libbb/sha256: code shrink in 64-bit x86

function                                             old     new   delta
sha256_process_block64_shaNI                         701     680     -21

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

1 files changed, 14 insertions, 11 deletions

diff --git a/libbb/hash_md5_sha256_x86-64_shaNI.S b/libbb/hash_md5_sha256_x86-64_shaNI.S
index b5c950a9a..bc063b9cc 100644
--- a/libbb/hash_md5_sha256_x86-64_shaNI.S
+++ b/libbb/hash_md5_sha256_x86-64_shaNI.S
@@ -37,16 +37,18 @@
 #define ABEF_SAVE       %xmm9
 #define CDGH_SAVE       %xmm10
 
+#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         80+0*16(%rdi), STATE0
-        movu128         80+1*16(%rdi), STATE1
 
-        shuf128_32      $0xB1, STATE0, STATE0           /* CDAB */
-        shuf128_32      $0x1B, STATE1, STATE1           /* EFGH */
+        movu128         80+0*16(%rdi), STATE1 /* DCBA (msb-to-lsb: 3,2,1,0) */
+        movu128         80+1*16(%rdi), 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(%rip), XMMTMP
@@ -242,14 +244,15 @@ sha256_process_block64_shaNI:
         paddd           CDGH_SAVE, STATE1
 
         /* 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 */
 
         movu128         STATE0, 80+0*16(%rdi)
-        movu128         STATE1, 80+1*16(%rdi)
+        movu128         XMMTMP, 80+1*16(%rdi)
 
         ret
         .size   sha256_process_block64_shaNI, .-sha256_process_block64_shaNI