Revision bc30d6f83513724e9f832098d9e8d5fb87ebc9fc authored by Steven Johnson on 03 August 2023, 00:18:33 UTC, committed by GitHub on 03 August 2023, 00:18:33 UTC
* Revise labels on autoscheduler tests This is step 1 in fixing https://github.com/halide/Halide/issues/7731: it replaces the `autoschedulers` tag with more granular ones, so that we can modify the build script to test the right autoscheduler(s) for a given backend. (Note that the `autoschedulers` tag was unused by the buildbots, which only used the generic `auto_schedule` tag.) Step 2 will be to modify the buildbot script after this lands to use the new tags above. Step 3 will be to remove the `auto_schedule` tag. * Fix anderson2021 labels
1 parent 734df3f
CanonicalizeGPUVars.cpp
#include <cmath>
#include <sstream>
#include "CanonicalizeGPUVars.h"
#include "CodeGen_GPU_Dev.h"
#include "IR.h"
#include "IRMutator.h"
#include "Substitute.h"
namespace Halide {
namespace Internal {
using std::map;
using std::string;
using std::vector;
namespace {
string thread_names[] = {"__thread_id_x", "__thread_id_y", "__thread_id_z", "__thread_id_w"};
string block_names[] = {"__block_id_x", "__block_id_y", "__block_id_z", "__block_id_w"};
string get_thread_name(int index) {
internal_assert(index >= 0 && index < 4);
return thread_names[index];
}
string get_block_name(int index) {
internal_assert(index >= 0 && index < 4);
return block_names[index];
}
class CountGPUBlocksThreads : public IRVisitor {
using IRVisitor::visit;
// Counters that track the number of blocks, threads, and lanes loops that
// we're inside of, respectively. Lanes loops also count as threads loops.
int nb = 0, nt = 0, nl = 0;
void visit(const For *op) override {
// Figure out how much to increment each counter by based on the loop
// type.
int db = op->for_type == ForType::GPUBlock;
int dl = op->for_type == ForType::GPULane;
int dt = op->for_type == ForType::GPUThread;
// The threads counter includes lanes loops
dt += dl;
// Increment counters
nb += db;
nl += dl;
nt += dt;
// Update the maximum counter values seen.
nblocks = std::max(nb, nblocks);
nthreads = std::max(nt, nthreads);
nlanes = std::max(nl, nlanes);
// Visit the body
IRVisitor::visit(op);
// Decrement counters
nb -= db;
nl -= dl;
nt -= dt;
}
public:
// The maximum values hit by the counters above, which tells us the nesting
// depth of each type of loop within a Stmt.
int nblocks = 0;
int nthreads = 0;
int nlanes = 0;
};
class CanonicalizeGPUVars : public IRMutator {
map<string, string> gpu_vars;
using IRMutator::visit;
string find_replacement(const string &suffix, const string &name) {
vector<string> v = split_string(name, suffix);
internal_assert(v.size() == 2);
const auto &iter = gpu_vars.find(v[0]);
if (iter != gpu_vars.end()) {
return iter->second + suffix;
}
return name;
}
string canonicalize_let(const string &name) {
if (ends_with(name, ".loop_max")) {
return find_replacement(".loop_max", name);
} else if (ends_with(name, ".loop_min")) {
return find_replacement(".loop_min", name);
} else if (ends_with(name, ".loop_extent")) {
return find_replacement(".loop_extent", name);
} else {
return name;
}
}
Stmt visit(const For *op) override {
string name = op->name;
Expr min = mutate(op->min);
Expr extent = mutate(op->extent);
Stmt body = mutate(op->body);
if ((op->for_type == ForType::GPUBlock) ||
(op->for_type == ForType::GPUThread) ||
(op->for_type == ForType::GPULane)) {
CountGPUBlocksThreads counter;
op->body.accept(&counter);
internal_assert(counter.nblocks <= 4)
<< op->name << " can only have maximum of 4 block dimensions\n";
internal_assert(counter.nthreads <= 4)
<< op->name << " can only have maximum of 4 thread dimensions\n";
if (op->for_type == ForType::GPUBlock) {
name += "." + get_block_name(counter.nblocks);
debug(5) << "Replacing " << op->name << " with GPU block name " << name << "\n";
} else if (op->for_type == ForType::GPUThread) {
name += "." + get_thread_name(counter.nthreads);
debug(5) << "Replacing " << op->name << " with GPU thread name " << name << "\n";
} else if (op->for_type == ForType::GPULane) {
user_assert(counter.nlanes == 0) << "Cannot nest multiple loops over gpu lanes: " << name << "\n";
name += "." + get_thread_name(0);
}
if (name != op->name) {
// Canonicalize the GPU for loop name
gpu_vars.emplace(op->name, name);
Expr new_var = Variable::make(Int(32), name);
min = substitute(op->name, new_var, min);
extent = substitute(op->name, new_var, extent);
body = substitute(op->name, new_var, body);
}
}
if ((name == op->name) &&
min.same_as(op->min) &&
extent.same_as(op->extent) &&
body.same_as(op->body)) {
return op;
} else {
return For::make(name, min, extent, op->for_type, op->device_api, body);
}
}
Stmt visit(const LetStmt *op) override {
vector<std::pair<string, Expr>> lets;
Stmt result;
do {
lets.emplace_back(op->name, mutate(op->value));
result = op->body;
} while ((op = op->body.as<LetStmt>()));
result = mutate(result);
for (auto it = lets.rbegin(); it != lets.rend(); it++) {
string name = canonicalize_let(it->first);
if (name != it->first) {
Expr new_var = Variable::make(Int(32), name);
result = substitute(it->first, new_var, result);
}
result = LetStmt::make(name, it->second, result);
}
return result;
}
Stmt visit(const IfThenElse *op) override {
Expr condition = mutate(op->condition);
map<string, string> old_gpu_vars;
old_gpu_vars.swap(gpu_vars);
Stmt then_case = mutate(op->then_case);
gpu_vars = old_gpu_vars;
Stmt else_case = mutate(op->else_case);
if (condition.same_as(op->condition) &&
then_case.same_as(op->then_case) &&
else_case.same_as(op->else_case)) {
return op;
} else {
return IfThenElse::make(condition, then_case, else_case);
}
}
};
} // anonymous namespace
Stmt canonicalize_gpu_vars(Stmt s) {
CanonicalizeGPUVars canonicalizer;
s = canonicalizer.mutate(s);
return s;
}
} // namespace Internal
} // namespace Halide
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