&mov ("edx","ecx");
&function_end("OPENSSL_ia32_cpuid");
-&external_label("OPENSSL_ia32cap");
+&external_label("OPENSSL_ia32cap_P");
-&function_begin_B("OPENSSL_rdtsc");
+&function_begin_B("OPENSSL_rdtsc","EXTRN\t_OPENSSL_ia32cap_P:DWORD");
&xor ("eax","eax");
&xor ("edx","edx");
- &picmeup("ecx","OPENSSL_ia32cap");
+ &picmeup("ecx","OPENSSL_ia32cap_P");
&bt (&DWP(0,"ecx"),4);
&jnc (&label("notsc"));
&rdtsc ();
&ret ();
&function_end_B("OPENSSL_rdtsc");
-&initseg("OPENSSL_cpuid_setup") if ($main'elf);
+# This works in Ring 0 only [read DJGPP+MS-DOS+privileged DPMI host],
+# but it's safe to call it on any [supported] 32-bit platform...
+# Just check for [non-]zero return value...
+&function_begin_B("OPENSSL_instrument_halt","EXTRN\t_OPENSSL_ia32cap_P:DWORD");
+ &picmeup("ecx","OPENSSL_ia32cap_P");
+ &bt (&DWP(0,"ecx"),4);
+ &jnc (&label("nohalt")); # no TSC
+
+ &data_word(0x9058900e); # push %cs; pop %eax
+ &and ("eax",3);
+ &jnz (&label("nohalt")); # not enough privileges
+
+ &pushf ();
+ &pop ("eax")
+ &bt ("eax",9);
+ &jnc (&label("nohalt")); # interrupts are disabled
+
+ &rdtsc ();
+ &push ("edx");
+ &push ("eax");
+ &halt ();
+ &rdtsc ();
+
+ &sub ("eax",&DWP(0,"esp"));
+ &sbb ("edx",&DWP(4,"esp"));
+ &add ("esp",8);
+ &ret ();
+
+&set_label("nohalt");
+ &xor ("eax","eax");
+ &xor ("edx","edx");
+ &ret ();
+&function_end_B("OPENSSL_instrument_halt");
+
+&initseg("OPENSSL_cpuid_setup");
&asm_finish();