This is the mail archive of the gcc@gcc.gnu.org mailing list for the GCC project.

Index Nav:	[Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav:	[Date Prev] [Date Next]	[Thread Prev] [Thread Next]
Other format:	[Raw text]

Re: Reload going wrong for addition.

From: Richard Henderson <rth at redhat dot com>
To: Mohamed Shafi <shafitvm at gmail dot com>
Cc: GCC <gcc at gcc dot gnu dot org>
Date: Mon, 28 Sep 2009 10:31:44 -0700
Subject: Re: Reload going wrong for addition.
References: <ba0bd44d0909280725l4ca2b85creee505e88d54cb08@mail.gmail.com>

On 09/28/2009 07:25 AM, Mohamed Shafi wrote:

Hope someone suggests me a solution.

The solution is almost certainly something involving the TARGET_SECONDARY_RELOAD hook. You need to inform reload that it's going to need some scratch registers in order to perform the operation.

It's been a long time since I had to fiddle with this sort of thing, so I forget all the details involved. Perhaps someone else has some additional advice.

P.S Can i have commutative operation for the constraint combination
(t, 0, t) i.e (t, %0, t). If so what will be the output template?

You can use commutative operations for constraints. You do not need to adjust the output template at all; if reload decides that a swap is needed, it will swap the operands in the rtl too.

r~

References:
- Reload going wrong for addition.
  - From: Mohamed Shafi

Index Nav:	[Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav:	[Date Prev] [Date Next]	[Thread Prev] [Thread Next]