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

[Wei Mi via llvm-commits]

wmi added inline comments.


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Comment at: lib/CodeGen/TargetInstrInfo.cpp:547
+        unsigned SubRegSize = TRI->getSubRegIdxSize(SubReg);
+        if (SubRegSize > 0 && !(SubRegSize % 8))
+          OpSize = SubRegSize / 8;
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In which case we will have (SubRegSize % 8) != 0?


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Comment at: lib/Target/X86/X86InstrInfo.cpp:6281
+                                    MachineInstr *LoadMI) const {
+  // We only support folding into loads from stack-slots.
+  if (LoadMI || MO.isDef())
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Why only folding from stack-slot is supported but folding from load is not?


https://reviews.llvm.org/D26521