Optimization issues

dump-2.ll

; Function Attrs: uwtable
define internal fastcc void @_ZN4main16_d7d397690bb61803_00E() #1 {
static_allocas:
  %tmp.i = alloca { i64, %tydesc*, {}*, {}*, { i64* } }, align 8
  %tmp5 = alloca i64, align 8
  %tmp13 = bitcast i64* %tmp5 to i8*
  call void @llvm.lifetime.start(i64 8, i8* %tmp13)
  store i64 543210, i64* %tmp5, align 8
  %0 = bitcast { i64, %tydesc*, {}*, {}*, { i64* } }* %tmp.i to i8*
  call void @llvm.lifetime.start(i64 40, i8* %0)
  %tmp6.i = bitcast { i64, %tydesc*, {}*, {}*, { i64* } }* %tmp.i to { i64, %tydesc*, i8*, i8*, i8 }*
  %tmp7.i = getelementptr inbounds { i64, %tydesc*, {}*, {}*, { i64* } }* %tmp.i, i64 0, i32 0
  store i64 305419896, i64* %tmp7.i, align 8
  %tmp8.i1 = getelementptr inbounds { i64, %tydesc*, {}*, {}*, { i64* } }* %tmp.i, i64 0, i32 4, i32 0
  store i64* %tmp5, i64** %tmp8.i1, align 8
  call void @llvm.lifetime.end(i64 40, i8* %0)
  %tmp12.i = call {} @_ZN4test4anon4anon12expr_fn_2958E({ i64, %tydesc*, i8*, i8*, i8 }* %tmp6.i)
  call void @llvm.lifetime.end(i64 8, i8* %tmp13)
  ret void
}
;*** IR Dump After Dead Store Elimination ***
; Function Attrs: uwtable
define internal fastcc void @_ZN4main16_d7d397690bb61803_00E() #1 {
static_allocas:
  %tmp.i = alloca { i64, %tydesc*, {}*, {}*, { i64* } }, align 8
  %tmp5 = alloca i64, align 8
  %tmp13 = bitcast i64* %tmp5 to i8*
  call void @llvm.lifetime.start(i64 8, i8* %tmp13)
  %0 = bitcast { i64, %tydesc*, {}*, {}*, { i64* } }* %tmp.i to i8*
  call void @llvm.lifetime.start(i64 40, i8* %0)
  %tmp6.i = bitcast { i64, %tydesc*, {}*, {}*, { i64* } }* %tmp.i to { i64, %tydesc*, i8*, i8*, i8 }*
  call void @llvm.lifetime.end(i64 40, i8* %0)
  %tmp12.i = call {} @_ZN4test4anon4anon12expr_fn_2958E({ i64, %tydesc*, i8*, i8*, i8 }* %tmp6.i)
  call void @llvm.lifetime.end(i64 8, i8* %tmp13)
  ret void
}

; So for some reason, the store to %tmp5 and the store to the ref-count are eliminated as dead.
; I can't see why though.

dump.ll

;*** IR Dump After Simplify the CFG ***
; Function Attrs: uwtable
define internal fastcc void @_ZN4main16_d7d397690bb61803_00E() #1 {
static_allocas:
  %0 = alloca {}, align 8
  %1 = bitcast {}* %0 to i8*
  call void @llvm.lifetime.start(i64 0, i8* %1)
  %2 = load i64** undef, align 8
  store i64 1, i64* %2, align 8
  call void @llvm.lifetime.end(i64 0, i8* %1)
  ret void
}
;*** IR Dump After Combine redundant instructions ***
; Function Attrs: uwtable
define internal fastcc void @_ZN4main16_d7d397690bb61803_00E() #1 {
static_allocas:
  store i64* undef, i64** null, align 536870912 ; How does it get this? (536870912 = 0x20000000)
  store i64 1, i64* undef, align 8
  ret void
}
;*** IR Dump After Tail Call Elimination ***
; Function Attrs: uwtable
define internal fastcc void @_ZN4main16_d7d397690bb61803_00E() #1 {
static_allocas:
  store i64* undef, i64** null, align 536870912
  store i64 1, i64* undef, align 8
  ret void
}
;*** IR Dump After Simplify the CFG ***
; Function Attrs: uwtable
define internal fastcc void @_ZN4main16_d7d397690bb61803_00E() #1 {
static_allocas:
  call void @llvm.trap()
  unreachable
}