Mercurial > projects > ldc

comparison gen/llvmhelpers.cpp @ 1356:59c2aa9def23

Find changesets by keywords (author, files, the commit message), revision number or hash, or revset expression.
Enabled fix for ticket #294 . It will try it's best to let LLVM handle the alignment, and fall back to manual padding when that's not possible. If this causes problems again, we'll have to consistently pad manually using packed structs.
author Tomas Lindquist Olsen <tomas.l.olsen gmail com>
date Fri, 15 May 2009 17:05:35 +0200
parents c5410f294c89
children e5c5d354c649
comparison
equal deleted inserted replaced
1355:c5410f294c89 1356:59c2aa9def23
1449 // if the aligned offset already matches the input offset 1449 // if the aligned offset already matches the input offset
1450 // don't waste time checking things are ok! 1450 // don't waste time checking things are ok!
1451 if (alignedoffset == offset) 1451 if (alignedoffset == offset)
1452 return alignedoffset; 1452 return alignedoffset;
1453 1453
1454 // disabled since this can fail for opaques. if the check above is not in place 1454 // we cannot get the llvm alignment if the type is still opaque, this can happen in some
1455 // it does so for gcx.d!!! 1455 // forward reference situations, so when this happens we fall back to manual padding.
1456 // this needs to be investigated, but I don't have time right now! 1456 const llvm::Type* T = DtoType(type);
1457 #if 0 1457 if (llvm::isa<llvm::OpaqueType>(T))
1458 // if not, we have to make sure it agrees with what llvm thinks is the alignment 1458 {
1459 // sometimes this is different from what we really need (in case of unions, see #294) 1459 return offset;
1460 // so if there we get different results we don't realign the offset at all and instead 1460 }
1461 // just return the original offset, and rely on the users to insert padding manually. 1461
1462 IF_LOG Logger::cout() << "getting alignment for type " << type->toChars() 1462 // then we check against the llvm alignment
1463 << " with llvm type " << *DtoType(type) << std::endl; 1463 size_t alignsize2 = gTargetData->getABITypeAlignment(T);
1464 size_t alignsize2 = gTargetData->getABITypeAlignment(DtoType(type)); 1464
1465 1465 // if it differs we need to insert manual padding as well
1466 if (alignsize != alignsize2) 1466 if (alignsize != alignsize2)
1467 { 1467 {
1468 assert(alignsize > alignsize2 && "this is not good, the D and LLVM " 1468 assert(alignsize > alignsize2 && "this is not good, the D and LLVM "
1469 "type alignments differ, but LLVM's is bigger! This will break " 1469 "type alignments differ, but LLVM's is bigger! This will break "
1470 "the type mapping algorithms"); 1470 "aggregate type mapping");
1471 // don't try and align the offset, and let the mappers pad 100% manually 1471 // don't try and align the offset, and let the mappers pad 100% manually
1472 return offset; 1472 return offset;
1473 } 1473 }
1474 #endif 1474
1475 1475 // ok, we're good, llvm will align properly!
1476 return alignedoffset; 1476 return alignedoffset;
1477 } 1477 }
1478 1478
1479 ////////////////////////////////////////////////////////////////////////////////////////// 1479 //////////////////////////////////////////////////////////////////////////////////////////