Use indirect calls in PowerPC JIT.

[oota-llvm.git] / lib / Target / PowerPC / PPCSubtarget.cpp

diff --git a/lib/Target/PowerPC/PPCSubtarget.cpp b/lib/Target/PowerPC/PPCSubtarget.cpp
index b909b5b39ebcffb04693fe968aa8a372a2900dc6..5d46065d96f22dc6e759b9c8824f903a56871c97 100644 (file)
--- a/lib/Target/PowerPC/PPCSubtarget.cpp
+++ b/lib/Target/PowerPC/PPCSubtarget.cpp
@@ -2,8 +2,8 @@
 //
 //                     The LLVM Compiler Infrastructure
 //
-// This file was developed by Nate Begeman and is distributed under the
-// University of Illinois Open Source License. See LICENSE.TXT for details.
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 //
@@ -13,9 +13,10 @@
 
 #include "PPCSubtarget.h"
 #include "PPC.h"
-#include "llvm/Module.h"
+#include "llvm/GlobalValue.h"
+#include "llvm/Target/TargetMachine.h"
 #include "PPCGenSubtarget.inc"
-#include <iostream>
+#include <cstdlib>
 using namespace llvm;
 
 #if defined(__APPLE__)
@@ -56,9 +57,10 @@ static const char *GetCurrentPowerPCCPU() {
 #endif
 
 
-PPCSubtarget::PPCSubtarget(const Module &M, const std::string &FS, bool is64Bit)
+PPCSubtarget::PPCSubtarget(const std::string &TT, const std::string &FS,
+                           bool is64Bit)
   : StackAlignment(16)
-  , InstrItins()
+  , DarwinDirective(PPC::DIR_NONE)
   , IsGigaProcessor(false)
   , Has64BitSupport(false)
   , Use64BitRegs(false)
@@ -66,8 +68,9 @@ PPCSubtarget::PPCSubtarget(const Module &M, const std::string &FS, bool is64Bit)
   , HasAltivec(false)
   , HasFSQRT(false)
   , HasSTFIWX(false)
-  , IsAIX(false)
-  , IsDarwin(false) {
+  , HasLazyResolverStubs(false)
+  , IsJITCodeModel(false)
+  , DarwinVers(0) {
 
   // Determine default and user specified characteristics
   std::string CPU = "generic";
@@ -80,35 +83,60 @@ PPCSubtarget::PPCSubtarget(const Module &M, const std::string &FS, bool is64Bit)
 
   // If we are generating code for ppc64, verify that options make sense.
   if (is64Bit) {
-    if (!has64BitSupport()) {
-      std::cerr << "PPC: Generation of 64-bit code for a 32-bit processor "
-                   "requested.  Ignoring 32-bit processor feature.\n";
-      Has64BitSupport = true;
-      // Silently force 64-bit register use on ppc64.
-      Use64BitRegs = true;
-    }
+    Has64BitSupport = true;
+    // Silently force 64-bit register use on ppc64.
+    Use64BitRegs = true;
   }
   
   // If the user requested use of 64-bit regs, but the cpu selected doesn't
-  // support it, warn and ignore.
-  if (use64BitRegs() && !has64BitSupport()) {
-    std::cerr << "PPC: 64-bit registers requested on CPU without support.  "
-                 "Disabling 64-bit register use.\n";
+  // support it, ignore.
+  if (use64BitRegs() && !has64BitSupport())
     Use64BitRegs = false;
-  }
   
   // Set the boolean corresponding to the current target triple, or the default
   // if one cannot be determined, to true.
-  const std::string& TT = M.getTargetTriple();
-  if (TT.length() > 5) {
-    IsDarwin = TT.find("-darwin") != std::string::npos;
-    if (!IsDarwin)
-      IsAIX = TT.find("-aix") != std::string::npos;
-  } else if (TT.empty()) {
-#if defined(_POWER)
-    IsAIX = true;
-#elif defined(__APPLE__)
-    IsDarwin = true;
-#endif
+  if (TT.length() > 7) {
+    // Determine which version of darwin this is.
+    size_t DarwinPos = TT.find("-darwin");
+    if (DarwinPos != std::string::npos) {
+      if (isdigit(TT[DarwinPos+7]))
+        DarwinVers = atoi(&TT[DarwinPos+7]);
+      else
+        DarwinVers = 8;  // Minimum supported darwin is Tiger.
+    }
   }
+
+  // Set up darwin-specific properties.
+  if (isDarwin())
+    HasLazyResolverStubs = true;
+}
+
+/// SetJITMode - This is called to inform the subtarget info that we are
+/// producing code for the JIT.
+void PPCSubtarget::SetJITMode() {
+  // JIT mode doesn't want lazy resolver stubs, it knows exactly where
+  // everything is.  This matters for PPC64, which codegens in PIC mode without
+  // stubs.
+  HasLazyResolverStubs = false;
+
+  // Calls to external functions need to use indirect calls
+  IsJITCodeModel = true;
+}
+
+
+/// hasLazyResolverStub - Return true if accesses to the specified global have
+/// to go through a dyld lazy resolution stub.  This means that an extra load
+/// is required to get the address of the global.
+bool PPCSubtarget::hasLazyResolverStub(const GlobalValue *GV,
+                                       const TargetMachine &TM) const {
+  // We never hae stubs if HasLazyResolverStubs=false or if in static mode.
+  if (!HasLazyResolverStubs || TM.getRelocationModel() == Reloc::Static)
+    return false;
+  // If symbol visibility is hidden, the extra load is not needed if
+  // the symbol is definitely defined in the current translation unit.
+  bool isDecl = GV->isDeclaration() && !GV->isMaterializable();
+  if (GV->hasHiddenVisibility() && !isDecl && !GV->hasCommonLinkage())
+    return false;
+  return GV->hasWeakLinkage() || GV->hasLinkOnceLinkage() ||
+         GV->hasCommonLinkage() || isDecl;
 }