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[NVPTX] deprecate nvvm.rotate.* intrinsics, cleanup funnel-shift handling #107655

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merged 4 commits into from
Sep 23, 2024
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[NVPTX] deprecate nvvm.rotate.* intrinsics, cleanup funnel-shift handling #107655

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008d778
[NVPTX] deprecate nvvm.rotate.* intrinsics, cleanup funnel-shift hand…
AlexMaclean Sep 5, 2024
0e3ba7a
add release note
AlexMaclean Sep 12, 2024
b967616
[NVPTX] Fixup rotate lowering correctness
AlexMaclean Sep 21, 2024
979aa53
address comments - update rotate_64.ll
AlexMaclean Sep 23, 2024
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6 changes: 6 additions & 0 deletions llvm/docs/ReleaseNotes.rst
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Expand Up @@ -63,6 +63,12 @@ Changes to the LLVM IR
* ``llvm.nvvm.bitcast.d2ll``
* ``llvm.nvvm.bitcast.ll2d``

* Remove the following intrinsics which can be replaced with a funnel-shift:

* ``llvm.nvvm.rotate.b32``
* ``llvm.nvvm.rotate.right.b64``
* ``llvm.nvvm.rotate.b64``

Changes to LLVM infrastructure
------------------------------

Expand Down
16 changes: 0 additions & 16 deletions llvm/include/llvm/IR/IntrinsicsNVVM.td
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Expand Up @@ -4479,22 +4479,6 @@ def int_nvvm_sust_p_3d_v4i32_trap
"llvm.nvvm.sust.p.3d.v4i32.trap">,
ClangBuiltin<"__nvvm_sust_p_3d_v4i32_trap">;


def int_nvvm_rotate_b32
: DefaultAttrsIntrinsic<[llvm_i32_ty], [llvm_i32_ty, llvm_i32_ty],
[IntrNoMem, IntrSpeculatable], "llvm.nvvm.rotate.b32">,
ClangBuiltin<"__nvvm_rotate_b32">;

def int_nvvm_rotate_b64
: DefaultAttrsIntrinsic<[llvm_i64_ty], [llvm_i64_ty, llvm_i32_ty],
[IntrNoMem, IntrSpeculatable], "llvm.nvvm.rotate.b64">,
ClangBuiltin<"__nvvm_rotate_b64">;

def int_nvvm_rotate_right_b64
: DefaultAttrsIntrinsic<[llvm_i64_ty], [llvm_i64_ty, llvm_i32_ty],
[IntrNoMem, IntrSpeculatable], "llvm.nvvm.rotate.right.b64">,
ClangBuiltin<"__nvvm_rotate_right_b64">;

def int_nvvm_swap_lo_hi_b64
: DefaultAttrsIntrinsic<[llvm_i64_ty], [llvm_i64_ty],
[IntrNoMem, IntrSpeculatable], "llvm.nvvm.swap.lo.hi.b64">,
Expand Down
184 changes: 106 additions & 78 deletions llvm/lib/IR/AutoUpgrade.cpp
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Expand Up @@ -1272,6 +1272,9 @@ static bool upgradeIntrinsicFunction1(Function *F, Function *&NewFn,
// nvvm.bitcast.{f2i,i2f,ll2d,d2ll}
Expand =
Name == "f2i" || Name == "i2f" || Name == "ll2d" || Name == "d2ll";
else if (Name.consume_front("rotate."))
// nvvm.rotate.{b32,b64,right.b64}
Expand = Name == "b32" || Name == "b64" || Name == "right.b64";
else
Expand = false;

Expand Down Expand Up @@ -2258,6 +2261,108 @@ void llvm::UpgradeInlineAsmString(std::string *AsmStr) {
}
}

static Value *upgradeNVVMIntrinsicCall(StringRef Name, CallBase *CI,
Function *F, IRBuilder<> &Builder) {
Value *Rep = nullptr;

if (Name == "abs.i" || Name == "abs.ll") {
Value *Arg = CI->getArgOperand(0);
Value *Neg = Builder.CreateNeg(Arg, "neg");
Value *Cmp = Builder.CreateICmpSGE(
Arg, llvm::Constant::getNullValue(Arg->getType()), "abs.cond");
Rep = Builder.CreateSelect(Cmp, Arg, Neg, "abs");
} else if (Name.starts_with("atomic.load.add.f32.p") ||
Name.starts_with("atomic.load.add.f64.p")) {
Value *Ptr = CI->getArgOperand(0);
Value *Val = CI->getArgOperand(1);
Rep = Builder.CreateAtomicRMW(AtomicRMWInst::FAdd, Ptr, Val, MaybeAlign(),
AtomicOrdering::SequentiallyConsistent);
} else if (Name.consume_front("max.") &&
(Name == "s" || Name == "i" || Name == "ll" || Name == "us" ||
Name == "ui" || Name == "ull")) {
Value *Arg0 = CI->getArgOperand(0);
Value *Arg1 = CI->getArgOperand(1);
Value *Cmp = Name.starts_with("u")
? Builder.CreateICmpUGE(Arg0, Arg1, "max.cond")
: Builder.CreateICmpSGE(Arg0, Arg1, "max.cond");
Rep = Builder.CreateSelect(Cmp, Arg0, Arg1, "max");
} else if (Name.consume_front("min.") &&
(Name == "s" || Name == "i" || Name == "ll" || Name == "us" ||
Name == "ui" || Name == "ull")) {
Value *Arg0 = CI->getArgOperand(0);
Value *Arg1 = CI->getArgOperand(1);
Value *Cmp = Name.starts_with("u")
? Builder.CreateICmpULE(Arg0, Arg1, "min.cond")
: Builder.CreateICmpSLE(Arg0, Arg1, "min.cond");
Rep = Builder.CreateSelect(Cmp, Arg0, Arg1, "min");
} else if (Name == "clz.ll") {
// llvm.nvvm.clz.ll returns an i32, but llvm.ctlz.i64 returns an i64.
Value *Arg = CI->getArgOperand(0);
Value *Ctlz = Builder.CreateCall(
Intrinsic::getDeclaration(F->getParent(), Intrinsic::ctlz,
{Arg->getType()}),
{Arg, Builder.getFalse()}, "ctlz");
Rep = Builder.CreateTrunc(Ctlz, Builder.getInt32Ty(), "ctlz.trunc");
} else if (Name == "popc.ll") {
// llvm.nvvm.popc.ll returns an i32, but llvm.ctpop.i64 returns an
// i64.
Value *Arg = CI->getArgOperand(0);
Value *Popc = Builder.CreateCall(
Intrinsic::getDeclaration(F->getParent(), Intrinsic::ctpop,
{Arg->getType()}),
Arg, "ctpop");
Rep = Builder.CreateTrunc(Popc, Builder.getInt32Ty(), "ctpop.trunc");
} else if (Name == "h2f") {
Rep = Builder.CreateCall(
Intrinsic::getDeclaration(F->getParent(), Intrinsic::convert_from_fp16,
{Builder.getFloatTy()}),
CI->getArgOperand(0), "h2f");
} else if (Name.consume_front("bitcast.") &&
(Name == "f2i" || Name == "i2f" || Name == "ll2d" ||
Name == "d2ll")) {
Rep = Builder.CreateBitCast(CI->getArgOperand(0), CI->getType());
} else if (Name == "rotate.b32") {
Value *Arg = CI->getOperand(0);
Value *ShiftAmt = CI->getOperand(1);
Rep = Builder.CreateIntrinsic(Builder.getInt32Ty(), Intrinsic::fshl,
{Arg, Arg, ShiftAmt});
} else if (Name == "rotate.b64") {
Type *Int64Ty = Builder.getInt64Ty();
Value *Arg = CI->getOperand(0);
Value *ZExtShiftAmt = Builder.CreateZExt(CI->getOperand(1), Int64Ty);
Rep = Builder.CreateIntrinsic(Int64Ty, Intrinsic::fshl,
{Arg, Arg, ZExtShiftAmt});
} else if (Name == "rotate.right.b64") {
Type *Int64Ty = Builder.getInt64Ty();
Value *Arg = CI->getOperand(0);
Value *ZExtShiftAmt = Builder.CreateZExt(CI->getOperand(1), Int64Ty);
Rep = Builder.CreateIntrinsic(Int64Ty, Intrinsic::fshr,
{Arg, Arg, ZExtShiftAmt});
} else {
Intrinsic::ID IID = shouldUpgradeNVPTXBF16Intrinsic(Name);
if (IID != Intrinsic::not_intrinsic &&
!F->getReturnType()->getScalarType()->isBFloatTy()) {
rename(F);
Function *NewFn = Intrinsic::getDeclaration(F->getParent(), IID);
SmallVector<Value *, 2> Args;
for (size_t I = 0; I < NewFn->arg_size(); ++I) {
Value *Arg = CI->getArgOperand(I);
Type *OldType = Arg->getType();
Type *NewType = NewFn->getArg(I)->getType();
Args.push_back(
(OldType->isIntegerTy() && NewType->getScalarType()->isBFloatTy())
? Builder.CreateBitCast(Arg, NewType)
: Arg);
}
Rep = Builder.CreateCall(NewFn, Args);
if (F->getReturnType()->isIntegerTy())
Rep = Builder.CreateBitCast(Rep, F->getReturnType());
}
}

return Rep;
}

static Value *upgradeX86IntrinsicCall(StringRef Name, CallBase *CI, Function *F,
IRBuilder<> &Builder) {
LLVMContext &C = F->getContext();
Expand Down Expand Up @@ -4208,85 +4313,8 @@ void llvm::UpgradeIntrinsicCall(CallBase *CI, Function *NewFn) {

if (!IsX86 && Name == "stackprotectorcheck") {
Rep = nullptr;
} else if (IsNVVM && (Name == "abs.i" || Name == "abs.ll")) {
Value *Arg = CI->getArgOperand(0);
Value *Neg = Builder.CreateNeg(Arg, "neg");
Value *Cmp = Builder.CreateICmpSGE(
Arg, llvm::Constant::getNullValue(Arg->getType()), "abs.cond");
Rep = Builder.CreateSelect(Cmp, Arg, Neg, "abs");
} else if (IsNVVM && (Name.starts_with("atomic.load.add.f32.p") ||
Name.starts_with("atomic.load.add.f64.p"))) {
Value *Ptr = CI->getArgOperand(0);
Value *Val = CI->getArgOperand(1);
Rep = Builder.CreateAtomicRMW(AtomicRMWInst::FAdd, Ptr, Val, MaybeAlign(),
AtomicOrdering::SequentiallyConsistent);
} else if (IsNVVM && Name.consume_front("max.") &&
(Name == "s" || Name == "i" || Name == "ll" || Name == "us" ||
Name == "ui" || Name == "ull")) {
Value *Arg0 = CI->getArgOperand(0);
Value *Arg1 = CI->getArgOperand(1);
Value *Cmp = Name.starts_with("u")
? Builder.CreateICmpUGE(Arg0, Arg1, "max.cond")
: Builder.CreateICmpSGE(Arg0, Arg1, "max.cond");
Rep = Builder.CreateSelect(Cmp, Arg0, Arg1, "max");
} else if (IsNVVM && Name.consume_front("min.") &&
(Name == "s" || Name == "i" || Name == "ll" || Name == "us" ||
Name == "ui" || Name == "ull")) {
Value *Arg0 = CI->getArgOperand(0);
Value *Arg1 = CI->getArgOperand(1);
Value *Cmp = Name.starts_with("u")
? Builder.CreateICmpULE(Arg0, Arg1, "min.cond")
: Builder.CreateICmpSLE(Arg0, Arg1, "min.cond");
Rep = Builder.CreateSelect(Cmp, Arg0, Arg1, "min");
} else if (IsNVVM && Name == "clz.ll") {
// llvm.nvvm.clz.ll returns an i32, but llvm.ctlz.i64 returns an i64.
Value *Arg = CI->getArgOperand(0);
Value *Ctlz = Builder.CreateCall(
Intrinsic::getDeclaration(F->getParent(), Intrinsic::ctlz,
{Arg->getType()}),
{Arg, Builder.getFalse()}, "ctlz");
Rep = Builder.CreateTrunc(Ctlz, Builder.getInt32Ty(), "ctlz.trunc");
} else if (IsNVVM && Name == "popc.ll") {
// llvm.nvvm.popc.ll returns an i32, but llvm.ctpop.i64 returns an
// i64.
Value *Arg = CI->getArgOperand(0);
Value *Popc = Builder.CreateCall(
Intrinsic::getDeclaration(F->getParent(), Intrinsic::ctpop,
{Arg->getType()}),
Arg, "ctpop");
Rep = Builder.CreateTrunc(Popc, Builder.getInt32Ty(), "ctpop.trunc");
} else if (IsNVVM) {
if (Name == "h2f") {
Rep =
Builder.CreateCall(Intrinsic::getDeclaration(
F->getParent(), Intrinsic::convert_from_fp16,
{Builder.getFloatTy()}),
CI->getArgOperand(0), "h2f");
} else if (Name.consume_front("bitcast.") &&
(Name == "f2i" || Name == "i2f" || Name == "ll2d" ||
Name == "d2ll")) {
Rep = Builder.CreateBitCast(CI->getArgOperand(0), CI->getType());
} else {
Intrinsic::ID IID = shouldUpgradeNVPTXBF16Intrinsic(Name);
if (IID != Intrinsic::not_intrinsic &&
!F->getReturnType()->getScalarType()->isBFloatTy()) {
rename(F);
NewFn = Intrinsic::getDeclaration(F->getParent(), IID);
SmallVector<Value *, 2> Args;
for (size_t I = 0; I < NewFn->arg_size(); ++I) {
Value *Arg = CI->getArgOperand(I);
Type *OldType = Arg->getType();
Type *NewType = NewFn->getArg(I)->getType();
Args.push_back((OldType->isIntegerTy() &&
NewType->getScalarType()->isBFloatTy())
? Builder.CreateBitCast(Arg, NewType)
: Arg);
}
Rep = Builder.CreateCall(NewFn, Args);
if (F->getReturnType()->isIntegerTy())
Rep = Builder.CreateBitCast(Rep, F->getReturnType());
}
}
Rep = upgradeNVVMIntrinsicCall(Name, CI, F, Builder);
} else if (IsX86) {
Rep = upgradeX86IntrinsicCall(Name, CI, F, Builder);
} else if (IsARM) {
Expand Down
21 changes: 7 additions & 14 deletions llvm/lib/Target/NVPTX/NVPTXISelLowering.cpp
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Expand Up @@ -594,20 +594,13 @@ NVPTXTargetLowering::NVPTXTargetLowering(const NVPTXTargetMachine &TM,
setOperationAction(ISD::BITREVERSE, MVT::i32, Legal);
setOperationAction(ISD::BITREVERSE, MVT::i64, Legal);

// TODO: we may consider expanding ROTL/ROTR on older GPUs. Currently on GPUs
// that don't have h/w rotation we lower them to multi-instruction assembly.
// See ROT*_sw in NVPTXIntrInfo.td
setOperationAction(ISD::ROTL, MVT::i64, Legal);
setOperationAction(ISD::ROTR, MVT::i64, Legal);
setOperationAction(ISD::ROTL, MVT::i32, Legal);
setOperationAction(ISD::ROTR, MVT::i32, Legal);

setOperationAction(ISD::ROTL, MVT::i16, Expand);
setOperationAction(ISD::ROTL, MVT::v2i16, Expand);
setOperationAction(ISD::ROTR, MVT::i16, Expand);
setOperationAction(ISD::ROTR, MVT::v2i16, Expand);
setOperationAction(ISD::ROTL, MVT::i8, Expand);
setOperationAction(ISD::ROTR, MVT::i8, Expand);
setOperationAction({ISD::ROTL, ISD::ROTR},
{MVT::i8, MVT::i16, MVT::v2i16, MVT::i32, MVT::i64},
Expand);

if (STI.hasHWROT32())
setOperationAction({ISD::FSHL, ISD::FSHR}, MVT::i32, Legal);

setOperationAction(ISD::BSWAP, MVT::i16, Expand);

setOperationAction(ISD::BR_JT, MVT::Other, Custom);
Expand Down
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