[Issue 6733] Regression(2.054) ICE(cod2.c) struct literals as template arguments
http://d.puremagic.com/issues/show_bug.cgi?id=6733 Don clugd...@yahoo.com.au changed: What|Removed |Added Keywords||ice-on-valid-code CC||clugd...@yahoo.com.au Summary|DMD Crash (internal error) |Regression(2.054) ||ICE(cod2.c) struct literals ||as template arguments Severity|critical|regression --- Comment #2 from Don clugd...@yahoo.com.au 2011-10-21 00:03:39 PDT --- This worked in 2.053 and earlier. -- Configure issuemail: http://d.puremagic.com/issues/userprefs.cgi?tab=email --- You are receiving this mail because: ---
[Issue 6733] Regression(2.054) ICE(cod2.c) struct literals as template arguments
http://d.puremagic.com/issues/show_bug.cgi?id=6733 Brad Roberts bra...@puremagic.com changed: What|Removed |Added CC||bra...@puremagic.com --- Comment #3 from Brad Roberts bra...@puremagic.com 2011-10-21 00:44:05 PDT --- I just bisected it down to: commit 4c9661fa9fbd427909a334133dfc7f3869e47c31 Author: Walter Bright wal...@walterbright.com Date: Thu Jun 23 00:50:46 2011 -0700 nothrow inference Reverting it from tip of master yields a successful build of the code above. -- Configure issuemail: http://d.puremagic.com/issues/userprefs.cgi?tab=email --- You are receiving this mail because: ---
[Issue 6733] Regression(2.054) ICE(cod2.c) struct literals as template arguments
http://d.puremagic.com/issues/show_bug.cgi?id=6733 --- Comment #4 from Don clugd...@yahoo.com.au 2011-10-21 01:04:13 PDT --- (In reply to comment #3) I just bisected it down to: commit 4c9661fa9fbd427909a334133dfc7f3869e47c31 Author: Walter Bright wal...@walterbright.com Date: Thu Jun 23 00:50:46 2011 -0700 nothrow inference Reverting it from tip of master yields a successful build of the code above. Thanks. The backend failure is occuring inside a comma expression (x, y). Fails because x isn't an expression, it's just a parameter (presumably the struct literal). -- Configure issuemail: http://d.puremagic.com/issues/userprefs.cgi?tab=email --- You are receiving this mail because: ---
[Issue 6733] Regression(2.054) ICE(cod2.c) struct literals as template arguments
http://d.puremagic.com/issues/show_bug.cgi?id=6733
--- Comment #5 from Don clugd...@yahoo.com.au 2011-10-21 01:19:10 PDT ---
Actually this is more a pseudo-regresssion, it's just an expansion of an
existing bug into a few more cases. Walter's commit has nothing to do with the
root cause. The test case below fails in exactly the same way on 2.025 (but
passed on 2.023).
struct Zero { int x; }
void test(T)(T a, T b) pure nothrow { }
void main() { test(Zero(7), Zero(4)); }
The bug is triggered when test() gets completely optimized away because it's
pure nothrow.
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[Issue 6733] Regression(2.054) ICE(cod2.c) struct literals as template arguments
http://d.puremagic.com/issues/show_bug.cgi?id=6733
--- Comment #6 from Don clugd...@yahoo.com.au 2011-10-21 05:05:58 PDT ---
Reduced test case:
void bug6733(int a, int b) pure nothrow { }
void main() {
int z;
bug6733(z++, z++);
}
This is definitely a backend bug. What happens is, that since it's pure nothrow
and the result is unused, it's a no-side-effect call (OPcallns).
In the first optimisation step (optelem in cgelem.c), the call gets discarded,
and simply replaced with the parameter list (wrapped in an OPparam). If the
parameters had no side-effects, the whole thing would be discarded.
If there's only one with a side-effect, it's the only thing that's left. But if
there are TWO with side-effects, the OPparam remains.
The rest of the backend can't cope with a naked OPparam. Boom.
Solution would be to replace the OPparam with comma expressions.
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