fix a SCCP miscompilation that could happen when a

forced constant is changed to a constant, we would end
up adding the instruction to the wrong worklist, 
preventing it from being properly revisited.  This fixes
rdar://7832370


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@100837 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 95 insertions, 0 deletions

diff --git a/test/Transforms/SCCP/undef-resolve.ll b/test/Transforms/SCCP/undef-resolve.ll
new file mode 100644
index 0000000..d2f3d02
--- /dev/null
+++ b/test/Transforms/SCCP/undef-resolve.ll
@@ -0,0 +1,95 @@
+; RUN: opt %s -sccp -S | FileCheck %s
+; rdar://7832370
+; Check that lots of stuff doesn't get turned into undef.
+
+define i32 @main() nounwind readnone ssp {
+init:
+  br label %control.outer.outer
+
+control.outer.loopexit.us-lcssa:                  ; preds = %control
+  br label %control.outer.loopexit
+
+control.outer.loopexit:                           ; preds = %control.outer.loopexit.us-lcssa.us, %control.outer.loopexit.us-lcssa
+  br label %control.outer.outer.backedge
+
+control.outer.outer:                              ; preds = %control.outer.outer.backedge, %init
+  %switchCond.0.ph.ph = phi i32 [ 2, %init ], [ 3, %control.outer.outer.backedge ] ; <i32> [#uses=2]
+  %i.0.ph.ph = phi i32 [ undef, %init ], [ %i.0.ph.ph.be, %control.outer.outer.backedge ] ; <i32> [#uses=1]
+  %tmp4 = icmp eq i32 %i.0.ph.ph, 0               ; <i1> [#uses=1]
+  br i1 %tmp4, label %control.outer.outer.split.us, label %control.outer.outer.control.outer.outer.split_crit_edge
+
+control.outer.outer.control.outer.outer.split_crit_edge: ; preds = %control.outer.outer
+  br label %control.outer
+
+control.outer.outer.split.us:                     ; preds = %control.outer.outer
+  br label %control.outer.us
+
+control.outer.us:                                 ; preds = %bb3.us, %control.outer.outer.split.us
+  %A.0.ph.us = phi i32 [ %switchCond.0.us, %bb3.us ], [ 4, %control.outer.outer.split.us ] ; <i32> [#uses=2]
+  %switchCond.0.ph.us = phi i32 [ %A.0.ph.us, %bb3.us ], [ %switchCond.0.ph.ph, %control.outer.outer.split.us ] ; <i32> [#uses=1]
+  br label %control.us
+
+bb3.us:                                           ; preds = %control.us
+  br label %control.outer.us
+
+bb0.us:                                           ; preds = %control.us
+  br label %control.us
+
+; CHECK: control.us:                                       ; preds = %bb0.us, %control.outer.us
+; CHECK-NEXT:  %switchCond.0.us = phi i32
+; CHECK-NEXT:  switch i32 %switchCond.0.us
+control.us:                                       ; preds = %bb0.us, %control.outer.us
+  %switchCond.0.us = phi i32 [ %A.0.ph.us, %bb0.us ], [ %switchCond.0.ph.us, %control.outer.us ] ; <i32> [#uses=2]
+  switch i32 %switchCond.0.us, label %control.outer.loopexit.us-lcssa.us [
+    i32 0, label %bb0.us
+    i32 1, label %bb1.us-lcssa.us
+    i32 3, label %bb3.us
+    i32 4, label %bb4.us-lcssa.us
+  ]
+
+control.outer.loopexit.us-lcssa.us:               ; preds = %control.us
+  br label %control.outer.loopexit
+
+bb1.us-lcssa.us:                                  ; preds = %control.us
+  br label %bb1
+
+bb4.us-lcssa.us:                                  ; preds = %control.us
+  br label %bb4
+
+control.outer:                                    ; preds = %bb3, %control.outer.outer.control.outer.outer.split_crit_edge
+  %A.0.ph = phi i32 [ %nextId17, %bb3 ], [ 4, %control.outer.outer.control.outer.outer.split_crit_edge ] ; <i32> [#uses=1]
+  %switchCond.0.ph = phi i32 [ 0, %bb3 ], [ %switchCond.0.ph.ph, %control.outer.outer.control.outer.outer.split_crit_edge ] ; <i32> [#uses=1]
+  br label %control
+
+control:                                          ; preds = %bb0, %control.outer
+  %switchCond.0 = phi i32 [ %A.0.ph, %bb0 ], [ %switchCond.0.ph, %control.outer ] ; <i32> [#uses=2]
+  switch i32 %switchCond.0, label %control.outer.loopexit.us-lcssa [
+    i32 0, label %bb0
+    i32 1, label %bb1.us-lcssa
+    i32 3, label %bb3
+    i32 4, label %bb4.us-lcssa
+  ]
+
+bb4.us-lcssa:                                     ; preds = %control
+  br label %bb4
+
+bb4:                                              ; preds = %bb4.us-lcssa, %bb4.us-lcssa.us
+  br label %control.outer.outer.backedge
+
+control.outer.outer.backedge:                     ; preds = %bb4, %control.outer.loopexit
+  %i.0.ph.ph.be = phi i32 [ 1, %bb4 ], [ 0, %control.outer.loopexit ] ; <i32> [#uses=1]
+  br label %control.outer.outer
+
+bb3:                                              ; preds = %control
+  %nextId17 = add i32 %switchCond.0, -2           ; <i32> [#uses=1]
+  br label %control.outer
+
+bb0:                                              ; preds = %control
+  br label %control
+
+bb1.us-lcssa:                                     ; preds = %control
+  br label %bb1
+
+bb1:                                              ; preds = %bb1.us-lcssa, %bb1.us-lcssa.us
+  ret i32 0
+}