[openssl/openssl] cfbec3: bn_nist: replace pointer bit-fiddling with ternary

[Alois Klink]

  Branch: refs/heads/openssl-3.1
  Home:   https://github.com/openssl/openssl
  Commit: cfbec3543f7d1475739e49599945e649ef9bb531
      https://github.com/openssl/openssl/commit/cfbec3543f7d1475739e49599945e649ef9bb531
  Author: Alois Klink <alois at aloisklink.com>
  Date:   2023-04-18 (Tue, 18 Apr 2023)

  Changed paths:
    M crypto/bn/bn_nist.c

  Log Message:
  -----------
  bn_nist: replace pointer bit-fiddling with ternary

Bit-fiddling pointers is technically implementation defined behavior
in the C specification so the following code is not supported in all
platforms:

    PTR_SIZE_INT mask;
    void * a, b, c;
    int boolean_flag;

    mask = 0 - boolean_flag;
    /* Not guaranteed to be a valid ptr to a or b on all platforms  */
    a = (void *)
        ((((PTR_SIZE_INT) b & ~mask) | (((PTR_SIZE_INT)) c & mask)));

Using a ternary conditional operator is supported on all platforms
(i.e. `a = boolean_flag ? b : c;`).

On most modern compilers/CPUs, this will be faster, since it will
get converted to a CMOV instruction.

Reviewed-by: Richard Levitte <levitte at openssl.org>
Reviewed-by: Paul Dale <pauli at openssl.org>
(Merged from https://github.com/openssl/openssl/pull/20748)

(cherry picked from commit 326af4ad171b849ba1e76fd425d8f337718c4108)


  Commit: 3eca58faf5a4a3734755c26d1878ca2362ae2dc1
      https://github.com/openssl/openssl/commit/3eca58faf5a4a3734755c26d1878ca2362ae2dc1
  Author: Alois Klink <alois at aloisklink.com>
  Date:   2023-04-18 (Tue, 18 Apr 2023)

  Changed paths:
    M crypto/bn/bn_nist.c

  Log Message:
  -----------
  bn_nist: remove unused type-punning union `u`

We no longer need to cast function pointers to PTR_SIZE_INT.

Reviewed-by: Richard Levitte <levitte at openssl.org>
Reviewed-by: Paul Dale <pauli at openssl.org>
(Merged from https://github.com/openssl/openssl/pull/20748)

(cherry picked from commit f659f7a1c70709caa1727bb0b7f836d170d35bb5)


  Commit: bf64571916ca294a4a52fa8de303c6bea462341d
      https://github.com/openssl/openssl/commit/bf64571916ca294a4a52fa8de303c6bea462341d
  Author: Alois Klink <alois at aloisklink.com>
  Date:   2023-04-18 (Tue, 18 Apr 2023)

  Changed paths:
    M crypto/bn/bn_local.h

  Log Message:
  -----------
  bn_local: remove unused `PTR_SIZE_INT` definition

Reviewed-by: Richard Levitte <levitte at openssl.org>
Reviewed-by: Paul Dale <pauli at openssl.org>
(Merged from https://github.com/openssl/openssl/pull/20748)

(cherry picked from commit dcfeb617477dd957f69e713cbc61fd4dca0f2db4)


Compare: https://github.com/openssl/openssl/compare/c299be277f24...bf64571916ca