From 1eb12c437bbeb2c748291bcd23733d4a59d5d1ca Mon Sep 17 00:00:00 2001 From: Andy Polyakov Date: Wed, 8 Jun 2016 15:55:35 +0200 Subject: [PATCH] perlasm/x86_64-xlate.pl: add commentary. Reviewed-by: Rich Salz --- crypto/perlasm/x86_64-xlate.pl | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) diff --git a/crypto/perlasm/x86_64-xlate.pl b/crypto/perlasm/x86_64-xlate.pl index f050b23f00..391362d46e 100755 --- a/crypto/perlasm/x86_64-xlate.pl +++ b/crypto/perlasm/x86_64-xlate.pl @@ -692,7 +692,13 @@ sub rex { push @$opcode,($rex|0x40) if ($rex); } -# older gas and ml64 don't handle SSE>2 instructions +# Upon initial x86_64 introduction SSE>2 extensions were not introduced +# yet. In order not to be bothered by tracing exact assembler versions, +# but at the same time to provide a bare security minimum of AES-NI, we +# hard-code some instructions. Extensions past AES-NI on the other hand +# are traced by examining assembler version in individual perlasm +# modules... + my %regrm = ( "%eax"=>0, "%ecx"=>1, "%edx"=>2, "%ebx"=>3, "%esp"=>4, "%ebp"=>5, "%esi"=>6, "%edi"=>7 ); -- 2.25.1