On Fri, Mar 1, 2019 at 2:37 PM Jason E. Aten <j.e.a...@gmail.com> wrote: > > On Friday, March 1, 2019 at 4:13:49 PM UTC-6, Ian Lance Taylor wrote: >> >> Go assembly code is compiled by the Go assembler, cmd/asm. The author >> of the assembly code is required to specify how much stack space the >> assembly function requires, in the TEXT pseudo-op that introduces the >> function. For more about this, see https://golang.org/doc/asm. The >> cmd/asm program will use that user declaration to insert a function >> prologue that ensures that enough stack space is available, copying >> the stack if necessary. The cmd/asm program will also produce a stack >> map that the garbage collector will use when tracing back the stack; >> in practice it's quite difficult for the assembler code to define this >> stack map as anything other than "this stack contains no pointers", >> but see runtime/funcdata.h. >> >> In any case, your Fortran 90 code will have none of that information. >> Of course, if you know the exact stack usage of your Fortran code, and >> if the code never stores pointers on the stack, then you could with >> some effort write Go assembly code that defines the appropriate stack >> information and then calls the Fortran code. I think that would, but >> it would require a lot of manual hand-holding. > > > I was thinking I could write a prelude and then launch into the .f90 > compiled routines... that I manually inline > but I see that the assembler is a little higher level than actual amd64 > machine code. > > But there > does appear to be a BYTE escape hatch in the assembler. So if I compile my > .f90 to machine code and then run > through each byte and generate a BYTE instruction to the Go assembler, would > that (at least in theory), let > me call the .f90 code? (Ignoring for the moment that I need to get the > parameters passed in from Go to .f90 in > a way that the .f90 code expects; I think I will have to hand-craft some > assembly glue to make that work of course.)
In theory, sure, as long as you accommodate the difference in calling convention and accurately record the stack requirements. Ian -- You received this message because you are subscribed to the Google Groups "golang-nuts" group. To unsubscribe from this group and stop receiving emails from it, send an email to golang-nuts+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout.
