[all-commits] [llvm/llvm-project] 805899: [libc] Change FEnv to use MXCSR as source of truth

[michaelrj-google via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: 805899e68a83916211a164600c3278f3a65b5292
      https://github.com/llvm/llvm-project/commit/805899e68a83916211a164600c3278f3a65b5292
  Author: Michael Jones <michaelrj at google.com>
  Date:   2022-03-23 (Wed, 23 Mar 2022)

  Changed paths:
    M libc/config/windows/entrypoints.txt
    M libc/src/__support/FPUtil/x86_64/FEnvImpl.h
    M libc/test/src/fenv/getenv_and_setenv_test.cpp

  Log Message:
  -----------
  [libc] Change FEnv to use MXCSR as source of truth

This patch primarily fixes the fenv implementation on Windows, since
Windows uses the MXCSR in place of the x87 status registers for storing
information about the floating point environment. This allows FEnv to
work correctly on Windows, and successfully build.

Reviewed By: lntue

Differential Revision: https://reviews.llvm.org/D121839