On Thursday, 15 November 2018 at 21:32:10 UTC, pineapple wrote:
On the less positive side: I still have no clue how to return my 16-byte struct. The Microsoft x64 ABI documentation I've seen so far explains how return values of 8 bytes and fewer work, but haven't explained how larger return values work. The obvious answer of "RAX or EAX contains a pointer" is either not working or my asm is wrong. (The latter is certainly a possibility.)
The MS docs are complete IIRC. The pointer to the pre-allocated result of your 16-bytes struct is passed in RCX. If unsure, just reverse-engineer what you need: type it down in normal D and analyze the generated assembly. You can even do so online via run.dlang.io (https://run.dlang.io/is/rhsDBF); just select LDC and add `-mtriple=x86_64-pc-windows-msvc` to generate Win64 assembly. Note that run.dlang.io displays AT&T-style asm, not the Intel one. You can use LDC offline via `-output-s -x86-asm-syntax=intel` to generate a .s file with Intel syntax.
