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| author | Chris Lattner <sabre@nondot.org> | 2006-05-06 23:05:41 +0000 |
|---|---|---|
| committer | Chris Lattner <sabre@nondot.org> | 2006-05-06 23:05:41 +0000 |
| commit | b9ebacdb4dccd0048b7fc8bcd2559d17e5293d38 (patch) | |
| tree | 72542cc8a484594144eecec5cf883eecf1a4fdc5 /lib/CodeGen/SelectionDAG/SelectionDAG.cpp | |
| parent | 541a24f7af685610838b5a89b2feffc2285937db (diff) | |
constant fold sign_extend_inreg
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@28151 91177308-0d34-0410-b5e6-96231b3b80d8
Diffstat (limited to 'lib/CodeGen/SelectionDAG/SelectionDAG.cpp')
| -rw-r--r-- | lib/CodeGen/SelectionDAG/SelectionDAG.cpp | 10 |
1 files changed, 9 insertions, 1 deletions
diff --git a/lib/CodeGen/SelectionDAG/SelectionDAG.cpp b/lib/CodeGen/SelectionDAG/SelectionDAG.cpp index 4809db4775..60a749df2f 100644 --- a/lib/CodeGen/SelectionDAG/SelectionDAG.cpp +++ b/lib/CodeGen/SelectionDAG/SelectionDAG.cpp @@ -1335,6 +1335,14 @@ SDOperand SelectionDAG::getNode(unsigned Opcode, MVT::ValueType VT, ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N1.Val); ConstantSDNode *N2C = dyn_cast<ConstantSDNode>(N2.Val); if (N1C) { + if (Opcode == ISD::SIGN_EXTEND_INREG) { + int64_t Val = N1C->getValue(); + unsigned FromBits = MVT::getSizeInBits(cast<VTSDNode>(N2)->getVT()); + Val <<= 64-FromBits; + Val >>= 64-FromBits; + return getConstant(Val, VT); + } + if (N2C) { uint64_t C1 = N1C->getValue(), C2 = N2C->getValue(); switch (Opcode) { @@ -1441,7 +1449,7 @@ SDOperand SelectionDAG::getNode(unsigned Opcode, MVT::ValueType VT, } } - // Fold a bunch of operators that + // Fold a bunch of operators when the RHS is undef. if (N2.getOpcode() == ISD::UNDEF) { switch (Opcode) { case ISD::ADD: |