Don't crash trying to promote VLAs.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@79226 91177308-0d34-0410-b5e6-96231b3b80d8

2 files changed, 27 insertions, 1 deletions

diff --git a/lib/Transforms/Scalar/ScalarReplAggregates.cpp b/lib/Transforms/Scalar/ScalarReplAggregates.cpp
index 6857162dc4..4f99ee8e6e 100644
--- a/lib/Transforms/Scalar/ScalarReplAggregates.cpp
+++ b/lib/Transforms/Scalar/ScalarReplAggregates.cpp
@@ -255,9 +255,12 @@ bool SROA::performScalarRepl(Function &F) {
     // value cannot be decomposed at all.
     uint64_t AllocaSize = TD->getTypeAllocSize(AI->getAllocatedType());
 
+    // Do not promote [0 x %struct].
+    if (AllocaSize == 0) continue;
+
     // Do not promote any struct whose size is too big.
     if (AllocaSize > SRThreshold) continue;
-        
+
     if ((isa<StructType>(AI->getAllocatedType()) ||
          isa<ArrayType>(AI->getAllocatedType())) &&
         // Do not promote any struct into more than "32" separate vars.
diff --git a/test/Transforms/ScalarRepl/2009-08-16-VLA.ll b/test/Transforms/ScalarRepl/2009-08-16-VLA.ll
new file mode 100644
index 0000000000..61e67ad563
--- /dev/null
+++ b/test/Transforms/ScalarRepl/2009-08-16-VLA.ll
@@ -0,0 +1,23 @@
+; RUN: llvm-as < %s | opt -scalarrepl -disable-opt
+
+	%struct.Item = type { [4 x i16], %struct.rule* }
+	%struct.rule = type { [4 x i16], i32, i32, i32, %struct.nonterminal*, %struct.pattern*, i8 }
+	%struct.nonterminal = type { i8*, i32, i32, i32, %struct.plankMap*, %struct.rule* }
+	%struct.plankMap = type { %struct.list*, i32, %struct.stateMap* }
+	%struct.list = type { i8*, %struct.list* }
+	%struct.stateMap = type { i8*, %struct.plank*, i32, i16* }
+	%struct.plank = type { i8*, %struct.list*, i32 }
+	%struct.pattern = type { %struct.nonterminal*, %struct.operator*, [2 x %struct.nonterminal*] }
+	%struct.operator = type { i8*, i8, i32, i32, i32, i32, %struct.table* }
+	%struct.table = type { %struct.operator*, %struct.list*, i16*, [2 x %struct.dimension*], %struct.item_set** }
+	%struct.dimension = type { i16*, %struct.Index_Map, %struct.mapping*, i32, %struct.plankMap* }
+	%struct.Index_Map = type { i32, %struct.item_set** }
+	%struct.item_set = type { i32, i32, %struct.operator*, [2 x %struct.item_set*], %struct.item_set*, i16*, %struct.Item*, %struct.Item* }
+	%struct.mapping = type { %struct.list**, i32, i32, i32, %struct.item_set** }
+
+define void @addHP_2_0() {
+bb4.i:
+	%0 = malloc [0 x %struct.Item]		; <[0 x %struct.Item]*> [#uses=1]
+	%.sub.i.c.i = getelementptr [0 x %struct.Item]* %0, i32 0, i32 0		; <%struct.Item*> [#uses=0]
+	unreachable
+}