Scop::getParameterValues: extract parameter values directly from context

This simplifies the code.
It would probably be even simpler to simply store the parameter values
directly and to derive the context from those values instead
of the other way around.

Author: Sven Verdoolaege

tc/core/polyhedral/scop.cc

@@ -272,32 +272,6 @@ void Scop::promoteEverythingAt(std::vector<size_t> pos) {
   insertSyncsAroundCopies(tree);
 }
 
-namespace {
-typedef std::unordered_map<isl::id, long, isl::IslIdIslHash> IslParamValueMap;
-
-// Extract the fixed values of the parameters from the given (context) set.
-IslParamValueMap extractParamValueMap(isl::set set) {
-  CHECK(set.is_singleton()) << "set must be singleton to extract fixed values";
-
-  auto ctx = set.get_ctx();
-  auto longMax = isl::val(ctx, std::numeric_limits<long>::max());
-  auto p = set.sample_point();
-  auto space = p.get_space();
-
-  IslParamValueMap paramValueMap;
-  int i = 0;
-  for (auto id : isl::DimIds<isl::space, isl::dim_type::param>(space)) {
-    auto val = p.get_coordinate_val(isl::dim_type::param, i);
-    CHECK_EQ(val.get_den_si(), 1) << "fractional parameters unsupported";
-    CHECK(val.le(longMax)) << "parameter value overflows long";
-    paramValueMap[id] = val.get_num_si();
-    ++i;
-  }
-
-  return paramValueMap;
-}
-} // namespace
-
 // Compute the values of parameters based on the effective sizes of the
 // tensors provided as arguments and their parametric expressions stored in
 // Halide InputImage.  We only know input sizes, output sizes are inferred.
@@ -325,24 +299,24 @@ isl::set Scop::makeContextFromInputs(
 }
 
 std::vector<long> Scop::getParameterValues(isl::set context) const {
-  IslParamValueMap pvm = extractParamValueMap(context);
+  auto ctx = context.get_ctx();
+  auto longMax = isl::val(ctx, std::numeric_limits<long>::max());
+  auto space = context.get_space();
+  auto p = context.sample_point();
+  CHECK(context.is_equal(p));
 
   // Scop holds a vector of Variables.
   // Iterate over parameters in order, checking if the
-  // ParamValueMap contains an id whose name corresponds to that
+  // context contains a parameter whose name corresponds to that
   // Variable and push respective parameter values.
   std::vector<long> paramValues;
   for (auto const& param : halide.params) {
-    size_t previousSize = paramValues.size();
-    for (auto p : pvm) {
-      isl::id id = p.first;
-      if (id.get_name() == param.name()) {
-        paramValues.push_back(p.second);
-      }
-    }
-    CHECK_EQ(previousSize + 1, paramValues.size())
-        << "parameter " << param.name() << " is not present in the context "
-        << context << "; mind identical names in Halide.";
+    isl::id id(ctx, param.name());
+    CHECK(context.involves_param(id));
+    auto val = isl::aff::param_on_domain_space(space, id).eval(p);
+    CHECK(val.is_int()) << "fractional parameters unsupported";
+    CHECK(val.le(longMax)) << "parameter value overflows long";
+    paramValues.push_back(val.get_num_si());
   }
   return paramValues;
 }

tc/external/detail/isl_mu_wrappers.h

@@ -17,5 +17,4 @@
 
 #include <isl/cpp.h>
 
-#include "tc/external/detail/isl_mu_wrappers.h"
 #include "tc/external/detail/islpp.h"