ThinLTO: handles modules with empty summaries

We need to add an entry in the combined-index for modules that have
a hash but otherwise empty summary, this is needed so that we can
get the hash for the module.

Also, if no entry is present in the combined index for a module, we
need to skip it when trying to compute a cache entry.

Differential Revision: https://reviews.llvm.org/D25300

llvm-svn: 283654

1 files changed, 8 insertions, 0 deletions

diff --git a/llvm/test/ThinLTO/X86/Inputs/empty_module_with_cache.ll b/llvm/test/ThinLTO/X86/Inputs/empty_module_with_cache.ll
new file mode 100644
index 00000000000..1c55e078ea3
--- /dev/null
+++ b/llvm/test/ThinLTO/X86/Inputs/empty_module_with_cache.ll
@@ -0,0 +1,8 @@
+target datalayout = "e-m:o-i64:64-f80:128-n8:16:32:64-S128"
+target triple = "x86_64-apple-macosx10.11.0"
+
+
+define i32 @main() {
+entry:
+  ret i32 0
+}