libbb/sha256: code shrink in 32-bit x86

function                                             old     new   delta
sha256_process_block64_shaNI                         697     676     -21

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>

1 files changed, 16 insertions, 13 deletions

diff --git a/libbb/hash_md5_sha256_x86-32_shaNI.S b/libbb/hash_md5_sha256_x86-32_shaNI.S
index a849dfcc2..846230e3e 100644
--- a/libbb/hash_md5_sha256_x86-32_shaNI.S
+++ b/libbb/hash_md5_sha256_x86-32_shaNI.S
@@ -34,16 +34,18 @@
 
 #define XMMTMP          %xmm7
 
+#define SHUF(a,b,c,d) $(a+(b<<2)+(c<<4)+(d<<6))
+
         .balign 8       # allow decoders to fetch at least 2 first insns
 sha256_process_block64_shaNI:
-        movu128         76+0*16(%eax), STATE0
-        movu128         76+1*16(%eax), STATE1
 
-        shuf128_32      $0xB1, STATE0, STATE0           /* CDAB */
-        shuf128_32      $0x1B, STATE1, STATE1           /* EFGH */
+        movu128         76+0*16(%eax), STATE1 /* DCBA (msb-to-lsb: 3,2,1,0) */
+        movu128         76+1*16(%eax), STATE0 /* HGFE */
+/* shufps takes dwords 0,1 from *2nd* operand, and dwords 2,3 from 1st one */
         mova128         STATE0, XMMTMP
-        palignr         $8, STATE1, STATE0              /* ABEF */
-        pblendw         $0xF0, XMMTMP, STATE1           /* CDGH */
+        shufps          SHUF(1,0,1,0), STATE1, STATE0 /* ABEF */
+        shufps          SHUF(3,2,3,2), STATE1, XMMTMP /* CDGH */
+        mova128         XMMTMP, STATE1
 
 /* XMMTMP holds flip mask from here... */
         mova128         PSHUFFLE_BSWAP32_FLIP_MASK, XMMTMP
@@ -231,18 +233,19 @@ sha256_process_block64_shaNI:
                 sha256rnds2     STATE1, STATE0
 
         /* Write hash values back in the correct order */
-        shuf128_32      $0x1B, STATE0, STATE0           /* FEBA */
-        shuf128_32      $0xB1, STATE1, STATE1           /* DCHG */
+        /* STATE0: ABEF (msb-to-lsb: 3,2,1,0) */
+        /* STATE1: CDGH */
         mova128         STATE0, XMMTMP
-        pblendw         $0xF0, STATE1, STATE0           /* DCBA */
-        palignr         $8, XMMTMP, STATE1              /* HGFE */
+/* shufps takes dwords 0,1 from *2nd* operand, and dwords 2,3 from 1st one */
+        shufps          SHUF(3,2,3,2), STATE1, STATE0 /* DCBA */
+        shufps          SHUF(1,0,1,0), STATE1, XMMTMP /* HGFE */
         /* add current hash values to previous ones */
+        movu128         76+1*16(%eax), STATE1
+        paddd           XMMTMP, STATE1
+        movu128         STATE1, 76+1*16(%eax)
         movu128         76+0*16(%eax), XMMTMP
         paddd           XMMTMP, STATE0
-        movu128         76+1*16(%eax), XMMTMP
         movu128         STATE0, 76+0*16(%eax)
-        paddd           XMMTMP, STATE1
-        movu128         STATE1, 76+1*16(%eax)
 
         ret
         .size   sha256_process_block64_shaNI, .-sha256_process_block64_shaNI