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Re: [RFC][PR target/39726 P4 regression] match.pd pattern to do type narrowing

From: Jeff Law <law at redhat dot com>
To: Richard Biener <richard dot guenther at gmail dot com>
Cc: Joseph Myers <joseph at codesourcery dot com>, GCC Patches <gcc-patches at gcc dot gnu dot org>
Date: Wed, 11 Feb 2015 08:56:20 -0700
Subject: Re: [RFC][PR target/39726 P4 regression] match.pd pattern to do type narrowing
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On 02/11/15 04:16, Richard Biener wrote:


Application of this pattern (and the one I posted for 47477) is a concern
for targets that don't do sub-word arithmetic/logicals.  But I just did a
sniff test of one such target (v850-elf because it was handy) and I couldn't
spot a change in the end code using both the 47477 patch and my WIP patch
for this BZ.


The c-family frontends perform this kind of narrowing already anyway
(via the shorten_* stuff which is misplaced there and should be done
elsewhere for all frontends - thus in match.pd, thanks for starting that).

True, but I wanted to see if there was any impact, but thankfully thereisn't.

The fact that the C/C++ front-ends are doing most of the shortening nowprobably explains why the fix for 47477 only affected code generationfor the Java front-end.


Jeff

Follow-Ups:
- Re: [RFC][PR target/39726 P4 regression] match.pd pattern to do type narrowing
  - From: Jakub Jelinek

References:
- Re: [RFC][PR target/39726 P4 regression] match.pd pattern to do type narrowing
  - From: Joseph Myers
- Re: [RFC][PR target/39726 P4 regression] match.pd pattern to do type narrowing
  - From: Jeff Law
- Re: [RFC][PR target/39726 P4 regression] match.pd pattern to do type narrowing
  - From: Joseph Myers
- Re: [RFC][PR target/39726 P4 regression] match.pd pattern to do type narrowing
  - From: Jeff Law
- Re: [RFC][PR target/39726 P4 regression] match.pd pattern to do type narrowing
  - From: Jeff Law
- Re: [RFC][PR target/39726 P4 regression] match.pd pattern to do type narrowing
  - From: Joseph Myers
- Re: [RFC][PR target/39726 P4 regression] match.pd pattern to do type narrowing
  - From: Jeff Law
- Re: [RFC][PR target/39726 P4 regression] match.pd pattern to do type narrowing
  - From: Richard Biener

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