Tail call optimization improvements:

Move platform independent code (lowering of possibly overwritten
arguments, check for tail call optimization eligibility) from
target X86ISelectionLowering.cpp to TargetLowering.h and
SelectionDAGISel.cpp.

Initial PowerPC tail call implementation:

Support ppc32 implemented and tested (passes my tests and
test-suite llvm-test).  
Support ppc64 implemented and half tested (passes my tests).
On ppc tail call optimization is performed if 
  caller and callee are fastcc
  call is a tail call (in tail call position, call followed by ret)
  no variable argument lists or byval arguments
  option -tailcallopt is enabled
Supported:
 * non pic tail calls on linux/darwin
 * module-local tail calls on linux(PIC/GOT)/darwin(PIC)
 * inter-module tail calls on darwin(PIC)
If constraints are not met a normal call will be emitted.

A test checking the argument lowering behaviour on x86-64 was added.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@50477 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 3 insertions, 1 deletions

diff --git a/lib/Target/PowerPC/PPCRegisterInfo.td b/lib/Target/PowerPC/PPCRegisterInfo.td
index dba17fa9f5..86a8c5cef8 100644
--- a/lib/Target/PowerPC/PPCRegisterInfo.td
+++ b/lib/Target/PowerPC/PPCRegisterInfo.td
@@ -346,4 +346,6 @@ def CRBITRC : RegisterClass<"PPC", [i32], 32,
   let CopyCost = -1;
 }
 
-  
+
+def CTRRC : RegisterClass<"PPC", [i32], 32, [CTR]>;
+def CTRRC8 : RegisterClass<"PPC", [i64], 64, [CTR8]>;