[llvm-commits] [llvm] r126176 - /llvm/trunk/lib/Target/ARM/ARMFastISel.cpp

[Eric Christopher]

Author: echristo
Date: Mon Feb 21 19:37:10 2011
New Revision: 126176

URL: http://llvm.org/viewvc/llvm-project?rev=126176&view=rev
Log:
Only use blx for external function calls on thumb, these could be fixed
up by the dynamic linker, but it's better to use the correct instruction
to begin with.

Fixes rdar://9011034

Modified:
    llvm/trunk/lib/Target/ARM/ARMFastISel.cpp

Modified: llvm/trunk/lib/Target/ARM/ARMFastISel.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/ARM/ARMFastISel.cpp?rev=126176&r1=126175&r2=126176&view=diff
==============================================================================
--- llvm/trunk/lib/Target/ARM/ARMFastISel.cpp (original)
+++ llvm/trunk/lib/Target/ARM/ARMFastISel.cpp Mon Feb 21 19:37:10 2011
@@ -172,6 +172,7 @@
     unsigned ARMMaterializeGV(const GlobalValue *GV, EVT VT);
     unsigned ARMMoveToFPReg(EVT VT, unsigned SrcReg);
     unsigned ARMMoveToIntReg(EVT VT, unsigned SrcReg);
+    unsigned ARMSelectCallOp(const GlobalValue *GV);
 
     // Call handling routines.
   private:
@@ -1633,6 +1634,25 @@
   return true;
 }
 
+unsigned ARMFastISel::ARMSelectCallOp(const GlobalValue *GV) {
+
+  // Depend our opcode for thumb on whether or not we're targeting an
+  // externally callable function. For libcalls we'll just pass a NULL GV
+  // in here.
+  bool isExternal = false;
+  if (!GV || GV->hasExternalLinkage()) isExternal = true;
+  
+  // Darwin needs the r9 versions of the opcodes.
+  bool isDarwin = Subtarget->isTargetDarwin();
+  if (isThumb && isExternal) {
+    return isDarwin ? ARM::tBLXi_r9 : ARM::tBLXi;
+  } else if (isThumb) {
+    return isDarwin ? ARM::tBLr9 : ARM::tBL;
+  } else  {
+    return isDarwin ? ARM::BLr9 : ARM::BL;
+  }
+}
+
 // A quick function that will emit a call for a named libcall in F with the
 // vector of passed arguments for the Instruction in I. We can assume that we
 // can emit a call for any libcall we can produce. This is an abridged version
@@ -1694,20 +1714,17 @@
   // Issue the call, BLXr9 for darwin, BLX otherwise. This uses V5 ops.
   // TODO: Turn this into the table of arm call ops.
   MachineInstrBuilder MIB;
-  unsigned CallOpc;
-  if(isThumb) {
-    CallOpc = Subtarget->isTargetDarwin() ? ARM::tBLXi_r9 : ARM::tBLXi;
+  unsigned CallOpc = ARMSelectCallOp(NULL);
+  if(isThumb)
     // Explicitly adding the predicate here.
     MIB = AddDefaultPred(BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DL,
                          TII.get(CallOpc)))
                          .addExternalSymbol(TLI.getLibcallName(Call));
-  } else {
-    CallOpc = Subtarget->isTargetDarwin() ? ARM::BLr9 : ARM::BL;
+  else
     // Explicitly adding the predicate here.
     MIB = AddDefaultPred(BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DL,
                          TII.get(CallOpc))
           .addExternalSymbol(TLI.getLibcallName(Call)));
-  }
 
   // Add implicit physical register uses to the call.
   for (unsigned i = 0, e = RegArgs.size(); i != e; ++i)
@@ -1813,21 +1830,18 @@
   // Issue the call, BLXr9 for darwin, BLX otherwise. This uses V5 ops.
   // TODO: Turn this into the table of arm call ops.
   MachineInstrBuilder MIB;
-  unsigned CallOpc;
+  unsigned CallOpc = ARMSelectCallOp(GV);
   // Explicitly adding the predicate here.
-  if(isThumb) {
-    CallOpc = Subtarget->isTargetDarwin() ? ARM::tBLXi_r9 : ARM::tBLXi;
+  if(isThumb)
     // Explicitly adding the predicate here.
     MIB = AddDefaultPred(BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DL,
                          TII.get(CallOpc)))
           .addGlobalAddress(GV, 0, 0);
-  } else {
-    CallOpc = Subtarget->isTargetDarwin() ? ARM::BLr9 : ARM::BL;
+  else
     // Explicitly adding the predicate here.
     MIB = AddDefaultPred(BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DL,
                          TII.get(CallOpc))
           .addGlobalAddress(GV, 0, 0));
-  }
   
   // Add implicit physical register uses to the call.
   for (unsigned i = 0, e = RegArgs.size(); i != e; ++i)