[llvm-commits] [llvm] r164934 - in /llvm/trunk: lib/Transforms/Utils/SimplifyCFG.cpp test/Transforms/SimplifyCFG/switch_to_lookup_table.ll

[Benjamin Kramer]

Author: d0k
Date: Mon Oct  1 06:31:48 2012
New Revision: 164934

URL: http://llvm.org/viewvc/llvm-project?rev=164934&view=rev
Log:
SimplifyCFG: Don't crash when forming a switch bitmap with an undef default value.

Fixes PR13985.

Modified:
    llvm/trunk/lib/Transforms/Utils/SimplifyCFG.cpp
    llvm/trunk/test/Transforms/SimplifyCFG/switch_to_lookup_table.ll

Modified: llvm/trunk/lib/Transforms/Utils/SimplifyCFG.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/Utils/SimplifyCFG.cpp?rev=164934&r1=164933&r2=164934&view=diff
==============================================================================
--- llvm/trunk/lib/Transforms/Utils/SimplifyCFG.cpp (original)
+++ llvm/trunk/lib/Transforms/Utils/SimplifyCFG.cpp Mon Oct  1 06:31:48 2012
@@ -3351,8 +3351,11 @@
     APInt TableInt(TableSize * IT->getBitWidth(), 0);
     for (uint64_t I = TableSize; I > 0; --I) {
       TableInt <<= IT->getBitWidth();
-      ConstantInt *Val = cast<ConstantInt>(TableContents[I - 1]);
-      TableInt |= Val->getValue().zext(TableInt.getBitWidth());
+      // Insert values into the bitmap. Undef values are set to zero.
+      if (!isa<UndefValue>(TableContents[I - 1])) {
+        ConstantInt *Val = cast<ConstantInt>(TableContents[I - 1]);
+        TableInt |= Val->getValue().zext(TableInt.getBitWidth());
+      }
     }
     BitMap = ConstantInt::get(M.getContext(), TableInt);
     BitMapElementTy = IT;

Modified: llvm/trunk/test/Transforms/SimplifyCFG/switch_to_lookup_table.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/SimplifyCFG/switch_to_lookup_table.ll?rev=164934&r1=164933&r2=164934&view=diff
==============================================================================
--- llvm/trunk/test/Transforms/SimplifyCFG/switch_to_lookup_table.ll (original)
+++ llvm/trunk/test/Transforms/SimplifyCFG/switch_to_lookup_table.ll Mon Oct  1 06:31:48 2012
@@ -269,3 +269,27 @@
 ; CHECK: switch
 ; CHECK: phi
 }
+
+; PR13985
+define i1 @undef(i32 %tmp) uwtable ssp {
+bb:
+  switch i32 %tmp, label %bb3 [
+    i32 0, label %bb1
+    i32 1, label %bb1
+    i32 7, label %bb2
+    i32 8, label %bb2
+  ]
+
+bb1:                                              ; preds = %bb, %bb
+  br label %bb3
+
+bb2:                                              ; preds = %bb, %bb
+  br label %bb3
+
+bb3:                                              ; preds = %bb2, %bb1, %bb
+  %tmp4 = phi i1 [ undef, %bb ], [ false, %bb2 ], [ true, %bb1 ]
+  ret i1 %tmp4
+; CHECK: define i1 @undef
+; CHECK: %switch.cast = trunc i32 %switch.tableidx to i9
+; CHECK: %switch.downshift = lshr i9 3, %switch.shiftamt
+}