leave:
ret i32 22
}
+
+; TODO: We don't really need trunc/zext here because when iv.next overflows,
+; its value is not used.
+define i32 @test11(i32 %start, i32* %p, i32* %q) {
+; CHECK-LABEL: @test11(
+; CHECK-NEXT: entry:
+; CHECK-NEXT: [[TMP0:%.*]] = zext i32 [[START:%.*]] to i64
+; CHECK-NEXT: br label [[LOOP:%.*]]
+; CHECK: loop:
+; CHECK-NEXT: [[INDVARS_IV:%.*]] = phi i64 [ [[INDVARS_IV_NEXT:%.*]], [[BACKEDGE:%.*]] ], [ [[TMP0]], [[ENTRY:%.*]] ]
+; CHECK-NEXT: [[TMP1:%.*]] = trunc i64 [[INDVARS_IV]] to i32
+; CHECK-NEXT: [[IV_NEXT:%.*]] = add i32 [[TMP1]], -1
+; CHECK-NEXT: [[COND:%.*]] = icmp eq i64 [[INDVARS_IV]], 0
+; CHECK-NEXT: br i1 [[COND]], label [[EXIT:%.*]], label [[BACKEDGE]]
+; CHECK: backedge:
+; CHECK-NEXT: [[INDEX:%.*]] = zext i32 [[IV_NEXT]] to i64
+; CHECK-NEXT: [[STORE_ADDR:%.*]] = getelementptr i32, i32* [[P:%.*]], i64 [[INDEX]]
+; CHECK-NEXT: store i32 1, i32* [[STORE_ADDR]], align 4
+; CHECK-NEXT: [[LOAD_ADDR:%.*]] = getelementptr i32, i32* [[Q:%.*]], i64 [[INDEX]]
+; CHECK-NEXT: [[STOP:%.*]] = load i32, i32* [[Q]], align 4
+; CHECK-NEXT: [[LOOP_COND:%.*]] = icmp eq i32 [[STOP]], 0
+; CHECK-NEXT: [[INDVARS_IV_NEXT]] = add nsw i64 [[INDVARS_IV]], -1
+; CHECK-NEXT: br i1 [[LOOP_COND]], label [[LOOP]], label [[FAILURE:%.*]]
+; CHECK: exit:
+; CHECK-NEXT: ret i32 0
+; CHECK: failure:
+; CHECK-NEXT: unreachable
+;
+entry:
+ br label %loop
+
+loop:
+ %iv = phi i32 [%start, %entry], [%iv.next, %backedge]
+ %iv.next = add i32 %iv, -1
+ %cond = icmp eq i32 %iv, 0
+ br i1 %cond, label %exit, label %backedge
+
+backedge:
+ %index = zext i32 %iv.next to i64
+ %store.addr = getelementptr i32, i32* %p, i64 %index
+ store i32 1, i32* %store.addr
+ %load.addr = getelementptr i32, i32* %q, i64 %index
+ %stop = load i32, i32* %q
+ %loop.cond = icmp eq i32 %stop, 0
+ br i1 %loop.cond, label %loop, label %failure
+
+exit:
+ ret i32 0
+
+failure:
+ unreachable
+}