Alexandre Julliard : ntdll: Fully initialize the i386 FPU context on ARM64.

[Alexandre Julliard]

Module: wine
Branch: master
Commit: d4f36570cd08260d9ac66c8795f74d87a50a8592
URL:    https://gitlab.winehq.org/wine/wine/-/commit/d4f36570cd08260d9ac66c8795f74d8...

Author: Alexandre Julliard 
Date:   Fri Mar 24 15:44:14 2023 +0100

ntdll: Fully initialize the i386 FPU context on ARM64.

---

dlls/ntdll/unix/signal_arm64.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/dlls/ntdll/unix/signal_arm64.c b/dlls/ntdll/unix/signal_arm64.c
index 2736c43e3b5..da78a7a8036 100644
--- a/dlls/ntdll/unix/signal_arm64.c
+++ b/dlls/ntdll/unix/signal_arm64.c
@@ -1615,6 +1615,7 @@ void DECLSPEC_HIDDEN call_init_thunk( LPTHREAD_START_ROUTINE entry, void *arg, B

if ((i386_context = get_cpu_area( IMAGE_FILE_MACHINE_I386 )))
     {
+        XMM_SAVE_AREA32 *fpu = (XMM_SAVE_AREA32 *)i386_context->ExtendedRegisters;
         i386_context->ContextFlags = CONTEXT_I386_ALL;
         i386_context->Eax = (ULONG_PTR)entry;
         i386_context->Ebx = (arg == peb ? (ULONG_PTR)wow_peb : (ULONG_PTR)arg);
@@ -1627,8 +1628,9 @@ void DECLSPEC_HIDDEN call_init_thunk( LPTHREAD_START_ROUTINE entry, void *arg, B
         i386_context->SegGs = 0x2b;
         i386_context->SegSs = 0x2b;
         i386_context->EFlags = 0x202;
-        i386_context->FloatSave.ControlWord = 0x27f;
-        ((XSAVE_FORMAT *)i386_context->ExtendedRegisters)->MxCsr = 0x1f80;
+        fpu->ControlWord = 0x27f;
+        fpu->MxCsr = 0x1f80;
+        fpux_to_fpu( &i386_context->FloatSave, fpu );
     }
     else if ((arm_context = get_cpu_area( IMAGE_FILE_MACHINE_ARMNT )))
     {