(_aes_crypt): Decrement round when looping, saving yet some

instructions.

Rev: src/nettle/sparc/aes.asm:1.61

diff --git a/sparc/aes.asm b/sparc/aes.asm
index 4dbe1800b40c38058dab2119a47a1d01342058db..8256d7a8e070d2c5d3f1ad6344e3c6d6f1c5a09c 100644 (file)
--- a/sparc/aes.asm
+++ b/sparc/aes.asm
@@ -27,7 +27,7 @@ define(diff, %l2)
 define(nrounds, %l3)
 
 ! Loop variables
-define(round, %l4) ! Really 16 * round
+define(round, %l4)
 define(i, %l5)
 
 ! Further loop invariants
@@ -57,24 +57,22 @@ _aes_crypt:
        ! Compute xor, so that we can swap efficiently.
        xor     wtxt, tmp, diff
        ! The loop variable will be multiplied by 16.
-       sll     nrounds, 4, nrounds
-       
        ! More loop invariants
        add     T, AES_TABLE0, T0
+       
        add     T, AES_TABLE1, T1
        add     T, AES_TABLE2, T2
        add     T, AES_TABLE3, T3
-               
-.Lblock_loop:
        ! Read src, and add initial subkey
-       ! Difference between ctx and src
+       ! Difference between ctx and src.
+       ! NOTE: This isntruction is duplicated in the delay slot
        sub     ctx, src, %g2
+.Lblock_loop:
        ! Difference between wtxt and src
        sub     wtxt, src, %g3
        ! For stop condition. Note that src is incremented in the
        ! delay slot
        add     src, 8, %g4
-       nop
        
 .Lsource_loop:
        ldub    [src+3], t3
@@ -98,7 +96,7 @@ _aes_crypt:
        bleu    .Lsource_loop
        add     src, 4, src
 
-       mov     16, round
+       sub     nrounds, 1, round
        add     ctx, 16, key
 
 .Lround_loop:
@@ -158,11 +156,10 @@ _aes_crypt:
        
        ! switch roles for tmp and wtxt
        xor     wtxt, diff, wtxt
-       add     round, 16, round
+       subcc   round, 1, round
        add     key, 16, key
-       cmp     round, nrounds
 
-       blu     .Lround_loop
+       bne     .Lround_loop
        xor     tmp, diff, tmp
 
        ! final round
@@ -218,8 +215,8 @@ _aes_crypt:
        
        addcc   length, -16, length
        bne     .Lblock_loop
-       nop
-       !       add     dst, 16, dst
+       sub     ctx, src, %g2
+
 .Lend:
        ret
        restore