Get rid of all compiler version checks in perlasm files.

Since we pre-generate our perlasm, having the output of these files be
sensitive to the environment the run in is unhelpful. It would be bad to
suddenly change what features we do or don't compile in whenever workstations'
toolchains change or if developers do or don't have CC variables set.

Previously, all compiler-version-gated features were turned on in
https://boringssl-review.googlesource.com/6260, but this broke the build. I
also wasn't thorough enough in gathering performance numbers. So, flip them all
to off instead. I'll enable them one-by-one as they're tested.

This should result in no change to generated assembly.

Change-Id: Ib4259b3f97adc4939cb0557c5580e8def120d5bc
Reviewed-on: https://boringssl-review.googlesource.com/6383
Reviewed-by: Adam Langley <agl@google.com>

2 files changed, 12 insertions, 36 deletions

diff --git a/crypto/modes/asm/aesni-gcm-x86_64.pl b/crypto/modes/asm/aesni-gcm-x86_64.pl
index 7e4e04ea..0ca89c7d 100644
--- a/crypto/modes/asm/aesni-gcm-x86_64.pl
+++ b/crypto/modes/asm/aesni-gcm-x86_64.pl
@@ -41,24 +41,12 @@ $0 =~ m/(.*[\/\\])[^\/\\]+$/; $dir=$1;
 ( $xlate="${dir}../../perlasm/x86_64-xlate.pl" and -f $xlate) or
 die "can't locate x86_64-xlate.pl";
 
-if (`$ENV{CC} -Wa,-v -c -o /dev/null -x assembler /dev/null 2>&1`
-		=~ /GNU assembler version ([2-9]\.[0-9]+)/) {
-	$avx = ($1>=2.19) + ($1>=2.22);
-}
-
-if (!$avx && $win64 && ($flavour =~ /nasm/ || $ENV{ASM} =~ /nasm/) &&
-	    `nasm -v 2>&1` =~ /NASM version ([2-9]\.[0-9]+)/) {
-	$avx = ($1>=2.09) + ($1>=2.10);
-}
-
-if (!$avx && $win64 && ($flavour =~ /masm/ || $ENV{ASM} =~ /ml64/) &&
-	    `ml64 2>&1` =~ /Version ([0-9]+)\./) {
-	$avx = ($1>=10) + ($1>=11);
-}
-
-if (!$avx && `$ENV{CC} -v 2>&1` =~ /(^clang version|based on LLVM) ([3-9]\.[0-9]+)/) {
-	$avx = ($2>=3.0) + ($2>3.0);
-}
+# In upstream, this is controlled by shelling out to the compiler to check
+# versions, but BoringSSL is intended to be used with pre-generated perlasm
+# output, so this isn't useful anyway.
+#
+# TODO(davidben): Enable this after testing. $avx goes up to 2.
+$avx = 0;
 
 open OUT,"| \"$^X\" $xlate $flavour $output";
 *STDOUT=*OUT;
diff --git a/crypto/modes/asm/ghash-x86_64.pl b/crypto/modes/asm/ghash-x86_64.pl
index 5a7ce394..e42ca321 100644
--- a/crypto/modes/asm/ghash-x86_64.pl
+++ b/crypto/modes/asm/ghash-x86_64.pl
@@ -90,24 +90,12 @@ $0 =~ m/(.*[\/\\])[^\/\\]+$/; $dir=$1;
 ( $xlate="${dir}../../perlasm/x86_64-xlate.pl" and -f $xlate) or
 die "can't locate x86_64-xlate.pl";
 
-if (`$ENV{CC} -Wa,-v -c -o /dev/null -x assembler /dev/null 2>&1`
-		=~ /GNU assembler version ([2-9]\.[0-9]+)/) {
-	$avx = ($1>=2.19) + ($1>=2.22);
-}
-
-if (!$avx && $win64 && ($flavour =~ /nasm/ || $ENV{ASM} =~ /nasm/) &&
-	    `nasm -v 2>&1` =~ /NASM version ([2-9]\.[0-9]+)/) {
-	$avx = ($1>=2.09) + ($1>=2.10);
-}
-
-if (!$avx && $win64 && ($flavour =~ /masm/ || $ENV{ASM} =~ /ml64/) &&
-	    `ml64 2>&1` =~ /Version ([0-9]+)\./) {
-	$avx = ($1>=10) + ($1>=11);
-}
-
-if (!$avx && `$ENV{CC} -v 2>&1` =~ /(^clang version|based on LLVM) ([3-9]\.[0-9]+)/) {
-	$avx = ($2>=3.0) + ($2>3.0);
-}
+# In upstream, this is controlled by shelling out to the compiler to check
+# versions, but BoringSSL is intended to be used with pre-generated perlasm
+# output, so this isn't useful anyway.
+#
+# TODO(davidben): Enable this after testing. $avx goes up to 2.
+$avx = 0;
 
 open OUT,"| \"$^X\" $xlate $flavour $output";
 *STDOUT=*OUT;