Author: Artem Belevich Date: 2021-08-06T11:13:52-07:00 New Revision: 6a9cf21f5a2dcd02f90075d6d3576a87f1abd8a9
URL: https://github.com/llvm/llvm-project/commit/6a9cf21f5a2dcd02f90075d6d3576a87f1abd8a9 DIFF: https://github.com/llvm/llvm-project/commit/6a9cf21f5a2dcd02f90075d6d3576a87f1abd8a9.diff LOG: [CUDA, MemCpyOpt] Add a flag to force-enable memcpyopt and use it for CUDA. Attempt to enable MemCpyOpt unconditionally in D104801 uncovered the fact that there are users that do not expect LLVM to materialize `memset` intrinsic. While other passes can do that, too, MemCpyOpt triggers it more frequently and breaks sanitizers and some downstream users. For now introduce a flag to force-enable the flag and opt-in only CUDA compilation with NVPTX back-end. Differential Revision: https://reviews.llvm.org/D106401 Added: Modified: clang/lib/Driver/ToolChains/Cuda.cpp llvm/lib/Transforms/Scalar/MemCpyOptimizer.cpp llvm/test/Transforms/MemCpyOpt/no-libcalls.ll Removed: ################################################################################ diff --git a/clang/lib/Driver/ToolChains/Cuda.cpp b/clang/lib/Driver/ToolChains/Cuda.cpp index c4d1ebdf6913..37a4da80c03c 100644 --- a/clang/lib/Driver/ToolChains/Cuda.cpp +++ b/clang/lib/Driver/ToolChains/Cuda.cpp @@ -685,7 +685,8 @@ void CudaToolChain::addClangTargetOptions( "Only OpenMP or CUDA offloading kinds are supported for NVIDIA GPUs."); if (DeviceOffloadingKind == Action::OFK_Cuda) { - CC1Args.push_back("-fcuda-is-device"); + CC1Args.append( + {"-fcuda-is-device", "-mllvm", "-enable-memcpyopt-without-libcalls"}); if (DriverArgs.hasFlag(options::OPT_fcuda_approx_transcendentals, options::OPT_fno_cuda_approx_transcendentals, false)) diff --git a/llvm/lib/Transforms/Scalar/MemCpyOptimizer.cpp b/llvm/lib/Transforms/Scalar/MemCpyOptimizer.cpp index 0dd0b45cf054..42650f3b6f2e 100644 --- a/llvm/lib/Transforms/Scalar/MemCpyOptimizer.cpp +++ b/llvm/lib/Transforms/Scalar/MemCpyOptimizer.cpp @@ -67,6 +67,10 @@ using namespace llvm; #define DEBUG_TYPE "memcpyopt" +static cl::opt<bool> EnableMemCpyOptWithoutLibcalls( + "enable-memcpyopt-without-libcalls", cl::init(false), cl::Hidden, + cl::desc("Enable memcpyopt even when libcalls are disabled")); + static cl::opt<bool> EnableMemorySSA("enable-memcpyopt-memoryssa", cl::init(true), cl::Hidden, cl::desc("Use MemorySSA-backed MemCpyOpt.")); @@ -677,8 +681,9 @@ bool MemCpyOptPass::processStore(StoreInst *SI, BasicBlock::iterator &BBI) { // the corresponding libcalls are not available. // TODO: We should really distinguish between libcall availability and // our ability to introduce intrinsics. - if (T->isAggregateType() && TLI->has(LibFunc_memcpy) && - TLI->has(LibFunc_memmove)) { + if (T->isAggregateType() && + (EnableMemCpyOptWithoutLibcalls || + (TLI->has(LibFunc_memcpy) && TLI->has(LibFunc_memmove)))) { MemoryLocation LoadLoc = MemoryLocation::get(LI); // We use alias analysis to check if an instruction may store to @@ -806,7 +811,7 @@ bool MemCpyOptPass::processStore(StoreInst *SI, BasicBlock::iterator &BBI) { // this if the corresponding libfunc is not available. // TODO: We should really distinguish between libcall availability and // our ability to introduce intrinsics. - if (!TLI->has(LibFunc_memset)) + if (!(TLI->has(LibFunc_memset) || EnableMemCpyOptWithoutLibcalls)) return false; // There are two cases that are interesting for this code to handle: memcpy diff --git a/llvm/test/Transforms/MemCpyOpt/no-libcalls.ll b/llvm/test/Transforms/MemCpyOpt/no-libcalls.ll index c4d935158435..ac7cfc55ce50 100644 --- a/llvm/test/Transforms/MemCpyOpt/no-libcalls.ll +++ b/llvm/test/Transforms/MemCpyOpt/no-libcalls.ll @@ -1,6 +1,8 @@ ; NOTE: Assertions have been autogenerated by utils/update_test_checks.py ; RUN: opt -S -memcpyopt < %s | FileCheck %s --check-prefixes=CHECK,LIBCALLS ; RUN: opt -S -memcpyopt -mtriple=amdgcn-- < %s | FileCheck %s --check-prefixes=CHECK,NO-LIBCALLS +; RUN: opt -S -memcpyopt -mtriple=amdgcn-- -enable-memcpyopt-without-libcalls < %s \ +; RUN: | FileCheck %s --check-prefixes=CHECK,LIBCALLS ; REQUIRES: amdgpu-registered-target _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
