Constant-time code on POWER9 #771

1. 
   real-or-random commented at 10:27 pm on July 24, 2020: contributor

   GCC 9.2.1 on POWER9 emits a lot of branches for carries in the 32-bit scalar code. :( The issue seems to be similar to the one in the ECDH code. Those comparisons aren’t reliably turned into constant time assembly.

   Originally posted by @gmaxwell in #708 (comment)

2. 
   real-or-random commented at 10:27 pm on July 24, 2020: contributor

   See also http://gnusha.org/secp256k1/2020-01-11.log at 11:29 and 11:37
3. real-or-random cross-referenced this on Jul 24, 2020 from issue Improve constant-timeness on PowerPC by real-or-random
4. real-or-random referenced this in commit 10a4b2b34a on Jul 26, 2020
5. real-or-random referenced this in commit 5b196338f0 on Jul 26, 2020
6. real-or-random closed this on Jul 28, 2020

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7. real-or-random referenced this in commit 214cb3c321 on Jul 28, 2020
8. real-or-random cross-referenced this on Dec 3, 2021 from issue -Wunused-parameter warnings when cross-compiling for riscv64-linux-gnu by hebasto

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