Alpha JIT (beta)

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@22500 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 273 insertions, 0 deletions

diff --git a/lib/Target/Alpha/AlphaJITInfo.cpp b/lib/Target/Alpha/AlphaJITInfo.cpp
new file mode 100644
index 0000000..ff09f09
--- /dev/null
+++ b/lib/Target/Alpha/AlphaJITInfo.cpp
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+//===-- AlphaJITInfo.cpp - Implement the JIT interfaces for the Alpha ---===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file was developed by the LLVM research group and is distributed under
+// the University of Illinois Open Source License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file implements the JIT interfaces for the Alpha target.
+//
+//===----------------------------------------------------------------------===//
+
+#define DEBUG_TYPE "jit"
+#include "AlphaJITInfo.h"
+#include "AlphaRelocations.h"
+#include "llvm/CodeGen/MachineCodeEmitter.h"
+#include "llvm/Config/alloca.h"
+#include "llvm/Support/Debug.h"
+#include <cstdlib>
+#include <iostream>
+#include <map>
+using namespace std;
+using namespace llvm;
+
+#define BUILD_LDA(RD, RS, IMM16) \
+  ((0x08 << 26) | ((RD) << 21) | ((RS) << 16) | ((IMM16) & 65535))
+#define BUILD_LDAH(RD, RS, IMM16) \
+  ((0x09 << 26) | ((RD) << 21) | ((RS) << 16) | ((IMM16) & 65535))
+
+#define MERGE_PARTS(HH, HL, LH, LL) \
+  (((HH * 65536 + HL) << 32) + (LH * 65536 + LL))
+
+#define BUILD_LDQ(RD, RS, IMM16) \
+  ((0x29 << 26) | ((RD) << 21) | ((RS) << 16) | ((IMM16) & 0xFFFF))
+
+#define BUILD_JMP(RD, RS, IMM16) \
+  ((0x1A << 26) | ((RD) << 21) | ((RS) << 16) | ((IMM16) & 0xFFFF))
+
+static void EmitBranchToAt(void *At, void *To, bool isCall) {
+  //FIXME
+  assert(0);
+}
+
+void AlphaJITInfo::replaceMachineCodeForFunction(void *Old, void *New) {
+  //FIXME
+  assert(0);
+}
+
+static TargetJITInfo::JITCompilerFn JITCompilerFunction;
+//static AlphaJITInfo* AlphaJTI;
+
+extern "C" {
+#if 0
+
+  void AlphaCompilationCallbackC(long* oldsp)
+  {
+    void* CameFromStub = (void*)*(oldsp - 1);
+    void* CameFromOrig = (void*)*(oldsp - 2);
+
+    void* Target = JITCompilerFunction(CameFromStub);
+    
+    //rewrite the stub to an unconditional branch
+    EmitBranchToAt(CameFromStub, Target, false);
+
+    //Change pv to new Target
+    *(oldsp - 1) = (long)Target;
+
+    //special epilog
+    register long* RSP asm ("$0") = oldsp;
+    __asm__ __volatile__ (
+      "ldq $16,   0($0)\n"
+      "ldq $17,   8($0)\n"
+      "ldq $18,  16($0)\n"
+      "ldq $19,  24($0)\n"
+      "ldq $20,  32($0)\n"
+      "ldq $21,  40($0)\n"
+      "ldt $f16, 48($0)\n"
+      "ldt $f17, 56($0)\n"
+      "ldt $f18, 64($0)\n"
+      "ldt $f19, 72($0)\n"
+      "ldt $f20, 80($0)\n"
+      "ldt $f21, 88($0)\n"
+      "ldq $9,   96($0)\n"
+      "ldq $10, 104($0)\n"
+      "ldq $11, 112($0)\n"
+      "ldq $12, 120($0)\n"
+      "ldq $13, 128($0)\n"
+      "ldq $14, 136($0)\n"
+      "ldt $f2, 144($0)\n"
+      "ldt $f3, 152($0)\n"
+      "ldt $f4, 160($0)\n"
+      "ldt $f5, 168($0)\n"
+      "ldt $f6, 176($0)\n"
+      "ldt $f7, 184($0)\n"
+      "ldt $f8, 192($0)\n"
+      "ldt $f9, 200($0)\n"
+      "ldq $15, 208($0)\n"
+      "ldq $26, 216($0)\n"
+      "ldq $27, 224($0)\n"
+      "bis $30, $0, $0\n" //restore sp
+      "jmp $31, ($27)\n" //jump to the new function
+      "and $0, $31, $31\n" //dummy use of r0
+    );
+  }
+
+  void AlphaCompilationCallback(void);
+
+  asm(
+      ".text\n"
+      ".globl AlphaComilationCallbackC\n"
+      ".align 4\n"
+      ".globl AlphaCompilationCallback\n"
+      ".ent AlphaCompilationCallback\n"
+"AlphaCompilationCallback:\n"
+      //      //get JIT's GOT
+      //      "ldgp\n"
+      //Save args, callee saved, and perhaps others?
+      //args: $16-$21 $f16-$f21     (12)
+      //callee: $9-$14 $f2-$f9      (14)
+      //others: fp:$15 ra:$26 pv:$27 (3)
+      "bis $0, $30, $30\n" //0 = sp
+      "lda $30, -232($30)\n"
+      "stq $16,   0($30)\n"
+      "stq $17,   8($30)\n"
+      "stq $18,  16($30)\n"
+      "stq $19,  24($30)\n"
+      "stq $20,  32($30)\n"
+      "stq $21,  40($30)\n"
+      "stt $f16, 48($30)\n"
+      "stt $f17, 56($30)\n"
+      "stt $f18, 64($30)\n"
+      "stt $f19, 72($30)\n"
+      "stt $f20, 80($30)\n"
+      "stt $f21, 88($30)\n"
+      "stq $9,   96($30)\n"
+      "stq $10, 104($30)\n"
+      "stq $11, 112($30)\n"
+      "stq $12, 120($30)\n"
+      "stq $13, 128($30)\n"
+      "stq $14, 136($30)\n"
+      "stt $f2, 144($30)\n"
+      "stt $f3, 152($30)\n"
+      "stt $f4, 160($30)\n"
+      "stt $f5, 168($30)\n"
+      "stt $f6, 176($30)\n"
+      "stt $f7, 184($30)\n"
+      "stt $f8, 192($30)\n"
+      "stt $f9, 200($30)\n"
+      "stq $15, 208($30)\n"
+      "stq $26, 216($30)\n"
+      "stq $27, 224($30)\n"
+      "bis $16, $0, $0\n" //pass the old sp as the first arg
+      "bsr $31, AlphaCompilationCallbackC\n"
+      ".end AlphaCompilationCallback\n"
+      );
+#else
+  void AlphaCompilationCallback() {
+    std::cerr << "Cannot call AlphaCompilationCallback() on a non-Alpha arch!\n";
+    abort();
+  }
+#endif
+}
+
+void *AlphaJITInfo::emitFunctionStub(void *Fn, MachineCodeEmitter &MCE) {
+//   // If this is just a call to an external function, emit a branch instead of a
+//   // call.  This means looking up Fn and storing that in R27 so as to appear to
+//   // have called there originally
+//   if (Fn != AlphaCompilationCallback) {
+//     int idx = AlphaJTI->getNewGOTEntry(Fn);
+//     //R27 = ldq idx(R29)
+//     //R31 = JMP R27, 0
+//     MCE.startFunctionStub(2*4);
+//     void *Addr = (void*)(intptr_t)MCE.getCurrentPCValue();
+//     MCE.emitWord(BUILD_LDQ(27, 29, idx << 3));
+//     MCE.emitWord(BUILD_JMP(31, 27, 0));
+//     return MCE.finishFunctionStub(0);
+//   }
+
+  assert(0 && "Need to be able to jump to this guy too");
+}
+
+TargetJITInfo::LazyResolverFn
+AlphaJITInfo::getLazyResolverFunction(JITCompilerFn F) {
+  JITCompilerFunction = F;
+  //  setZerothGOTEntry((void*)AlphaCompilationCallback);
+  return AlphaCompilationCallback;
+}
+
+//These describe LDAx
+static const int IMM_LOW  = -32768;
+static const int IMM_HIGH = 32767;
+static const int IMM_MULT = 65536;
+
+static long getUpper16(long l)
+{
+  long y = l / IMM_MULT;
+  if (l % IMM_MULT > IMM_HIGH)
+    ++y;
+  if (l % IMM_MULT < IMM_LOW)
+    --y;
+  assert((short)y == y && "displacement out of range");
+  return y;
+}
+
+static long getLower16(long l)
+{
+  long h = getUpper16(l);
+  long y = l - h * IMM_MULT;
+  assert(y == (short)y && "Displacement out of range");
+  return y;
+}
+
+void AlphaJITInfo::relocate(void *Function, MachineRelocation *MR,
+                            unsigned NumRelocs, unsigned char* GOTBase) {
+  //because gpdist are paired and relative to the pc of the first inst,
+  //we need to have some state
+
+  static map<pair<void*, int>, void*> gpdistmap;
+
+  for (unsigned i = 0; i != NumRelocs; ++i, ++MR) {
+    unsigned *RelocPos = (unsigned*)Function + MR->getMachineCodeOffset()/4;
+    long idx = 0;
+    switch ((Alpha::RelocationType)MR->getRelocationType()) {
+    default: assert(0 && "Unknown relocation type!");
+    case Alpha::reloc_literal:
+      //This is a LDQl
+      idx = MR->getGOTIndex();
+      DEBUG(std::cerr << "Literal relocation to slot " << idx);
+      idx = (idx - GOToffset) * 8;
+      DEBUG(std::cerr << " offset " << idx << "\n");
+      break;
+    case Alpha::reloc_gprellow:
+      idx = (unsigned char*)MR->getResultPointer() - &GOTBase[GOToffset * 8];
+      idx = getLower16(idx);
+      DEBUG(std::cerr << "gprellow relocation offset " << idx << "\n");
+      DEBUG(std::cerr << " Pointer is " << (void*)MR->getResultPointer()
+            << " GOT is " << (void*)&GOTBase[GOToffset * 8] << "\n");
+      break;
+    case Alpha::reloc_gprelhigh:
+      idx = (unsigned char*)MR->getResultPointer() - &GOTBase[GOToffset * 8];
+      idx = getUpper16(idx);
+      DEBUG(std::cerr << "gprelhigh relocation offset " << idx << "\n");
+      DEBUG(std::cerr << " Pointer is " << (void*)MR->getResultPointer()
+            << " GOT is " << (void*)&GOTBase[GOToffset * 8] << "\n");
+      break;
+    case Alpha::reloc_gpdist:
+      switch (*RelocPos >> 26) {
+      case 0x09: //LDAH
+        idx = &GOTBase[GOToffset * 8] - (unsigned char*)RelocPos;
+        idx = getUpper16(idx);
+        DEBUG(std::cerr << "LDAH: " << idx << "\n");
+        //add the relocation to the map
+        gpdistmap[make_pair(Function, MR->getConstantVal())] = RelocPos;
+        break;
+      case 0x08: //LDA
+        assert(gpdistmap[make_pair(Function, MR->getConstantVal())] &&
+               "LDAg without seeing LDAHg");
+        idx = &GOTBase[GOToffset * 8] - 
+          (unsigned char*)gpdistmap[make_pair(Function, MR->getConstantVal())];
+        idx = getLower16(idx);
+        DEBUG(std::cerr << "LDA: " << idx << "\n");
+        break;
+      default:
+        assert(0 && "Cannot handle gpdist yet");
+      }
+      break;
+    }
+    short x = (short)idx;
+    assert(x == idx);
+    *(short*)RelocPos = x;
+  }
+}