Andrew Pinski <pins...@gmail.com> writes: > On Fri, May 11, 2018 at 10:15 AM, Richard Sandiford > <richard.sandif...@linaro.org> wrote: >> There are four optabs for various forms of fused multiply-add: >> fma, fms, fnma and fnms. Of these, only fma had a direct gimple >> representation. For the other three we relied on special pattern- >> matching during expand, although tree-ssa-math-opts.c did have >> some code to try to second-guess what expand would do. >> >> This patch removes the old FMA_EXPR representation of fma and >> introduces four new internal functions, one for each optab. >> IFN_FMA is tied to BUILT_IN_FMA* while the other three are >> independent directly-mapped internal functions. It's then >> possible to do the pattern-matching in match.pd and >> tree-ssa-math-opts.c (via folding) can select the exact >> FMA-based operation. >> >> The patch removes the gimple FE support for __FMA rather than mapping >> it to the internal function. There's no reason now to treat it >> differently from other internal functions (although the FE doesn't >> handle those yet). >> >> The BRIG & HSA parts are a best guess, but seem relatively simple. >> >> The genmatch.c changes are structured to allow ternary ops in which >> the second two rather than the first two operands are commutative. >> A later patch makes use of this. >> >> Tested on aarch64-linux-gnu (with and without SVE), aarch64_be-elf, >> x86_64-linux-gnu and powerpc64le-linux-gnu. OK to install? > > > I think there might be an issue with long double and __float128 > support here (for both PowerPC and x86_64). Please add testcases for > those to show they are not problematic. > What about half float on the aarch64 case? Is that handle correctly? > I did not see a testcase for that case either.
What specific kind of problem are you thinking of? The patch is type-generic and the internal functions are only used if the target advertises the appropriate optab. Targets already check (or should check) that the optabs are used under the appropriate conditions for that target. E.g. gcc.target/powerpc/float128-fma1.c checks for the four cases of __float128 for PowerPC. Thanks, Richard
