From 5667b2c24b6e2b277e9478152ae318c4e01d3d09 Mon Sep 17 00:00:00 2001 From: WANG Rui Date: Wed, 22 May 2024 15:14:28 +0800 Subject: [PATCH 1/2] [LoongArch] Adjust LA64 data layout by using n32:64 in layout string Although i32 type is illegal in the backend, LA64 has pretty good support for i32 types by using W instructions. By adding n32 to the DataLayout string, middle end optimizations will consider i32 to be a native type. One known effect of this is enabling LoopStrengthReduce on loops with i32 induction variables. This can be beneficial because C/C++ code often has loops with i32 induction variables due to the use of `int` or `unsigned int`. If this patch exposes performance issues, those are better addressed by tuning LSR or other passes. --- clang/lib/Basic/Targets/LoongArch.h | 2 +- llvm/docs/ReleaseNotes.rst | 4 ++++ llvm/lib/IR/AutoUpgrade.cpp | 4 ++-- llvm/lib/Target/LoongArch/LoongArchTargetMachine.cpp | 2 +- llvm/unittests/Bitcode/DataLayoutUpgradeTest.cpp | 5 +++++ 5 files changed, 13 insertions(+), 4 deletions(-) diff --git a/clang/lib/Basic/Targets/LoongArch.h b/clang/lib/Basic/Targets/LoongArch.h index 68572843f2d748..5fc223483951e9 100644 --- a/clang/lib/Basic/Targets/LoongArch.h +++ b/clang/lib/Basic/Targets/LoongArch.h @@ -133,7 +133,7 @@ class LLVM_LIBRARY_VISIBILITY LoongArch64TargetInfo LongWidth = LongAlign = PointerWidth = PointerAlign = 64; IntMaxType = Int64Type = SignedLong; HasUnalignedAccess = true; - resetDataLayout("e-m:e-p:64:64-i64:64-i128:128-n64-S128"); + resetDataLayout("e-m:e-p:64:64-i64:64-i128:128-n32:64-S128"); // TODO: select appropriate ABI. setABI("lp64d"); } diff --git a/llvm/docs/ReleaseNotes.rst b/llvm/docs/ReleaseNotes.rst index 1e1ccb495c3669..7acdf22462b364 100644 --- a/llvm/docs/ReleaseNotes.rst +++ b/llvm/docs/ReleaseNotes.rst @@ -107,6 +107,10 @@ Changes to the Hexagon Backend Changes to the LoongArch Backend -------------------------------- +* i32 is now a native type in the datalayout string. This enables + LoopStrengthReduce for loops with i32 induction variables, among other + optimizations. + Changes to the MIPS Backend --------------------------- diff --git a/llvm/lib/IR/AutoUpgrade.cpp b/llvm/lib/IR/AutoUpgrade.cpp index a7ed2de6e8a5ff..b66c9bfd22932e 100644 --- a/llvm/lib/IR/AutoUpgrade.cpp +++ b/llvm/lib/IR/AutoUpgrade.cpp @@ -5368,8 +5368,8 @@ std::string llvm::UpgradeDataLayoutString(StringRef DL, StringRef TT) { return DL.empty() ? std::string("G1") : (DL + "-G1").str(); } - if (T.isRISCV64()) { - // Make i32 a native type for 64-bit RISC-V. + if (T.isRISCV64() || T.isLoongArch64()) { + // Make i32 a native type for 64-bit RISC-V and LoongArch. auto I = DL.find("-n64-"); if (I != StringRef::npos) return (DL.take_front(I) + "-n32:64-" + DL.drop_front(I + 5)).str(); diff --git a/llvm/lib/Target/LoongArch/LoongArchTargetMachine.cpp b/llvm/lib/Target/LoongArch/LoongArchTargetMachine.cpp index 2b2d4e478cc821..60e09bb2f058a2 100644 --- a/llvm/lib/Target/LoongArch/LoongArchTargetMachine.cpp +++ b/llvm/lib/Target/LoongArch/LoongArchTargetMachine.cpp @@ -46,7 +46,7 @@ static cl::opt static std::string computeDataLayout(const Triple &TT) { if (TT.isArch64Bit()) - return "e-m:e-p:64:64-i64:64-i128:128-n64-S128"; + return "e-m:e-p:64:64-i64:64-i128:128-n32:64-S128"; assert(TT.isArch32Bit() && "only LA32 and LA64 are currently supported"); return "e-m:e-p:32:32-i64:64-n32-S128"; } diff --git a/llvm/unittests/Bitcode/DataLayoutUpgradeTest.cpp b/llvm/unittests/Bitcode/DataLayoutUpgradeTest.cpp index 7148e2902fa7ab..ca50187e5e5ee0 100644 --- a/llvm/unittests/Bitcode/DataLayoutUpgradeTest.cpp +++ b/llvm/unittests/Bitcode/DataLayoutUpgradeTest.cpp @@ -63,6 +63,11 @@ TEST(DataLayoutUpgradeTest, ValidDataLayoutUpgrade) { "riscv64"), "e-m:e-p:64:64-i64:64-i128:128-n32:64-S128"); + // Check that LoongArch64 upgrades -n64 to -n32:64. + EXPECT_EQ(UpgradeDataLayoutString("e-m:e-p:64:64-i64:64-i128:128-n64-S128", + "loongarch64"), + "e-m:e-p:64:64-i64:64-i128:128-n32:64-S128"); + // Check that SPIR && SPIRV targets add -G1 if it's not present. EXPECT_EQ(UpgradeDataLayoutString("e-p:32:32", "spir"), "e-p:32:32-G1"); EXPECT_EQ(UpgradeDataLayoutString("e-p:32:32", "spir64"), "e-p:32:32-G1"); From 0a0a4231f02db14583288f093e5d9cde00c433fb Mon Sep 17 00:00:00 2001 From: WANG Rui Date: Thu, 6 Jun 2024 09:44:11 +0800 Subject: [PATCH 2/2] Address SixWeining's comment --- llvm/lib/IR/AutoUpgrade.cpp | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/llvm/lib/IR/AutoUpgrade.cpp b/llvm/lib/IR/AutoUpgrade.cpp index b66c9bfd22932e..2f4b8351e747aa 100644 --- a/llvm/lib/IR/AutoUpgrade.cpp +++ b/llvm/lib/IR/AutoUpgrade.cpp @@ -5368,8 +5368,8 @@ std::string llvm::UpgradeDataLayoutString(StringRef DL, StringRef TT) { return DL.empty() ? std::string("G1") : (DL + "-G1").str(); } - if (T.isRISCV64() || T.isLoongArch64()) { - // Make i32 a native type for 64-bit RISC-V and LoongArch. + if (T.isLoongArch64() || T.isRISCV64()) { + // Make i32 a native type for 64-bit LoongArch and RISC-V. auto I = DL.find("-n64-"); if (I != StringRef::npos) return (DL.take_front(I) + "-n32:64-" + DL.drop_front(I + 5)).str();