If two-address def is dead and the instruction does not define other registers, and it doesn't produce side effects, just delete the instruction.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@65218 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/test/CodeGen/X86/twoaddr-delete.ll b/test/CodeGen/X86/twoaddr-delete.ll
new file mode 100644
index 0000000..bbf4e62
--- /dev/null
+++ b/test/CodeGen/X86/twoaddr-delete.ll
@@ -0,0 +1,43 @@
+; RUN: llvm-as < %s | llc -march=x86 -stats |& grep {twoaddrinstr} | grep {Number of dead instructions deleted}
+
+ %struct.anon = type { [3 x double], double, %struct.node*, [64 x %struct.bnode*], [64 x %struct.bnode*] }
+ %struct.bnode = type { i16, double, [3 x double], i32, i32, [3 x double], [3 x double], [3 x double], double, %struct.bnode*, %struct.bnode* }
+ %struct.node = type { i16, double, [3 x double], i32, i32 }
+
+define i32 @main(i32 %argc, i8** nocapture %argv) nounwind {
+entry:
+ %0 = malloc %struct.anon ; <%struct.anon*> [#uses=2]
+ %1 = getelementptr %struct.anon* %0, i32 0, i32 2 ; <%struct.node**> [#uses=1]
+ br label %bb14.i
+
+bb14.i: ; preds = %bb14.i, %entry
+ %i8.0.reg2mem.0.i = phi i32 [ 0, %entry ], [ %2, %bb14.i ] ; <i32> [#uses=1]
+ %2 = add i32 %i8.0.reg2mem.0.i, 1 ; <i32> [#uses=2]
+ %exitcond74.i = icmp eq i32 %2, 32 ; <i1> [#uses=1]
+ br i1 %exitcond74.i, label %bb32.i, label %bb14.i
+
+bb32.i: ; preds = %bb32.i, %bb14.i
+ %tmp.0.reg2mem.0.i = phi i32 [ %indvar.next63.i, %bb32.i ], [ 0, %bb14.i ] ; <i32> [#uses=1]
+ %indvar.next63.i = add i32 %tmp.0.reg2mem.0.i, 1 ; <i32> [#uses=2]
+ %exitcond64.i = icmp eq i32 %indvar.next63.i, 64 ; <i1> [#uses=1]
+ br i1 %exitcond64.i, label %bb47.loopexit.i, label %bb32.i
+
+bb.i.i: ; preds = %bb47.loopexit.i
+ unreachable
+
+stepsystem.exit.i: ; preds = %bb47.loopexit.i
+ store %struct.node* null, %struct.node** %1, align 4
+ br label %bb.i6.i
+
+bb.i6.i: ; preds = %bb.i6.i, %stepsystem.exit.i
+ br i1 false, label %bb107.i.i, label %bb.i6.i
+
+bb107.i.i: ; preds = %bb107.i.i, %bb.i6.i
+ %q_addr.0.i.i.in = phi %struct.bnode** [ null, %bb107.i.i ], [ %3, %bb.i6.i ] ; <%struct.bnode**> [#uses=0]
+ br label %bb107.i.i
+
+bb47.loopexit.i: ; preds = %bb32.i
+ %3 = getelementptr %struct.anon* %0, i32 0, i32 4, i32 0 ; <%struct.bnode**> [#uses=1]
+ %4 = icmp eq %struct.node* null, null ; <i1> [#uses=1]
+ br i1 %4, label %stepsystem.exit.i, label %bb.i.i
+}