IR: Add COMDATs to the IR
This new IR facility allows us to represent the object-file semantic of
a COMDAT group.
COMDATs allow us to tie together sections and make the inclusion of one
dependent on another. This is required to implement features like MS
ABI VFTables and optimizing away certain kinds of initialization in C++.
This functionality is only representable in COFF and ELF, Mach-O has no
similar mechanism.
Differential Revision: http://reviews.llvm.org/D4178
llvm-svn: 211920
diff --git a/llvm/test/Linker/comdat.ll b/llvm/test/Linker/comdat.ll
new file mode 100644
index 0000000..4d2aef7
--- /dev/null
+++ b/llvm/test/Linker/comdat.ll
@@ -0,0 +1,32 @@
+; RUN: llvm-link %s %p/Inputs/comdat.ll -S -o - | FileCheck %s
+target datalayout = "e-m:w-p:32:32-i64:64-f80:32-n8:16:32-S32"
+target triple = "i686-pc-windows-msvc"
+
+$foo = comdat largest
+@foo = global i32 42, comdat $foo
+
+define i32 @bar() comdat $foo {
+ ret i32 42
+}
+
+$qux = comdat largest
+@qux = global i64 12, comdat $qux
+
+define i32 @baz() comdat $qux {
+ ret i32 12
+}
+
+$any = comdat any
+@any = global i64 6, comdat $any
+
+; CHECK: $qux = comdat largest
+; CHECK: $foo = comdat largest
+; CHECK: $any = comdat any
+
+; CHECK: @qux = global i64 12, comdat $qux
+; CHECK: @any = global i64 6, comdat $any
+; CHECK: @foo = global i64 43, comdat $foo
+; CHECK-NOT: @in_unselected_group = global i32 13, comdat $qux
+
+; CHECK: define i32 @baz() comdat $qux
+; CHECK: define i32 @bar() comdat $foo