; preds = %bb store i8* %tmp4, i8* %tmp5, align 8 store i8 62, i8 %tmp4, align 8 store i64 1, i64 %tmp6, align 8 store i8 0, i8 %tmp7, align 1 %tmp16 = call zeroext i1 @callee_takes_string(%class.basic_string* nonnull %tmp) br label %_ZN9__gnu_cxx17__sso_string_baseIcSt11char_traitsIcESaIcEED2Ev.exit3
_ZN9__gnu_cxx17__sso_string_baseIcSt11char_traitsIcESaIcEED2Ev.exit3: ; preds = %_ZN12basic_stringIcSt11chartraitsIcESaIcEEC2EPKcRKS2.exit ;; The following stores are eliminated, but they can be read through the call %tmp17! store i8* %tmp11, i8* %tmp12, align 8 store i8 125, i8 %tmp11, align 8 store i64 1, i64 %tmp13, align 8 store i8 0, i8 %tmp14, align 1 %tmp17 = call zeroext i1 @callee_takes_string(%class.basic_string nonnull %tmp1) ;; Commenting out the following memsets brings the stores back. call void @llvm.memset.p0i8.i64(i8 %tmp11, i8 -51, i64 16, i32 8, i1 false) #0 call void @llvm.memset.p0i8.i64(i8 %tmp15, i8 -51, i64 32, i32 8, i1 false) #0 call void @llvm.memset.p0i8.i64(i8 %tmp4, i8 -51, i64 16, i32 8, i1 false) #0 call void @llvm.memset.p0i8.i64(i8* %tmp8, i8 -51, i64 32, i32 8, i1 false) #0 ret i1 %tmp17 }
attributes #0 = { nounwind } attributes #1 = { noinline nounwind readonly uwtable "less-precise-fpmad"="false" "no-frame-pointer-elim"="false" "no-frame-pointer-elim-non-leaf" "no-infs-fp-math"="false" "no-nans-fp-math"="false" "stack-protector-buffer-size"="8" "unsafe-fp-math"="false" "use-soft-float"="false" } attributes #2 = { nounwind uwtable "less-precise-fpmad"="false" "no-frame-pointer-elim"="false" "no-frame-pointer-elim-non-leaf" "no-infs-fp-math"="false" "no-nans-fp-math"="false" "stack-protector-buffer-size"="8" "unsafe-fp-math"="false" "use-soft-float"="false" }
!llvm.ident = !{#0}
!0 = metadata !{metadata !"clang version r212716"}