Bug 25629 - -mcpu=601 doesn't use MQ register
Summary: -mcpu=601 doesn't use MQ register
Status: RESOLVED WONTFIX
Alias: None
Product: gcc
Classification: Unclassified
Component: target (show other bugs)
Version: 4.0.1
: P3 normal
Target Milestone: ---
Assignee: Not yet assigned to anyone
URL:
Keywords:
Depends on:
Blocks:
 
Reported: 2006-01-01 20:06 UTC by Stef Simoens
Modified: 2012-08-16 10:12 UTC (History)
2 users (show)

See Also:
Host:
Target: powerpc*-*-* (601)
Build:
Known to work:
Known to fail:
Last reconfirmed:

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Description Stef Simoens 2006-01-01 20:06:27 UTC 
(up to) gcc-3.4.3 -mcpu=601 compiled code uses the MQ register

(at least) gcc-4.0.1 -mcpu=601 compiled code doesn't use MQ any more

tested with:
simple function which calculates remainder

int mod(int a, int b) {
  return a % b;
}

Why is that?
Comment 1 Andrew Pinski 2006-01-01 20:15:04 UTC 
This is most likely a cost issue.
Comment 2 Segher Boessenkool 2012-08-16 10:12:11 UTC 
Nothing will ever use the MQ register anymore: all support for
the old POWER ISA has been removed, and PowerPC does not have
an MQ register.