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a virtual register to eliminate a frame index, it can return that register and the constant stored there to PEI to track. When scavenging to allocate for those registers, PEI then tracks the last-used register and value, and if it is still available and matches the value for the next index, reuses the existing value rather and removes the re-materialization instructions. Fancier tracking and adjustment of scavenger allocations to keep more values live for longer is possible, but not yet implemented and would likely be better done via a different, less special-purpose, approach to the problem. eliminateFrameIndex() is modified so the target implementations can return the registers they wish to be tracked for reuse. ARM Thumb1 implements and utilizes the new mechanism. All other targets are simply modified to adjust for the changed eliminateFrameIndex() prototype. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@83467 91177308-0d34-0410-b5e6-96231b3b80d8 |
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.. | ||
AsmPrinter | ||
TargetInfo | ||
CMakeLists.txt | ||
DelaySlotFiller.cpp | ||
FPMover.cpp | ||
Makefile | ||
README.txt | ||
Sparc.h | ||
Sparc.td | ||
SparcCallingConv.td | ||
SparcInstrFormats.td | ||
SparcInstrInfo.cpp | ||
SparcInstrInfo.h | ||
SparcInstrInfo.td | ||
SparcISelDAGToDAG.cpp | ||
SparcISelLowering.cpp | ||
SparcISelLowering.h | ||
SparcMachineFunctionInfo.h | ||
SparcMCAsmInfo.cpp | ||
SparcMCAsmInfo.h | ||
SparcRegisterInfo.cpp | ||
SparcRegisterInfo.h | ||
SparcRegisterInfo.td | ||
SparcSubtarget.cpp | ||
SparcSubtarget.h | ||
SparcTargetMachine.cpp | ||
SparcTargetMachine.h |
To-do ----- * Keep the address of the constant pool in a register instead of forming its address all of the time. * We can fold small constant offsets into the %hi/%lo references to constant pool addresses as well. * When in V9 mode, register allocate %icc[0-3]. * Add support for isel'ing UMUL_LOHI instead of marking it as Expand. * Emit the 'Branch on Integer Register with Prediction' instructions. It's not clear how to write a pattern for this though: float %t1(int %a, int* %p) { %C = seteq int %a, 0 br bool %C, label %T, label %F T: store int 123, int* %p br label %F F: ret float undef } codegens to this: t1: save -96, %o6, %o6 1) subcc %i0, 0, %l0 1) bne .LBBt1_2 ! F nop .LBBt1_1: ! T or %g0, 123, %l0 st %l0, [%i1] .LBBt1_2: ! F restore %g0, %g0, %g0 retl nop 1) should be replaced with a brz in V9 mode. * Same as above, but emit conditional move on register zero (p192) in V9 mode. Testcase: int %t1(int %a, int %b) { %C = seteq int %a, 0 %D = select bool %C, int %a, int %b ret int %D } * Emit MULX/[SU]DIVX instructions in V9 mode instead of fiddling with the Y register, if they are faster. * Codegen bswap(load)/store(bswap) -> load/store ASI * Implement frame pointer elimination, e.g. eliminate save/restore for leaf fns. * Fill delay slots