[all-commits] [llvm/llvm-project] 6f8033: [libc][NFC] Add supporting class for atof implemen...

[michaelrj-google via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: 6f80339b18da61be986e75b4824ff5b308412ead
      https://github.com/llvm/llvm-project/commit/6f80339b18da61be986e75b4824ff5b308412ead
  Author: Michael Jones <michaelrj at google.com>
  Date:   2021-10-04 (Mon, 04 Oct 2021)

  Changed paths:
    M libc/src/__support/CMakeLists.txt
    A libc/src/__support/high_precision_decimal.h
    M libc/test/src/__support/CMakeLists.txt
    A libc/test/src/__support/high_precision_decimal_test.cpp
    A libc/utils/mathtools/GenerateHPDConstants.py

  Log Message:
  -----------
  [libc][NFC] Add supporting class for atof implementation

This change adds the High Precision Decimal described here:
https://nigeltao.github.io/blog/2020/parse-number-f64-simple.html
It will be used for the atof implementation later, but is complete and
tested now.

The code is inspired by the golang implmentation of the HPD class, which
can be found here: https://github.com/golang/go/blob/release-branch.go1.16/src/strconv/decimal.go

Reviewed By: sivachandra

Differential Revision: https://reviews.llvm.org/D110454