Factor GC metadata table assembly generation out of Collector in preparation for splitting AsmPrinter into its own library.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@54881 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/OcamlGCPrinter.cpp b/lib/CodeGen/OcamlGCPrinter.cpp
new file mode 100644
index 0000000..efa7f67
--- /dev/null
+++ b/lib/CodeGen/OcamlGCPrinter.cpp
@@ -0,0 +1,163 @@
+//===-- OcamlCollector.cpp - Ocaml frametable emitter ---------------------===//
+//
+// The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file implements lowering for the llvm.gc* intrinsics compatible with
+// Objective Caml 3.10.0, which uses a liveness-accurate static stack map.
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/CodeGen/GCs.h"
+#include "llvm/CodeGen/AsmPrinter.h"
+#include "llvm/CodeGen/GCStrategy.h"
+#include "llvm/Module.h"
+#include "llvm/Target/TargetAsmInfo.h"
+#include "llvm/Target/TargetData.h"
+#include "llvm/Target/TargetMachine.h"
+
+using namespace llvm;
+
+namespace {
+
+ class VISIBILITY_HIDDEN OcamlGCMetadataPrinter : public GCMetadataPrinter {
+ public:
+ void beginAssembly(std::ostream &OS, AsmPrinter &AP,
+ const TargetAsmInfo &TAI);
+
+ void finishAssembly(std::ostream &OS, AsmPrinter &AP,
+ const TargetAsmInfo &TAI);
+ };
+
+}
+
+static GCMetadataPrinterRegistry::Add<OcamlGCMetadataPrinter>
+Y("ocaml", "ocaml 3.10-compatible collector");
+
+GCMetadataPrinter *llvm::createOcamlMetadataPrinter() {
+ return new OcamlGCMetadataPrinter();
+}
+
+static void EmitCamlGlobal(const Module &M, std::ostream &OS, AsmPrinter &AP,
+ const TargetAsmInfo &TAI, const char *Id) {
+ const std::string &MId = M.getModuleIdentifier();
+
+ std::string Mangled;
+ Mangled += TAI.getGlobalPrefix();
+ Mangled += "caml";
+ size_t Letter = Mangled.size();
+ Mangled.append(MId.begin(), std::find(MId.begin(), MId.end(), '.'));
+ Mangled += "__";
+ Mangled += Id;
+
+ // Capitalize the first letter of the module name.
+ Mangled[Letter] = toupper(Mangled[Letter]);
+
+ if (const char *GlobalDirective = TAI.getGlobalDirective())
+ OS << GlobalDirective << Mangled << "\n";
+ OS << Mangled << ":\n";
+}
+
+void OcamlGCMetadataPrinter::beginAssembly(std::ostream &OS, AsmPrinter &AP,
+ const TargetAsmInfo &TAI) {
+ AP.SwitchToTextSection(TAI.getTextSection());
+ EmitCamlGlobal(getModule(), OS, AP, TAI, "code_begin");
+
+ AP.SwitchToDataSection(TAI.getDataSection());
+ EmitCamlGlobal(getModule(), OS, AP, TAI, "data_begin");
+}
+
+/// emitAssembly - Print the frametable. The ocaml frametable format is thus:
+///
+/// extern "C" struct align(sizeof(intptr_t)) {
+/// uint16_t NumDescriptors;
+/// struct align(sizeof(intptr_t)) {
+/// void *ReturnAddress;
+/// uint16_t FrameSize;
+/// uint16_t NumLiveOffsets;
+/// uint16_t LiveOffsets[NumLiveOffsets];
+/// } Descriptors[NumDescriptors];
+/// } caml${module}__frametable;
+///
+/// Note that this precludes programs from stack frames larger than 64K
+/// (FrameSize and LiveOffsets would overflow). FrameTablePrinter will abort if
+/// either condition is detected in a function which uses the collector.
+///
+void OcamlGCMetadataPrinter::finishAssembly(std::ostream &OS, AsmPrinter &AP,
+ const TargetAsmInfo &TAI) {
+ const char *AddressDirective;
+ int AddressAlignLog;
+ if (AP.TM.getTargetData()->getPointerSize() == sizeof(int32_t)) {
+ AddressDirective = TAI.getData32bitsDirective();
+ AddressAlignLog = 2;
+ } else {
+ AddressDirective = TAI.getData64bitsDirective();
+ AddressAlignLog = 3;
+ }
+
+ AP.SwitchToTextSection(TAI.getTextSection());
+ EmitCamlGlobal(getModule(), OS, AP, TAI, "code_end");
+
+ AP.SwitchToDataSection(TAI.getDataSection());
+ EmitCamlGlobal(getModule(), OS, AP, TAI, "data_end");
+
+ OS << AddressDirective << 0; // FIXME: Why does ocaml emit this??
+ AP.EOL();
+
+ AP.SwitchToDataSection(TAI.getDataSection());
+ EmitCamlGlobal(getModule(), OS, AP, TAI, "frametable");
+
+ for (iterator FI = begin(), FE = end(); FI != FE; ++FI) {
+ CollectorMetadata &MD = **FI;
+
+ OS << "\t" << TAI.getCommentString() << " live roots for "
+ << MD.getFunction().getNameStart() << "\n";
+
+ for (CollectorMetadata::iterator PI = MD.begin(),
+ PE = MD.end(); PI != PE; ++PI) {
+
+ uint64_t FrameSize = MD.getFrameSize();
+ if (FrameSize >= 1<<16) {
+ cerr << "Function '" << MD.getFunction().getNameStart()
+ << "' is too large for the ocaml collector! "
+ << "Frame size " << FrameSize << " >= 65536.\n";
+ abort(); // Very rude!
+ }
+
+ size_t LiveCount = MD.live_size(PI);
+ if (LiveCount >= 1<<16) {
+ cerr << "Function '" << MD.getFunction().getNameStart()
+ << "' is too large for the ocaml collector! "
+ << "Live root count " << LiveCount << " >= 65536.\n";
+ abort(); // Very rude!
+ }
+
+ OS << AddressDirective
+ << TAI.getPrivateGlobalPrefix() << "label" << PI->Num;
+ AP.EOL("call return address");
+
+ AP.EmitInt16(FrameSize);
+ AP.EOL("stack frame size");
+
+ AP.EmitInt16(LiveCount);
+ AP.EOL("live root count");
+
+ for (CollectorMetadata::live_iterator LI = MD.live_begin(PI),
+ LE = MD.live_end(PI);
+ LI != LE; ++LI) {
+ assert(LI->StackOffset < 1<<16 &&
+ "GC root stack offset is outside of fixed stack frame and out "
+ "of range for Ocaml collector!");
+
+ OS << "\t.word\t" << LI->StackOffset;
+ AP.EOL("stack offset");
+ }
+
+ AP.EmitAlignment(AddressAlignLog);
+ }
+ }
+}