New files, testing for a crash in ADCE compiling QT and a missed optimization.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@20226 91177308-0d34-0410-b5e6-96231b3b80d8

test/Transforms/ADCE/2005-02-17-PHI-Invoke-Crash.ll

@@ -0,0 +1,49 @@
+; RUN: llvm-as < %s | opt -adce -disable-output
+
+implementation   ; Functions:
+
+declare {  }* %llvm.dbg.region.end({  }*)
+
+declare void %strlen()
+
+declare void %_ZN10QByteArray6resizeEi()
+
+declare void %q_atomic_decrement()
+
+void %_ZNK10QByteArray13leftJustifiedEicb() {
+entry:
+	invoke void %strlen( )
+			to label %tmp.3.i.noexc unwind label %invoke_catch.0
+
+tmp.3.i.noexc:		; preds = %entry
+	br bool false, label %then.0, label %else.0
+
+invoke_catch.0:		; preds = %entry
+	invoke void %q_atomic_decrement( )
+			to label %tmp.1.i.i183.noexc unwind label %terminate
+
+tmp.1.i.i183.noexc:		; preds = %invoke_catch.0
+	unwind
+
+then.0:		; preds = %tmp.3.i.noexc
+	invoke void %_ZN10QByteArray6resizeEi( )
+			to label %invoke_cont.1 unwind label %invoke_catch.1
+
+invoke_catch.1:		; preds = %then.0
+	invoke void %q_atomic_decrement( )
+			to label %tmp.1.i.i162.noexc unwind label %terminate
+
+tmp.1.i.i162.noexc:		; preds = %invoke_catch.1
+	ret void
+
+invoke_cont.1:		; preds = %then.0
+	ret void
+
+else.0:		; preds = %tmp.3.i.noexc
+	ret void
+
+terminate:		; preds = %invoke_catch.1, %invoke_catch.0
+	%dbg.0.1 = phi {  }* [ null, %invoke_catch.1 ], [ null, %invoke_catch.0 ]		; <{  }*> [#uses=1]
+	%dbg.tmp.43 = call {  }* %llvm.dbg.region.end( {  }* %dbg.0.1 )		; <{  }*> [#uses=0]
+	unreachable
+}

test/Transforms/ADCE/dead-phi-edge.ll

@@ -0,0 +1,15 @@
+; RUN: llvm-as < %s | opt -adce | llvm-dis | not grep call
+
+; The call is not live just because the PHI uses the call retval!
+
+int %test(int %X) {
+	br label %Done
+
+DeadBlock:
+	%Y = call int %test(int 0)
+	br label %Done
+
+Done:
+	%Z = phi int [%X, %0], [%Y, %DeadBlock]
+	ret int %Z
+}