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author | Owen Anderson <resistor@mac.com> | 2008-08-06 18:36:17 +0000 |
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committer | Owen Anderson <resistor@mac.com> | 2008-08-06 18:36:17 +0000 |
commit | 9b49120408e6c0e10e18ce38cae7120c954fe708 (patch) | |
tree | d34777812b5c07a32e23a33830b7bee53c1318db /lib/CodeGen/StrongPHIElimination.cpp | |
parent | 788d04152a132121dfc04e63382c1e87e7b9607f (diff) | |
download | external_llvm-9b49120408e6c0e10e18ce38cae7120c954fe708.zip external_llvm-9b49120408e6c0e10e18ce38cae7120c954fe708.tar.gz external_llvm-9b49120408e6c0e10e18ce38cae7120c954fe708.tar.bz2 |
Only trim a live interval if the register is not used after the PHI node.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@54421 91177308-0d34-0410-b5e6-96231b3b80d8
Diffstat (limited to 'lib/CodeGen/StrongPHIElimination.cpp')
-rw-r--r-- | lib/CodeGen/StrongPHIElimination.cpp | 7 |
1 files changed, 5 insertions, 2 deletions
diff --git a/lib/CodeGen/StrongPHIElimination.cpp b/lib/CodeGen/StrongPHIElimination.cpp index 545544a..b276e80 100644 --- a/lib/CodeGen/StrongPHIElimination.cpp +++ b/lib/CodeGen/StrongPHIElimination.cpp @@ -896,13 +896,16 @@ bool StrongPHIElimination::runOnMachineFunction(MachineFunction &Fn) { } } else { // Trim live intervals of input registers. They are no longer live into - // this block. + // this block if they died after the PHI. If they lived after it, don't + // trim them because they might have other legitimate uses. for (unsigned i = 1; i < PInstr->getNumOperands(); i += 2) { unsigned reg = PInstr->getOperand(i).getReg(); MachineBasicBlock* MBB = PInstr->getOperand(i+1).getMBB(); LiveInterval& InputI = LI.getInterval(reg); if (MBB != PInstr->getParent() && - InputI.liveAt(LI.getMBBStartIdx(PInstr->getParent()))) + InputI.liveAt(LI.getMBBStartIdx(PInstr->getParent())) && + InputI.expiredAt(LI.getInstructionIndex(PInstr) + + LiveIntervals::InstrSlots::NUM)) InputI.removeRange(LI.getMBBStartIdx(PInstr->getParent()), LI.getInstructionIndex(PInstr), true); |