On Wed, Apr 20, 2011 at 12:15 PM, Justin Holewinski <[email protected]> wrote: > On Wed, Apr 20, 2011 at 2:17 PM, Eli Friedman <[email protected]> > wrote: >> >> On Wed, Apr 20, 2011 at 10:58 AM, Justin Holewinski >> <[email protected]> wrote: >> > >> > >> > On Wed, Apr 20, 2011 at 1:52 PM, Eli Friedman <[email protected]> >> > wrote: >> >> >> >> On Wed, Apr 20, 2011 at 10:50 AM, Eli Friedman <[email protected]> >> >> wrote: >> >> > On Wed, Apr 20, 2011 at 10:14 AM, Justin Holewinski >> >> > <[email protected]> wrote: >> >> >> The attached patch adds target triples for the PTX back-end, and >> >> >> adds >> >> >> the >> >> >> currently implemented PTX intrinsics as builtin functions. I would >> >> >> like for >> >> >> someone familiar with the Clang targets/triples and builtins code to >> >> >> review >> >> >> this patch. I have been involved in the PTX back-end for several >> >> >> months >> >> >> now, but this is my first patch to Clang. >> >> > >> >> > + PTXTargetInfo(const std::string& triple) : TargetInfo(triple) { >> >> > + TLSSupported = false; >> >> > + IntWidth = IntAlign = 32; >> >> > + LongWidth = LongLongWidth = LongAlign = LongLongAlign = 64; >> >> > + } >> >> > >> >> > You can skip setting IntWidth/IntAlign/LongLongWidth/LongLongAlign; >> >> > the defaults are correct. >> > >> > Okay, will do. >> > >> >> >> >> > >> >> > + class PTX32TargetInfo : public PTXTargetInfo { >> >> > + public: >> >> > + PTX32TargetInfo(const std::string& triple) : PTXTargetInfo(triple) >> >> > { >> >> > + PointerWidth = PointerAlign = 32; >> >> > + DescriptionString >> >> > + = >> >> > "e-p:32:32-i64:32:32-f64:32:32-v128:32:128-v64:32:64-n32:64"; >> >> > + } >> >> > + }; >> >> > >> >> > The target description string isn't using the same alignment for long >> >> > and for double as the clang TargetInfo. Also, the alignment for v64 >> >> > and v128 looks wrong. >> > >> > Would there be any issue with just removing the v64 and v128 specifiers >> > for >> > now? The back-end does not currently support them. >> >> That's fine. >> >> >> >> >> > >> >> > BUILTIN(__builtin_ptx_read_tid_x, "i", "nc") >> >> > >> >> > The "c" means that the value returned by these builtins never >> >> > changes; >> >> > that doesn't seem right. >> >> > >> > >> > This is an interesting case. I assumed the "const" meant that >> > successive >> > calls to the builtin will return the same value (which is true). >> > However, >> > different threads will see different values. What is the recommended >> > behavior here? For a given piece of C code that will compile down to >> > PTX, >> > it is perfectly valid for constant propagation to eliminate any >> > successive >> > calls. >> >> It should be fine for __builtin_ptx_read_tid_x, but it seems a bit >> weird for __builtin_ptx_read_clock, and very wrong for >> __builtin_ptx_bar_sync. > > Oops, that is a copy-paste error. > >> >> >> >> >> Oh, one more thing: this description unconditionally defines size_t >> >> and friends to a 64-bit type; that isn't wrong, exactly, but probably >> >> not what you want. >> > >> > Where exactly is this defined? I'm not too familiar with Clang's >> > TargetInfo >> > class yet. >> >> SizeType, PtrDiffType, IntPtrType. > > Fixed. > >> >> -Eli > > Attached is an updated patch.
Looks good. -Eli _______________________________________________ cfe-commits mailing list [email protected] http://lists.cs.uiuc.edu/mailman/listinfo/cfe-commits
