Split x86's ADJCALLSTACK instructions into 32-bit and 64-bit forms.
This allows the 64-bit forms to use+def RSP instead of ESP. This
doesn't fix any real bugs today, but it is more precise and it
makes the debug dumps on x86-64 look more consistent.

Also, add some comments describing the CALL instructions' physreg
operand uses and defs.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@56925 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Target/X86/X86FastISel.cpp b/lib/Target/X86/X86FastISel.cpp
index 74850da..59500ad 100644
--- a/lib/Target/X86/X86FastISel.cpp
+++ b/lib/Target/X86/X86FastISel.cpp
@@ -960,7 +960,8 @@
   unsigned NumBytes = CCInfo.getNextStackOffset();
 
   // Issue CALLSEQ_START
-  BuildMI(MBB, TII.get(X86::ADJCALLSTACKDOWN)).addImm(NumBytes);
+  unsigned AdjStackDown = TM.getRegisterInfo()->getCallFrameSetupOpcode();
+  BuildMI(MBB, TII.get(AdjStackDown)).addImm(NumBytes);
 
   // Process argumenet: walk the register/memloc assignments, inserting
   // copies / loads.
@@ -1051,7 +1052,8 @@
   }
 
   // Issue CALLSEQ_END
-  BuildMI(MBB, TII.get(X86::ADJCALLSTACKUP)).addImm(NumBytes).addImm(0);
+  unsigned AdjStackUp = TM.getRegisterInfo()->getCallFrameDestroyOpcode();
+  BuildMI(MBB, TII.get(AdjStackUp)).addImm(NumBytes).addImm(0);
 
   // Now handle call return value (if any).
   if (RetVT.getSimpleVT() != MVT::isVoid) {