[IPCP] Remove unreachable code

[IPCP] Remove unreachable code

[kugan]

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Hi,

I noticed that in ipcp_bits_lattice::meet_with we have:

   else if (TREE_CODE_CLASS (code) == tcc_unary)
   ....
   else if (code == NOP_EXPR)
   ....

Since TREE_CODE_CLASS for NOP_EXPR is tcc_unary, if (code == NOP_EXPR) 
is unreachable and therefore removing it. I also don't think that we 
need any special casing for NOP_EXPR here. bit_value_unop handles 
already handles CASE_CONVERT.

Is this OK if no regressions in bootstrap and regression testing.

Thanks,
Kugan




gcc/ChangeLog:

2016-10-25  Kugan Vivekanandarajah  <kuganv@linaro.org>

	* ipa-cp.c (ipcp_bits_lattice::meet_with): Remove unreachable code.

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diff --git a/gcc/ipa-cp.c b/gcc/ipa-cp.c
index 1dc5cb6..527ff27 100644
--- a/gcc/ipa-cp.c
+++ b/gcc/ipa-cp.c
@@ -1070,12 +1070,6 @@ ipcp_bits_lattice::meet_with (ipcp_bits_lattice& other, unsigned precision,
 	return set_to_bottom ();
     }
 
-  else if (code == NOP_EXPR)
-    {
-      adjusted_value = other.m_value;
-      adjusted_mask = other.m_mask;
-    }
-
   else
     return set_to_bottom ();
 

Re: [IPCP] Remove unreachable code

[Prathamesh Kulkarni]

On 25 October 2016 at 04:16, kugan <kugan.vivekanandarajah@linaro.org> wrote:
> Hi,
>
> I noticed that in ipcp_bits_lattice::meet_with we have:
>
>   else if (TREE_CODE_CLASS (code) == tcc_unary)
>   ....
>   else if (code == NOP_EXPR)
>   ....
>
> Since TREE_CODE_CLASS for NOP_EXPR is tcc_unary, if (code == NOP_EXPR) is
> unreachable and therefore removing it. I also don't think that we need any
> special casing for NOP_EXPR here. bit_value_unop handles already handles
> CASE_CONVERT.
Oops, sorry about that :/
IICU NOP_EXPR is present when the pass-thru operation is "simple"
involving only the argument.
bit_value_unop() already handles the case for NOP_EXPR in
CASE_CONVERT, so I suppose
NOP_EXPR won't need any special casing.
Thanks for catching this!

Regards,
Prathamesh
>
> Is this OK if no regressions in bootstrap and regression testing.
>
> Thanks,
> Kugan
>
>
>
>
> gcc/ChangeLog:
>
> 2016-10-25  Kugan Vivekanandarajah  <kuganv@linaro.org>
>
>         * ipa-cp.c (ipcp_bits_lattice::meet_with): Remove unreachable code.

Re: [IPCP] Remove unreachable code

[Jeff Law]

On 10/24/2016 04:46 PM, kugan wrote:
> Hi,
>
> I noticed that in ipcp_bits_lattice::meet_with we have:
>
>   else if (TREE_CODE_CLASS (code) == tcc_unary)
>   ....
>   else if (code == NOP_EXPR)
>   ....
>
> Since TREE_CODE_CLASS for NOP_EXPR is tcc_unary, if (code == NOP_EXPR)
> is unreachable and therefore removing it. I also don't think that we
> need any special casing for NOP_EXPR here. bit_value_unop handles
> already handles CASE_CONVERT.
>
> Is this OK if no regressions in bootstrap and regression testing.
>
> Thanks,
> Kugan
>
>
>
>
> gcc/ChangeLog:
>
> 2016-10-25  Kugan Vivekanandarajah  <kuganv@linaro.org>
>
>     * ipa-cp.c (ipcp_bits_lattice::meet_with): Remove unreachable code.
OK.
jeff