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Re: [PATCH][v3] GIMPLE store merging pass

From: Bernd Schmidt <bschmidt at redhat dot com>
To: Richard Biener <rguenther at suse dot de>, Jakub Jelinek <jakub at redhat dot com>
Cc: Kyrill Tkachov <kyrylo dot tkachov at foss dot arm dot com>, Uros Bizjak <ubizjak at gmail dot com>, GCC Patches <gcc-patches at gcc dot gnu dot org>
Date: Wed, 7 Sep 2016 15:07:16 +0200
Subject: Re: [PATCH][v3] GIMPLE store merging pass
Authentication-results: sourceware.org; auth=none
References: <57CEDD67.6010801@foss.arm.com> <20160906153250.GK14857@tucnak.redhat.com> <57CEE7DB.8070604@foss.arm.com> <20160906162133.GL14857@tucnak.redhat.com> <alpine.LSU.2.11.1609071010210.26629@t29.fhfr.qr>



On 09/07/2016 10:19 AM, Richard Biener wrote:

On Tue, 6 Sep 2016, Jakub Jelinek wrote:

If you want a 64-bit store, you'd need to merge the two, and that would be
even more expensive.  It is a matter of say:
	movl $0x12345678, (%rsp)
	movl $0x09abcdef, 4(%rsp)
vs.
	movabsq $0x09abcdef12345678, %rax
	movq %rax, (%rsp)
vs.
	movl $0x09abcdef, %eax
	salq $32, %rax
	orq $0x12345678, %rax
	movq $rax, (%rsp)


vs.

        movq $LC0, (%rsp)

?


Not the same. That moves the address of $LC0.


Bernd

References:
- [PATCH][v3] GIMPLE store merging pass
  - From: Kyrill Tkachov
- Re: [PATCH][v3] GIMPLE store merging pass
  - From: Jakub Jelinek
- Re: [PATCH][v3] GIMPLE store merging pass
  - From: Kyrill Tkachov
- Re: [PATCH][v3] GIMPLE store merging pass
  - From: Jakub Jelinek
- Re: [PATCH][v3] GIMPLE store merging pass
  - From: Richard Biener

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