* Move stub allocation inside the JITEmitter, instead of exposing a

way for each TargetJITInfo subclass to allocate its own stubs. This
means stubs aren't as exactly-sized anymore, but it lets us get rid of
TargetJITInfo::emitFunctionStubAtAddr(), which lets ARM and PPC
support the eager JIT, fixing http://llvm.org/PR4816.

* Rename the JITEmitter's stub creation functions to describe the kind
of stub they create. So far, all of them create lazy-compilation
stubs, but they sometimes get used when far-call stubs are needed.
Fixing http://llvm.org/PR5201 will involve fixing this.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@89715 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 17 insertions, 10 deletions

diff --git a/include/llvm/Target/TargetJITInfo.h b/include/llvm/Target/TargetJITInfo.h
index 809f1830ab..7208a8dc44 100644
--- a/include/llvm/Target/TargetJITInfo.h
+++ b/include/llvm/Target/TargetJITInfo.h
@@ -18,6 +18,7 @@
 #define LLVM_TARGET_TARGETJITINFO_H
 
 #include <cassert>
+#include "llvm/Support/ErrorHandling.h"
 #include "llvm/System/DataTypes.h"
 
 namespace llvm {
@@ -48,22 +49,28 @@ namespace llvm {
       return 0;
     }
 
+    /// Records the required size and alignment for a call stub in bytes.
+    struct StubLayout {
+      size_t Size;
+      size_t Alignment;
+    };
+    /// Returns the maximum size and alignment for a call stub on this target.
+    virtual StubLayout getStubLayout() {
+      llvm_unreachable("This target doesn't implement getStubLayout!");
+      StubLayout Result = {0, 0};
+      return Result;
+    }
+
     /// emitFunctionStub - Use the specified JITCodeEmitter object to emit a
     /// small native function that simply calls the function at the specified
-    /// address.  Return the address of the resultant function.
-    virtual void *emitFunctionStub(const Function* F, void *Fn,
+    /// address.  The JITCodeEmitter must already have storage allocated for the
+    /// stub.  Return the address of the resultant function, which may have been
+    /// aligned from the address the JCE was set up to emit at.
+    virtual void *emitFunctionStub(const Function* F, void *Target,
                                    JITCodeEmitter &JCE) {
       assert(0 && "This target doesn't implement emitFunctionStub!");
       return 0;
     }
-    
-    /// emitFunctionStubAtAddr - Use the specified JITCodeEmitter object to
-    /// emit a small native function that simply calls Fn. Emit the stub into
-    /// the supplied buffer.
-    virtual void emitFunctionStubAtAddr(const Function* F, void *Fn,
-                                        void *Buffer, JITCodeEmitter &JCE) {
-      assert(0 && "This target doesn't implement emitFunctionStubAtAddr!");
-    }
 
     /// getPICJumpTableEntry - Returns the value of the jumptable entry for the
     /// specific basic block.