1 files changed, 55 insertions, 0 deletions
diff --git a/llvm/test/LTO/Resolution/X86/lto-unit-check.ll b/llvm/test/LTO/Resolution/X86/lto-unit-check.ll
new file mode 100644
index 00000000000..1736a5b216a
--- /dev/null
+++ b/llvm/test/LTO/Resolution/X86/lto-unit-check.ll
@@ -0,0 +1,55 @@
+; Test to ensure that the Enable Split LTO Unit flag is set properly in the
+; summary, and that we correctly silently handle linking bitcode files with
+; different values of this flag.
+
+; Linking bitcode both with EnableSplitLTOUnit set should work
+; RUN: opt -thinlto-bc -thinlto-split-lto-unit -o %t1 %s
+; RUN: llvm-bcanalyzer -dump %t1 | FileCheck %s --check-prefix=SPLITLTOUNIT
+; RUN: llvm-dis -o - %t1 | FileCheck %s --check-prefix=ENABLESPLITFLAG
+; RUN: opt -thinlto-bc -thinlto-split-lto-unit -o %t2 %s
+; RUN: llvm-bcanalyzer -dump %t2 | FileCheck %s --check-prefix=SPLITLTOUNIT
+; RUN: llvm-dis -o - %t2 | FileCheck %s --check-prefix=ENABLESPLITFLAG
+; RUN: llvm-lto2 run -o %t3 %t1 %t2
+
+; Linking bitcode both without EnableSplitLTOUnit set should work
+; RUN: opt -thinlto-bc -thinlto-split-lto-unit=false -o %t1 %s
+; RUN: llvm-bcanalyzer -dump %t1 | FileCheck %s --check-prefix=NOSPLITLTOUNIT
+; RUN: llvm-dis -o - %t1 | FileCheck %s --check-prefix=NOENABLESPLITFLAG
+; RUN: opt -thinlto-bc -thinlto-split-lto-unit=false -o %t2 %s
+; RUN: llvm-bcanalyzer -dump %t2 | FileCheck %s --check-prefix=NOSPLITLTOUNIT
+; RUN: llvm-dis -o - %t2 | FileCheck %s --check-prefix=NOENABLESPLITFLAG
+; RUN: llvm-lto2 run -o %t3 %t1 %t2
+
+; Linking bitcode with different values of EnableSplitLTOUnit should succeed
+; (silently skipping any optimizations like whole program devirt that rely
+; on all modules being split).
+; RUN: opt -thinlto-bc -thinlto-split-lto-unit -o %t1 %s
+; RUN: llvm-bcanalyzer -dump %t1 | FileCheck %s --check-prefix=SPLITLTOUNIT
+; RUN: llvm-dis -o - %t1 | FileCheck %s --check-prefix=ENABLESPLITFLAG
+; RUN: opt -thinlto-bc -thinlto-split-lto-unit=false -o %t2 %s
+; RUN: llvm-bcanalyzer -dump %t2 | FileCheck %s --check-prefix=NOSPLITLTOUNIT
+; RUN: llvm-dis -o - %t2 | FileCheck %s --check-prefix=NOENABLESPLITFLAG
+; RUN: llvm-lto2 run -o %t3 %t1 %t2
+
+; Linking bitcode with different values of EnableSplitLTOUnit (reverse order)
+; should succeed (silently skipping any optimizations like whole program devirt
+; that rely on all modules being split).
+; RUN: opt -thinlto-bc -thinlto-split-lto-unit=false -o %t1 %s
+; RUN: llvm-bcanalyzer -dump %t1 | FileCheck %s --check-prefix=NOSPLITLTOUNIT
+; RUN: llvm-dis -o - %t1 | FileCheck %s --check-prefix=NOENABLESPLITFLAG
+; RUN: opt -thinlto-bc -thinlto-split-lto-unit -o %t2 %s
+; RUN: llvm-bcanalyzer -dump %t2 | FileCheck %s --check-prefix=SPLITLTOUNIT
+; RUN: llvm-dis -o - %t2 | FileCheck %s --check-prefix=ENABLESPLITFLAG
+; RUN: llvm-lto2 run -o %t3 %t1 %t2
+
+; The flag should be set when splitting is disabled (for backwards compatibility
+; with older bitcode where it was always enabled).
+; SPLITLTOUNIT: <FLAGS op0=8/>
+; NOSPLITLTOUNIT: <FLAGS op0=0/>
+
+; Check that the corresponding module flag is set when expected.
+; ENABLESPLITFLAG: !{i32 1, !"EnableSplitLTOUnit", i32 1}
+; NOENABLESPLITFLAG-NOT: !{i32 1, !"EnableSplitLTOUnit", i32 1}
+
+target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"
+target triple = "x86_64-unknown-linux-gnu"