x86[_64]cpuid.pl: add function accessing rdrand instruction.

crypto/perlasm/x86_64-xlate.pl

@@ -625,7 +625,7 @@ my %globals;
 		/\.comm/    && do { my @str=split(/,\s*/,$line);
 				    my $v=undef;
 				    if ($nasm) {
-					$v.="common	$prefix@str[0] @str[1]:near";
+					$v.="common	$prefix@str[0] @str[1]";
 				    } else {
 					$v="$current_segment\tENDS\n" if ($current_segment);
 					$current_segment = ".data";
@@ -757,6 +757,19 @@ my $pclmulqdq = sub {
     }
 };
 
+my $rdrand = sub {
+    if (shift =~ /%[er](\w+)/) {
+      my @opcode=();
+      my $dst=$1;
+	if ($dst !~ /[0-9]+/) { $dst = $regrm{"%e$dst"}; }
+	rex(\@opcode,0,$1,8);
+	push @opcode,0x0f,0xc7,0xf0|($dst&7);
+	@opcode;
+    } else {
+	();
+    }
+};
+
 if ($nasm) {
     print <<___;
 default	rel

crypto/perlasm/x86asm.pl

@@ -123,6 +123,14 @@ sub ::pclmulqdq
     {	&::generic("pclmulqdq",@_);		}
 }
 
+sub ::rdrand
+{ my ($dst)=@_;
+    if ($dst =~ /(e[a-dsd][ixp])/)
+    {	&::data_byte(0x0f,0xc7,0xf0|$regrm{$dst});	}
+    else
+    {	&::generic("rdrand",@_);	}
+}
+
 # label management
 $lbdecor="L";		# local label decoration, set by package
 $label="000";

crypto/x86_64cpuid.pl

@@ -7,7 +7,11 @@ if ($flavour =~ /\./) { $output = $flavour; undef $flavour; }
 $win64=0; $win64=1 if ($flavour =~ /[nm]asm|mingw64/ || $output =~ /\.asm$/);
 
 $0 =~ m/(.*[\/\\])[^\/\\]+$/; $dir=$1;
-open STDOUT,"| $^X ${dir}perlasm/x86_64-xlate.pl $flavour $output";
+( $xlate="${dir}x86_64-xlate.pl" and -f $xlate ) or
+( $xlate="${dir}perlasm/x86_64-xlate.pl" and -f $xlate) or
+die "can't locate x86_64-xlate.pl";
+
+open STDOUT,"| $^X $xlate $flavour $output";
 
 ($arg1,$arg2,$arg3,$arg4)=$win64?("%rcx","%rdx","%r8", "%r9") :	# Win64 order
 				 ("%rdi","%rsi","%rdx","%rcx");	# Unix order
@@ -349,4 +353,21 @@ OPENSSL_instrument_bus2:
 ___
 }
 
+print<<___;
+.globl	OPENSSL_ia32_rdrand
+.type	OPENSSL_ia32_rdrand,\@abi-omnipotent
+.align	16
+OPENSSL_ia32_rdrand:
+	mov	\$8,%ecx
+.Loop_rdrand:
+	rdrand	%rax
+	jc	.Lbreak_rdrand
+	loop	.Loop_rdrand
+.Lbreak_rdrand:
+	cmp	\$0,%rax
+	cmove	%rcx,%rax
+	ret
+.size	OPENSSL_ia32_rdrand,.-OPENSSL_ia32_rdarnd
+___
+
 close STDOUT;	# flush

crypto/x86cpuid.pl

@@ -442,6 +442,18 @@ my $max = "ebp";
 &function_end("OPENSSL_instrument_bus2");
 }
 
+&function_begin_B("OPENSSL_ia32_rdrand");
+	&mov	("ecx",8);
+&set_label("loop");
+	&rdrand	("eax");
+	&jc	(&label("break"));
+	&loop	(&label("loop"));
+&set_label("break");
+	&cmp	("eax",0);
+	&cmove	("eax","ecx");
+	&ret	();
+&function_end_B("OPENSSL_ia32_rdrand");
+
 &initseg("OPENSSL_cpuid_setup");
 
 &asm_finish();

doc/crypto/OPENSSL_ia32cap.pod

@@ -51,6 +51,8 @@ moment of this writing following bits are significant:
 
 =item bit #60 denoting AVX extension;
 
+=item bit #62 denoting availability of RDRAND instruction;
+
 For example, clearing bit #26 at run-time disables high-performance
 SSE2 code present in the crypto library, while clearing bit #24
 disables SSE2 code operating on 128-bit XMM register bank. You might