[PATCH] D58869: [X86] Allow 8-bit INC/DEC to be converted to LEA.

[Craig Topper via Phabricator via llvm-commits]

craig.topper added a comment.

llc always uses "generic" as the cpu by default. With some special code to force "sse2" on 64-bit. Clang makes a platform specific decision. "pentium4" and "x86-64" are the 32-bit and 64-bit defaults for linux. Macs default to "yonah" and "core2" for 32-bit and 64-bit respectively. Less sure about other platforms. These are intended to enable mininum ISAs, but are also affecting our tuning decisions.

We should maybe look into making more tuning cpus for clang to use. Or we should support -mtune. So we can have separate default ISAs and tuning flags.


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  https://reviews.llvm.org/D58869/new/

https://reviews.llvm.org/D58869