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| author | Evan Cheng <evan.cheng@apple.com> | 2007-06-19 00:02:56 +0000 |
|---|---|---|
| committer | Evan Cheng <evan.cheng@apple.com> | 2007-06-19 00:02:56 +0000 |
| commit | 49892af2643cb81d33209a5f30ba02a04d6d52bc (patch) | |
| tree | 325a0bdd7d08ce7066b7c64af76a80569f59ccc8 | |
| parent | d2e8442a1364ed945f11dc35d3fd905957895723 (diff) | |
| download | external_llvm-49892af2643cb81d33209a5f30ba02a04d6d52bc.zip external_llvm-49892af2643cb81d33209a5f30ba02a04d6d52bc.tar.gz external_llvm-49892af2643cb81d33209a5f30ba02a04d6d52bc.tar.bz2 | |
Look for VECTOR_SHUFFLE that's identity operation on either LHS or RHS. This can happen before DAGCombiner catches it.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@37636 91177308-0d34-0410-b5e6-96231b3b80d8
| -rw-r--r-- | lib/Target/X86/X86ISelLowering.cpp | 21 |
1 files changed, 19 insertions, 2 deletions
diff --git a/lib/Target/X86/X86ISelLowering.cpp b/lib/Target/X86/X86ISelLowering.cpp index f8b6cea..2b92c9e 100644 --- a/lib/Target/X86/X86ISelLowering.cpp +++ b/lib/Target/X86/X86ISelLowering.cpp @@ -1954,6 +1954,16 @@ bool X86::isMOVSLDUPMask(SDNode *N) { return HasHi; } +/// isIdentityMask - Return true if the specified VECTOR_SHUFFLE operand +/// specifies a identity operation on the LHS or RHS. +static bool isIdentityMask(SDNode *N, bool RHS = false) { + unsigned NumElems = N->getNumOperands(); + for (unsigned i = 0; i < NumElems; ++i) + if (!isUndefOrEqual(N->getOperand(i), i + (RHS ? NumElems : 0))) + return false; + return true; +} + /// isSplatMask - Return true if the specified VECTOR_SHUFFLE operand specifies /// a splat of a single element. static bool isSplatMask(SDNode *N) { @@ -2630,6 +2640,11 @@ X86TargetLowering::LowerVECTOR_SHUFFLE(SDOperand Op, SelectionDAG &DAG) { if (isZeroShuffle(Op.Val)) return getZeroVector(VT, DAG); + if (isIdentityMask(PermMask.Val)) + return V1; + else if (isIdentityMask(PermMask.Val, true)) + return V2; + if (isSplatMask(PermMask.Val)) { if (NumElems <= 4) return Op; // Promote it to a v4i32 splat. @@ -4316,12 +4331,14 @@ X86TargetLowering::isShuffleMaskLegal(SDOperand Mask, MVT::ValueType VT) const { // Only do shuffles on 128-bit vector types for now. if (MVT::getSizeInBits(VT) == 64) return false; return (Mask.Val->getNumOperands() <= 4 || + isIdentityMask(Mask.Val) || + isIdentityMask(Mask.Val, true) || isSplatMask(Mask.Val) || isPSHUFHW_PSHUFLWMask(Mask.Val) || X86::isUNPCKLMask(Mask.Val) || + X86::isUNPCKHMask(Mask.Val) || X86::isUNPCKL_v_undef_Mask(Mask.Val) || - X86::isUNPCKH_v_undef_Mask(Mask.Val) || - X86::isUNPCKHMask(Mask.Val)); + X86::isUNPCKH_v_undef_Mask(Mask.Val)); } bool X86TargetLowering::isVectorClearMaskLegal(std::vector<SDOperand> &BVOps, |