| Message ID | 1411143374-26536-1-git-send-email-james.greenhalgh@arm.com |
|---|---|
| State | New |
| Headers | show |
On 09/19/14 10:16, James Greenhalgh wrote: > > On Fri, Sep 19, 2014 at 04:10:34PM +0100, Andreas Krebbel wrote: >> On 09/19/2014 02:59 PM, James Greenhalgh wrote: >>> >>> Hi, >>> >>> After https://gcc.gnu.org/ml/gcc-patches/2014-09/msg01615.html we error >>> on the use of constraints in define_splits, define_expands and >>> define_peephole2s. These are never looked at by the compiler, and so >>> have no reason to be set. >>> >>> I expect there will be more fallout as Jan's auto-builder makes its way >>> through ports I haven't tested, I'll fix those up as they come up. >>> >>> These are build failures, and the fixes are "obvious", but I don't know >>> my way around these ports, so I'd like an explicit maintainer ack. >>> >>> For testing, I've just checked that the build error is resolved. In >>> principal, these are not functional changes as the constraints are >>> not looked at. >> >> S/390 bootstrap fails with: >> gcc/gcc/config/s390/s390.md:8397: operand 5 missing output reload >> >> For the branch on index instruction we have a define_insn_and_split with a >> single alternative forcing a split before reload. In this pattern to my >> understanding the constraints are not really required. > > Yes, if that is the existing supported behaviour for MATCH_OPERANDs (it > must be or your pattern would have been failing before), I don't want to > make MATCH_SCRATCH more restrictive. > > The fix is a one-liner. Jeff, I presume we still want to permit this? > The alternate fix would be to make this an error in both cases. > > Ok? > > Thanks, > James > > --- > 2014-09-14 James Greenhalgh <james.greenhalgh@arm.com> > > * genrecog.c (validate_pattern): Allow empty constraints in > a match_scratch. OK. Yea, I think we want to permit -- I have vague recollections this is documented somewhere as "accept anything". jeff
diff --git a/gcc/genrecog.c b/gcc/genrecog.c index 0134585..c1dc8fa 100644 --- a/gcc/genrecog.c +++ b/gcc/genrecog.c @@ -461,6 +461,7 @@ validate_pattern (rtx pattern, rtx insn, rtx set, int set_code) /* If a MATCH_SCRATCH is used in a context requiring an write-only or read/write register, validate that. */ if (set_code == '=' + && constraints0 && constraints0 != '=' && constraints0 != '+') {