Issue 11435 - -O optimization flag causes invalid 32 bit codegen

[yebblies]

Do not emit a push from memory instruction for 8 or 16-byte words, ever.

@WalterBright Is there some way to detect it's pushing from a stack slot? (and therefore is always safe)

https://issues.dlang.org/show_bug.cgi?id=11435

[Safety0ff]

Is there some way to detect it's pushing from a stack slot? (and therefore is always safe)

Would checking e->oper == OPvar be sufficient? (I'm not very familiar with subtle back end details.)

I think the condition on szb should be something like: szb <= 1 + !I16.

Out of curiosity, why is the fix done in the case OPvar section?

[yebblies]

OPvar includes globals/tls/etc. Maybe those are safe?

I put it there because that's where the gotos went. I don't know why it fails, the condition I added should have been conservative. I haven't gotten around to looking into it yet.

[schuetzm]

Ketmar says this PR causes problems for him, please see here:
http://forum.dlang.org/thread/20141027022550.429e0244@ketmar.no-ip.org
http://forum.dlang.org/thread/mailman.1173.1414369559.9932.digitalmars-d-learn@puremagic.com

[yebblies]

Of course it causes problems, it fails the autotester.

[schuetzm]

Yes, but he posted a reduced example. Maybe it helps in finding the cause.

[andralex]

@yebblies ping

[yebblies]

Eh I can't be bothered with this right now.