From: dmitry dulesov <dmitry.dulesov@gmail.com>
Date: Thu, 30 Jan 2020 02:49:50 +0000 (+0300)
Subject: gosthash2012: Optimize out temporary `buf' from `stage3'
X-Git-Tag: v3.0.0~215
X-Git-Url: http://www.wagner.pp.ru/gitweb/?p=openssl-gost%2Fengine.git;a=commitdiff_plain;h=31138d02d9c3698c039154b3078c16f205e25902

gosthash2012: Optimize out temporary `buf' from `stage3'

On-stack `buf' is replaced by manipulation directly on `CTX->buffer'.

Committed-by: Vitaly Chikunov <vt@altlinux.org>
---

diff --git a/gosthash2012.c b/gosthash2012.c
index b844ab3..ddd35fa 100644
--- a/gosthash2012.c
+++ b/gosthash2012.c
@@ -158,28 +158,19 @@ static INLINE void stage2(gost2012_hash_ctx * CTX, const union uint512_u *data)
 
 static INLINE void stage3(gost2012_hash_ctx * CTX)
 {
-    ALIGN(16) union uint512_u buf;
-
-    memset(&buf, 0x00, sizeof buf);
-    memcpy(&buf, &(CTX->buffer), CTX->bufsize);
-    memcpy(&(CTX->buffer), &buf, sizeof(uint512_u));
+    pad(CTX);
+    g(&(CTX->h), &(CTX->N), &(CTX->buffer));
+    add512(&(CTX->Sigma), &CTX->buffer);
 
-    memset(&buf, 0x00, sizeof buf);
+    memset(&(CTX->buffer.B[0]), 0, sizeof(uint512_u));
 #ifndef __GOST3411_BIG_ENDIAN__
-    buf.QWORD[0] = CTX->bufsize << 3;
+    CTX->buffer.QWORD[0] = CTX->bufsize << 3;
 #else
-    buf.QWORD[0] = BSWAP64(CTX->bufsize << 3);
+    CTX->buffer.QWORD[0] = BSWAP64(CTX->bufsize << 3);
 #endif
-
-    pad(CTX);
-
-    g(&(CTX->h), &(CTX->N), &(CTX->buffer));
-
-    add512(&(CTX->N), &buf);
-    add512(&(CTX->Sigma), &CTX->buffer);
+    add512(&(CTX->N), &(CTX->buffer));
 
     g(&(CTX->h), &buffer0, &(CTX->N));
-
     g(&(CTX->h), &buffer0, &(CTX->Sigma));
 }