March 16, 2014 [Issue 12384] New: Improve optimization of nothrow code | ||||
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https://d.puremagic.com/issues/show_bug.cgi?id=12384 Summary: Improve optimization of nothrow code Product: D Version: D2 Platform: All OS/Version: All Status: NEW Severity: enhancement Priority: P2 Component: DMD AssignedTo: nobody@puremagic.com ReportedBy: bugzilla@digitalmars.com --- Comment #0 from Walter Bright <bugzilla@digitalmars.com> 2014-03-16 16:48:55 PDT --- Consider: ---------------------------- import core.stdc.stdlib; void fun() nothrow; struct B { int* p; size_t x; } size_t fun4(ref B a) { B b; scope (exit) free(b.p); fun(); return b.x + a.x; } ---------------------------- This current sets up an exception handler to call free(b.p), even though no exceptions can be thrown. Instead, the code rewrite should be: --------------------- size_t fun4(ref B a) { B b; fun(); auto tmp = b.x + a.x; free(b.p); return tmp; } ----------------------- This will result in significant performance improvements. Currently, only one such rewrite case is handled in TryFinallyStatement::semantic(). There's more low hanging fruit, such as the return statement case above, that should be handled there. (scope-statements are rewritten as try-finally-statements.) -- Configure issuemail: https://d.puremagic.com/issues/userprefs.cgi?tab=email ------- You are receiving this mail because: ------- |
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