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Re: [PATCH] Make basic asm implicitly clobber memory

From: Bernd Schmidt <bschmidt at redhat dot com>
To: Bernd Edlinger <bernd dot edlinger at hotmail dot de>, Richard Biener <rguenther at suse dot de>
Cc: "gcc-patches at gcc dot gnu dot org" <gcc-patches at gcc dot gnu dot org>, Jeff Law <law at redhat dot com>, Jakub Jelinek <jakub at redhat dot com>, David Wohlferd <dw at LimeGreenSocks dot com>
Date: Mon, 9 May 2016 15:46:19 +0200
Subject: Re: [PATCH] Make basic asm implicitly clobber memory
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On 05/09/2016 03:37 PM, Bernd Edlinger wrote:

On 05/09/16 09:56, Richard Biener wrote:


At least it sounds to me that its semantics can be fully expressed
with generic asms?  (Maybe apart from the only-if-ASM_STRING-is-empty
part)


That was also my first idea too.

In simple cases an asm ("whatever"); should do the same as
asm ("whatever" ::: );

Adding a "memory" to the clobber list would be simple that's true.

But in general it can be pretty complicated, especially if the
string contains the special characters % { | }.

Is the only difference in how the string is output? Maybe we can have aslightly different form of ASM_OPERANDS (with a bit set, or with thestring wrapped in something else) to indicate that it's old-style.



Bernd

Follow-Ups:
- Re: [PATCH] Make basic asm implicitly clobber memory
  - From: Bernd Edlinger

References:
- [PATCH] Make basic asm implicitly clobber memory
  - From: Bernd Edlinger
- Re: [PATCH] Make basic asm implicitly clobber memory
  - From: Richard Biener
- Re: [PATCH] Make basic asm implicitly clobber memory
  - From: Bernd Edlinger

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