Fix logic inversion for RI-mode address selection

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@76052 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Target/SystemZ/SystemZISelDAGToDAG.cpp b/lib/Target/SystemZ/SystemZISelDAGToDAG.cpp
index 4fccbf2..bc9c5ec 100644
--- a/lib/Target/SystemZ/SystemZISelDAGToDAG.cpp
+++ b/lib/Target/SystemZ/SystemZISelDAGToDAG.cpp
@@ -241,7 +241,7 @@
       break;
     }
     // Test if the index field is free for use.
-    if (AM.IndexReg.getNode() && !AM.isRI) {
+    if (AM.IndexReg.getNode() || AM.isRI) {
       AM = Backup;
       break;
     }
diff --git a/test/CodeGen/SystemZ/2009-07-11-InvalidRIISel.ll b/test/CodeGen/SystemZ/2009-07-11-InvalidRIISel.ll
new file mode 100644
index 0000000..03831f9
--- /dev/null
+++ b/test/CodeGen/SystemZ/2009-07-11-InvalidRIISel.ll
@@ -0,0 +1,32 @@
+; RUN: llvm-as < %s | llc
+
+target datalayout = "E-p:64:64:64-i8:8:16-i16:16:16-i32:32:32-i64:64:64-f32:32:32-f64:64:64-f128:128:128-a0:16:16"
+target triple = "s390x-linux"
+
+define signext i32 @dfg_parse() nounwind {
+entry:
+	br i1 undef, label %if.then2208, label %if.else2360
+
+if.then2208:		; preds = %entry
+	br i1 undef, label %bb.nph3189, label %for.end2270
+
+bb.nph3189:		; preds = %if.then2208
+	unreachable
+
+for.end2270:		; preds = %if.then2208
+	%call2279 = call i64 @strlen(i8* undef) nounwind		; <i64> [#uses=1]
+	%add2281 = add i64 0, %call2279		; <i64> [#uses=1]
+	%tmp2283 = trunc i64 %add2281 to i32		; <i32> [#uses=1]
+	%tmp2284 = alloca i8, i32 %tmp2283, align 2		; <i8*> [#uses=1]
+	%yyd.0.i2561.13 = getelementptr i8* %tmp2284, i64 13		; <i8*> [#uses=1]
+	store i8 117, i8* %yyd.0.i2561.13
+	br label %while.cond.i2558
+
+while.cond.i2558:		; preds = %while.cond.i2558, %for.end2270
+	br label %while.cond.i2558
+
+if.else2360:		; preds = %entry
+	unreachable
+}
+
+declare i64 @strlen(i8* nocapture) nounwind readonly