reserving a physical register ($gp or $28) for that purpose.
This will completely eliminate loads that restore the value of $gp after every
function call, if the register allocator assigns a callee-saved register, or
eliminate unnecessary loads if it assigns a temporary register.
example:
.cpload $25 // set $gp.
...
.cprestore 16 // store $gp to stack slot 16($sp).
...
jalr $25 // function call. clobbers $gp.
lw $gp, 16($sp) // not emitted if callee-saved reg is chosen.
...
lw $2, 4($gp)
...
jalr $25 // function call.
lw $gp, 16($sp) // not emitted if $gp is not live after this instruction.
...
llvm-svn: 151402
argument registers on the callee's stack frame, along with functions that set
and get it.
It is not necessary to add the size of this area when computing stack size in
emitPrologue, since it has already been accounted for in
PEI::calculateFrameObjectOffsets.
llvm-svn: 144549
moving them out of the loop. Previously, stores and loads to a stack frame
object were inserted to accomplish this. Remove the code that was needed to do
this. Patch by Sasa Stankovic.
llvm-svn: 135415
nand), atomic.swap and atomic.cmp.swap, all in i8, i16 and i32 versions.
The intrinsics are implemented by creating pseudo-instructions, which are
then expanded in the method MipsTargetLowering::EmitInstrWithCustomInserter.
Patch by Sasa Stankovic.
llvm-svn: 132323
The following improvements are accomplished as a result of applying this patch:
- Fixed frame objects' offsets (relative to either the virtual frame pointer or
the stack pointer) are set before instruction selection is completed. There is
no need to wait until Prologue/Epilogue Insertion is run to set them.
- Calculation of final offsets of fixed frame objects is straightforward. It is
no longer necessary to assign negative offsets to fixed objects for incoming
arguments in order to distinguish them from the others.
- Since a fixed object has its relative offset set during instruction
selection, there is no need to conservatively set its alignment to 4.
- It is no longer necessary to reorder non-fixed frame objects in
MipsFrameLowering::adjustMipsStackFrame.
llvm-svn: 131915
Instead of awkwardly encoding calling-convention information with ISD::CALL,
ISD::FORMAL_ARGUMENTS, ISD::RET, and ISD::ARG_FLAGS nodes, TargetLowering
provides three virtual functions for targets to override:
LowerFormalArguments, LowerCall, and LowerRet, which replace the custom
lowering done on the special nodes. They provide the same information, but
in a more immediately usable format.
This also reworks much of the target-independent tail call logic. The
decision of whether or not to perform a tail call is now cleanly split
between target-independent portions, and the target dependent portion
in IsEligibleForTailCallOptimization.
This also synchronizes all in-tree targets, to help enable future
refactoring and feature work.
llvm-svn: 78142
carry GlobalBaseReg, and GlobalRetAddr too in Alpha's case. This
eliminates the need for them to search through the
MachineRegisterInfo livein list in order to identify these
virtual registers. EmitLiveInCopies is now the only user of the
virtual register portion of MachineRegisterInfo's livein data.
llvm-svn: 72802
Added fp register clobbering during calls.
Added AsmPrinter support for "fmask", a bitmask that indicates where on the
stack the fp callee saved registers are.
Fixed the stack frame layout for Mips, now the callee saved regs
are in the right stack location (a little documentation about how this
stack frame must look like is present in MipsRegisterInfo.cpp).
This was done using the method MipsRegisterInfo::adjustMipsStackFrame
To be more clear, these are examples of what is solves :
1) FP and RA are also callee saved, and despite they aren't in CSI they
must be saved before the fp callee saved registers.
2) The ABI requires that local varibles are allocated before the callee
saved register area, the opposite behavior from the default allocation.
3) CPU and FPU saved register area must be aligned independent of each
other.
llvm-svn: 54403
important.
- Cleanup in the Subtarget info with addition of new features, not all support
yet, but they allow the future inclusion of features easier. Among new features,
we have : Arch family info (mips1, mips2, ...), ABI info (o32, eabi), 64-bit
integer
and float registers, allegrex vector FPU (VFPU), single float only support.
- TargetMachine now detects allegrex core.
- Added allegrex (Mips32r2) sext_inreg instructions.
- *Added Float Point Instructions*, handling single float only, and
aliased accesses for 32-bit FPUs.
- Some cleanup in FP instruction formats and FP register classes.
- Calling conventions improved to support mips 32-bit EABI.
- Added Asm Printer support for fp cond codes.
- Added support for sret copy to a return register.
- EABI support added into LowerCALL and FORMAL_ARGS.
- MipsFunctionInfo now keeps a virtual register per function to track the
sret on function entry until function ret.
- MipsInstrInfo FP support into methods (isMoveInstr, isLoadFromStackSlot, ...),
FP cond codes mapping and initial FP Branch Analysis.
- Two new Mips SDNode to handle fp branch and compare instructions : FPBrcond,
FPCmp
- MipsTargetLowering : handling different FP classes, Allegrex support, sret
return copy, no homing location within EABI, non 32-bit stack objects
arguments, and asm constraint for float.
llvm-svn: 53146
- Added a function to hold the stack location
where GP must be stored during LowerCALL
- AsmPrinter now emits directives based on
relocation type
- PIC_ set to default relocation type (same as GCC)
llvm-svn: 42779
Akira Hatanaka