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c++ new operators are not malloc-like functions because they do not return uninitialized memory. 

Users may overide new-operators and implement any function that they like.

llvm-svn: 179071
This commit is contained in:
Nadav Rotem 2013-04-08 23:40:47 +00:00
parent c20bb32c45
commit 9dd90ac5b4
4 changed files with 21 additions and 25 deletions
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8
llvm/lib/Analysis/MemoryBuiltins.cpp
View File

@ -52,14 +52,6 @@ struct AllocFnsTy {
static const AllocFnsTy AllocationFnData[] = {
{LibFunc::malloc, MallocLike, 1, 0, -1},
{LibFunc::valloc, MallocLike, 1, 0, -1},
{LibFunc::Znwj, MallocLike, 1, 0, -1}, // new(unsigned int)
{LibFunc::ZnwjRKSt9nothrow_t, MallocLike, 2, 0, -1}, // new(unsigned int, nothrow)
{LibFunc::Znwm, MallocLike, 1, 0, -1}, // new(unsigned long)
{LibFunc::ZnwmRKSt9nothrow_t, MallocLike, 2, 0, -1}, // new(unsigned long, nothrow)
{LibFunc::Znaj, MallocLike, 1, 0, -1}, // new[](unsigned int)
{LibFunc::ZnajRKSt9nothrow_t, MallocLike, 2, 0, -1}, // new[](unsigned int, nothrow)
{LibFunc::Znam, MallocLike, 1, 0, -1}, // new[](unsigned long)
{LibFunc::ZnamRKSt9nothrow_t, MallocLike, 2, 0, -1}, // new[](unsigned long, nothrow)
{LibFunc::posix_memalign, MallocLike, 3, 2, -1},
{LibFunc::calloc, CallocLike, 2, 0, 1},
{LibFunc::realloc, ReallocLike, 2, 1, -1},

20
llvm/test/Transforms/GVN/newoperator.ll Normal file
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@ -0,0 +1,20 @@
; RUN: opt < %s -basicaa -gvn -S | FileCheck %s
; We can't remove the load because new operators are overideable and can return non-undefined memory.
;CHECK: main
;CHECK: load
;CHECK: ret
define i32 @main(i32 %argc, i8** nocapture %argv) ssp uwtable {
%1 = tail call noalias i8* @_Znam(i64 800)
%2 = bitcast i8* %1 to i32**
%3 = load i32** %2, align 8, !tbaa !0
%4 = icmp eq i32* %3, null
%5 = zext i1 %4 to i32
ret i32 %5
}
declare noalias i8* @_Znam(i64)
!0 = metadata !{metadata !"any pointer", metadata !1}
!1 = metadata !{metadata !"omnipotent char", metadata !2}
!2 = metadata !{metadata !"Simple C/C++ TBAA"}

16
llvm/test/Transforms/InstCombine/invoke.ll
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@ -47,19 +47,3 @@ lpad:
unreachable
}
; CHECK: @f3
define void @f3() nounwind uwtable ssp {
; CHECK: invoke void @llvm.donothing()
%call = invoke noalias i8* @_Znwm(i64 13)
to label %invoke.cont unwind label %lpad
invoke.cont:
ret void
lpad:
%1 = landingpad { i8*, i32 } personality i8* bitcast (i32 (...)* @__gxx_personality_v0 to i8*)
filter [0 x i8*] zeroinitializer
%2 = extractvalue { i8*, i32 } %1, 0
tail call void @__cxa_call_unexpected(i8* %2) noreturn nounwind
unreachable
}

2
llvm/test/Transforms/InstCombine/objsize-64.ll
View File

@ -25,7 +25,7 @@ entry:
to label %invoke.cont unwind label %lpad
invoke.cont:
; CHECK: ret i64 13
; CHECK: ret i64 %0
store i8* %call, i8** %esc
%0 = tail call i64 @llvm.objectsize.i64(i8* %call, i1 false)
ret i64 %0