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Codechange: [OSX] Prevent the compiler from using SSE4 instructions unless we want to. #8476

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merged 1 commit into from
Jan 2, 2021
Merged

Codechange: [OSX] Prevent the compiler from using SSE4 instructions unless we want to. #8476

merged 1 commit into from
Jan 2, 2021
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michicc
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@michicc michicc commented Jan 2, 2021

Motivation / Problem

Apple clang might default to use SSE4 instructions in the optimizer that don't work on old systems.

Description

Tell the compiler to not use SSE4 in general, except for those files where we specifically want it.

Limitations

We might loose a tiny fraction of performance on newer systems.

Checklist for review

Some things are not automated, and forgotten often. This list is a reminder for the reviewers.

  • The bug fix is important enough to be backported? (label: 'backport requested')
  • This PR affects the save game format? (label 'savegame upgrade')
  • This PR affects the GS/AI API? (label 'needs review: Script API')
    • ai_changelog.hpp, gs_changelog.hpp need updating.
    • The compatibility wrappers (compat_*.nut) need updating.
  • This PR affects the NewGRF API? (label 'needs review: NewGRF')

@michicc
Codechange: [OSX] Prevent the compiler from using SSE4 instructions u…
1aad542 
…nless we want to.

This improves compatibility on older systems. We don't need to disable anything
older, as there are no SSE2-only Macs.
@michicc michicc added OS: MacOS This issue is related to a Mac OS problem size: trivial This Pull Request is trivial labels Jan 2, 2021
TrueBrain
TrueBrain approved these changes Jan 2, 2021
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Let's just ship this, assuming it fixes the problems for older machines :)

@michicc michicc merged commit 5b1fb94 into OpenTTD:master Jan 2, 2021
@michicc michicc deleted the pr/osx_sse branch January 2, 2021 00:26
@michicc michicc mentioned this pull request Jan 4, 2021
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