[PATCH] D109417: Cost model for VPMemory operations on PowerPC.

[Roland Froese via Phabricator via llvm-commits]

RolandF added inline comments.


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Comment at: llvm/lib/Target/PowerPC/PPCTargetTransformInfo.cpp:1398
+    // will flush a full pipeline about half the time.
+    // The cost when this happens is about 80 cycles.
+    return P9PipelineFlushEstimate / 2;
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I don't follow this reasoning.  Maybe 64-bit data is aligned half the time, but how is that true for char data for instance?


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Comment at: llvm/lib/Target/PowerPC/PPCTargetTransformInfo.cpp:1434
+      NumElems * BaseT::getMemoryOpCost(Opcode, SrcVTy->getScalarType(),
+                                        Alignment, AddressSpace, CostKind);
+  assert(ScalarMemOpInstrCost.isValid() && "Expected valid instruction cost");
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The scalar loads have scalar type results.  I assume if the code is being vectorized and the function of a vector load is being replaced, the results have to go in a vector.  I think there is some insert cost here.


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https://reviews.llvm.org/D109417