diff options
Diffstat (limited to 'llvm')
| -rw-r--r-- | llvm/include/llvm/Target/TargetLowering.h | 9 | ||||
| -rw-r--r-- | llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp | 6 | ||||
| -rw-r--r-- | llvm/lib/CodeGen/SelectionDAG/TargetLowering.cpp | 13 |
3 files changed, 23 insertions, 5 deletions
diff --git a/llvm/include/llvm/Target/TargetLowering.h b/llvm/include/llvm/Target/TargetLowering.h index c1d0b32f7d7..994480ebc90 100644 --- a/llvm/include/llvm/Target/TargetLowering.h +++ b/llvm/include/llvm/Target/TargetLowering.h @@ -2678,6 +2678,15 @@ public: const SelectionDAG &DAG, unsigned Depth = 0) const; + /// Determine which of the bits of FrameIndex \p FIOp are known to be 0. + /// Default implementation computes low bits based on alignment + /// information. This should preserve known bits passed into it. + virtual void computeKnownBitsForFrameIndex(const SDValue FIOp, + KnownBits &Known, + const APInt &DemandedElts, + const SelectionDAG &DAG, + unsigned Depth = 0) const; + /// This method can be implemented by targets that want to expose additional /// information about sign bits to the DAG Combiner. The DemandedElts /// argument allows us to only collect the minimum sign bits that are shared diff --git a/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp b/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp index e5de280508b..2fb2615b072 100644 --- a/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp +++ b/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp @@ -2893,11 +2893,7 @@ void SelectionDAG::computeKnownBits(SDValue Op, KnownBits &Known, } case ISD::FrameIndex: case ISD::TargetFrameIndex: - if (unsigned Align = InferPtrAlignment(Op)) { - // The low bits are known zero if the pointer is aligned. - Known.Zero.setLowBits(Log2_32(Align)); - break; - } + TLI->computeKnownBitsForFrameIndex(Op, Known, DemandedElts, *this, Depth); break; default: diff --git a/llvm/lib/CodeGen/SelectionDAG/TargetLowering.cpp b/llvm/lib/CodeGen/SelectionDAG/TargetLowering.cpp index fe553bc986a..1f6fafb039e 100644 --- a/llvm/lib/CodeGen/SelectionDAG/TargetLowering.cpp +++ b/llvm/lib/CodeGen/SelectionDAG/TargetLowering.cpp @@ -1288,6 +1288,19 @@ void TargetLowering::computeKnownBitsForTargetNode(const SDValue Op, Known.resetAll(); } +void TargetLowering::computeKnownBitsForFrameIndex(const SDValue Op, + KnownBits &Known, + const APInt &DemandedElts, + const SelectionDAG &DAG, + unsigned Depth) const { + assert(isa<FrameIndexSDNode>(Op) && "expected FrameIndex"); + + if (unsigned Align = DAG.InferPtrAlignment(Op)) { + // The low bits are known zero if the pointer is aligned. + Known.Zero.setLowBits(Log2_32(Align)); + } +} + /// This method can be implemented by targets that want to expose additional /// information about sign bits to the DAG Combiner. unsigned TargetLowering::ComputeNumSignBitsForTargetNode(SDValue Op, |
