[PATCH] D26817: [APFloat] Implement PPCDoubleDouble add and subtract.

[Tim Shen via Phabricator via llvm-commits]

timshen added inline comments.


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Comment at: llvm/lib/Support/APFloat.cpp:4069
+  }
+  llvm_unreachable("");
+}
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echristo wrote:
> kbarton wrote:
> > Why is this an empty string?
> Still an empty string :)
Removed unnecessary llvm_unreachable.


================
Comment at: llvm/lib/Support/APFloat.cpp:3948
+    Status |= zz.add(c, RM);
+    Status |= q.add(z, RM);
+    Status |= q.subtract(a, RM);
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hfinkel wrote:
> It looks here like q = (a - z), but it would be useful to put that in the comment explicitly. Also, is there a reason for computing (a - (q + z)) as -((q + z) - a)?
We compute -((q + z) - a) instead of (a-(q+z)) to avoid creating temporary APFloat variables, thus avoid copying the object. Added a comment about that.


https://reviews.llvm.org/D26817