(_aes_crypt): Some peep hole optimizations, duplicating some

instructions to fill nop:s, and put branch instructions on even
word addresses.

Rev: src/nettle/sparc/aes.asm:1.66

diff --git a/sparc/aes.asm b/sparc/aes.asm
index e49a195d33e45d158e0543067bfc995e504b17c1..c2420ba75e58e25bd53aa7012189e07716d5b37f 100644 (file)
--- a/sparc/aes.asm
+++ b/sparc/aes.asm
@@ -69,12 +69,12 @@ _aes_crypt:
        add     T, AES_SIDX3, IDX3
        ! Read src, and add initial subkey
        ! Difference between ctx and src.
-       ! NOTE: This instruction is duplicated in the delay slot
+       ! NOTE: These instruction is duplicated in the delay slot,
+       ! and the instruction before the branch
        sub     ctx, src, %g2
-
-.Lblock_loop:
        ! Difference between wtxt and src
        sub     wtxt, src, %g3
+.Lblock_loop:
        ! For stop condition. Note that src is incremented in the
        ! delay slot
        add     src, 8, %g4
@@ -105,6 +105,7 @@ _aes_crypt:
        add     ctx, 16, key
 .Lround_loop:
        ! 4*i
+       ! NOTE: Instruction duplicated in delay slot
        mov     0, i
 .Linner_loop:
        ! The comments mark which j in T->table[j][ Bj(wtxt[IDXi(i)]) ]
@@ -151,21 +152,23 @@ _aes_crypt:
        add     i, 4, i
        ! switch roles for tmp and wtxt
        xor     wtxt, diff, wtxt
+       xor     tmp, diff, tmp
+
        subcc   round, 1, round
-       
        add     key, 16, key
-       nop
-       bne     .Lround_loop
-       xor     tmp, diff, tmp
+       bne     .Linner_loop
+       mov     0, i
 
        ! final round
-       ! 4*i
-       mov     0, i
+       ! Use round as the loop variable, as it's already zero
+undefine(<i>)
+define(i, round)
 
-.Lfinal_loop:
        ! Comments mark which j in T->sbox[Bj(wtxt[IDXj(i)])]
        ! the instruction is part of
+       ! NOTE: First instruction duplicated in delay slot
        ld      [IDX1+i], t1    ! 1
+.Lfinal_loop:
        ! IDX2(j) = j XOR 2
        xor     i, 8, t2
        ! ld    [idx-16], t2    ! 2
@@ -205,15 +208,15 @@ _aes_crypt:
        stb     t3, [dst+3]
        stb     t2, [dst+2]
        stb     t0, [dst]
+       add     dst, 4, dst
        
        bleu    .Lfinal_loop
-       add     dst, 4, dst
-
+       ld      [IDX1+i], t1    ! 1
        addcc   length, -16, length
-       nop
+       sub     ctx, src, %g2
        
        bne     .Lblock_loop
-       sub     ctx, src, %g2
+       sub     wtxt, src, %g3
 
 .Lend:
        ret