Do not use $gp as a dedicated global register if the target ABI is not O32.

llvm-svn: 155522

Convert more uses of XXXRegisterClass to &XXXRegClass. No functional change since they are equivalent.

llvm-svn: 155188

remove blanks, and some code format

llvm-svn: 151625

Add an option to use a virtual register as the global base register instead of
reserving a physical register ($gp or $28) for that purpose.

This will completely eliminate loads that restore the valu

Add an option to use a virtual register as the global base register instead of
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

show more ...

remove Emacs-tag form .cpp files in Mips Backend, and fix some typo.

llvm-svn: 150805

Unweaken vtables as per http://llvm.org/docs/CodingStandards.html#ll_virtual_anch

llvm-svn: 146960