On 22.02.2024 18:45, Andrew Pinski wrote:
On Thu, Feb 22, 2024 at 3:56 AM Richard Earnshaw (lists)
<richard.earns...@arm.com> wrote:
On 21/02/2024 18:30, Evgeny Karpov wrote:
+/* X18 reserved for the TEB on Windows. */
+#ifdef TARGET_ARM64_MS_ABI
+# define FIXED_X18 1
+# define CALL_USED_X18 0
+#else
+# define FIXED_X18 0
+# define CALL_USED_X18 1
+#endif
I'm not overly keen on ifdefs like this (and the one below), it can get quite
confusing if we have to support more than a couple of ABIs. Perhaps we could
create a couple of new headers, one for the EABI (which all existing targets
would then need to include) and one for the MS ABI. Then the mingw port would
use that instead of the EABI header.
An alternative is to make all this dynamic, based on the setting of the
aarch64_calling_abi enum and to make the adjustments in
aarch64_conditional_register_usage.
Dynamically might be needed also if we want to support ms_abi
attribute and/or -mabi=ms to support the wine folks.
Wine no longer needs ms_abi, it was needed for PE-in-ELF modules in the
past. We use use proper PE files now, so we need a cross compiler, but
no special attributes. aarch64-w64-mingw32 is already well supported by
Wine when using llvm-mingw, so as soon as GCC properly supports the ABI,
Wine should just work with it, in theory. I didn't try it, but I don't
see things like vararg support in this patchset nor in the repo, so I
assume it won't work yet.
Thanks for the work!
Jacek
