On Thu, 15 Aug 2019 at 12:56, Richard Henderson <richard.hender...@linaro.org> wrote: > > > > > > > >This patch is fine, but I noticed while reviewing it that tcg/README > >labels both the extrl_i64_i32 and extrh_i64_i32 operations as > >"for 64-bit hosts only". Presumably that's a documentation error, > >since we're not guarding the existing uses of the extrl_i64_i32 > >here with any kind of ifdeffery to restrict them to 64-bit hosts ? > > > > > A documentation unclarity in that the opcodes are for 64-bit hosts. The > tcg_gen_* functions are always available, and expand to INDEX_op_mov_i32 on > 32-bit hosts.
Oh, I see. We should probably split that document out properly into a primary "what you need to know to generate TCG code as a target" (which is the main audience) and "what you need to implement for a TCG backend (which I guess is relevant to fewer people). thanks -- PMM