Zubin pushed to branch wip/testsuite-validate-regparm at Glasgow Haskell Compiler / GHC

Commits:

• 4ccb6634
  by Zubin Duggal at 2026-06-10T21:54:27+05:30

  rts: fix validate build with gcc 16. `__attribute__((regparm(1)))` is ignored on x86_64 and now
  gcc warns that it is ignored:
  
  rts/sm/Evac.h:35:1: error:
       error: ‘regparm’ attribute ignored [-Werror=attributes]
  
  See https://gcc.gnu.org/git/?p=gcc.git;a=commit;h=ccead81bbc39668376eb5cf47066acb446cc43f3
  
  Fixes #27366
  

1 changed file:

• rts/sm/Evac.h

Changes:

 //         registers EAX, EDX, and ECX instead of on the stack. Functions that

 //         take a variable number of arguments will continue to be passed all of

 //         their arguments on the stack.

-#if defined(x86_64_HOST_ARCH) || defined(i386_HOST_ARCH)

+// On x86-64 the attribute has no effect (the first argument is already

+// passed in a register) and GCC 16 warns that it is ignored.

+#if defined(i386_HOST_ARCH)

 #define REGPARM1 __attribute__((regparm(1)))

 #else

 #define REGPARM1