Enable DeadMachineInstructionElim when Fast-ISel is enabled.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@56604 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/include/llvm/Target/TargetOptions.h b/include/llvm/Target/TargetOptions.h
index fa739507db0f05ecbc3e80ba756dc504e5409086..42011d928c05145cd7628e27c892626c11184245 100644 (file)
--- a/include/llvm/Target/TargetOptions.h
+++ b/include/llvm/Target/TargetOptions.h
@@ -101,6 +101,12 @@ namespace llvm {
   /// DisableJumpTables - This flag indicates jump tables should not be 
   /// generated.
   extern bool DisableJumpTables;
+
+  /// FastISel - This flag enables fast-path instruction selection
+  /// which trades away generated code quality in favor of reducing
+  /// compile time.
+  extern bool EnableFastISel;
+
 } // End llvm namespace
 
 #endif

diff --git a/lib/CodeGen/LLVMTargetMachine.cpp b/lib/CodeGen/LLVMTargetMachine.cpp
index 60925f31ddf0347a4b568ba328d95fefd5ddd92f..936854013693b7a093d54d53b2436ad7091e4a78 100644 (file)
--- a/lib/CodeGen/LLVMTargetMachine.cpp
+++ b/lib/CodeGen/LLVMTargetMachine.cpp
@@ -25,6 +25,10 @@
 #include "llvm/Support/raw_ostream.h"
 using namespace llvm;
 
+namespace llvm {
+  bool EnableFastISel;
+}
+
 static cl::opt<bool> PrintLSR("print-lsr-output", cl::Hidden,
     cl::desc("Print LLVM IR produced by the loop-reduce pass"));
 static cl::opt<bool> PrintISelInput("print-isel-input", cl::Hidden,
@@ -49,6 +53,11 @@ DisablePostRAScheduler("disable-post-RA-scheduler",
                        cl::desc("Disable scheduling after register allocation"),
                        cl::init(true));
 
+static cl::opt<bool, true>
+FastISelOption("fast-isel", cl::Hidden,
+               cl::desc("Enable the experimental \"fast\" instruction selector"),
+               cl::location(EnableFastISel));
+
 FileModel::Model
 LLVMTargetMachine::addPassesToEmitFile(PassManagerBase &PM,
                                        raw_ostream &Out,
@@ -168,6 +177,10 @@ bool LLVMTargetMachine::addCommonCodeGenPasses(PassManagerBase &PM, bool Fast) {
   if (PrintMachineCode)
     PM.add(createMachineFunctionPrinterPass(cerr));
 
+  // If we're using Fast-ISel, clean up the mess.
+  if (EnableFastISel)
+    PM.add(createDeadMachineInstructionElimPass());
+
   if (EnableLICM)
     PM.add(createMachineLICMPass());
 

diff --git a/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp b/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp
index afb290d822ca49658efdea92e128f5153f596c93..9e12a272ad6e4c6833ecdb3282bdae0e0fc54ab8 100644 (file)
--- a/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp
+++ b/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp
@@ -56,9 +56,6 @@ EnableValueProp("enable-value-prop", cl::Hidden);
 static cl::opt<bool>
 EnableLegalizeTypes("enable-legalize-types", cl::Hidden);
 static cl::opt<bool>
-EnableFastISel("fast-isel", cl::Hidden,
-          cl::desc("Enable the experimental \"fast\" instruction selector"));
-static cl::opt<bool>
 EnableFastISelVerbose("fast-isel-verbose", cl::Hidden,
           cl::desc("Enable verbose messages in the experimental \"fast\" "
                    "instruction selector"));