diff options
Diffstat (limited to 'llvm/lib/IR/DataLayout.cpp')
| -rw-r--r-- | llvm/lib/IR/DataLayout.cpp | 16 |
1 files changed, 15 insertions, 1 deletions
diff --git a/llvm/lib/IR/DataLayout.cpp b/llvm/lib/IR/DataLayout.cpp index 62c67127276..18d502a52ca 100644 --- a/llvm/lib/IR/DataLayout.cpp +++ b/llvm/lib/IR/DataLayout.cpp @@ -808,15 +808,29 @@ int64_t DataLayout::getIndexedOffsetInType(Type *ElemTy, /// global. This includes an explicitly requested alignment (if the global /// has one). unsigned DataLayout::getPreferredAlignment(const GlobalVariable *GV) const { + unsigned GVAlignment = GV->getAlignment(); + // If a section is specified, always precisely honor explicit alignment, + // so we don't insert padding into a section we don't control. + if (GVAlignment && GV->hasSection()) + return GVAlignment; + + // If no explicit alignment is specified, compute the alignment based on + // the IR type. If an alignment is specified, increase it to match the ABI + // alignment of the IR type. + // + // FIXME: Not sure it makes sense to use the alignment of the type if + // there's already an explicit alignment specification. Type *ElemType = GV->getValueType(); unsigned Alignment = getPrefTypeAlignment(ElemType); - unsigned GVAlignment = GV->getAlignment(); if (GVAlignment >= Alignment) { Alignment = GVAlignment; } else if (GVAlignment != 0) { Alignment = std::max(GVAlignment, getABITypeAlignment(ElemType)); } + // If no explicit alignment is specified, and the global is large, increase + // the alignment to 16. + // FIXME: Why 16, specifically? if (GV->hasInitializer() && GVAlignment == 0) { if (Alignment < 16) { // If the global is not external, see if it is large. If so, give it a |
