[openssl-dev] Usage of assembler code on ARM architectures

Stefan.Neis at t-online.de Stefan.Neis at t-online.de
Thu Mar 12 15:17:38 UTC 2015


               Hi,

While looking at the Configure script, I found that there is the armv4_asm variable, which seems to promise a speedup for ARM architectures (and the "4" in ARMv4 sounds like it should work "everywhere"?).
However, further looking at that Configure file, I see it's only used for "linux-armv4" and "android-armv7", but not for e.g. iphoneos-cross. 
Does that imply you know/suspect it doesn't work anyway? Or does it imply there is no measurable speedup? Or does it just imply you never bothered to actually test it? And in the last case, would you expect it's going to work (or "almost") or would you rather expect it's going to be lots of trouble?
Similar question for Android: You only use the assembler code for the "android-armv7" configuration. For maximum compatibility, I'm usually compiling with "-march=armv5te", which still sounds like using "armv4" assembler should be safe, but for some reason, you're restricting its use to the "android-armv7" configuration which explicitly sets "-march=armv7-a". Why?

          Regards,
                       Stefan




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