Fix PR299: [Sparc] Code generator asserts on alloc of zero size type

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@12504 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/Target/SparcV9/SparcV9InstrSelection.cpp b/lib/Target/SparcV9/SparcV9InstrSelection.cpp
index 5a0d86312336417103d121656fa96b3b6d011bef..480af95aada4090fcffef0e1f0fc3aa308153f11 100644 (file)
--- a/lib/Target/SparcV9/SparcV9InstrSelection.cpp
+++ b/lib/Target/SparcV9/SparcV9InstrSelection.cpp
@@ -1156,12 +1156,18 @@ CreateCodeForFixedSizeAlloca(const TargetMachine& target,
                              unsigned numElements,
                              std::vector<MachineInstr*>& getMvec)
 {
-  assert(tsize > 0 && "Illegal (zero) type size for alloca");
   assert(result && result->getParent() &&
          "Result value is not part of a function?");
   Function *F = result->getParent()->getParent();
   MachineFunction &mcInfo = MachineFunction::get(F);
 
+  // If the alloca is of zero bytes (which is perfectly legal) we bump it up to
+  // one byte.  This is unnecessary, but I really don't want to break any
+  // fragile logic in this code.  FIXME.
+  if (tsize == 0)
+    tsize = 1;
+
+
   // Put the variable in the dynamically sized area of the frame if either:
   // (a) The offset is too large to use as an immediate in load/stores
   //     (check LDX because all load/stores have the same-size immed. field).