1 files changed, 26 insertions, 0 deletions
diff --git a/llvm/test/ThinLTO/X86/index-const-prop-dead.ll b/llvm/test/ThinLTO/X86/index-const-prop-dead.ll
new file mode 100644
index 00000000000..f3ffca8cbdf
--- /dev/null
+++ b/llvm/test/ThinLTO/X86/index-const-prop-dead.ll
@@ -0,0 +1,26 @@
+; RUN: opt -module-summary %s -o %t1.bc
+; RUN: opt -module-summary %p/Inputs/index-const-prop-define-g.ll -o %t2.bc
+; RUN: llvm-lto2 run -save-temps %t2.bc -r=%t2.bc,g,pl \
+; RUN:               %t1.bc -r=%t1.bc,main,plx -r=%t1.bc,foo,pl -r=%t1.bc,g, -o %t3
+; RUN: llvm-dis %t3.2.3.import.bc -o - | FileCheck %s
+
+; Dead globals are converted to declarations by ThinLTO in dropDeadSymbols
+; If we try to internalize such we'll get a broken module. 
+; CHECK: @g = external dso_local global i32
+
+target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"
+target triple = "x86_64-unknown-linux-gnu"
+
+@g = external global i32
+
+; We need at least one live symbol to enable dead stripping
+; Otherwise ModuleSummaryIndex::isGlobalValueLive will always
+; return true.
+define i32 @main() {
+  ret i32 42
+}
+
+define i32 @foo() {
+  %v = load i32, i32* @g
+  ret i32 %v
+}