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Re: [PATCH] Fix up computed goto on POINTERS_EXTEND_UNSIGNED targets (PR middle-end/63974)

From: Jeff Law <law at redhat dot com>
To: Jakub Jelinek <jakub at redhat dot com>, Richard Biener <rguenther at suse dot de>
Cc: gcc-patches at gcc dot gnu dot org, "H.J. Lu" <hjl dot tools at gmail dot com>, Andrew Pinski <pinskia at gmail dot com>, Kyrill Tkachov <kyrylo dot tkachov at arm dot com>
Date: Mon, 12 Jan 2015 13:34:11 -0700
Subject: Re: [PATCH] Fix up computed goto on POINTERS_EXTEND_UNSIGNED targets (PR middle-end/63974)
Authentication-results: sourceware.org; auth=none
References: <20150112201908 dot GS1405 at tucnak dot redhat dot com>

On 01/12/15 13:19, Jakub Jelinek wrote:

Hi!

The 991213-3.c testcase ICEs on aarch64-linux with -mabi=ilp32
since wide-int merge.  The problem is that
x = convert_memory_address (Pmode, x)
is used twice on a VOIDmode CONST_INT, which is wrong.
For non-VOIDmode rtl the second convert_memory_address
is a NOP, but for VOIDmode the second call treats the CONST_INT
returned by the first call as if it was again ptr_mode, rather
than Pmode.  On aarch64-linux in particular, the constant is
zero-extended from SImode to DImode in the first call, so it
is not valid SImode CONST_INT any longer.

emit_indirect_jump always calls convert_memory_address (Pmode, ...)
on the operand in optabs.c when handling EXPAND_ADDRESS case
in maybe_legitimize_operand, so the first convert_memory_address
is both unnecessary and harmful.

Fixed thusly, bootstrapped/regtested on x86_64-linux and i686-linux
(which do not define POINTERS_EXTEND_UNSIGNED) and tested on the
problematic testcase with aarch64-linux cross.  Can anyone with
easy access to POINTERS_EXTEND_UNSIGNED targets (aarch64-linux ilp32,
x86_64 -mx32, ia64-hpux) please test this?

Ok for trunk if it works there?

2015-01-12  Jakub Jelinek  <jakub@redhat.com>

	PR middle-end/63974
	* cfgexpand.c (expand_computed_goto): Don't call
	convert_memory_address here.

OK.
jeff

References:
- [PATCH] Fix up computed goto on POINTERS_EXTEND_UNSIGNED targets (PR middle-end/63974)
  - From: Jakub Jelinek

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