FPU: Keep SSE state in backends even if it doesn't change.

dosemu2 · Jan 27, 2023 · 99071c3 · 99071c3
1 parent f587481
commit 99071c3
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Showing 4 changed files with 17 additions and 16 deletions.
diff --git a/src/base/emu-i386/do_vm86.c b/src/base/emu-i386/do_vm86.c
@@ -487,17 +487,15 @@ static int true_vm86(union vm86_union *x)
 
 void true_vm86_set_fpu_state(const emu_fpstate *fpstate)
 {
-    if (config.cpufxsr)
-        true_vm86_fxsave = *fpstate;
-    else
+    true_vm86_fxsave = *fpstate;
+    if (!config.cpufxsr)
         fxsave_to_fsave(fpstate, &true_vm86_fsave);
 }
 
 void true_vm86_get_fpu_state(emu_fpstate *fpstate)
 {
-    if (config.cpufxsr)
-        *fpstate = true_vm86_fxsave;
-    else
+    *fpstate = true_vm86_fxsave;
+    if (!config.cpufxsr)
         fsave_to_fxsave(&true_vm86_fsave, fpstate);
 }
 #endif

diff --git a/src/base/emu-i386/simx86/cpu-emu.c b/src/base/emu-i386/simx86/cpu-emu.c
@@ -583,24 +583,23 @@ void Cpu2Reg (void)
 
 void e_set_fpu_state(const emu_fpstate *fpstate)
 {
+  TheCPU._fpstate = *fpstate;
   if (CONFIG_CPUSIM)
     fp87_load_fpstate(fpstate);
   else {
     // unmasked exception settings are emulated
     TheCPU.fpuc = fpstate->cwd;
-    TheCPU._fpstate = *fpstate;
     TheCPU._fpstate.cwd |= 0x3f;
   }
 }
 
 void e_get_fpu_state(emu_fpstate *fpstate)
 {
+  *fpstate = TheCPU._fpstate;
   if (CONFIG_CPUSIM)
     fp87_save_fpstate(fpstate);
-  else {
-    *fpstate = TheCPU._fpstate;
+  else
     fpstate->cwd = (fpstate->cwd & ~0x3f) | (TheCPU.fpuc & 0x3f);
-  }
 }
 
 /* ======================================================================= */

diff --git a/src/dosext/dpmi/dnative/dnative.c b/src/dosext/dpmi/dnative/dnative.c
@@ -76,6 +76,9 @@ static void convert_from_fxsr(fpregset_t fptr,
 		  "size mismatch");
   fxsave_to_fsave(fxsave, (struct emu_fsave *)fptr);
 }
+
+/* since the kernel may not be able to keep SSE state, keep it here */
+static struct emu_fpxstate fxsave_state_holder_i386;
 #endif
 
 static void copy_to_dpmi(sigcontext_t *scp, cpuctx_t *s)
@@ -119,9 +122,10 @@ void native_dpmi_set_fpu_state(const emu_fpstate *fpstate)
 #else
     /* i386: convert fxsave state to fsave state */
     convert_from_fxsr(scp_fpregs, fpstate);
-    if ((scp_fpregs->status >> 16) != EMU_X86_FXSR_MAGIC)
-      return;
-    fpregs = &scp_fpregs->status + 1;
+    if ((scp_fpregs->status >> 16) == EMU_X86_FXSR_MAGIC)
+      fpregs = &scp_fpregs->status + 1;
+    else
+      fpregs = &fxsave_state_holder_i386;
 #endif
     memcpy(fpregs, fpstate, sizeof(*fpstate));
   }
@@ -163,8 +167,8 @@ void native_dpmi_get_fpu_state(emu_fpstate *fpstate)
     if ((scp_fpregs->status >> 16) == EMU_X86_FXSR_MAGIC)
       fpregs = &scp_fpregs->status + 1;
     else {
-      fsave_to_fxsave(fpregs, &vm86_fpu_state);
-      return;
+      fsave_to_fxsave(fpregs, &fxsave_state_holder_i386);
+      fpregs = &fxsave_state_holder_i386;
     }
 #endif
     memcpy(fpstate, fpregs, sizeof(*fpstate));

diff --git a/src/dosext/dpmi/dpmi.c b/src/dosext/dpmi/dpmi.c
@@ -420,7 +420,7 @@ static void print_ldt(void)
 
 static void dpmi_set_pm(int pm)
 {
-  static emu_fpstate fpstate;
+  emu_fpstate fpstate;
   assert(pm <= 1);
   if (pm == dpmi_pm) {
     if (!pm)