Index: llvm/lib/Transforms/IPO/LowerTypeTests.cpp =================================================================== --- llvm/lib/Transforms/IPO/LowerTypeTests.cpp +++ llvm/lib/Transforms/IPO/LowerTypeTests.cpp @@ -771,10 +771,12 @@ // Compute the amount of padding required. uint64_t Padding = NextPowerOf2(InitSize - 1) - InitSize; - // Cap at 128 was found experimentally to have a good data/instruction - // overhead tradeoff. - if (Padding > 128) - Padding = alignTo(InitSize, 128) - InitSize; + // Experiments of different caps with Chromium on both x64 and ARM64 + // have shown that now the 32-byte cap generates the smallest binary on + // both platforms while different caps yield similar performance. + // (see https://lists.llvm.org/pipermail/llvm-dev/2018-July/124694.html) + if (Padding > 32) + Padding = alignTo(InitSize, 32) - InitSize; GlobalInits.push_back( ConstantAggregateZero::get(ArrayType::get(Int8Ty, Padding)));