[PATCH] D47059: [InstCombine] Calloc-ed strings optimizations

[Dávid Bolvanský via Phabricator via llvm-commits]

xbolva00 added inline comments.


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Comment at: lib/Transforms/Utils/SimplifyLibCalls.cpp:215
+    B.CreateMemCpy(Dst, 1, Src, 1,
+                   ConstantInt::get(DL.getIntPtrType(CI->getContext()), Len));
+    return Dst;
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bkramer wrote:
> What if strlen(Src) < Len?
That is ok
Len < SrcLen case is handled below...
and then we  return emitStrLenMemCpy(Src, Dst, SrcLen, B);
  


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Comment at: lib/Transforms/Utils/SimplifyLibCalls.cpp:207
 
+  // strncat("\0", str, len) -> strncpy("\0", str, len))
+  uint64_t DstLen = GetStringLength(Dst, TLI);
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bkramer wrote:
> Is this correct? strncpy fills the rest of the string with null bytes, strncat does not.
Good point. So we can do nothing at all in this case? or use memcpy + store null byte?


https://reviews.llvm.org/D47059