[llvm-commits] [llvm] r104722 - in /llvm/trunk: include/llvm/CodeGen/MachineFunction.h lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp lib/CodeGen/StackSlotColoring.cpp

[Bill Wendling]

Author: void
Date: Wed May 26 14:46:12 2010
New Revision: 104722

URL: http://llvm.org/viewvc/llvm-project?rev=104722&view=rev
Log:
Move the check for "calls setjmp" to SelectionDAGISel so that it can be used by
more than just the stack slot coloring algorithm.

Modified:
    llvm/trunk/include/llvm/CodeGen/MachineFunction.h
    llvm/trunk/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp
    llvm/trunk/lib/CodeGen/StackSlotColoring.cpp

Modified: llvm/trunk/include/llvm/CodeGen/MachineFunction.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/CodeGen/MachineFunction.h?rev=104722&r1=104721&r2=104722&view=diff
==============================================================================
--- llvm/trunk/include/llvm/CodeGen/MachineFunction.h (original)
+++ llvm/trunk/include/llvm/CodeGen/MachineFunction.h Wed May 26 14:46:12 2010
@@ -114,9 +114,14 @@
   ///
   unsigned FunctionNumber;
   
-  /// The alignment of the function.
+  /// Alignment - The alignment of the function.
   unsigned Alignment;
 
+  /// CallsSetJmp - True if the function calls setjmp or sigsetjmp. This is used
+  /// to limit optimizations which cannot reason about the control flow of
+  /// setjmp.
+  bool CallsSetJmp;
+
   MachineFunction(const MachineFunction &); // DO NOT IMPLEMENT
   void operator=(const MachineFunction&);   // DO NOT IMPLEMENT
 public:
@@ -181,6 +186,17 @@
   void EnsureAlignment(unsigned A) {
     if (Alignment < A) Alignment = A;
   }
+
+  /// callsSetJmp - Returns true if the function calls setjmp or sigsetjmp.
+  bool callsSetJmp() const {
+    return CallsSetJmp;
+  }
+
+  /// setCallsSetJmp - Set a flag that indicates if there's a call to setjmp or
+  /// sigsetjmp.
+  void setCallsSetJmp(bool B) {
+    CallsSetJmp = B;
+  }
   
   /// getInfo - Keep track of various per-function pieces of information for
   /// backends that would like to do so.

Modified: llvm/trunk/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp?rev=104722&r1=104721&r2=104722&view=diff
==============================================================================
--- llvm/trunk/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp (original)
+++ llvm/trunk/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp Wed May 26 14:46:12 2010
@@ -25,6 +25,7 @@
 #include "llvm/Intrinsics.h"
 #include "llvm/IntrinsicInst.h"
 #include "llvm/LLVMContext.h"
+#include "llvm/Module.h"
 #include "llvm/CodeGen/FastISel.h"
 #include "llvm/CodeGen/GCStrategy.h"
 #include "llvm/CodeGen/GCMetadata.h"
@@ -191,6 +192,34 @@
   MachineFunctionPass::getAnalysisUsage(AU);
 }
 
+/// FunctionCallsSetJmp - Return true if the function has a call to setjmp or
+/// sigsetjmp. This is used to limit code-gen optimizations on the machine
+/// function.
+static bool FunctionCallsSetJmp(const Function *F) {
+  const Module *M = F->getParent();
+  const Function *SetJmp = M->getFunction("setjmp");
+  const Function *SigSetJmp = M->getFunction("sigsetjmp");
+
+  if (!SetJmp && !SigSetJmp)
+    return false;
+
+  if (SetJmp && !SetJmp->use_empty())
+    for (Value::const_use_iterator
+           I = SetJmp->use_begin(), E = SetJmp->use_end(); I != E; ++I)
+      if (const CallInst *CI = dyn_cast<CallInst>(I))
+        if (CI->getParent()->getParent() == F)
+          return true;
+
+  if (SigSetJmp && !SigSetJmp->use_empty())
+    for (Value::const_use_iterator
+           I = SigSetJmp->use_begin(), E = SigSetJmp->use_end(); I != E; ++I)
+      if (const CallInst *CI = dyn_cast<CallInst>(I))
+        if (CI->getParent()->getParent() == F)
+          return true;
+
+  return false;
+}
+
 bool SelectionDAGISel::runOnMachineFunction(MachineFunction &mf) {
   // Do some sanity-checking on the command-line options.
   assert((!EnableFastISelVerbose || EnableFastISel) &&
@@ -253,6 +282,9 @@
   done:;
   }
 
+  // Determine if there is a call to setjmp in the machine function.
+  MF->setCallsSetJmp(FunctionCallsSetJmp(&Fn));
+
   // Release function-specific state. SDB and CurDAG are already cleared
   // at this point.
   FuncInfo->clear();

Modified: llvm/trunk/lib/CodeGen/StackSlotColoring.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/StackSlotColoring.cpp?rev=104722&r1=104721&r2=104722&view=diff
==============================================================================
--- llvm/trunk/lib/CodeGen/StackSlotColoring.cpp (original)
+++ llvm/trunk/lib/CodeGen/StackSlotColoring.cpp Wed May 26 14:46:12 2010
@@ -162,34 +162,6 @@
   };
 }
 
-/// CheckForSetJmpCall - Return true if there's a call to setjmp/sigsetjmp in
-/// this function.
-bool StackSlotColoring::CheckForSetJmpCall(const MachineFunction &MF) const {
-  const Function *F = MF.getFunction();
-  const Module *M = F->getParent();
-  const Function *SetJmp = M->getFunction("setjmp");
-  const Function *SigSetJmp = M->getFunction("sigsetjmp");
-
-  if (!SetJmp && !SigSetJmp)
-    return false;
-
-  if (SetJmp && !SetJmp->use_empty())
-    for (Value::const_use_iterator
-           I = SetJmp->use_begin(), E = SetJmp->use_end(); I != E; ++I)
-      if (const CallInst *CI = dyn_cast<CallInst>(I))
-        if (CI->getParent()->getParent() == F)
-          return true;
-
-  if (SigSetJmp && !SigSetJmp->use_empty())
-    for (Value::const_use_iterator
-           I = SigSetJmp->use_begin(), E = SigSetJmp->use_end(); I != E; ++I)
-      if (const CallInst *CI = dyn_cast<CallInst>(I))
-        if (CI->getParent()->getParent() == F)
-          return true;
-
-  return false;
-}
-
 /// ScanForSpillSlotRefs - Scan all the machine instructions for spill slot
 /// references and update spill slot weights.
 void StackSlotColoring::ScanForSpillSlotRefs(MachineFunction &MF) {
@@ -757,10 +729,7 @@
   // coloring. The stack could be modified before the longjmp is executed,
   // resulting in the wrong value being used afterwards. (See
   // <rdar://problem/8007500>.)
-  //
-  // FIXME: This goes beyond the setjmp/sigsetjmp functions. Ideally, we should
-  // check for the GCC "returns twice" attribute.
-  if (CheckForSetJmpCall(MF))
+  if (MF.callsSetJmp())
     return false;
 
   // Gather spill slot references