[PATCH] D90265: [llvm][StringExtras] Add a fail-able version of `fromHex` and optimize hex digit lookup

[David Blaikie via Phabricator via llvm-commits]

dblaikie added inline comments.


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Comment at: llvm/include/llvm/ADT/StringExtras.h:70-101
+  static unsigned LUT[255] = {
+    /// 0-47: Non hexadecimal digits
+    -1U, -1U, -1U, -1U, -1U, -1U, -1U, -1U, -1U, -1U, -1U, -1U, -1U, -1U, -1U,
+    -1U, -1U, -1U, -1U, -1U, -1U, -1U, -1U, -1U, -1U, -1U, -1U, -1U, -1U, -1U,
+    -1U, -1U, -1U, -1U, -1U, -1U, -1U, -1U, -1U, -1U, -1U, -1U, -1U, -1U, -1U,
+    -1U, -1U, -1U,
+    /// 48-57: `0`-`9` hexadecimal digits
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dexonsmith wrote:
> Can this change be separated out and committed first? It doesn't seem tightly entangled to me...
+1 for this being a separate NFC/perf-only change (would be good to have some perf measurements to support the change too)


Repository:
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  https://reviews.llvm.org/D90265/new/

https://reviews.llvm.org/D90265