llvm-6502/lib/Target/IA64
Dan Gohman e8be6c6391 Add a new function, ReplaceAllUsesOfValuesWith, which handles bulk
replacement of multiple values. This is slightly more efficient
than doing multiple ReplaceAllUsesOfValueWith calls, and theoretically
could be optimized even further. However, an important property of this
new function is that it handles the case where the source value set and
destination value set overlap. This makes it feasible for isel to use
SelectNodeTo in many very common cases, which is advantageous because
SelectNodeTo avoids a temporary node and it doesn't require CSEMap
updates for users of values that don't change position.

Revamp MorphNodeTo, which is what does all the work of SelectNodeTo, to
handle operand lists more efficiently, and to correctly handle a number
of corner cases to which its new wider use exposes it.

This commit also includes a change to the encoding of post-isel opcodes
in SDNodes; now instead of being sandwiched between the target-independent
pre-isel opcodes and the target-dependent pre-isel opcodes, post-isel
opcodes are now represented as negative values. This makes it possible
to test if an opcode is pre-isel or post-isel without having to know
the size of the current target's post-isel instruction set.

These changes speed up llc overall by 3% and reduce memory usage by 10%
on the InstructionCombining.cpp testcase with -fast and -regalloc=local.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@53728 91177308-0d34-0410-b5e6-96231b3b80d8
2008-07-17 19:10:17 +00:00
..
IA64.h Remove attribution from file headers, per discussion on llvmdev. 2007-12-29 20:36:04 +00:00
IA64.td Remove attribution from file headers, per discussion on llvmdev. 2007-12-29 20:36:04 +00:00
IA64AsmPrinter.cpp Add CommonLinkage; currently tentative definitions 2008-05-14 20:12:51 +00:00
IA64Bundling.cpp Remove attribution from file headers, per discussion on llvmdev. 2007-12-29 20:36:04 +00:00
IA64InstrBuilder.h Remove attribution from file headers, per discussion on llvmdev. 2007-12-29 20:36:04 +00:00
IA64InstrFormats.td Remove attribution from file headers, per discussion on llvmdev. 2007-12-29 20:36:04 +00:00
IA64InstrInfo.cpp Pool-allocation for MachineInstrs, MachineBasicBlocks, and 2008-07-07 23:14:23 +00:00
IA64InstrInfo.h Change target-specific classes to use more precise static types. 2008-05-14 01:58:56 +00:00
IA64InstrInfo.td Replace all target specific implicit def instructions with a target independent one: TargetInstrInfo::IMPLICIT_DEF. 2008-03-15 00:03:38 +00:00
IA64ISelDAGToDAG.cpp Add a new function, ReplaceAllUsesOfValuesWith, which handles bulk 2008-07-17 19:10:17 +00:00
IA64ISelLowering.cpp Split ISD::LABEL into ISD::DBG_LABEL and ISD::EH_LABEL, eliminating 2008-07-01 00:05:16 +00:00
IA64ISelLowering.h Replace some std::vectors that showed up in heap profiling with 2008-06-30 20:31:15 +00:00
IA64MachineFunctionInfo.h Remove trailing whitespace 2005-04-21 23:13:11 +00:00
IA64RegisterInfo.cpp Pool-allocation for MachineInstrs, MachineBasicBlocks, and 2008-07-07 23:14:23 +00:00
IA64RegisterInfo.h Move reMaterialize() from TargetRegisterInfo to TargetInstrInfo. 2008-03-31 20:40:39 +00:00
IA64RegisterInfo.td make sure ar.pfs is in a register class, this fixes test/CodeGen/IA64/ret-0.ll 2008-03-09 20:12:44 +00:00
IA64TargetAsmInfo.cpp Remove attribution from file headers, per discussion on llvmdev. 2007-12-29 20:36:04 +00:00
IA64TargetAsmInfo.h Remove attribution from file headers, per discussion on llvmdev. 2007-12-29 20:36:04 +00:00
IA64TargetMachine.cpp Clean up the use of static and anonymous namespaces. This turned up 2008-05-13 00:00:25 +00:00
IA64TargetMachine.h Change target-specific classes to use more precise static types. 2008-05-14 01:58:56 +00:00
Makefile remove attribution from lib Makefiles. 2007-12-29 20:09:26 +00:00
README Stuff noticed while grepping code 2008-02-11 23:47:56 +00:00

TODO:
  - Un-bitrot ISel
  - Hook up If-Conversion a la ARM target
  - Hook up all branch analysis functions
  - Instruction scheduling
  - Bundling
  - Dynamic Optimization
  - Testing and bugfixing
  - stop passing FP args in both FP *and* integer regs when not required
  - allocate low (nonstacked) registers more aggressively
  - clean up and thoroughly test the isel patterns.
  - fix stacked register allocation order: (for readability) we don't want
    the out? registers being the first ones used
  - fix up floating point
    (nb http://gcc.gnu.org/wiki?pagename=ia64%20floating%20point )
  - bundling!
    (we will avoid the mess that is:
     http://gcc.gnu.org/ml/gcc/2003-12/msg00832.html )
  - instruction scheduling (hmmmm! ;)
  - counted loop support
  - make integer + FP mul/div more clever (we have fixed pseudocode atm)
  - track and use comparison complements

INFO:
  - we are strictly LP64 here, no support for ILP32 on HP-UX. Linux users
    don't need to worry about this.
  - i have instruction scheduling/bundling pseudocode, that really works
    (has been tested, albeit at the perl-script level).
    so, before you go write your own, send me an email!

KNOWN DEFECTS AT THE CURRENT TIME:
  - C++ vtables contain naked function pointers, not function descriptors,
  which is bad. see http://llvm.cs.uiuc.edu/bugs/show_bug.cgi?id=406
  - varargs are broken
  - alloca doesn't work (indeed, stack frame layout is bogus)
  - no support for big-endian environments
  - (not really the backend, but...) the CFE has some issues on IA64.
    these will probably be fixed soon.
  
ACKNOWLEDGEMENTS:
  - Chris Lattner (x100)
  - Other LLVM developers ("hey, that looks familiar")

CONTACT:
  - You can email me at duraid@octopus.com.au. If you find a small bug,
    just email me. If you find a big bug, please file a bug report
    in bugzilla! http://llvm.cs.uiuc.edu is your one stop shop for all
    things LLVM.