Improve some comments explaining the "handle kills" stuff better.

llvm-svn: 47395
This commit is contained in:
Bill Wendling 2008-02-20 19:35:34 +00:00
parent 6b30fd310d
commit cf2d1aa485
1 changed files with 4 additions and 2 deletions

View File

@ -296,6 +296,7 @@ void LiveVariables::addRegisterKills(unsigned Reg, MachineInstr *MI,
/// last def/use of the register, or
/// - The register has sub-registers and none of them are killed elsewhere.
///
/// SubKills is filled with the set of sub-registers that are killed elsewhere.
bool LiveVariables::HandlePhysRegKill(unsigned Reg, const MachineInstr *RefMI,
SmallSet<unsigned, 4> &SubKills) {
const unsigned *SubRegs = RegInfo->getImmediateSubRegisters(Reg);
@ -320,8 +321,9 @@ bool LiveVariables::HandlePhysRegKill(unsigned Reg, const MachineInstr *RefMI,
return false;
}
/// HandlePhysRegKill - Calls the recursive version of HandlePhysRegKill. (See
/// above for details.)
/// HandlePhysRegKill - Returns true if the whole register is killed in the
/// machine instruction. If only some of its sub-registers are killed in this
/// machine instruction, then mark those as killed and return false.
bool LiveVariables::HandlePhysRegKill(unsigned Reg, MachineInstr *RefMI) {
SmallSet<unsigned, 4> SubKills;