Add negative test for ISD::TRUNCATE

Author: justinfargnoli

llvm/test/CodeGen/NVPTX/combine-truncate.ll

@@ -1,10 +1,22 @@
 ; RUN: llc < %s | FileCheck %s
 
-define i32 @foo(i64 %a, i64 %b) {
+define i32 @trunc(i64 %a, i64 %b) {
+; CHECK-LABEL: trunc
 ; CHECK: or.b32
 ; CHECK-NOT: or.b64
 entry:
   %or = or i64 %a, %b
   %trunc = trunc i64 %or to i32
   ret i32 %trunc
 }
+
+define i32 @trunc_not(i64 %a, i64 %b, ptr %p) {
+; CHECK-LABEL: trunc_not
+; CHECK: or.b64
+; CHECK-NOT: or.b32
+entry:
+  %or = or i64 %a, %b
+  %trunc = trunc i64 %or to i32
+  store i64 %or, ptr %p
+  ret i32 %trunc
+}