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author | Chris Lattner <sabre@nondot.org> | 2010-09-21 15:58:55 +0000 |
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committer | Chris Lattner <sabre@nondot.org> | 2010-09-21 15:58:55 +0000 |
commit | f16580665589584d3249d8a3c4dd4ea90dfb9e47 (patch) | |
tree | bcc68e39ed4ee0398c94e01cc00acb1eae42c09c /lib/CodeGen | |
parent | 1806161a0bfbc3fa57aa90470d467425ffaf05bb (diff) | |
download | llvm-f16580665589584d3249d8a3c4dd4ea90dfb9e47.tar.gz llvm-f16580665589584d3249d8a3c4dd4ea90dfb9e47.tar.bz2 llvm-f16580665589584d3249d8a3c4dd4ea90dfb9e47.tar.xz |
simplify DAGCombiner::SimplifySelectOps step #2/2.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@114437 91177308-0d34-0410-b5e6-96231b3b80d8
Diffstat (limited to 'lib/CodeGen')
-rw-r--r-- | lib/CodeGen/SelectionDAG/DAGCombiner.cpp | 108 |
1 files changed, 53 insertions, 55 deletions
diff --git a/lib/CodeGen/SelectionDAG/DAGCombiner.cpp b/lib/CodeGen/SelectionDAG/DAGCombiner.cpp index f43fd699dc..65926adbe7 100644 --- a/lib/CodeGen/SelectionDAG/DAGCombiner.cpp +++ b/lib/CodeGen/SelectionDAG/DAGCombiner.cpp @@ -6609,65 +6609,63 @@ bool DAGCombiner::SimplifySelectOps(SDNode *TheSelect, SDValue LHS, RLD->getPointerInfo().getAddrSpace() != 0) return false; + // Check that the select condition doesn't reach either load. If so, + // folding this will induce a cycle into the DAG. If not, this is safe to + // xform, so create a select of the addresses. SDValue Addr; if (TheSelect->getOpcode() == ISD::SELECT) { - // Check that the condition doesn't reach either load. If so, folding - // this will induce a cycle into the DAG. - if ((!LLD->hasAnyUseOfValue(1) || - !LLD->isPredecessorOf(TheSelect->getOperand(0).getNode())) && - (!RLD->hasAnyUseOfValue(1) || - !RLD->isPredecessorOf(TheSelect->getOperand(0).getNode()))) { - Addr = DAG.getNode(ISD::SELECT, TheSelect->getDebugLoc(), - LLD->getBasePtr().getValueType(), - TheSelect->getOperand(0), LLD->getBasePtr(), - RLD->getBasePtr()); - } + SDNode *CondNode = TheSelect->getOperand(0).getNode(); + if ((LLD->hasAnyUseOfValue(1) && LLD->isPredecessorOf(CondNode)) || + (RLD->hasAnyUseOfValue(1) && RLD->isPredecessorOf(CondNode))) + return false; + Addr = DAG.getNode(ISD::SELECT, TheSelect->getDebugLoc(), + LLD->getBasePtr().getValueType(), + TheSelect->getOperand(0), LLD->getBasePtr(), + RLD->getBasePtr()); } else { // Otherwise SELECT_CC - // Check that the condition doesn't reach either load. If so, folding - // this will induce a cycle into the DAG. - if ((!LLD->hasAnyUseOfValue(1) || - (!LLD->isPredecessorOf(TheSelect->getOperand(0).getNode()) && - !LLD->isPredecessorOf(TheSelect->getOperand(1).getNode()))) && - (!RLD->hasAnyUseOfValue(1) || - (!RLD->isPredecessorOf(TheSelect->getOperand(0).getNode()) && - !RLD->isPredecessorOf(TheSelect->getOperand(1).getNode())))) { - Addr = DAG.getNode(ISD::SELECT_CC, TheSelect->getDebugLoc(), - LLD->getBasePtr().getValueType(), - TheSelect->getOperand(0), - TheSelect->getOperand(1), - LLD->getBasePtr(), RLD->getBasePtr(), - TheSelect->getOperand(4)); - } - } - - if (Addr.getNode()) { - SDValue Load; - if (LLD->getExtensionType() == ISD::NON_EXTLOAD) { - Load = DAG.getLoad(TheSelect->getValueType(0), - TheSelect->getDebugLoc(), - // FIXME: Discards pointer info. - LLD->getChain(), Addr, MachinePointerInfo(), - LLD->isVolatile(), LLD->isNonTemporal(), - LLD->getAlignment()); - } else { - Load = DAG.getExtLoad(LLD->getExtensionType(), - TheSelect->getValueType(0), - TheSelect->getDebugLoc(), - // FIXME: Discards pointer info. - LLD->getChain(), Addr, MachinePointerInfo(), - LLD->getMemoryVT(), LLD->isVolatile(), - LLD->isNonTemporal(), LLD->getAlignment()); - } + SDNode *CondLHS = TheSelect->getOperand(0).getNode(); + SDNode *CondRHS = TheSelect->getOperand(1).getNode(); - // Users of the select now use the result of the load. - CombineTo(TheSelect, Load); - - // Users of the old loads now use the new load's chain. We know the - // old-load value is dead now. - CombineTo(LHS.getNode(), Load.getValue(0), Load.getValue(1)); - CombineTo(RHS.getNode(), Load.getValue(0), Load.getValue(1)); - return true; - } + if ((LLD->hasAnyUseOfValue(1) && + (LLD->isPredecessorOf(CondLHS) || LLD->isPredecessorOf(CondRHS))) || + (LLD->hasAnyUseOfValue(1) && + (LLD->isPredecessorOf(CondLHS) || LLD->isPredecessorOf(CondRHS)))) + return false; + + Addr = DAG.getNode(ISD::SELECT_CC, TheSelect->getDebugLoc(), + LLD->getBasePtr().getValueType(), + TheSelect->getOperand(0), + TheSelect->getOperand(1), + LLD->getBasePtr(), RLD->getBasePtr(), + TheSelect->getOperand(4)); + } + + SDValue Load; + if (LLD->getExtensionType() == ISD::NON_EXTLOAD) { + Load = DAG.getLoad(TheSelect->getValueType(0), + TheSelect->getDebugLoc(), + // FIXME: Discards pointer info. + LLD->getChain(), Addr, MachinePointerInfo(), + LLD->isVolatile(), LLD->isNonTemporal(), + LLD->getAlignment()); + } else { + Load = DAG.getExtLoad(LLD->getExtensionType(), + TheSelect->getValueType(0), + TheSelect->getDebugLoc(), + // FIXME: Discards pointer info. + LLD->getChain(), Addr, MachinePointerInfo(), + LLD->getMemoryVT(), LLD->isVolatile(), + LLD->isNonTemporal(), LLD->getAlignment()); + } + + // Users of the select now use the result of the load. + CombineTo(TheSelect, Load); + + // Users of the old loads now use the new load's chain. We know the + // old-load value is dead now. + CombineTo(LHS.getNode(), Load.getValue(0), Load.getValue(1)); + CombineTo(RHS.getNode(), Load.getValue(0), Load.getValue(1)); + return true; } return false; |