struct Node { size_t _left; Node* left() { return cast(Node*) (_left & 1); } bool useLeft() { return left is null; } } Result: Internal error: ..\ztc\cgelem.c 3387 This one is really hard to reproduce. If you change this test program in even very small ways, it's no longer reproduced.
I can't reproduce this (on Windows) with either D2 or D1. I tried several compiler versions, it compiled correctly in all cases.
Didn't realize it at the time, but I've looked into this further. It only happens when you compile w/ -O -inline.
Reduced test case. Compile with -O (-inline not required). Not a regression; fails on DMD0.165. bool foo() { int x; return cast(void*) (x & 1) == null; } Internal error: ztc\cgelem.c 3387 Really peculiar thing is that replacing & with | or ^ makes the bug disappear.
This assert is actually completely harmless. It's part of a check for if the equality comparison can be reduced to a single byte comparison. This can happen if it's a pointer with all the high bits clear, which includes null. Here are 3 cases which trigger the same bug. bool foo() { int x; // return cast(void*) (x & 1) == null; // Case 1 // return cast(void*) (x & 1) == cast(void *)(2); // Case 2 return cast(bool function()) (x & 1) == null; // Case 3 } ================ PATCH: cgelem.c, line 3387. /* Try to convert to byte/word comparison for ((x & c)==d) when mask c essentially casts x to a smaller type */ if (OPTIMIZER && e1->Eoper == OPand && e1->E2->Eoper == OPconst && (sz = tysize(e2->Ety)) > CHARSIZE) { int op; - assert(tyintegral(e2->Ety)); + assert(tyintegral(e2->Ety) || (e2->Ety == TYnptr)); #if TX86 /* ending up with byte ops in A regs */ if (!(el_tolong(e2) & ~CHARMASK) && !(el_tolong(e1->E2) & ~CHARMASK) ) {
SVN commit: http://www.dsource.org/projects/dmd/changeset/267
Fixed 2.037.
Fixed dmd 1.053 and 2.037