llvm/test/Transforms/GlobalOpt/externally-initialized.ll
Oliver Stannard 30430397ea GlobalOpt does not treat externally_initialized globals correctly
GlobalOpt currently merges stores into the initialisers of internal,
externally_initialized globals, but should not do so as the value of the global
may change between the initialiser and any code in the module being run.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@250035 91177308-0d34-0410-b5e6-96231b3b80d8
2015-10-12 13:20:52 +00:00

38 lines
1.0 KiB
LLVM

; RUN: opt < %s -S -globalopt | FileCheck %s
; This global is externally_initialized, which may modify the value between
; it's static initializer and any code in this module being run, so the only
; write to it cannot be merged into the static initialiser.
; CHECK: @a = internal unnamed_addr externally_initialized global i32 undef
@a = internal externally_initialized global i32 undef
; This global is stored to by the external initialization, so cannot be
; constant-propagated and removed, despite the fact that there are no writes
; to it.
; CHECK: @b = internal unnamed_addr externally_initialized global i32 undef
@b = internal externally_initialized global i32 undef
define void @foo() {
; CHECK-LABEL: foo
entry:
; CHECK: store i32 42, i32* @a
store i32 42, i32* @a
ret void
}
define i32 @bar() {
; CHECK-LABEL: bar
entry:
; CHECK: %val = load i32, i32* @a
%val = load i32, i32* @a
ret i32 %val
}
define i32 @baz() {
; CHECK-LABEL: baz
entry:
; CHECK: %val = load i32, i32* @b
%val = load i32, i32* @b
ret i32 %val
}