On Mon, 12 Mar 2018, Jakub Jelinek wrote:
> Hi!
>
> The following two match.pd spots assume that integer_pow2p will return
> true only for INTEGER_CSTs (it uses wi::to_wide on it), but as the testcase
> shows, that is not always the case, we can get there with COMPLEX_CSTs.
>
> Fixed by requiring that it is both INTEGER_CST and integer_pow2p,
> bootstrapped/regtested on x86_64-linux and i686-linux, ok for trunk?
Ok.
Richard.
> I went through other spots where integer_pow2p is used in match.pd and think
> all other spots should be safe, I don't think we e.g. allow BIT_AND_EXPR
> with COMPLEX_CST operand etc.
>
> 2018-03-12 Jakub Jelinek <ja...@redhat.com>
>
> PR middle-end/84834
> * match.pd ((A & C) != 0 ? D : 0): Use INTEGER_CST@2 instead of
> integer_pow2p@2 and test integer_pow2p in condition.
> (A < 0 ? C : 0): Similarly for @1.
>
> * gcc.dg/pr84834.c: New test.
>
> --- gcc/match.pd.jj 2018-03-06 08:06:13.000000000 +0100
> +++ gcc/match.pd 2018-03-12 19:18:24.144577077 +0100
> @@ -3566,16 +3566,18 @@ DEFINE_INT_AND_FLOAT_ROUND_FN (RINT)
> (simplify
> (cond
> (ne (bit_and @0 integer_pow2p@1) integer_zerop)
> - integer_pow2p@2 integer_zerop)
> - (with {
> - int shift = (wi::exact_log2 (wi::to_wide (@2))
> - - wi::exact_log2 (wi::to_wide (@1)));
> - }
> - (if (shift > 0)
> - (bit_and
> - (lshift (convert @0) { build_int_cst (integer_type_node, shift); }) @2)
> - (bit_and
> - (convert (rshift @0 { build_int_cst (integer_type_node, -shift); }))
> @2))))
> + INTEGER_CST@2 integer_zerop)
> + (if (integer_pow2p (@2))
> + (with {
> + int shift = (wi::exact_log2 (wi::to_wide (@2))
> + - wi::exact_log2 (wi::to_wide (@1)));
> + }
> + (if (shift > 0)
> + (bit_and
> + (lshift (convert @0) { build_int_cst (integer_type_node, shift); }) @2)
> + (bit_and
> + (convert (rshift @0 { build_int_cst (integer_type_node, -shift); }))
> + @2)))))
>
> /* If we have (A & C) != 0 where C is the sign bit of A, convert
> this into A < 0. Similarly for (A & C) == 0 into A >= 0. */
> @@ -3595,8 +3597,9 @@ DEFINE_INT_AND_FLOAT_ROUND_FN (RINT)
> (simplify
> (cond
> (lt @0 integer_zerop)
> - integer_pow2p@1 integer_zerop)
> - (if (!TYPE_UNSIGNED (TREE_TYPE (@0)))
> + INTEGER_CST@1 integer_zerop)
> + (if (integer_pow2p (@1)
> + && !TYPE_UNSIGNED (TREE_TYPE (@0)))
> (with {
> int shift = element_precision (@0) - wi::exact_log2 (wi::to_wide (@1)) -
> 1;
> }
> --- gcc/testsuite/gcc.dg/pr84834.c.jj 2018-03-12 19:21:15.677631881 +0100
> +++ gcc/testsuite/gcc.dg/pr84834.c 2018-03-12 19:20:59.105626588 +0100
> @@ -0,0 +1,15 @@
> +/* PR middle-end/84834 */
> +/* { dg-do compile } */
> +/* { dg-options "-O2" } */
> +
> +_Complex int
> +foo (int a)
> +{
> + return a < 0;
> +}
> +
> +_Complex int
> +bar (int a)
> +{
> + return (a & 8) ? (_Complex int) 16 : (_Complex int) 0;
> +}
>
> Jakub
>
>
--
Richard Biener <rguent...@suse.de>
SUSE LINUX GmbH, GF: Felix Imendoerffer, Jane Smithard, Graham Norton, HRB
21284 (AG Nuernberg)
