[codegen] worked around bug seemingly from nvptx/ptxas by simplifying multiplications by 1:

- Generated LLVM-IR looked correct
- Illegal addressing disappeared when running cuda-memcheck
- Illegal addressing disappeared when using nvptx-short-pointer
This commit is contained in:
Philippe Tillet
2019-08-29 21:34:23 -07:00
parent 141a823799
commit 7e0af2118c
9 changed files with 108 additions and 82 deletions

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@@ -23,6 +23,7 @@ private:
bool rewrite_dot_fp32(ir::dot_inst *dot, ir::builder& builder, bool trans_a, bool trans_b, ir::value *A, ir::value *B, ir::value *D);
bool rewrite_dot_hmma(ir::dot_inst *dot, ir::builder& builder, bool trans_a, bool trans_b, ir::value *A, ir::value *B, ir::value *D);
bool rewrite_dot(ir::instruction *value, ir::builder& builder);
bool rewrite_mult(ir::instruction *value, ir::builder& builder);
bool rewrite_unit_red(ir::instruction *value, ir::builder& builder);
bool rewrite_gep_ptr_min_off_plus_off(ir::instruction *value, ir::builder& builder);

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@@ -95,7 +95,7 @@ void grids::init_c_graph(ir::instruction *v) {
}
// Splat
else if(dynamic_cast<ir::splat_inst*>(v)){
return;
}
// Trans
else if(auto *x = dynamic_cast<ir::trans_inst*>(v)){

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@@ -469,21 +469,21 @@ Instruction *selection::llvm_inst(ir::instruction *inst, std::function<Value*(ir
return (Instruction*)res;
}
if(ir::atomic_add_inst* ii = dynamic_cast<ir::atomic_add_inst*>(inst)){
Value *ptr = value(ii->get_operand(0));
Value *val = value(ii->get_operand(1));
Value *atom_f_add = nullptr;
if(val->getType()->isFloatTy())
atom_f_add = Intrinsic::getDeclaration(builder.GetInsertBlock()->getModule(), Intrinsic::nvvm_atomic_load_add_f32, {ptr->getType()});
else if(val->getType()->isHalfTy()){
Type *fp16 = Type::getHalfTy(ctx);
// Value *ptr = value(ii->get_operand(0));
// Value *val = value(ii->get_operand(1));
// Value *atom_f_add = nullptr;
// if(val->getType()->isFloatTy())
// atom_f_add = Intrinsic::getDeclaration(builder.GetInsertBlock()->getModule(), Intrinsic::nvvm_atomic_load_add_f32, {ptr->getType()});
// else if(val->getType()->isHalfTy()){
// Type *fp16 = Type::getHalfTy(ctx);
FunctionType *atom_ty = FunctionType::get(fp16, {fp16->getPointerTo(), fp16}, false);
atom_f_add = InlineAsm::get(atom_ty, " atom.relaxed.global.gpu.add.noftz.f16 $0, [$1], $2;", "=h,l,h", true);
}
if(atom_f_add == nullptr)
throw std::runtime_error("unsupported atomic add");
Value *res = builder.CreateCall(atom_f_add, {ptr, val});
return (Instruction*)res;
// FunctionType *atom_ty = FunctionType::get(fp16, {fp16->getPointerTo(), fp16}, false);
// atom_f_add = InlineAsm::get(atom_ty, " atom.relaxed.global.gpu.add.noftz.f16 $0, [$1], $2;", "=h,l,h", true);
// }
// if(atom_f_add == nullptr)
throw std::runtime_error("unsupported");
// Value *res = builder.CreateCall(atom_f_add, {ptr, val});
// return (Instruction*)res;
}
if(ir::sqrt_inst* ii = dynamic_cast<ir::sqrt_inst*>(inst)){
Value *val = value(ii->get_operand(0));

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@@ -169,6 +169,7 @@ bool peephole::rewrite_dot(ir::instruction *value, ir::builder& builder){
return false;
ir::value *a = dot->get_operand(0);
ir::value *b = dot->get_operand(1);
builder.set_insert_point(add);
ir::value * new_dot = builder.insert(ir::dot_inst::create(a, b, other,
dot->is_a_trans(), dot->is_b_trans(),
dot->get_name()));
@@ -212,6 +213,30 @@ bool peephole::rewrite_unit_red(ir::instruction *value, ir::builder& builder){
return false;
}
bool peephole::rewrite_mult(ir::instruction *value, ir::builder& builder) {
auto binop = dynamic_cast<ir::binary_operator*>(value);
if(binop && binop->get_op() == ir::binary_op_t::Mul) {
ir::value *lhs = binop->get_operand(0);
ir::value *rhs = binop->get_operand(1);
ir::constant_int *_1_lhs = nullptr;
if(ir::splat_inst *splat = dynamic_cast<ir::splat_inst*>(lhs))
_1_lhs = dynamic_cast<ir::constant_int*>(splat->get_operand(0));
ir::constant_int *_1_rhs = nullptr;
if(ir::splat_inst *splat = dynamic_cast<ir::splat_inst*>(rhs))
_1_rhs = dynamic_cast<ir::constant_int*>(splat->get_operand(0));
if(_1_lhs){
binop->replace_all_uses_with(rhs);
return true;
}
else if(_1_rhs){
binop->replace_all_uses_with(lhs);
return true;
}
}
return false;
}
bool peephole::rewrite_gep_ptr_min_off_plus_off(ir::instruction *value, ir::builder& builder) {
auto x = dynamic_cast<ir::getelementptr_inst*>(value);
if(!x)
@@ -250,8 +275,9 @@ void peephole::run(ir::module &mod) {
if(seen.find(i) != seen.end())
continue;
bool was_modified = rewrite_dot(i, builder);
if(was_modified)
if(was_modified){
seen.insert(i);
}
}
}while(seen.size() != n_seen);
@@ -265,6 +291,7 @@ void peephole::run(ir::module &mod) {
if(seen.find(i) != seen.end())
continue;
bool was_modified = false;
was_modified = was_modified || rewrite_mult(i, builder);
was_modified = was_modified || rewrite_trans_phi(i, builder);
was_modified = was_modified || rewrite_unit_red(i, builder);
was_modified = was_modified || rewrite_gep_ptr_min_off_plus_off(i, builder);

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@@ -218,29 +218,24 @@ ocl_module::ocl_module(driver::context * context, llvm::Module* src): module(con
/* ------------------------ */
std::string cu_module::compile_llvm_module(llvm::Module* module) {
// set data layout
std::string layout = "e";
bool is_64bit = true;
bool use_short_pointers = true;
if (!is_64bit)
layout += "-p:32:32";
else if (use_short_pointers)
layout += "-p3:32:32-p4:32:32-p5:32:32";
layout += "-i64:64-i128:128-v16:16-v32:32-n16:32:64";
// create
llvm::SmallVector<char, 0> buffer;
module::compile_llvm_module(module, "nvptx64-nvidia-cuda", "sm_70", layout, buffer, "", Assembly);
std::string result(buffer.begin(), buffer.end());
size_t start_replace = result.find(".version");
size_t end_replace = result.find('\n', start_replace);
assert(start_replace != std::string::npos);
result.replace(start_replace, end_replace - start_replace, ".version 6.4");
return result;
// options
auto options = llvm::cl::getRegisteredOptions();
static_cast<llvm::cl::opt<bool>*>(options["nvptx-short-ptr"])->setValue(true);
// create
llvm::SmallVector<char, 0> buffer;
module::compile_llvm_module(module, "nvptx64-nvidia-cuda", "sm_70", "", buffer, "", Assembly);
std::string result(buffer.begin(), buffer.end());
size_t start_replace = result.find(".version");
size_t end_replace = result.find('\n', start_replace);
assert(start_replace != std::string::npos);
result.replace(start_replace, end_replace - start_replace, ".version 6.4");
return result;
}
cu_module::cu_module(driver::context * context, llvm::Module* ll_module): cu_module(context, compile_llvm_module(ll_module)) { }
cu_module::cu_module(driver::context * context, std::string const & source) : module(context, CUmodule(), true), source_(source){
// std::cout << source << std::endl;
cu_context::context_switcher ctx_switch(*context);
// JIT compile source-code
CUjit_option opt[] = {CU_JIT_ERROR_LOG_BUFFER_SIZE_BYTES, CU_JIT_ERROR_LOG_BUFFER};

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@@ -49,8 +49,13 @@ void print(module &mod, std::ostream& os) {
size_t num_ops = inst->get_num_operands();
if(num_ops > 0)
os << " ";;
for(unsigned i = 0; i < num_ops; i++)
os << get_name(ops[i], cnt++) << (i < num_ops - 1?", ":"");
for(unsigned i = 0; i < num_ops; i++){
if(auto *x = dynamic_cast<ir::constant_int*>(ops[i]))
os << x->get_value();
else
os << get_name(ops[i], cnt++);
os << (i < num_ops - 1?", ":"");
}
os << ";" << std::endl;
}
os << std::endl;

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@@ -217,6 +217,7 @@ std::unique_ptr<driver::module> function::make_bin(ir::module &module, driver::c
dce.run(module);
vectorize.run(module);
dce.run(module);
// ir::print(module, std::cout);
// generate llvm code
llvm::LLVMContext ctx;
std::unique_ptr<llvm::Module> llvm(new llvm::Module(module.get_name(), ctx));

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@@ -1,23 +1,43 @@
import triton
import tensorflow as tf
import triton
import numpy as np
src = """
#if AT == 1
#define USEA ^a
#define STRIDE_AK lda
#define STRIDE_AM 1
#define BROADCAST_AK :, newaxis
#define BROADCAST_AM newaxis, :
#define SHAPE_A TK, TM
#else
#define USEA a
#define STRIDE_AK 1
#define STRIDE_AM lda
#define BROADCAST_AK newaxis, :
#define BROADCAST_AM :, newaxis
#define SHAPE_A TM, TK
#endif
#if BT == 1
#define USEB ^b
#define STRIDE_BK 1
#define STRIDE_BN ldb
#define BROADCAST_BK newaxis, :
#define BROADCAST_BN :, newaxis
#define SHAPE_B TN, TK
#else
#define USEB b
#define STRIDE_BK ldb
#define STRIDE_BN 1
#define BROADCAST_BK :, newaxis
#define BROADCAST_BN newaxis, :
#define SHAPE_B TK, TN
#endif
void dot(TYPE * A __noalias __readonly __aligned(16),
TYPE * B __noalias __readonly __aligned(16),
TYPE * C __noalias __readonly __aligned(16),
void dot(TYPE * A,
TYPE * B,
TYPE * C,
int M, int N, int K,
int lda __multipleof(8),
int ldb __multipleof(8),
@@ -31,42 +51,20 @@ void dot(TYPE * A __noalias __readonly __aligned(16),
int rka[TK] = 0 ... TK;
int rkb[TK] = 0 ... TK;
float xc[TM, TN] = 0;
/* pointers for A */
#if AT == 1
TYPE* pa[TK, TM] = A + rka[:, newaxis]*lda + rxa[newaxis, :];
TYPE a[TK, TM] = *pa;
#else
TYPE* pa[TM, TK] = A + rka[newaxis, :] + rxa[:, newaxis]*lda;
TYPE a[TM, TK] = *pa;
#endif
/* pointers for B */
#if BT == 1
TYPE* pb[TN, TK] = B + rkb[newaxis, :] + ryb[:, newaxis]*ldb;
TYPE b[TN, TK] = *pb;
#else
TYPE* pb[TK, TN] = B + rkb[:, newaxis]*ldb + ryb[newaxis, :];
TYPE b[TK, TN] = *pb;
#endif
/* pointers for operands */
TYPE* pa[SHAPE_A] = A + rka[BROADCAST_AK] * STRIDE_AK + rxa[BROADCAST_AM] * STRIDE_AM;
TYPE* pb[SHAPE_B] = B + rkb[BROADCAST_BK] * STRIDE_BK + ryb[BROADCAST_BN] * STRIDE_BN;
/* prefetches operands */
TYPE a[SHAPE_A] = *pa;
TYPE b[SHAPE_B] = *pb;
/* reduction loop */
for(int k = K; k > 0; k = k - TK){
xc = USEA @ USEB + xc;
#if AT == 1
pa = pa + TK*lda;
#else
pa = pa + TK;
#endif
#if BT == 1
pb = pb + TK;
#else
pb = pb + TK*ldb;
#endif
pa = pa + TK * STRIDE_AK;
pb = pb + TK * STRIDE_BK;
a = *pa;
b = *pb;
}
/* epilogue */
int rxc[TM] = ridx * TM + (0 ... TM);
int ryc[TN] = ridy * TN + (0 ... TN);
@@ -75,7 +73,7 @@ void dot(TYPE * A __noalias __readonly __aligned(16),
bool checkc0[TM] = rxc < M;
bool checkc1[TN] = ryc < N;
bool checkc[TM, TN] = checkc0[:, newaxis] && checkc1[newaxis, :];
*?(checkc) pc = c;
*pc = c;
}
"""
@@ -112,10 +110,12 @@ class dot_op:
AT = self.trans_a, BT = self.trans_b, TYPE = tf.float16,
TM = [128], TN = [ 128], TK = [32])
dot_nt = dot_op(False, True)
dot_nn = dot_op(False, False)
dot_tn = dot_op(True, False)
dot_tt = dot_op(True, True)
def dot(a, b, trans_a = False, trans_b = False):
if (trans_a, trans_b) not in dot.ops:
dot.ops[trans_a, trans_b] = dot_op(trans_a, trans_b)
return dot.ops[trans_a, trans_b](a, b)
dot.ops = dict()
# @triton.register_gradient(dot_op)
# def _dot_grad(op, dy):
@@ -127,9 +127,7 @@ def run_dot():
M, N, K = 128, 128, 128
a = tf.placeholder(tf.float16, shape=[M, K])
b = tf.placeholder(tf.float16, shape=[N, K])
# c = tf.matmul(a, b, transpose_a=True)
c = dot_nt(a, b)
# grads = tf.gradients(c, [a])
c = dot(a, b, trans_a = False, trans_b = True)
# Reference
ha = np.random.rand(M, K).astype(np.float16)
hb = np.random.rand(K, N).astype(np.float16)
@@ -142,8 +140,6 @@ def run_dot():
hresult = np.dot(ha, hb.T)
dif = np.abs(result - hresult)
np.savetxt('dif.dat', dif, '%2.4f')
print(hresult)
print(result)
print("dif: %f" % np.max(dif))
run_dot()

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@@ -105,7 +105,8 @@ def _build(src, path, framework):
if framework == tensorflow_id:
_import_tensorflow()
library_dirs += [tensorflow.sysconfig.get_lib()]
include_dirs += [tensorflow.sysconfig.get_lib()]
include_dirs += [tensorflow.sysconfig.get_include()]
include_dirs += ['/usr/local/cuda/include/']
libraries += ['tensorflow_framework']
elif framework == torch_id:
_import_torch()
@@ -215,7 +216,7 @@ class op:
self.fw_grids = dict()
self.src = src
self.outputs = outputs
self.framework = _find_framework(None)
self.framework = _find_framework(framework)
def __call__(self, *args, **kwargs):
# create a new op when defines are different