------- Additional Comments From aoliva at gcc dot gnu dot org 2005-03-25 13:41 ------- Subject: Re: [PR middle-end/20491] combine generates bad subregs
On Mar 24, 2005, [EMAIL PROTECTED] (Richard Kenner) wrote: > Combine doesn't ensure the subregs it generates are valid. In most > cases, insn recog will reject the invalid subregs, or reload will > some how make them fit, but if the constraint of the insn or the asm > operand is "X", this won't work, so I think we're better off ensuring > we don't ever introduce subregs of non-REGs. > Aside from calling recog combine doesn't check that *anything* it generates > is valid. Why should subregs be different? Because, as I said, generating an invalid subreg at that point, without any opportunity to fix it up later, will cause us to crash when the time comes to remove all subregs. -- http://gcc.gnu.org/bugzilla/show_bug.cgi?id=20491
