Use indirect calls in PowerPC JIT.

See PR5201. There is no way to know if direct calls will be within the allowed
range for BL. Hence emit all calls as indirect when in JIT mode.
Without this long-running applications will fail to JIT on PowerPC with a
relocation failure.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@110246 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/Target/PowerPC/PPCISelLowering.cpp b/lib/Target/PowerPC/PPCISelLowering.cpp
index 33d14412848a21ec7cd351e0c8b70f9958c62a25..14d1b154a5c9cc65928a1d9f9cc9ab14af817131 100644 (file)
--- a/lib/Target/PowerPC/PPCISelLowering.cpp
+++ b/lib/Target/PowerPC/PPCISelLowering.cpp
@@ -2467,18 +2467,31 @@ unsigned PrepareCall(SelectionDAG &DAG, SDValue &Callee, SDValue &InFlag,
 
   unsigned CallOpc = isSVR4ABI ? PPCISD::CALL_SVR4 : PPCISD::CALL_Darwin;
 
-  // If the callee is a GlobalAddress/ExternalSymbol node (quite common, every
-  // direct call is) turn it into a TargetGlobalAddress/TargetExternalSymbol
-  // node so that legalize doesn't hack it.
-  if (GlobalAddressSDNode *G = dyn_cast<GlobalAddressSDNode>(Callee))
-    Callee = DAG.getTargetGlobalAddress(G->getGlobal(), dl, 
-                                        Callee.getValueType());
-  else if (ExternalSymbolSDNode *S = dyn_cast<ExternalSymbolSDNode>(Callee))
-    Callee = DAG.getTargetExternalSymbol(S->getSymbol(), Callee.getValueType());
-  else if (SDNode *Dest = isBLACompatibleAddress(Callee, DAG))
+  bool needIndirectCall = true;
+  if (SDNode *Dest = isBLACompatibleAddress(Callee, DAG)) {
     // If this is an absolute destination address, use the munged value.
     Callee = SDValue(Dest, 0);
-  else {
+    needIndirectCall = false;
+  }
+  // XXX Work around for http://llvm.org/bugs/show_bug.cgi?id=5201
+  // Use indirect calls for ALL functions calls in JIT mode, since the
+  // far-call stubs may be outside relocation limits for a BL instruction.
+  if (!DAG.getTarget().getSubtarget<PPCSubtarget>().isJITCodeModel()) {
+    // If the callee is a GlobalAddress/ExternalSymbol node (quite common, every
+    // direct call is) turn it into a TargetGlobalAddress/TargetExternalSymbol
+    // node so that legalize doesn't hack it.
+    if (GlobalAddressSDNode *G = dyn_cast<GlobalAddressSDNode>(Callee)) {
+      Callee = DAG.getTargetGlobalAddress(G->getGlobal(), dl,
+                                         Callee.getValueType());
+      needIndirectCall = false;
+    }
+  }
+  if (ExternalSymbolSDNode *S = dyn_cast<ExternalSymbolSDNode>(Callee)) {
+      Callee = DAG.getTargetExternalSymbol(S->getSymbol(),
+                                          Callee.getValueType());
+      needIndirectCall = false;
+  }
+  if (needIndirectCall) {
     // Otherwise, this is an indirect call.  We have to use a MTCTR/BCTRL pair
     // to do the call, we can't use PPCISD::CALL.
     SDValue MTCTROps[] = {Chain, Callee, InFlag};

diff --git a/lib/Target/PowerPC/PPCSubtarget.cpp b/lib/Target/PowerPC/PPCSubtarget.cpp
index 40914ba62a70ea054133db7a53bca663b245c7a1..5d46065d96f22dc6e759b9c8824f903a56871c97 100644 (file)
--- a/lib/Target/PowerPC/PPCSubtarget.cpp
+++ b/lib/Target/PowerPC/PPCSubtarget.cpp
@@ -69,6 +69,7 @@ PPCSubtarget::PPCSubtarget(const std::string &TT, const std::string &FS,
   , HasFSQRT(false)
   , HasSTFIWX(false)
   , HasLazyResolverStubs(false)
+  , IsJITCodeModel(false)
   , DarwinVers(0) {
 
   // Determine default and user specified characteristics
@@ -117,6 +118,9 @@ void PPCSubtarget::SetJITMode() {
   // 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;
 }
 
 

diff --git a/lib/Target/PowerPC/PPCSubtarget.h b/lib/Target/PowerPC/PPCSubtarget.h
index 75fcf6238a27a0463237a86a8f4fda8178241d5f..00ec7474c9e39d95de39a16512a564a89da84efb 100644 (file)
--- a/lib/Target/PowerPC/PPCSubtarget.h
+++ b/lib/Target/PowerPC/PPCSubtarget.h
@@ -63,6 +63,7 @@ protected:
   bool HasFSQRT;
   bool HasSTFIWX;
   bool HasLazyResolverStubs;
+  bool IsJITCodeModel;
   
   /// DarwinVers - Nonzero if this is a darwin platform.  Otherwise, the numeric
   /// version of the platform, e.g. 8 = 10.4 (Tiger), 9 = 10.5 (Leopard), etc.
@@ -124,6 +125,9 @@ public:
   bool hasLazyResolverStub(const GlobalValue *GV, 
                            const TargetMachine &TM) const;
   
+  // isJITCodeModel - True if we're generating code for the JIT
+  bool isJITCodeModel() const { return IsJITCodeModel; }
+
   // Specific obvious features.
   bool hasFSQRT() const { return HasFSQRT; }
   bool hasSTFIWX() const { return HasSTFIWX; }