diff options
Diffstat (limited to 'test/Transforms/IndVarSimplify/exit_value_test2.ll')
| -rw-r--r-- | test/Transforms/IndVarSimplify/exit_value_test2.ll | 28 |
1 files changed, 25 insertions, 3 deletions
diff --git a/test/Transforms/IndVarSimplify/exit_value_test2.ll b/test/Transforms/IndVarSimplify/exit_value_test2.ll index ee641667506c..7b6e91a742b2 100644 --- a/test/Transforms/IndVarSimplify/exit_value_test2.ll +++ b/test/Transforms/IndVarSimplify/exit_value_test2.ll @@ -3,15 +3,14 @@ ; Check IndVarSimplify should not replace exit value because or else ; udiv will be introduced by expand and the cost will be high. -; -; CHECK-LABEL: @_Z3fooPKcjj( -; CHECK-NOT: udiv declare void @_Z3mixRjj(i32* dereferenceable(4), i32) declare void @llvm.lifetime.start.p0i8(i64, i8* nocapture) declare void @llvm.lifetime.end.p0i8(i64, i8* nocapture) define i32 @_Z3fooPKcjj(i8* nocapture readonly %s, i32 %len, i32 %c) { +; CHECK-LABEL: @_Z3fooPKcjj( +; CHECK-NOT: udiv entry: %a = alloca i32, align 4 %tmp = bitcast i32* %a to i8* @@ -50,3 +49,26 @@ while.end: ; preds = %while.cond.while.en call void @llvm.lifetime.end.p0i8(i64 4, i8* %tmp) ret i32 %tmp4 } + +define i32 @zero_backedge_count_test(i32 %unknown_init, i32* %unknown_mem) { +; CHECK-LABEL: @zero_backedge_count_test( +entry: + br label %loop + +loop: + %iv = phi i32 [ 0, %entry], [ %iv.inc, %loop ] + %unknown_phi = phi i32 [ %unknown_init, %entry ], [ %unknown_next, %loop ] + %iv.inc = add i32 %iv, 1 + %be_taken = icmp ne i32 %iv.inc, 1 + %unknown_next = load volatile i32, i32* %unknown_mem + br i1 %be_taken, label %loop, label %leave + +leave: +; We can fold %unknown_phi even though the backedge value for it is completely +; unknown, since we can prove that the loop's backedge taken count is 0. + +; CHECK: leave: +; CHECK: ret i32 %unknown_init + %exit_val = phi i32 [ %unknown_phi, %loop ] + ret i32 %exit_val +} |