+# 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");
+
+# Essentially there is only one use for this function. Under DJGPP:
+#
+# #include <go32.h>
+# ...
+# i=OPENSSL_far_spin(_dos_ds,0x46c);
+# ...
+# to obtain the number of spins till closest timer interrupt.
+
+&function_begin_B("OPENSSL_far_spin");
+ &pushf ();
+ &pop ("eax");
+ &bt ("eax",9);
+ &jnc (&label("nospin")); # interrupts are disabled
+
+ &mov ("eax",&DWP(4,"esp"));
+ &mov ("ecx",&DWP(8,"esp"));
+ &data_word (0x90d88e1e); # push %ds, mov %eax,%ds
+ &xor ("eax","eax");
+ &mov ("edx",&DWP(0,"ecx"));
+ &jmp (&label("spin"));
+
+ &align (16);
+&set_label("spin");
+ &inc ("eax");
+ &cmp ("edx",&DWP(0,"ecx"));
+ &je (&label("spin"));
+
+ &data_word (0x1f909090); # pop %ds
+ &ret ();
+
+&set_label("nospin");
+ &xor ("eax","eax");
+ &xor ("edx","edx");
+ &ret ();
+&function_end_B("OPENSSL_far_spin");
+
+&function_begin_B("OPENSSL_wipe_cpu","EXTRN\t_OPENSSL_ia32cap_P:DWORD");
+ &xor ("eax","eax");
+ &xor ("edx","edx");
+ &picmeup("ecx","OPENSSL_ia32cap_P");
+ &mov ("ecx",&DWP(0,"ecx"));
+ &bt (&DWP(0,"ecx"),1);
+ &jnc (&label("no_x87"));
+ if ($sse2) {
+ &and ("ecx",1<<26|1<<24); # check SSE2 and FXSR bits
+ &cmp ("ecx",1<<26|1<<24);
+ &jne (&label("no_sse2"));
+ &pxor ("xmm0","xmm0");
+ &pxor ("xmm1","xmm1");
+ &pxor ("xmm2","xmm2");
+ &pxor ("xmm3","xmm3");
+ &pxor ("xmm4","xmm4");
+ &pxor ("xmm5","xmm5");
+ &pxor ("xmm6","xmm6");
+ &pxor ("xmm7","xmm7");
+ &set_label("no_sse2");
+ }
+ # just a bunch of fldz to zap the fp/mm bank followed by finit...
+ &data_word(0xeed9eed9,0xeed9eed9,0xeed9eed9,0xeed9eed9,0x90e3db9b);
+&set_label("no_x87");
+ &lea ("eax",&DWP(4,"esp"));
+ &ret ();
+&function_end_B("OPENSSL_wipe_cpu");
+
+&function_begin_B("OPENSSL_atomic_add");
+ &mov ("edx",&DWP(4,"esp")); # fetch the pointer, 1st arg
+ &mov ("ecx",&DWP(8,"esp")); # fetch the increment, 2nd arg
+ &push ("ebx");
+ &nop ();
+ &mov ("eax",&DWP(0,"edx"));
+&set_label("spin");
+ &lea ("ebx",&DWP(0,"eax","ecx"));
+ &nop ();
+ &data_word(0x1ab10ff0); # lock; cmpxchg %ebx,(%edx) # %eax is involved and is always reloaded
+ &jne (&label("spin"));
+ &mov ("eax","ebx"); # OpenSSL expects the new value
+ &pop ("ebx");
+ &ret ();
+&function_end_B("OPENSSL_atomic_add");
+
+&function_begin_B("OPENSSL_cleanse");
+ &mov ("edx",&wparam(0));
+ &mov ("ecx",&wparam(1));
+ &xor ("eax","eax");
+ &cmp ("ecx",7);
+ &jae (&label("lot"));
+ &cmp ("ecx",0);
+ &je (&label("ret"));
+&set_label("little");
+ &mov (&BP(0,"edx"),"al");
+ &sub ("ecx",1);
+ &lea ("edx",&DWP(1,"edx"));
+ &jnz (&label("little"));
+&set_label("ret");
+ &ret ();
+
+&set_label("lot",16);
+ &test ("edx",3);
+ &jz (&label("aligned"));
+ &mov (&BP(0,"edx"),"al");
+ &lea ("ecx",&DWP(-1,"ecx"));
+ &lea ("edx",&DWP(1,"edx"));
+ &jmp (&label("lot"));
+&set_label("aligned");
+ &mov (&DWP(0,"edx"),"eax");
+ &lea ("ecx",&DWP(-4,"ecx"));
+ &test ("ecx",-4);
+ &lea ("edx",&DWP(4,"edx"));
+ &jnz (&label("aligned"));
+ &cmp ("ecx",0);
+ &jne (&label("little"));
+ &ret ();
+&function_end_B("OPENSSL_cleanse");
+
+&function_begin_B("CRYPTO_memcmp");
+ &push ("esi");
+ &push ("edi");
+ &mov ("esi",&wparam(0));
+ &mov ("edi",&wparam(1));
+ &mov ("ecx",&wparam(2));
+ &xor ("eax","eax");
+ &xor ("edx","edx");
+ &cmp ("ecx",0);
+ &je (&label("no_data"));
+&set_label("loop");
+ &mov ("dl",&BP(0,"esi"));
+ &lea ("esi",&DWP(1,"esi"));
+ &xor ("dl",&BP(0,"edi"));
+ &lea ("edi",&DWP(1,"edi"));
+ &or ("al","dl");
+ &dec ("ecx");
+ &jnz (&label("loop"));
+ &neg ("eax");
+ &shr ("eax",31);
+&set_label("no_data");
+ &pop ("edi");
+ &pop ("esi");
+ &ret ();
+&function_end_B("CRYPTO_memcmp");
+{
+my $lasttick = "esi";
+my $lastdiff = "ebx";
+my $out = "edi";
+my $cnt = "ecx";
+my $max = "ebp";
+
+&function_begin("OPENSSL_instrument_bus");
+ &mov ("eax",0);
+ if ($sse2) {
+ &picmeup("edx","OPENSSL_ia32cap_P");
+ &bt (&DWP(0,"edx"),4);
+ &jnc (&label("nogo")); # no TSC
+ &bt (&DWP(0,"edx"),19);
+ &jnc (&label("nogo")); # no CLFLUSH
+
+ &mov ($out,&wparam(0)); # load arguments
+ &mov ($cnt,&wparam(1));
+
+ # collect 1st tick
+ &rdtsc ();
+ &mov ($lasttick,"eax"); # lasttick = tick
+ &mov ($lastdiff,0); # lastdiff = 0
+ &clflush(&DWP(0,$out));
+ &data_byte(0xf0); # lock
+ &add (&DWP(0,$out),$lastdiff);
+ &jmp (&label("loop"));
+
+&set_label("loop",16);
+ &rdtsc ();
+ &mov ("edx","eax"); # put aside tick (yes, I neglect edx)
+ &sub ("eax",$lasttick); # diff
+ &mov ($lasttick,"edx"); # lasttick = tick
+ &mov ($lastdiff,"eax"); # lastdiff = diff
+ &clflush(&DWP(0,$out));
+ &data_byte(0xf0); # lock
+ &add (&DWP(0,$out),"eax"); # accumulate diff
+ &lea ($out,&DWP(4,$out)); # ++$out
+ &sub ($cnt,1); # --$cnt
+ &jnz (&label("loop"));
+
+ &mov ("eax",&wparam(1));
+&set_label("nogo");
+ }
+&function_end("OPENSSL_instrument_bus");
+
+&function_begin("OPENSSL_instrument_bus2");
+ &mov ("eax",0);
+ if ($sse2) {
+ &picmeup("edx","OPENSSL_ia32cap_P");
+ &bt (&DWP(0,"edx"),4);
+ &jnc (&label("nogo")); # no TSC
+ &bt (&DWP(0,"edx"),19);
+ &jnc (&label("nogo")); # no CLFLUSH
+
+ &mov ($out,&wparam(0)); # load arguments
+ &mov ($cnt,&wparam(1));
+ &mov ($max,&wparam(2));
+
+ &rdtsc (); # collect 1st tick
+ &mov ($lasttick,"eax"); # lasttick = tick
+ &mov ($lastdiff,0); # lastdiff = 0
+
+ &clflush(&DWP(0,$out));
+ &data_byte(0xf0); # lock
+ &add (&DWP(0,$out),$lastdiff);
+
+ &rdtsc (); # collect 1st diff
+ &mov ("edx","eax"); # put aside tick (yes, I neglect edx)
+ &sub ("eax",$lasttick); # diff
+ &mov ($lasttick,"edx"); # lasttick = tick
+ &mov ($lastdiff,"eax"); # lastdiff = diff
+ &jmp (&label("loop2"));
+
+&set_label("loop2",16);
+ &clflush(&DWP(0,$out));
+ &data_byte(0xf0); # lock
+ &add (&DWP(0,$out),"eax"); # accumulate diff
+
+ &sub ($max,1);
+ &jz (&label("done2"));
+
+ &rdtsc ();
+ &mov ("edx","eax"); # put aside tick (yes, I neglect edx)
+ &sub ("eax",$lasttick); # diff
+ &mov ($lasttick,"edx"); # lasttick = tick
+ &cmp ("eax",$lastdiff);
+ &mov ($lastdiff,"eax"); # lastdiff = diff
+ &mov ("edx",0);
+ &setne ("dl");
+ &sub ($cnt,"edx"); # conditional --$cnt
+ &lea ($out,&DWP(0,$out,"edx",4)); # conditional ++$out
+ &jnz (&label("loop2"));
+
+&set_label("done2");
+ &mov ("eax",&wparam(1));
+ &sub ("eax",$cnt);
+&set_label("nogo");
+ }
+&function_end("OPENSSL_instrument_bus2");
+}
+
+sub gen_random {
+my $rdop = shift;
+&function_begin_B("OPENSSL_ia32_${rdop}_bytes");
+ &push ("edi");
+ &push ("ebx");
+ &xor ("eax","eax"); # return value
+ &mov ("edi",&wparam(0));
+ &mov ("ebx",&wparam(1));
+
+ &cmp ("ebx",0);
+ &je (&label("done"));
+
+ &mov ("ecx",8);
+&set_label("loop");
+ &${rdop}("edx");
+ &jc (&label("break"));
+ &loop (&label("loop"));
+ &jmp (&label("done"));
+
+&set_label("break",16);
+ &cmp ("ebx",4);
+ &jb (&label("tail"));
+ &mov (&DWP(0,"edi"),"edx");
+ &lea ("edi",&DWP(4,"edi"));
+ &add ("eax",4);
+ &sub ("ebx",4);
+ &jz (&label("done"));
+ &mov ("ecx",8);
+ &jmp (&label("loop"));
+
+&set_label("tail",16);
+ &mov (&BP(0,"edi"),"dl");
+ &lea ("edi",&DWP(1,"edi"));
+ &inc ("eax");
+ &shr ("edx",8);
+ &dec ("ebx");
+ &jnz (&label("tail"));
+
+&set_label("done");
+ &xor ("edx","edx"); # Clear random value from registers
+ &pop ("ebx");
+ &pop ("edi");
+ &ret ();
+&function_end_B("OPENSSL_ia32_${rdop}_bytes");
+}
+&gen_random("rdrand");
+&gen_random("rdseed");
+