search for: __vectorcall

...ding more calling conventions unless > there's a really powerful need for one from an ABI perspective. This > sounds more like an optimization than an ABI need. I think that is the case. > What's more, I > worry (a little bit) about confusion that could be caused with the > __vectorcall calling convention (which we do not currently support, > but will need to at some point for MSVC compatibility). What does the __vectorcall does? > What should happen with this code? > > int foo() __attribute__((avx)); > > void bar(int (*fp)()) { > int i = fp(); > } >...

Adding Support For Vectorcall Calling Convention ===================================================== Vectorcall Calling Convention for x64 ---------------------------------------------------- The __vectorcall calling convention specifies that arguments to functions are to be passed in registers, when possible. __vectorcall uses more registers for arguments than __fastcall or the default x64 calling convention use. The __vectorcall calling convention is only supported in native code on x86 and x64 proces...

...lies to __m256 with YMM0-2 vs. YMM0-3. In theory, it would apply to __m512 as well, but currently clang doesn't support passing __m512 in x86 mode at all. ICC has the same behavior as GCC, and it seems that MSVC in 32-bit mode only *allows* up to 3 vector parameters per function (when not using __vectorcall), and these 3 are passed in XMM0-XMM2, which is closer to the GCC behavior. Unfortunately, it seems like there is no ABI specification to support either behavior as "correct": while the x32 ("ILP32") ABI explicitly specifies XMM0-XMM2, the latest version of the i386 psABI is to...

Hi all, I would like to find out whether anyone will find it useful to add an x86- specific calling convention for reducing emission of vzeroupper instructions. Current implementation: vzeroupper is inserted to any functions that use AVX instructions. The insertion points are: 1) before a call instruction; 2) before a return instruction; Background: vzeroupper is an AVX instruction; it is

On 8 Oct 2014, at 18:19, Reid Kleckner <rnk at google.com> wrote: > The one target I know about where varargs are passed differently from normal arguments is aarch64-apple-ios/macosx. After thinking a bit more, I think this forwarding thunk representation works fine even on that target. Typically a forwarding thunk is called indirectly, or at least through a bitcast, so the LLVM IR call