| 23 | namespace { |
| 24 | |
| 25 | align_t getAlignment(const Constant *c) { |
| 26 | assert(c); |
| 27 | |
| 28 | if (isa<BasicBlock>(c) || isa<Function>(c)) |
| 29 | return 1; |
| 30 | |
| 31 | // An undef value is never aligned. |
| 32 | if (isa<UndefValue>(c)) |
| 33 | return 1; |
| 34 | |
| 35 | if (const ConstantInt *cint = dyn_cast<ConstantInt>(c)) { |
| 36 | return static_cast<align_t>(std::abs(cint->getSExtValue())); |
| 37 | } |
| 38 | |
| 39 | // Other than that, only integer vector constants can be aligned. |
| 40 | if (!c->getType()->isVectorTy()) |
| 41 | return 1; |
| 42 | |
| 43 | // A zero-vector is aligned. |
| 44 | if (isa<ConstantAggregateZero>(c)) |
| 45 | return 0; |
| 46 | |
| 47 | if (const ConstantDataVector *cdv = dyn_cast<ConstantDataVector>(c)) { |
| 48 | if (!cdv->getElementType()->isIntegerTy()) |
| 49 | return 1; |
| 50 | |
| 51 | const int intValue = (align_t)cast<ConstantInt>(cdv->getAggregateElement(0U))->getZExtValue(); |
| 52 | |
| 53 | return static_cast<align_t>(std::abs(intValue)); |
| 54 | } |
| 55 | |
| 56 | assert(isa<ConstantVector>(c)); |
| 57 | const ConstantVector *cv = cast<ConstantVector>(c); |
| 58 | |
| 59 | if (!cv->getType()->getElementType()->isIntegerTy()) |
| 60 | return 1; |
| 61 | |
| 62 | assert(isa<ConstantInt>(cv->getOperand(0))); |
| 63 | const ConstantInt *celem = cast<ConstantInt>(cv->getOperand(0)); |
| 64 | const int intValue = (align_t)celem->getZExtValue(); |
| 65 | |
| 66 | // The vector is aligned if its first element is aligned |
| 67 | return static_cast<align_t>(std::abs(intValue)); |
| 68 | } |
| 69 | |
| 70 | } // namespace |
| 71 | |