Don't insert branch hint lables that are never used.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@138630 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Kalle Raiskila 2011-08-26 10:14:56 +00:00
parent 5a18f20dab
commit 54f8a9f54d
2 changed files with 0 additions and 23 deletions

View File

@ -181,18 +181,6 @@ void SPUFrameLowering::emitPrologue(MachineFunction &MF) const {
MachineLocation FPSrc(MachineLocation::VirtualFP);
Moves.push_back(MachineMove(ReadyLabel, FPDst, FPSrc));
}
} else {
// This is a leaf function -- insert a branch hint iff there are
// sufficient number instructions in the basic block. Note that
// this is just a best guess based on the basic block's size.
if (MBB.size() >= (unsigned) SPUFrameLowering::branchHintPenalty()) {
MachineBasicBlock::iterator MBBI = MBB.getLastNonDebugInstr();
dl = MBBI->getDebugLoc();
// Insert terminator label
BuildMI(MBB, MBBI, dl, TII.get(SPU::PROLOG_LABEL))
.addSym(MMI.getContext().CreateTempSymbol());
}
}
}

View File

@ -74,17 +74,6 @@ namespace llvm {
static int FItoStackOffset(int frame_index) {
return frame_index * stackSlotSize();
}
//! Number of instructions required to overcome hint-for-branch latency
/*!
HBR (hint-for-branch) instructions can be inserted when, for example,
we know that a given function is going to be called, such as printf(),
in the control flow graph. HBRs are only inserted if a sufficient number
of instructions occurs between the HBR and the target. Currently, HBRs
take 6 cycles, ergo, the magic number 6.
*/
static int branchHintPenalty() {
return 6;
}
};
}