[PATCH] D138883: [PowerPC] find and reuse ConstantSplatVector to combine constant store into extract and store

[Nemanja Ivanovic via Phabricator via llvm-commits]

nemanjai added a comment.

Sorry, I had unsubmitted comments. Not sure if they still apply.



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Comment at: llvm/lib/Target/PowerPC/PPCISelLowering.cpp:14886
 
+// findAndReuseSplatForConst - Search for opportunity that store constant int/fp
+// shares the same chain with another store constant vector, which is a splat of
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Nit: you don't need the name of the function here.


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Comment at: llvm/lib/Target/PowerPC/PPCISelLowering.cpp:14900
+
+  APInt ConstVal = dyn_cast<ConstantSDNode>(N->getOperand(1))->getAPIntValue();
+  auto StoreSizeInBits = ST->getMemoryVT().getSizeInBits();
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What if `dyn_cast` returns `null` (i.e. if operand 1 is not a constant)?


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Comment at: llvm/lib/Target/PowerPC/PPCISelLowering.cpp:14909-14911
+  APInt BitWidth(8, StoreSizeInBits);
+  if (!BitWidth.isPowerOf2())
+    return SDValue();
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We don't need to construct an `APInt` just to check whether it is a power of 2. You can just use `isPowerOf2_64()` from `MathExtras.h`.


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https://reviews.llvm.org/D138883