1 files changed, 78 insertions, 0 deletions
diff --git a/contrib/llvm-project/llvm/lib/Target/WebAssembly/WebAssemblySortRegion.cpp b/contrib/llvm-project/llvm/lib/Target/WebAssembly/WebAssemblySortRegion.cpp
new file mode 100644
index 000000000000..cd84e68aed14
--- /dev/null
+++ b/contrib/llvm-project/llvm/lib/Target/WebAssembly/WebAssemblySortRegion.cpp
@@ -0,0 +1,78 @@
+#include "WebAssemblySortRegion.h"
+#include "WebAssemblyExceptionInfo.h"
+#include "llvm/CodeGen/MachineLoopInfo.h"
+
+using namespace llvm;
+using namespace WebAssembly;
+
+namespace llvm {
+namespace WebAssembly {
+template <>
+bool ConcreteSortRegion<MachineLoop>::isLoop() const {
+  return true;
+}
+} // end namespace WebAssembly
+} // end namespace llvm
+
+const SortRegion *SortRegionInfo::getRegionFor(const MachineBasicBlock *MBB) {
+  const auto *ML = MLI.getLoopFor(MBB);
+  const auto *WE = WEI.getExceptionFor(MBB);
+  if (!ML && !WE)
+    return nullptr;
+  // We determine subregion relationship by domination of their headers, i.e.,
+  // if region A's header dominates region B's header, B is a subregion of A.
+  // WebAssemblyException contains BBs in all its subregions (loops or
+  // exceptions), but MachineLoop may not, because MachineLoop does not
+  // contain BBs that don't have a path to its header even if they are
+  // dominated by its header. So here we should use
+  // WE->contains(ML->getHeader()), but not ML->contains(WE->getHeader()).
+  if ((ML && !WE) || (ML && WE && WE->contains(ML->getHeader()))) {
+    // If the smallest region containing MBB is a loop
+    if (LoopMap.count(ML))
+      return LoopMap[ML].get();
+    LoopMap[ML] = std::make_unique<ConcreteSortRegion<MachineLoop>>(ML);
+    return LoopMap[ML].get();
+  } else {
+    // If the smallest region containing MBB is an exception
+    if (ExceptionMap.count(WE))
+      return ExceptionMap[WE].get();
+    ExceptionMap[WE] =
+        std::make_unique<ConcreteSortRegion<WebAssemblyException>>(WE);
+    return ExceptionMap[WE].get();
+  }
+}
+
+MachineBasicBlock *SortRegionInfo::getBottom(const SortRegion *R) {
+  if (R->isLoop())
+    return getBottom(MLI.getLoopFor(R->getHeader()));
+  else
+    return getBottom(WEI.getExceptionFor(R->getHeader()));
+}
+
+MachineBasicBlock *SortRegionInfo::getBottom(const MachineLoop *ML) {
+  MachineBasicBlock *Bottom = ML->getHeader();
+  for (MachineBasicBlock *MBB : ML->blocks()) {
+    if (MBB->getNumber() > Bottom->getNumber())
+      Bottom = MBB;
+    // MachineLoop does not contain all BBs dominated by its header. BBs that
+    // don't have a path back to the loop header aren't included. But for the
+    // purpose of CFG sorting and stackification, we need a bottom BB among all
+    // BBs that are dominated by the loop header. So we check if there is any
+    // WebAssemblyException contained in this loop, and computes the most bottom
+    // BB of them all.
+    if (MBB->isEHPad()) {
+      MachineBasicBlock *ExBottom = getBottom(WEI.getExceptionFor(MBB));
+      if (ExBottom->getNumber() > Bottom->getNumber())
+        Bottom = ExBottom;
+    }
+  }
+  return Bottom;
+}
+
+MachineBasicBlock *SortRegionInfo::getBottom(const WebAssemblyException *WE) {
+  MachineBasicBlock *Bottom = WE->getHeader();
+  for (MachineBasicBlock *MBB : WE->blocks())
+    if (MBB->getNumber() > Bottom->getNumber())
+      Bottom = MBB;
+  return Bottom;
+}