[CODEGEN] Fixed bug that caused conditional operator to not always

properly mask load operations

Also includes minor improvement to benchmarking infrastructure
This commit is contained in:
Philippe Tillet
2021-03-07 14:53:48 -05:00
parent d1d09566b1
commit 5b9afaa688
9 changed files with 146 additions and 64 deletions

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@@ -32,6 +32,7 @@ private:
bool rewrite_mult(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_unit_red(ir::instruction *value, ir::builder& builder);
bool rewrite_gep_ptr_min_off_plus_off(ir::instruction *value, ir::builder& builder); bool rewrite_gep_ptr_min_off_plus_off(ir::instruction *value, ir::builder& builder);
bool rewrite_select_masked_load(ir::instruction *value, ir::builder& builder);
bool rewrite_load_to_shared(ir::instruction *value, ir::builder& builder); bool rewrite_load_to_shared(ir::instruction *value, ir::builder& builder);
private: private:

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@@ -748,6 +748,9 @@ private:
public: public:
static instruction* create(value *pred, value *if_value, value *else_value, const std::string &name = "", instruction *next = nullptr); static instruction* create(value *pred, value *if_value, value *else_value, const std::string &name = "", instruction *next = nullptr);
value* get_pred_op() { return get_operand(0); }
value* get_if_value_op() { return get_operand(1); }
value* get_else_value_op() { return get_operand(2); }
}; };
//===----------------------------------------------------------------------===// //===----------------------------------------------------------------------===//

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@@ -1616,20 +1616,22 @@ void generator::visit_make_range(ir::make_range* x) {
} }
} }
void generator::visit_undef_value(ir::undef_value *x) {
Type* ty = cvt(x->get_type()->get_scalar_ty());
void generator::visit_undef_value(ir::undef_value *ud) { for(indices_t idx: idxs_.at(x))
vals_[ud][{}] = llvm::UndefValue::get(cvt(ud->get_type())); vals_[x][idx] = llvm::UndefValue::get(ty);
} }
void generator::visit_constant_int(ir::constant_int *cst){ void generator::visit_constant_int(ir::constant_int *x){
Type *ty = cvt(cst->get_type()->get_scalar_ty()); Type *ty = cvt(x->get_type()->get_scalar_ty());
vals_[cst][{}] = ConstantInt::get(ty, cst->get_value()); for(indices_t idx: idxs_.at(x))
vals_[x][idx] = ConstantInt::get(ty, x->get_value());
} }
void generator::visit_constant_fp(ir::constant_fp *cst){ void generator::visit_constant_fp(ir::constant_fp *x){
Type *ty = cvt(cst->get_type()->get_scalar_ty()); Type *ty = cvt(x->get_type()->get_scalar_ty());
vals_[cst][{}] = ConstantFP::get(ty, cst->get_value()); for(indices_t idx: idxs_.at(x))
vals_[x][idx] = ConstantFP::get(ty, x->get_value());
} }
void generator::visit_alloc_const(ir::alloc_const *alloc) { void generator::visit_alloc_const(ir::alloc_const *alloc) {

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@@ -193,6 +193,22 @@ bool peephole::rewrite_gep_ptr_min_off_plus_off(ir::instruction *value, ir::buil
return false; return false;
} }
bool peephole::rewrite_select_masked_load(ir::instruction *value, ir::builder& builder){
auto select = dynamic_cast<ir::select_inst*>(value);
if(!select)
return false;
auto if_value = dynamic_cast<ir::masked_load_inst*>(select->get_if_value_op());
if(!if_value)
return false;
if(select->get_pred_op() != if_value->get_mask_operand())
return false;
builder.set_insert_point(select);
ir::value* new_load = builder.create_masked_load(if_value->get_pointer_operand(),
if_value->get_mask_operand(),
select->get_else_value_op());
select->replace_all_uses_with(new_load);
return true;
}
void peephole::run(ir::module &mod) { void peephole::run(ir::module &mod) {
ir::builder &builder = mod.get_builder(); ir::builder &builder = mod.get_builder();
@@ -230,6 +246,7 @@ void peephole::run(ir::module &mod) {
// was_modified = was_modified || rewrite_trans_phi(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_unit_red(i, builder);
was_modified = was_modified || rewrite_gep_ptr_min_off_plus_off(i, builder); was_modified = was_modified || rewrite_gep_ptr_min_off_plus_off(i, builder);
was_modified = was_modified || rewrite_select_masked_load(i, builder);
if(tgt_->as_nvidia()->sm() >= 80) if(tgt_->as_nvidia()->sm() >= 80)
was_modified = was_modified || rewrite_load_to_shared(i, builder); was_modified = was_modified || rewrite_load_to_shared(i, builder);
if(was_modified) if(was_modified)

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@@ -267,23 +267,56 @@ void Generator::VisitTransOp(TransOp *trans) {
} }
void Generator::VisitConditionalOp(ConditionalOp* condOp) { void Generator::VisitConditionalOp(ConditionalOp* condOp) {
// auto &instructions = bld_->get_insert_block()->get_inst_list(); auto &instructions = bld_->get_insert_block()->get_inst_list();
VisitExpr(condOp->cond_); VisitExpr(condOp->cond_);
ir::value* cond = ret_; ir::value* true_cond = ret_;
ir::instruction* start = instructions.back();
VisitExpr(condOp->exprTrue_); VisitExpr(condOp->exprTrue_);
ir::value* true_val = ret_; ir::value* true_val = ret_;
VisitExpr(condOp->exprFalse_); VisitExpr(condOp->exprFalse_);
ir::value* false_val = ret_; ir::value* false_val = ret_;
if(ir::unmasked_load_inst* ld = dynamic_cast<ir::unmasked_load_inst*>(true_val)) { auto begin = std::find(instructions.begin(), instructions.end(), start);
if(true_val->get_type()->is_tile_ty() && !false_val->get_type()->is_tile_ty()) bool is_in_true_cond = true;
false_val = bld_->create_splat(false_val, cond->get_type()->get_tile_shapes()); for(auto it = begin; it != instructions.end(); it++){
ir::value* new_ld = bld_->create_masked_load(ld->get_pointer_operand(), cond, false_val); ir::instruction* instr = *it;
ld->replace_all_uses_with(new_ld); // we mask load with `cond` when used to compute true_value
ld->erase_from_parent(); // we mask load with `!cond` when used to compute false_value
return set_ret(new_ld); if(auto ld = dynamic_cast<ir::unmasked_load_inst*>(instr)){
bld_->set_insert_point(ld);
ir::type* ty = ld->get_type();
ir::value* cond = is_in_true_cond ? true_cond : true_cond;
ir::value* ptr = ld->get_pointer_operand();
ir::value* else_val = ir::undef_value::get(ty);
ir::value* masked_ld = bld_->create_masked_load(ptr, cond, else_val);
ld->replace_all_uses_with(masked_ld);
ld->erase_from_parent();
if(true_val == ld)
true_val = masked_ld;
if(false_val == ld)
false_val = masked_ld;
it = std::find(instructions.begin(), instructions.end(), masked_ld);
}
if(instr == true_val)
is_in_true_cond = false;
} }
return set_ret(bld_->create_select(cond, true_val, false_val)); bld_->set_insert_point(bld_->get_insert_block());
// return error_not_implemented(); return set_ret(bld_->create_select(true_cond, true_val, false_val));
// VisitExpr(condOp->cond_);
// ir::value* cond = ret_;
// VisitExpr(condOp->exprTrue_);
// ir::value* true_val = ret_;
// VisitExpr(condOp->exprFalse_);
// ir::value* false_val = ret_;
// if(ir::unmasked_load_inst* ld = dynamic_cast<ir::unmasked_load_inst*>(true_val)) {
// if(true_val->get_type()->is_tile_ty() && !false_val->get_type()->is_tile_ty())
// false_val = bld_->create_splat(false_val, cond->get_type()->get_tile_shapes());
// ir::value* new_ld = bld_->create_masked_load(ld->get_pointer_operand(), cond, false_val);
// ld->replace_all_uses_with(new_ld);
// ld->erase_from_parent();
// return set_ret(new_ld);
// }
// return set_ret(bld_->create_select(cond, true_val, false_val));
} }
void Generator::VisitFuncCall(FuncCall* funcCall) { void Generator::VisitFuncCall(FuncCall* funcCall) {

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@@ -156,6 +156,7 @@ std::tuple<std::shared_ptr<driver::module>,
layouts.run(ir); layouts.run(ir);
peephole.run(ir); peephole.run(ir);
dce.run(ir); dce.run(ir);
// ir::print(ir, std::cout);
if(target->is_gpu()) if(target->is_gpu())
cts.run(ir); cts.run(ir);
align.run(ir); align.run(ir);

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@@ -2,33 +2,39 @@ import triton
import torch import torch
import os import os
def rounded_linspace(low, high, steps, div): def rounded_linspace(low, high, steps, div):
ret = torch.linspace(low, high, steps) ret = torch.linspace(low, high, steps)
ret = (ret.int() + div - 1) // div * div ret = (ret.int() + div - 1) // div * div
ret = torch.unique(ret) ret = torch.unique(ret)
return list(map(int, ret)) return list(map(int, ret))
# Square benchmarks # Square benchmarks
nt = {False: "n", True: "t"} nt = {False: "n", True: "t"}
square_confs = [ square_confs = [
triton.testing.Benchmark( triton.testing.Benchmark(
x_names=["M", "N", "K"], x_names=["M", "N", "K"],
x_vals=rounded_linspace(512, 8192, 17, 128), x_vals=rounded_linspace(512, 8192, 32, 128),
y_name="provider", y_name="provider",
y_vals=["torch", "triton", "cutlass"], y_vals=["torch", "triton", "cutlass"],
y_lines=["Torch", "Triton", "CUTLASS"], y_lines=["Torch", "Triton", "CUTLASS"],
ylabel="TFLOPS", ylabel="TFLOPS",
loglog=False, loglog=False,
plot_name=f"matmul-square-{nt[AT]}{nt[BT]}", plot_name=f"matmul-square-{nt[AT]}{nt[BT]}",
args={"AT": AT, "BT": BT, "dtype": torch.float16}, args={
) for AT in [False, True] for BT in [False, True] "AT": AT,
"BT": BT,
"dtype": torch.float16
},
) for AT in [False] for BT in [False]
] ]
# Transformer training benchmarks # Transformer training benchmarks
transformer_confs = [ transformer_confs = [
triton.testing.Benchmark( triton.testing.Benchmark(
x_names=[x], x_names=[x],
x_vals = rounded_linspace(NK//16, NK, 33, 128), x_vals = rounded_linspace(NK//16, NK, 32, 128),
y_name="provider", y_name="provider",
y_vals=["torch", "triton", "cutlass"], y_vals=["torch", "triton", "cutlass"],
y_lines=["Torch", "Triton", "CUTLASS"], y_lines=["Torch", "Triton", "CUTLASS"],
@@ -41,21 +47,21 @@ transformer_confs = [
for M in [2048] for M in [2048]
] ]
@triton.testing.perf_report(square_confs)
def bench_op(M, N, K, AT, BT, dtype, provider, warmup=5, rep=40): @triton.testing.perf_report(transformer_confs)
def bench_op(M, N, K, AT, BT, dtype, provider, warmup=10, rep=50):
a = torch.rand((K, M) if AT else (M, K), device="cuda", dtype=dtype) a = torch.rand((K, M) if AT else (M, K), device="cuda", dtype=dtype)
b = torch.rand((N, K) if BT else (K, N), device="cuda", dtype=dtype) b = torch.rand((N, K) if BT else (K, N), device="cuda", dtype=dtype)
if AT: a = a.t() if AT: a = a.t()
if BT: b = b.t() if BT: b = b.t()
num_flops = 2 * M * N * K num_flops = 2 * M * N * K
tflops = lambda ms: 2. * M * N * K / ms * 1e-9
if provider == "torch": if provider == "torch":
torch_ms = triton.testing.do_bench(lambda: torch.matmul(a, b), warmup=warmup, rep=rep) ms, min_ms, max_ms = triton.testing.do_bench(lambda: torch.matmul(a, b), warmup=warmup, rep=rep)
torch_tflops = num_flops / torch_ms * 1e-9 return tflops(ms), tflops(max_ms), tflops(min_ms)
return torch_tflops
if provider == "triton": if provider == "triton":
triton_ms = triton.testing.do_bench(lambda: triton.ops.matmul(a, b), warmup=warmup, rep=rep) ms, min_ms, max_ms = triton.testing.do_bench(lambda: triton.ops.matmul(a, b), warmup=warmup, rep=rep)
triton_tflops = num_flops / triton_ms * 1e-9 return tflops(ms), tflops(max_ms), tflops(min_ms)
return triton_tflops
if provider == "cutlass" and "CUTLASS_PROFILER" in os.environ: if provider == "cutlass" and "CUTLASS_PROFILER" in os.environ:
import subprocess import subprocess
import tempfile import tempfile
@@ -87,6 +93,6 @@ def bench_op(M, N, K, AT, BT, dtype, provider, warmup=5, rep=40):
subprocess.run(cmd, stdout=subprocess.PIPE) subprocess.run(cmd, stdout=subprocess.PIPE)
# read CSV output # read CSV output
df_c = pd.read_csv(f"{fname}.gemm.csv") df_c = pd.read_csv(f"{fname}.gemm.csv")
cutlass_tflops = max(df_c["GFLOPs"]) / 1e3 tflops = max(df_c["GFLOPs"]) / 1e3
return cutlass_tflops return tflops
return None return None

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@@ -26,7 +26,7 @@ __global__ void backward(TYPE *neg_logprobs, long *indices, TYPE *dneg_logprobs,
TYPE local_dn = *(dneg_logprobs + row); TYPE local_dn = *(dneg_logprobs + row);
// We know d(-log(p[i])/dlogit[k] = -id_mat[i,k] + p[k] // We know d(-log(p[i])/dlogit[k] = -id_mat[i,k] + p[k]
// and we have -log(p[k]) stored, so this is easy // and we have -log(p[k]) stored, so this is easy
TYPE intermediate[TILE] = check ? exp(-(float[TILE]) * ? (check)px) : 0; TYPE intermediate[TILE] = check ? exp(-(float[TILE]) * px) : 0;
// selected_logit_idx is selected logit index for our token // selected_logit_idx is selected logit index for our token
bool find_one[TILE] = ((0 ... TILE) == local_ind); bool find_one[TILE] = ((0 ... TILE) == local_ind);
intermediate = intermediate - ((TYPE[TILE])find_one); intermediate = intermediate - ((TYPE[TILE])find_one);

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@@ -26,35 +26,34 @@ def allclose(x, y):
return err < tol return err < tol
def do_bench(fn, warmup=10, rep=50, grad_to_none=None, clear_l2=False): def do_bench(fn, warmup=10, rep=50, grad_to_none=None):
start_event = torch.cuda.Event(enable_timing=True)
end_event = torch.cuda.Event(enable_timing=True)
# warmup to put the clock in a stable regime
ret = fn()
for i in range(warmup):
fn()
torch.cuda.synchronize()
total_ms = 0
# We maintain a buffer of 256 MB that we clear # We maintain a buffer of 256 MB that we clear
# before each kernel call to make sure that the L2 # before each kernel call to make sure that the L2
# doesn't contain any input data before the run # doesn't contain any input data before the run
start_event = [torch.cuda.Event(enable_timing=True) for i in range(rep)]
end_event = [torch.cuda.Event(enable_timing=True) for i in range(rep)]
cache = torch.empty(int(256e6), dtype=torch.int8, device='cuda') cache = torch.empty(int(256e6), dtype=torch.int8, device='cuda')
for i in range(rep): for i in range(warmup + rep):
# we don't want `fn` to accumulate gradient values # we don't want `fn` to accumulate gradient values
# if it contains a backward pass. So we clear the # if it contains a backward pass. So we clear the
# provided gradients # provided gradients
if grad_to_none is not None: if grad_to_none is not None:
grad_to_none.grad = None grad_to_none.grad = None
# reset L2 # we clear the L2 cache before each run
cache.zero_() cache.zero_()
# record time of `fn` # record time of `fn`
start_event.record() if i >= warmup:
start_event[i - warmup].record()
fn() fn()
end_event.record() if i >= warmup:
torch.cuda.synchronize() end_event[i - warmup].record()
total_ms += start_event.elapsed_time(end_event) torch.cuda.synchronize()
# return the average runtime of `fn` times = torch.tensor([s.elapsed_time(e) for s, e in zip(start_event, end_event)])
return total_ms / rep q = torch.quantile(times, torch.tensor([0.1, 0.5, 0.9]))
min_ms = q[0].item()
mean_ms = q[1].item()
max_ms = q[2].item()
return mean_ms, min_ms, max_ms
class Benchmark: class Benchmark:
@@ -79,22 +78,42 @@ class Mark:
import matplotlib.pyplot as plt import matplotlib.pyplot as plt
import pandas as pd import pandas as pd
import os import os
y_mean = bench.y_lines
df = pd.DataFrame(columns=[bench.x_names[0]] + bench.y_lines) y_min = [f'{x}-min' for x in bench.y_lines]
y_max = [f'{x}-max' for x in bench.y_lines]
df = pd.DataFrame(columns=[bench.x_names[0]] + y_mean + y_min + y_max)
for x in bench.x_vals: for x in bench.x_vals:
x_args = {x_name: x for x_name in bench.x_names} x_args = {x_name: x for x_name in bench.x_names}
row = [self.fn(**x_args, **{bench.y_name: y}, **bench.args) for y in bench.y_vals] row_mean, row_min, row_max = [], [], []
df.loc[len(df)] = [x] + row for y in bench.y_vals:
ret = self.fn(**x_args, **{bench.y_name: y}, **bench.args)
try:
y_mean, y_min, y_max = ret
except TypeError:
y_mean, y_min, y_max = ret, None, None
row_mean += [y_mean]
row_min += [y_min]
row_max += [y_max]
df.loc[len(df)] = [x] + row_mean + row_min + row_max
if with_plot and bench.plot_name: if with_plot and bench.plot_name:
plt.figure()
ax = plt.subplot()
xlabel = " = ".join(bench.x_names) xlabel = " = ".join(bench.x_names)
plot = df.plot(x=bench.x_names[0], y=bench.y_lines) x = bench.x_names[0]
plot.set_xlabel(xlabel) for y in bench.y_lines:
plot.set_ylabel(bench.ylabel) y_min, y_max = df[y + '-min'], df[y + '-max']
plot.set_title(bench.plot_name) ax.plot(df[x], df[y], label=y)
plot.set_xscale("log" if bench.loglog else "linear") if y_min is not None and y_max is not None:
plot.set_yscale("log" if bench.loglog else "linear") ax.fill_between(df[x], y_min, y_max, alpha=0.5)
ax.legend()
ax.set_xlabel(xlabel)
ax.set_ylabel(bench.ylabel)
ax.set_title(bench.plot_name)
ax.set_xscale("log" if bench.loglog else "linear")
ax.set_yscale("log" if bench.loglog else "linear")
plt.savefig(os.path.join(result_path, f"{bench.plot_name}.png")) plt.savefig(os.path.join(result_path, f"{bench.plot_name}.png"))
df.to_csv(os.path.join(result_path, f"{bench.plot_name}.csv")) df = df[[bench.x_names[0]] + bench.y_lines]
df.to_csv(os.path.join(result_path, f"{bench.plot_name}.csv"), float_format='%.1f', index=False)
def run(self, result_path, with_plot): def run(self, result_path, with_plot):
with open(os.path.join(result_path, "results.html"), "w") as html: with open(os.path.join(result_path, "results.html"), "w") as html: