Use intrinsics only for LSB/MSB #1479
Closed
Conversation
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
The NO_BSF does not cover any real life use-case today. The only compilers that can compile SF today, with the current Makefile and no source code changes, are either GCC compatible (define __GNUC__) or MSVC compatible (define _MSC_VER). So they all support LSB/MSB intrinsics. Note the (legacy) MSVC/WIN32 case, where we use a 32-bit BSF/BSR solution, as 64-bit intrinsics aren't available there. No functional change.
|
Makefile should be updated too for consistency |
What do you mean? For the ARM case? |
|
@mcostalba: NO_BSF is not controlled by the Makefile. It's controlled by the compiler: @snicolet: There is no impact in ARM case. That's because the compiler is GCC or Clang, hence defined |
snicolet
pushed a commit
that referenced
this pull request
Mar 14, 2018
The NO_BSF does not cover any real life use-case today. The only compilers that can compile SF today, with the current Makefile and no source code changes, are either GCC compatible (define __GNUC__) or MSVC compatible (define _MSC_VER). So they all support LSB/MSB intrinsics. This patch simplifies away the software fall-backs of LSB/MSB that were still in Stockfish code, but unused in any of the officially supported compilers. Note the (legacy) MSVC/WIN32 case, where we use a 32-bit BSF/BSR solution, as 64-bit intrinsics aren't available there. Discussed in: #1447 and: #1479 No functional change.
|
Merged via edf4c07. |
goodkov
pushed a commit
to goodkov/Stockfish
that referenced
this pull request
Jul 21, 2018
The NO_BSF does not cover any real life use-case today. The only compilers that can compile SF today, with the current Makefile and no source code changes, are either GCC compatible (define __GNUC__) or MSVC compatible (define _MSC_VER). So they all support LSB/MSB intrinsics. This patch simplifies away the software fall-backs of LSB/MSB that were still in Stockfish code, but unused in any of the officially supported compilers. Note the (legacy) MSVC/WIN32 case, where we use a 32-bit BSF/BSR solution, as 64-bit intrinsics aren't available there. Discussed in: official-stockfish#1447 and: official-stockfish#1479 No functional change.
Closed
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
The NO_BSF does not cover any real life use-case today. The only compilers that
can compile SF today, with the current Makefile and no source code changes, are
either GCC compatible (define
__GNUC__) or MSVC compatible (define_MSC_VER). Sothey all support LSB/MSB intrinsics.
Note the (legacy) MSVC/WIN32 case, where we use a 32-bit BSF/BSR solution, as
64-bit intrinsics aren't available there.
No functional change.