1; When constant propogating terminator instructions, the basic block iterator 2; was not updated to refer to the final position of the new terminator. This 3; can be bad, f.e. because constproping a terminator can lead to the 4; destruction of PHI nodes, which invalidates the iterator! 5; 6; Fixed by adding new arguments to ConstantFoldTerminator 7; 8; RUN: opt < %s -constprop 9 10define void @build_tree(i32 %ml) { 11; <label>:0 12 br label %bb2 13 14bb2: ; preds = %bb2, %0 15 %reg137 = phi i32 [ %reg140, %bb2 ], [ 12, %0 ] ; <i32> [#uses=1] 16 %reg138 = phi i32 [ %reg139, %bb2 ], [ 0, %0 ] ; <i32> [#uses=1] 17 %reg139 = add i32 %reg138, 1 ; <i32> [#uses=1] 18 %reg140 = add i32 %reg137, -1 ; <i32> [#uses=1] 19 br i1 false, label %bb2, label %bb3 20 21bb3: ; preds = %bb2 22 ret void 23} 24 25