evaluate-bitcast-2.ll 1.51 KB
; RUN: opt < %s -globalopt -S | FileCheck %s

; Test the evaluation of a store and a load via a bitcast, and check
; that globals are constant folded to the correct value.

; CHECK: @u = dso_local local_unnamed_addr global %union.A { i8* inttoptr (i64 12345 to i8*) }, align 8
; CHECK: @l = dso_local local_unnamed_addr global i64 12345, align 8

; Test derived from:
;
; union A {
;   A(long long ll) : l(ll) {}
;   void *p;
;   long long l;
; } u(12345);
;
; long long l = u.l;

target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"
target triple = "x86_64-unknown-linux-gnu"

%union.A = type { i8* }

$_ZN1AC2Ex = comdat any

@u = dso_local global %union.A zeroinitializer, align 8
@l = dso_local global i64 0, align 8
@llvm.global_ctors = appending global [1 x { i32, void ()*, i8* }] [{ i32, void ()*, i8* } { i32 65535, void ()* @_GLOBAL__sub_I_test.cpp, i8* null }]

define internal void @__cxx_global_var_init() section ".text.startup" {
  call void @_ZN1AC2Ex(%union.A* @u, i64 12345)
  ret void
}

define linkonce_odr dso_local void @_ZN1AC2Ex(%union.A* %this, i64 %ll) unnamed_addr comdat align 2 {
  %l = bitcast %union.A* %this to i64*
  store i64 %ll, i64* %l, align 8
  ret void
}

define internal void @__cxx_global_var_init.1() section ".text.startup" {
  %1 = load i64, i64* bitcast (%union.A* @u to i64*), align 8
  store i64 %1, i64* @l, align 8
  ret void
}

define internal void @_GLOBAL__sub_I_test.cpp() section ".text.startup" {
  call void @__cxx_global_var_init()
  call void @__cxx_global_var_init.1()
  ret void
}