1 files changed, 117 insertions, 0 deletions
diff --git a/lib/Target/PowerPC/PPCJITInfo.cpp b/lib/Target/PowerPC/PPCJITInfo.cpp
new file mode 100644
index 0000000000..b86ff1609c
--- /dev/null
+++ b/lib/Target/PowerPC/PPCJITInfo.cpp
@@ -0,0 +1,117 @@
+//===-- PPC32JITInfo.cpp - Implement the JIT interfaces for the PowerPC ---===//
+// 
+//                     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 32-bit PowerPC target.
+//
+//===----------------------------------------------------------------------===//
+
+#define DEBUG_TYPE "jit"
+#include "PPC32JITInfo.h"
+#include "PPC32Relocations.h"
+#include "llvm/CodeGen/MachineCodeEmitter.h"
+#include "llvm/Config/alloca.h"
+using namespace llvm;
+
+static TargetJITInfo::JITCompilerFn JITCompilerFunction;
+
+#define BUILD_ADDIS(RD,RS,IMM16) \
+  ((15 << 26) | ((RD) << 21) | ((RS) << 16) | ((IMM16) & 65535))
+#define BUILD_ORI(RD,RS,UIMM16) \
+  ((24 << 26) | ((RS) << 21) | ((RD) << 16) | ((UIMM16) & 65535))
+#define BUILD_MTSPR(RS,SPR)      \
+  ((31 << 26) | ((RS) << 21) | ((SPR) << 16) | (467 << 1))
+#define BUILD_BCCTRx(BO,BI,LINK) \
+  ((19 << 26) | ((BO) << 21) | ((BI) << 16) | (528 << 1) | ((LINK) & 1))
+
+// Pseudo-ops
+#define BUILD_LIS(RD,IMM16)    BUILD_ADDIS(RD,0,IMM16)
+#define BUILD_MTCTR(RS)        BUILD_MTSPR(RS,9)
+#define BUILD_BCTR(LINK)       BUILD_BCCTRx(20,0,LINK)
+
+static void CompilationCallback() {
+  //JITCompilerFunction
+  assert(0 && "CompilationCallback not implemented yet!");
+}
+
+
+TargetJITInfo::LazyResolverFn 
+PPC32JITInfo::getLazyResolverFunction(JITCompilerFn Fn) {
+  return CompilationCallback;
+}
+
+static void EmitBranchToAt(void *At, void *To) {
+  intptr_t Addr = (intptr_t)To;
+
+  // FIXME: should special case the short branch case.
+  unsigned *AtI = (unsigned*)At;
+
+  AtI[0] = BUILD_LIS(12, Addr >> 16);   // lis r12, hi16(address)
+  AtI[1] = BUILD_ORI(12, 12, Addr);     // ori r12, r12, low16(address)
+  AtI[2] = BUILD_MTCTR(12);             // mtctr r12
+  AtI[3] = BUILD_BCTR(0);               // bctr
+}
+
+void *PPC32JITInfo::emitFunctionStub(void *Fn, MachineCodeEmitter &MCE) {
+  // If this is just a call to an external function, emit a branch instead of a
+  // call.  The code is the same except for one bit of the last instruction.
+  if (Fn != CompilationCallback) {
+    MCE.startFunctionStub(4*4);
+    void *Addr = (void*)(intptr_t)MCE.getCurrentPCValue();
+    MCE.emitWord(0);
+    MCE.emitWord(0);
+    MCE.emitWord(0);
+    MCE.emitWord(0);
+    EmitBranchToAt(Addr, Fn);
+    return MCE.finishFunctionStub(0);
+  }
+
+  MCE.startFunctionStub(4*4);
+  return MCE.finishFunctionStub(0);
+}
+
+
+void PPC32JITInfo::relocate(void *Function, MachineRelocation *MR,
+                            unsigned NumRelocs) {
+  for (unsigned i = 0; i != NumRelocs; ++i, ++MR) {
+    unsigned *RelocPos = (unsigned*)Function + MR->getMachineCodeOffset()/4;
+    intptr_t ResultPtr = (intptr_t)MR->getResultPointer();
+    switch ((PPC::RelocationType)MR->getRelocationType()) {
+    default: assert(0 && "Unknown relocation type!");
+    case PPC::reloc_pcrel_bx:
+      // PC-relative relocation for b and bl instructions.
+      ResultPtr = (ResultPtr-(intptr_t)RelocPos) >> 2;
+      assert(ResultPtr >= -(1 << 23) && ResultPtr < (1 << 23) &&
+             "Relocation out of range!");
+      *RelocPos |= (ResultPtr & ((1 << 24)-1))  << 2;
+      break;
+    case PPC::reloc_absolute_loadhi:   // Relocate high bits into addis
+    case PPC::reloc_absolute_la:       // Relocate low bits into addi
+      ResultPtr += MR->getConstantVal();
+
+      if (MR->getRelocationType() == PPC::reloc_absolute_loadhi) {
+        // If the low part will have a carry (really a borrow) from the low
+        // 16-bits into the high 16, add a bit to borrow from.
+        if (((int)ResultPtr << 16) < 0)
+          ResultPtr += 1 << 16;
+        ResultPtr >>= 16;
+      }
+
+      // Do the addition then mask, so the addition does not overflow the 16-bit
+      // immediate section of the instruction.
+      unsigned LowBits  = (*RelocPos + ResultPtr) & 65535;
+      unsigned HighBits = *RelocPos & ~65535;
+      *RelocPos = LowBits | HighBits;  // Slam into low 16-bits
+      break;
+    }
+  }
+}
+
+void PPC32JITInfo::replaceMachineCodeForFunction(void *Old, void *New) {
+  EmitBranchToAt(Old, New);
+}