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From: Jakub Jelinek <jakub@redhat.com>
To: Richard Biener <rguenther@suse.de>
Cc: gcc-patches@gcc.gnu.org
Subject: Re: [PATCH] tree-optimization/106513 - fix mistake in bswap symbolic number shifts
Date: Wed, 10 Aug 2022 15:59:34 +0200	[thread overview]
Message-ID: <YvO5xt5T8SPLT+9b@tucnak> (raw)
In-Reply-To: <20220810134711.51ABC13AB3@imap2.suse-dmz.suse.de>

On Wed, Aug 10, 2022 at 03:47:10PM +0200, Richard Biener via Gcc-patches wrote:
> This fixes a mistake in typing a local variable in the symbolic
> shift routine.
> 
> Bootstrap & regtest pending on x86_64-unknown-linux-gnu.
> 
> 	PR tree-optimization/106513
> 	* gimple-ssa-store-merging.cc (do_shift_rotate): Use uint64_t
> 	for head_marker.

Ok.

> 
> 	* gcc.dg/torture/pr106513.c: New testcase.

> --- /dev/null
> +++ b/gcc/testsuite/gcc.dg/torture/pr106513.c
> @@ -0,0 +1,26 @@
> +/* { dg-do run } */
> +
> +typedef __INT64_TYPE__ int64_t;
> +
> +__attribute__((noinline)) int64_t
> +swap64 (int64_t n)
> +{
> +  return (((n & (((int64_t) 0xff) )) << 56) |
> +          ((n & (((int64_t) 0xff) << 8)) << 40) |
> +          ((n & (((int64_t) 0xff) << 16)) << 24) |
> +          ((n & (((int64_t) 0xff) << 24)) << 8) |
> +          ((n & (((int64_t) 0xff) << 32)) >> 8) |
> +          ((n & (((int64_t) 0xff) << 40)) >> 24) |
> +          ((n & (((int64_t) 0xff) << 48)) >> 40) |
> +          ((n & ((int64_t)(0xffull << 56))) >> 56));
> +}
> +
> +int main (void)
> +{
> +  volatile int64_t n = 0x8000000000000000l;
> +
> +  if (swap64(n) != 0xffffffffffffff80l)
> +    __builtin_abort ();

Please use ll instead of l in both cases above.
Perhaps -0x80ll would be simpler...

	Jakub


      reply	other threads:[~2022-08-10 13:59 UTC|newest]

Thread overview: 2+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-08-10 13:47 Richard Biener
2022-08-10 13:59 ` Jakub Jelinek [this message]

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