llvm/test/Transforms/GlobalOpt/cxx-dtor.ll
Benjamin Kramer d469274743 GlobalOpt: Be more aggressive about elminating side-effect free static dtors.
GlobalOpt runs early in the pipeline (before inlining) and complex class
hierarchies often introduce bitcasts or GEPs which weren't optimized away.
Teach it to ignore side-effect free instructions instead of depending on
other passes to remove them.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@150174 91177308-0d34-0410-b5e6-96231b3b80d8
2012-02-09 14:26:06 +00:00

34 lines
1.1 KiB
LLVM

; RUN: opt < %s -globalopt -S | FileCheck %s
%0 = type { i32, void ()* }
%struct.A = type { i8 }
%struct.B = type { }
@a = global %struct.A zeroinitializer, align 1
@__dso_handle = external global i8*
@llvm.global_ctors = appending global [1 x %0] [%0 { i32 65535, void ()* @_GLOBAL__I_a }]
; CHECK-NOT: call i32 @__cxa_atexit
define internal void @__cxx_global_var_init() nounwind section "__TEXT,__StaticInit,regular,pure_instructions" {
%1 = call i32 @__cxa_atexit(void (i8*)* bitcast (void (%struct.A*)* @_ZN1AD1Ev to void (i8*)*), i8* getelementptr inbounds (%struct.A* @a, i32 0, i32 0), i8* bitcast (i8** @__dso_handle to i8*))
ret void
}
define linkonce_odr void @_ZN1AD1Ev(%struct.A* %this) nounwind align 2 {
%t = bitcast %struct.A* %this to %struct.B*
call void @_ZN1BD1Ev(%struct.B* %t)
ret void
}
declare i32 @__cxa_atexit(void (i8*)*, i8*, i8*)
define linkonce_odr void @_ZN1BD1Ev(%struct.B* %this) nounwind align 2 {
ret void
}
define internal void @_GLOBAL__I_a() nounwind section "__TEXT,__StaticInit,regular,pure_instructions" {
call void @__cxx_global_var_init()
ret void
}