llvm-6502/lib/Target/CellSPU
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
..
CellSDKIntrinsics.td Merge current work back to tree to minimize diffs and drift. Major highlights 2008-02-23 18:41:37 +00:00
Makefile More cleanups for CellSPU: 2008-01-30 02:55:46 +00:00
README.txt More cleanups for CellSPU: 2008-01-30 02:55:46 +00:00
SPU.h More cleanups for CellSPU: 2008-01-30 02:55:46 +00:00
SPU.td Remove attribution from file headers, per discussion on llvmdev. 2007-12-29 20:36:04 +00:00
SPUAsmPrinter.cpp Emit debug info for data-only files on Cell SPU. 2008-07-09 21:25:06 +00:00
SPUCallingConv.td Remove attribution from file headers, per discussion on llvmdev. 2007-12-29 20:36:04 +00:00
SPUFrameInfo.cpp Remove attribution from file headers, per discussion on llvmdev. 2007-12-29 20:36:04 +00:00
SPUFrameInfo.h Bug fixes and updates for CellSPU, syncing up with trunk. Most notable 2008-04-30 00:30:08 +00:00
SPUHazardRecognizers.cpp Remove attribution from file headers, per discussion on llvmdev. 2007-12-29 20:36:04 +00:00
SPUHazardRecognizers.h Remove attribution from file headers, per discussion on llvmdev. 2007-12-29 20:36:04 +00:00
SPUInstrBuilder.h Remove attribution from file headers, per discussion on llvmdev. 2007-12-29 20:36:04 +00:00
SPUInstrFormats.td Merge current work back to tree to minimize diffs and drift. Major highlights 2008-02-23 18:41:37 +00:00
SPUInstrInfo.cpp Pool-allocation for MachineInstrs, MachineBasicBlocks, and 2008-07-07 23:14:23 +00:00
SPUInstrInfo.h Change target-specific classes to use more precise static types. 2008-05-14 01:58:56 +00:00
SPUInstrInfo.td Add necessary 64-bit support so that gcc frontend compiles (mostly). Current 2008-06-02 22:18:03 +00:00
SPUISelDAGToDAG.cpp Add a new function, ReplaceAllUsesOfValuesWith, which handles bulk 2008-07-17 19:10:17 +00:00
SPUISelLowering.cpp Somehow, custom lowering of i64 multiplications got dropped along the way. 2008-07-16 17:17:29 +00:00
SPUISelLowering.h Wrap MVT::ValueType in a struct to get type safety 2008-06-06 12:08:01 +00:00
SPUMachineFunction.h Remove attribution from file headers, per discussion on llvmdev. 2007-12-29 20:36:04 +00:00
SPUNodes.td Add necessary 64-bit support so that gcc frontend compiles (mostly). Current 2008-06-02 22:18:03 +00:00
SPUOperands.td Add necessary 64-bit support so that gcc frontend compiles (mostly). Current 2008-06-02 22:18:03 +00:00
SPURegisterInfo.cpp Trim unnecessary #includes. 2008-07-11 20:38:31 +00:00
SPURegisterInfo.h Move reMaterialize() from TargetRegisterInfo to TargetInstrInfo. 2008-03-31 20:40:39 +00:00
SPURegisterInfo.td Remove attribution from file headers, per discussion on llvmdev. 2007-12-29 20:36:04 +00:00
SPURegisterNames.h Remove attribution from file headers, per discussion on llvmdev. 2007-12-29 20:36:04 +00:00
SPUSchedule.td Remove attribution from file headers, per discussion on llvmdev. 2007-12-29 20:36:04 +00:00
SPUSubtarget.cpp Remove attribution from file headers, per discussion on llvmdev. 2007-12-29 20:36:04 +00:00
SPUSubtarget.h Rewrite tblgen handling of subtarget features so 2008-02-14 23:35:16 +00:00
SPUTargetAsmInfo.cpp Overhaul Cell SPU's addressing mode internals so that there are now 2008-01-29 02:16:57 +00:00
SPUTargetAsmInfo.h Remove attribution from file headers, per discussion on llvmdev. 2007-12-29 20:36:04 +00:00
SPUTargetMachine.cpp Use PassManagerBase instead of FunctionPassManager for functions 2008-03-11 22:29:46 +00:00
SPUTargetMachine.h Change target-specific classes to use more precise static types. 2008-05-14 01:58:56 +00:00

//===- README.txt - Notes for improving CellSPU-specific code gen ---------===//

This code was contributed by a team from the Computer Systems Research
Department in The Aerospace Corporation:

- Scott Michel (head bottle washer and much of the non-floating point
  instructions)
- Mark Thomas (floating point instructions)
- Michael AuYeung (intrinsics)
- Chandler Carruth (LLVM expertise)

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, NONINFRINGEMENT, OR
OTHERWISE.  IN NO EVENT SHALL THE AEROSPACE CORPORATION BE LIABLE FOR DAMAGES
OF ANY KIND OR NATURE WHETHER BASED IN CONTRACT, TORT, OR OTHERWISE ARISING
OUT OF OR IN CONNECTION WITH THE USE OF THE SOFTWARE INCLUDING, WITHOUT
LIMITATION, DAMAGES RESULTING FROM LOST OR CONTAMINATED DATA, LOST PROFITS OR
REVENUE, COMPUTER MALFUNCTION, OR FOR ANY SPECIAL, INCIDENTAL, CONSEQUENTIAL,
OR PUNITIVE  DAMAGES, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGES OR
SUCH DAMAGES ARE FORESEEABLE. 

---------------------------------------------------------------------------
--WARNING--:
--WARNING--: The CellSPU work is work-in-progress and "alpha" quality code.
--WARNING--:

If you are brave enough to try this code or help to hack on it, be sure
to add 'spu' to configure's --enable-targets option, e.g.:

        ./configure <your_configure_flags_here> \
           --enable-targets=x86,x86_64,powerpc,spu

---------------------------------------------------------------------------

TODO:
* Finish branch instructions, branch prediction

  These instructions were started, but only insofar as to get llvm-gcc-4.2's
  crtbegin.ll working (which doesn't.)

* Double floating point support

  This was started. "What's missing?" to be filled in.

* Intrinsics

  Lots of progress. "What's missing/incomplete?" to be filled in.

===-------------------------------------------------------------------------===