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-rw-r--r--lib/Transforms/Scalar/GVN.cpp5
-rw-r--r--test/Transforms/GVN/crash.ll12
2 files changed, 17 insertions, 0 deletions
diff --git a/lib/Transforms/Scalar/GVN.cpp b/lib/Transforms/Scalar/GVN.cpp
index 1da5238bbb..2515fd112c 100644
--- a/lib/Transforms/Scalar/GVN.cpp
+++ b/lib/Transforms/Scalar/GVN.cpp
@@ -1607,6 +1607,11 @@ bool GVN::processLoad(LoadInst *L) {
if (L->isVolatile())
return false;
+ if (L->use_empty()) {
+ markInstructionForDeletion(L);
+ return true;
+ }
+
// ... to a pointer that has been loaded from before...
MemDepResult Dep = MD->getDependency(L);
diff --git a/test/Transforms/GVN/crash.ll b/test/Transforms/GVN/crash.ll
index 4a3aa1c55a..31eae256c6 100644
--- a/test/Transforms/GVN/crash.ll
+++ b/test/Transforms/GVN/crash.ll
@@ -151,3 +151,15 @@ dead:
dead2:
ret i32 %A
}
+
+
+; PR9841
+define fastcc i8 @test5(i8* %P) nounwind {
+entry:
+ %0 = load i8* %P, align 2
+
+ %Q = getelementptr i8* %P, i32 1
+ %1 = load i8* %Q, align 1
+ ret i8 %1
+}
+