On 8 April 2013 15:49, John Colvin <john.loughran.col...@gmail.com> wrote:
> On Monday, 8 April 2013 at 00:13:29 UTC, Iain Buclaw wrote: > >> If only that logic held water... >> >> GDC actually provided the implementation of iasm to LDC. Reasons why it >> was yanked out. >> - one big ugly x86 special case. >> > > Fair enough, although I see no reason why Ds iasm shouldn't be extended to > support other architectures in the future. > > > - depended on backend headers poisoned for use in the frontend. >> > > when you say poisoned, I presume you mean by the license? > > >From system.h --- /* Front ends should never have to include middle-end headers. Enforce this by poisoning the header double-include protection defines. */ #ifdef IN_GCC_FRONTEND #pragma GCC poison GCC_RTL_H GCC_EXCEPT_H GCC_EXPR_H #endif --- The implementation of IASM required access to rtl.h and expr.h - which is able to give you information about stack layout, etc. > > - frontend should not know or care about what arch it is targeting. >> > > what about all the other arch specific version statements? e.g. > version(ARM) > > They are handled in the backend via a macro: TARGET_CPU_D_BUILTINS, TARGET_OS_D_BUILTINS. If defined, these provide the frontend all version conditions without the frontend having a large portion of code #ifdef'ing all over the place. > - most iasm in druntime/phobos rely on dmd's non-standard calling >> convention. >> - it has been argued in the past that gdc should not define >> D_InlineAsm_X86 if it does not follow dmd's ABI. >> > > Is it a feasible idea to automatically convert dmds inline asm to gcc's > extended inline asm? > > This is what it did. However as stated about it depended on poisoned backend headers in order to get the correct information. Regards -- Iain Buclaw *(p < e ? p++ : p) = (c & 0x0f) + '0';
