[PATCH] D154725: [SimplifyLibCalls] Fold strcmp for short string literals

[Maksim Kita via Phabricator via llvm-commits]

kitaisreal added inline comments.


================
Comment at: llvm/lib/Transforms/Utils/SimplifyLibCalls.cpp:576
+    if (Str2.size() == 1) {
+      return FirstCharacterSub;
+    }
----------------
nikic wrote:
> This will return an incorrect result if the first character of Str1 and Str2 is the same, but Str1 has length greater than one.
Updated implementation.


================
Comment at: llvm/lib/Transforms/Utils/SimplifyLibCalls.cpp:581
+        B.CreateLoad(B.getInt8Ty(),
+                     B.CreateConstInBoundsGEP1_32(B.getInt8Ty(), Str1P, 1)),
+        B.getInt32Ty(), true);
----------------
nikic wrote:
> This may perform an out of bounds access for zero-length strings.
Updated implementation.


CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D154725/new/

https://reviews.llvm.org/D154725