Fix PR7647, handling the case when 'To' ends up being

mutated by recursive simplification.  This also enhances
ReplaceAndSimplifyAllUses to actually do a real RAUW
at the end of it, which updates any value handles
pointing to "From" to start pointing to "To".  This
seems useful for debug info and random other VH users.

llvm-svn: 108415

1 files changed, 47 insertions, 0 deletions

diff --git a/llvm/test/Transforms/JumpThreading/crash.ll b/llvm/test/Transforms/JumpThreading/crash.ll
index 480b4a04ee9..f0fc61e7370 100644
--- a/llvm/test/Transforms/JumpThreading/crash.ll
+++ b/llvm/test/Transforms/JumpThreading/crash.ll
@@ -387,3 +387,50 @@ if.end:                                           ; preds = %land.end69
   ret void
 }
 
+; PR7647
+define void @test15() nounwind {
+entry:
+  ret void
+  
+if.then237:
+  br label %lbl_664
+
+lbl_596:                                          ; preds = %lbl_664, %for.end37
+  volatile store i64 undef, i64* undef, align 4
+  br label %for.cond111
+
+for.cond111:                                      ; preds = %safe_sub_func_int64_t_s_s.exit, %lbl_596
+  %storemerge = phi i8 [ undef, %cond.true.i100 ], [ 22, %lbl_596 ] ; <i8> [#uses=1]
+  %l_678.5 = phi i64 [ %l_678.3, %cond.true.i100 ], [ undef, %lbl_596 ] ; <i64> [#uses=2]
+  %cmp114 = icmp slt i8 %storemerge, -2           ; <i1> [#uses=1]
+  br i1 %cmp114, label %lbl_664, label %if.end949
+
+lbl_664:                                          ; preds = %for.end1058, %if.then237, %for.cond111
+  %l_678.3 = phi i64 [ %l_678.5, %for.cond111 ], [ %l_678.2, %for.cond1035 ], [ 5, %if.then237 ] ; <i64> [#uses=1]
+  %tobool118 = icmp eq i32 undef, 0               ; <i1> [#uses=1]
+  br i1 %tobool118, label %cond.true.i100, label %lbl_596
+
+cond.true.i100:                                   ; preds = %for.inc120
+  br label %for.cond111
+
+lbl_709:
+  br label %if.end949
+  
+for.cond603:                                      ; preds = %for.body607, %if.end336
+  br i1 undef, label %for.cond603, label %if.end949
+
+if.end949:                                        ; preds = %for.cond603, %lbl_709, %for.cond111
+  %l_678.2 = phi i64 [ %l_678.5, %for.cond111 ], [ undef, %lbl_709 ], [ 5, %for.cond603 ] ; <i64> [#uses=1]
+  br label %for.body1016
+
+for.body1016:                                     ; preds = %for.cond1012
+  br label %for.body1016
+
+for.cond1035:                                     ; preds = %for.inc1055, %if.then1026
+  br i1 undef, label %for.cond1040, label %lbl_664
+
+for.cond1040:                                     ; preds = %for.body1044, %for.cond1035
+  ret void
+}
+
+