Make OPENSSL_IA32_SSE2 the default for i386 and remove the flag.

The OPENSSL_IA32_SSE2 flag controls whether a number of the perlasm
scripts generate additional implementations that use SSE2 functionality.
In all cases except ghash, the code checks OPENSSL_ia32cap_P for SSE2
support, before trying to run SSE2 code. For ghash it generates a CLMUL
based implementation in addition to different MMX version (one MMX
version hides behind OPENSSL_IA32_SSE2, the other does not), however this
does not appear to actually use SSE2. We also disable AES-NI on i386 if
OPENSSL_IA32_SSE2.

On OpenBSD, we've always defined OPENSSL_IA32_SSE2 so this is effectively
a no-op. The only change is that we now check MMX rather than SSE2 for the
ghash MMX implementation.

ok bcook@ beck@

2 files changed, 2 insertions, 9 deletions

diff --git a/src/lib/libcrypto/modes/asm/ghash-x86.pl b/src/lib/libcrypto/modes/asm/ghash-x86.pl
index 47833582b6..395c680cc5 100644
--- a/src/lib/libcrypto/modes/asm/ghash-x86.pl
+++ b/src/lib/libcrypto/modes/asm/ghash-x86.pl
@@ -119,8 +119,7 @@ require "x86asm.pl";
 
 &asm_init($ARGV[0],"ghash-x86.pl",$x86only = $ARGV[$#ARGV] eq "386");
 
-$sse2=0;
-for (@ARGV) { $sse2=1 if (/-DOPENSSL_IA32_SSE2/); }
+$sse2=1;
 
 ($Zhh,$Zhl,$Zlh,$Zll) = ("ebp","edx","ecx","ebx");
 $inp  = "edi";
diff --git a/src/lib/libcrypto/modes/gcm128.c b/src/lib/libcrypto/modes/gcm128.c
index 2540b7cf3d..8136c2cde2 100644
--- a/src/lib/libcrypto/modes/gcm128.c
+++ b/src/lib/libcrypto/modes/gcm128.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: gcm128.c,v 1.50 2025/06/08 07:49:45 jsing Exp $ */
+/* $OpenBSD: gcm128.c,v 1.51 2025/06/09 14:28:34 jsing Exp $ */
 /* ====================================================================
  * Copyright (c) 2010 The OpenSSL Project.  All rights reserved.
  *
@@ -259,7 +259,6 @@ CRYPTO_gcm128_init(GCM128_CONTEXT *ctx, void *key, block128_f block)
         ctx->H.u[1] = be64toh(ctx->H.u[1]);
 
 # if    defined(GHASH_ASM_X86_OR_64)
-#  if   !defined(GHASH_ASM_X86) || defined(OPENSSL_IA32_SSE2)
         /* check FXSR and PCLMULQDQ bits */
         if ((crypto_cpu_caps_ia32() & (CPUCAP_MASK_FXSR | CPUCAP_MASK_PCLMUL)) ==
             (CPUCAP_MASK_FXSR | CPUCAP_MASK_PCLMUL)) {
@@ -268,14 +267,9 @@ CRYPTO_gcm128_init(GCM128_CONTEXT *ctx, void *key, block128_f block)
                 ctx->ghash = gcm_ghash_clmul;
                 return;
         }
-#  endif
         gcm_init_4bit(ctx->Htable, ctx->H.u);
 #  if   defined(GHASH_ASM_X86)                  /* x86 only */
-#   if  defined(OPENSSL_IA32_SSE2)
-        if (crypto_cpu_caps_ia32() & CPUCAP_MASK_SSE) { /* check SSE bit */
-#   else
         if (crypto_cpu_caps_ia32() & CPUCAP_MASK_MMX) { /* check MMX bit */
-#   endif
                 ctx->gmult = gcm_gmult_4bit_mmx;
                 ctx->ghash = gcm_ghash_4bit_mmx;
         } else {