Summary: | Documentation change - GCC Internals MODES_TIEABLE_P | ||
---|---|---|---|
Product: | gcc | Reporter: | andy hutchinson <andrewhutchinson> |
Component: | other | Assignee: | Not yet assigned to anyone <unassigned> |
Status: | RESOLVED INVALID | ||
Severity: | minor | CC: | abnikant.singh, eric.weddington, gcc-bugs |
Priority: | P2 | ||
Version: | 3.4.3 | ||
Target Milestone: | --- | ||
Host: | Target: | ||
Build: | Known to work: | ||
Known to fail: | Last reconfirmed: | 2012-01-11 00:00:00 |
Description
andy hutchinson
2005-02-08 03:37:27 UTC
"If HARD_REGNO_MODE_OK (r, mode1) and HARD_REGNO_MODE_OK (r, mode2) are always the same for any r, then MODES_TIEABLE_P (mode1, mode2) should be nonzero. If they differ for any r, you should define this macro to return zero unless some other mechanism ensures the accessibility of the value in a narrower mode." In case of avr: if (mode1 != mode2) then HARD_REGNO_MODE_OK (r, mode1) != HARD_REGNO_MODE_OK (r, mode2) and hence MODES_TIEABLE_P (mode1, mode2) should be 0. [ But this is true only if we do not have other mechanism to access the value in narrower mode ] Is this still an issue? (In reply to Richard Biener from comment #2) > Is this still an issue? Reporter never replied; guess not |