[PATCH] D26521: [X86] Allow folding of reloads from stack slots when loading a subreg of the spilled reg

[Matthias Braun via llvm-commits]

MatzeB added inline comments.


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Comment at: include/llvm/Target/TargetInstrInfo.h:820-828
+  /// Check whether the target can fold a load that feeds a subreg operand
+  /// (or a subreg operand that feeds a store).
+  /// For stores, LoadMI is always null. For loads, LoadMI is non-null if
+  /// we're trying to fold an existing load instruction, and null if we are
+  /// trying to fold a load
+  virtual bool isSubregFoldable(MachineOperand &MO,
+                                MachineInstr *LoadMI) const {
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Shouldn't we better fix the existing foldMemoryOperand() implementations in the targets instead of adding more API? A "fix" in the sense to actually check the SubReg and return nullptr if it is set would be enough.


https://reviews.llvm.org/D26521