[libc-commits] [PATCH] D113681: [libc] Simplify decimalStringToFloat and hexadecimalStringToFloat in str_to_float.h and improve their performance.

[Tue Ly via Phabricator via libc-commits]

lntue created this revision.
lntue added reviewers: michaelrj, sivachandra.
Herald added subscribers: ecnelises, tschuett.
Herald added a project: libc-project.
lntue requested review of this revision.

Combine two loops in decimalStringToFloat and hexadecimalStringToFloat that extract the digits and re-arrange them a little bit.  This slightly improves the performance of strtof and strtod:
Running libc_str_to_float_comparison_test parse-number-fxx-test_data/data/* on my machine (Ryzen 1700)

- with glibc: ~1.92 seconds
- with current implementation: ~1.78 seconds
- with this change: ~1.67 seconds


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D113681

Files:
  libc/src/__support/str_to_float.h

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