[PATCH] D45722: [X86] Lowering SAD (sum of absolute differences) intrinsics to native IR (clang side)

[Craig Topper via Phabricator via cfe-commits]

craig.topper added inline comments.


================
Comment at: clang/lib/CodeGen/CGBuiltin.cpp:8426
+  llvm::Type *BTy = llvm::VectorType::get(CGF.Builder.getInt8Ty(), N * 8);
+  SmallVector<uint32_t, 8> ShuffleMask;
+  for (unsigned i = 0; i < N; ++i)
----------------
Size the ShuffleMask to N when it's created. Then you can use just direct assign each array entry in the loops. This will remove the need for the clear() in the later loop. It will also remove the hidden code that checks if we need to grow on every call to push_back.


https://reviews.llvm.org/D45722