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author | Jakob Stoklund Olesen <stoklund@2pi.dk> | 2009-08-08 21:42:22 +0000 |
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committer | Jakob Stoklund Olesen <stoklund@2pi.dk> | 2009-08-08 21:42:22 +0000 |
commit | 46151de6a0d08184c1bfc90bb39657ff1e21729e (patch) | |
tree | 21b45558c55af07bf1da9158438d5c8d77777533 /lib/Target/Blackfin/BlackfinISelLowering.cpp | |
parent | f7427e558dab6fa21a32003c474ddaa5c8cb6175 (diff) | |
download | external_llvm-46151de6a0d08184c1bfc90bb39657ff1e21729e.zip external_llvm-46151de6a0d08184c1bfc90bb39657ff1e21729e.tar.gz external_llvm-46151de6a0d08184c1bfc90bb39657ff1e21729e.tar.bz2 |
Add support for READCYCLECOUNTER in Blackfin back-end.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@78506 91177308-0d34-0410-b5e6-96231b3b80d8
Diffstat (limited to 'lib/Target/Blackfin/BlackfinISelLowering.cpp')
-rw-r--r-- | lib/Target/Blackfin/BlackfinISelLowering.cpp | 31 |
1 files changed, 31 insertions, 0 deletions
diff --git a/lib/Target/Blackfin/BlackfinISelLowering.cpp b/lib/Target/Blackfin/BlackfinISelLowering.cpp index ebfd61c..fe06d57 100644 --- a/lib/Target/Blackfin/BlackfinISelLowering.cpp +++ b/lib/Target/Blackfin/BlackfinISelLowering.cpp @@ -111,6 +111,9 @@ BlackfinTargetLowering::BlackfinTargetLowering(TargetMachine &TM) setOperationAction(ISD::CTLZ, MVT::i32, Expand); setOperationAction(ISD::CTTZ, MVT::i32, Expand); + // READCYCLECOUNTER needs special type legalization. + setOperationAction(ISD::READCYCLECOUNTER, MVT::i64, Custom); + // We don't have line number support yet. setOperationAction(ISD::DBG_STOPPOINT, MVT::Other, Expand); setOperationAction(ISD::DEBUG_LOC, MVT::Other, Expand); @@ -463,6 +466,34 @@ SDValue BlackfinTargetLowering::LowerOperation(SDValue Op, SelectionDAG &DAG) { } } +void +BlackfinTargetLowering::ReplaceNodeResults(SDNode *N, + SmallVectorImpl<SDValue> &Results, + SelectionDAG &DAG) { + DebugLoc dl = N->getDebugLoc(); + switch (N->getOpcode()) { + default: + llvm_unreachable("Do not know how to custom type legalize this operation!"); + return; + case ISD::READCYCLECOUNTER: { + // The low part of the cycle counter is in CYCLES, the high part in + // CYCLES2. Reading CYCLES will latch the value of CYCLES2, so we must read + // CYCLES2 last. + SDValue TheChain = N->getOperand(0); + SDValue lo = DAG.getCopyFromReg(TheChain, dl, BF::CYCLES, MVT::i32); + SDValue hi = DAG.getCopyFromReg(lo.getValue(1), dl, BF::CYCLES2, MVT::i32); + // Use a buildpair to merge the two 32-bit values into a 64-bit one. + Results.push_back(DAG.getNode(ISD::BUILD_PAIR, dl, MVT::i64, lo, hi)); + // Outgoing chain. If we were to use the chain from lo instead, it would be + // possible to entirely eliminate the CYCLES2 read in (i32 (trunc + // readcyclecounter)). Unfortunately this could possibly delay the CYCLES2 + // read beyond the next CYCLES read, leading to invalid results. + Results.push_back(hi.getValue(1)); + return; + } + } +} + /// getFunctionAlignment - Return the Log2 alignment of this function. unsigned BlackfinTargetLowering::getFunctionAlignment(const Function *F) const { return 2; |