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llvm-project/llvm/test/Transforms/GlobalOpt/preserve-comdats.ll

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GlobalOpt: Preserve comdats of unoptimized initializers Rather than slurping in and splatting out the whole ctor list, preserve the existing array entries without trying to understand them. Only remove the entries that we know we can optimize away. This way we don't need to wire through priority and comdats or anything else we might add. Fixes a linker issue where the .init_array or .ctors entry would point to discarded initialization code if the comdat group from the TU with the faulty global_ctors entry was dropped. llvm-svn: 218337
2014-09-24 06:33:01 +08:00
; RUN: opt -globalopt -S < %s | FileCheck %s
$comdat_global = comdat any
Change the .ll syntax for comdats and add a syntactic sugar. In order to make comdats always explicit in the IR, we decided to make the syntax a bit more compact for the case of a GlobalObject in a comdat with the same name. Just dropping the $name causes problems for @foo = globabl i32 0, comdat $bar = comdat ... and declare void @foo() comdat $bar = comdat ... So the syntax is changed to @g1 = globabl i32 0, comdat($c1) @g2 = globabl i32 0, comdat and declare void @foo() comdat($c1) declare void @foo() comdat llvm-svn: 225302
2015-01-07 06:55:16 +08:00
@comdat_global = weak_odr global i8 0, comdat($comdat_global)
GlobalOpt: Preserve comdats of unoptimized initializers Rather than slurping in and splatting out the whole ctor list, preserve the existing array entries without trying to understand them. Only remove the entries that we know we can optimize away. This way we don't need to wire through priority and comdats or anything else we might add. Fixes a linker issue where the .init_array or .ctors entry would point to discarded initialization code if the comdat group from the TU with the faulty global_ctors entry was dropped. llvm-svn: 218337
2014-09-24 06:33:01 +08:00
@simple_global = internal global i8 0
Change the .ll syntax for comdats and add a syntactic sugar. In order to make comdats always explicit in the IR, we decided to make the syntax a bit more compact for the case of a GlobalObject in a comdat with the same name. Just dropping the $name causes problems for @foo = globabl i32 0, comdat $bar = comdat ... and declare void @foo() comdat $bar = comdat ... So the syntax is changed to @g1 = globabl i32 0, comdat($c1) @g2 = globabl i32 0, comdat and declare void @foo() comdat($c1) declare void @foo() comdat llvm-svn: 225302
2015-01-07 06:55:16 +08:00
; CHECK: @comdat_global = weak_odr global i8 0, comdat{{$}}
GlobalOpt: Preserve comdats of unoptimized initializers Rather than slurping in and splatting out the whole ctor list, preserve the existing array entries without trying to understand them. Only remove the entries that we know we can optimize away. This way we don't need to wire through priority and comdats or anything else we might add. Fixes a linker issue where the .init_array or .ctors entry would point to discarded initialization code if the comdat group from the TU with the faulty global_ctors entry was dropped. llvm-svn: 218337
2014-09-24 06:33:01 +08:00
; CHECK: @simple_global = internal global i8 42
@llvm.global_ctors = appending global [2 x { i32, void ()*, i8* }] [
{ i32, void ()*, i8* } { i32 65535, void ()* @init_comdat_global, i8* @comdat_global },
{ i32, void ()*, i8* } { i32 65535, void ()* @init_simple_global, i8* null }
]
; CHECK: @llvm.global_ctors = appending global [1 x { i32, void ()*, i8* }]
; CHECK: [{ i32, void ()*, i8* } { i32 65535, void ()* @init_comdat_global, i8* @comdat_global }]
define void @init_comdat_global() {
store i8 42, i8* @comdat_global
ret void
}
; CHECK: define void @init_comdat_global()
Change the .ll syntax for comdats and add a syntactic sugar. In order to make comdats always explicit in the IR, we decided to make the syntax a bit more compact for the case of a GlobalObject in a comdat with the same name. Just dropping the $name causes problems for @foo = globabl i32 0, comdat $bar = comdat ... and declare void @foo() comdat $bar = comdat ... So the syntax is changed to @g1 = globabl i32 0, comdat($c1) @g2 = globabl i32 0, comdat and declare void @foo() comdat($c1) declare void @foo() comdat llvm-svn: 225302
2015-01-07 06:55:16 +08:00
define internal void @init_simple_global() comdat($comdat_global) {
GlobalOpt: Preserve comdats of unoptimized initializers Rather than slurping in and splatting out the whole ctor list, preserve the existing array entries without trying to understand them. Only remove the entries that we know we can optimize away. This way we don't need to wire through priority and comdats or anything else we might add. Fixes a linker issue where the .init_array or .ctors entry would point to discarded initialization code if the comdat group from the TU with the faulty global_ctors entry was dropped. llvm-svn: 218337
2014-09-24 06:33:01 +08:00
store i8 42, i8* @simple_global
ret void
}
; CHECK-NOT: @init_simple_global()
define i8* @use_simple() {
ret i8* @simple_global
}
; CHECK: define i8* @use_simple()
define i8* @use_comdat() {
ret i8* @comdat_global
}
; CHECK: define i8* @use_comdat()