openstack/deb-libisal
Code Issues Proposed changes

igzip: Modify encode_df_04 to behave more like encode_df_06 algorithm

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Change-Id: I39c5d0d8182efb0fe8aa6bea97d9361df4ee8ddf
Signed-off-by: Roy Oursler <roy.j.oursler@intel.com>
This commit is contained in:
Roy Oursler 2017-04-25 13:35:53 -07:00 committed by Xiaodong Liu
parent 5a55e3096c
commit edacadc8fb
1 changed files with 34 additions and 17 deletions
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51
igzip/encode_df_04.asm
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@ -246,6 +246,13 @@ encode_deflate_icf_ %+ ARCH:
vpsrldq codes1, 8
vpsrldq code_lens1, 8
;; Bit align dqwords
vpaddq code_lens1, code_lens1, code_lens2
vpand ybits_count, code_lens1, yoffset_mask ;Extra bits
vpermq ybits_count, ybits_count, 0xcf
vpaddq code_lens2, ybits_count
vpsllvq codes2, codes2, ybits_count
;; Merge two qwords into dqwords
vmovdqa ytmp, [q_64]
vpsubq code_lens3, ytmp, code_lens2
@ -256,27 +263,30 @@ encode_deflate_icf_ %+ ARCH:
vpxor codes1, codes1, codes3
vpxor codes1, codes1, codes2
vpaddq code_lens1, code_lens1, code_lens2
vmovq tmp, code_lens1 %+ x ;Number of bytes
shr tmp, 3
vpand ybits_count, code_lens1, yoffset_mask ;Extra bits
;; Extract last bytes
vpaddq code_lens2, code_lens1, ybits_count
vpsrlq code_lens2, code_lens2, 3
vpshufb codes2, codes1, code_lens2
vpand codes2, codes2, [bytes_mask]
vextracti128 ybits %+ x, codes2, 1
;; Check for short codes
vptest code_lens2, [min_write_mask]
jz .short_codes
.short_codes_next
vpermq codes2, codes2, 0x45
vpor codes1, codes1, codes2
;; bit shift upper dqword combined bits to line up with lower dqword
vextracti128 codes2 %+ x, codes1, 1
vextracti128 code_lens2 %+ x, code_lens1, 1
vpbroadcastq ybits_count, ybits_count %+ x
vpsrldq codes3, codes2, 1
vpsllvq codes2, codes2, ybits_count
vpsllvq codes3, codes3, ybits_count
vpslldq codes3, codes3, 1
vpor codes2, codes2, codes3
; Write out lower dqword of combined bits
vmovdqu [out_buf], codes1
movzx bits, byte [out_buf + tmp]
vmovq codes1 %+ x, bits
vpaddq code_lens1, code_lens1, code_lens2
vmovq tmp2, code_lens1 %+ x ;Number of bytes
@ -284,11 +294,8 @@ encode_deflate_icf_ %+ ARCH:
vpand ybits_count, code_lens1, yoffset_mask ;Extra bits
; Write out upper dqword of combined bits
vpor codes1 %+ x, codes1 %+ x, codes2 %+ x
vmovdqu [out_buf + tmp], codes1 %+ x
vextracti128 [out_buf + tmp], codes1, 1
add out_buf, tmp2
movzx bits, byte [out_buf]
vmovq ybits %+ x, bits
cmp ptr, in_buf_end
jbe .main_loop
@ -298,6 +305,11 @@ encode_deflate_icf_ %+ ARCH:
vmovq bits, ybits %+ x
jmp .finish
.short_codes:
;; Merge last bytes when the second dqword contains less than a byte
vpor ybits %+ x, codes2 %+ x
jmp .short_codes_next
.long_codes:
add end_ptr, VECTOR_SLOP
sub ptr, VECTOR_SIZE
@ -509,7 +521,9 @@ encode_deflate_icf_ %+ ARCH:
section .data
align 32
max_write_d:
dd 0x1c, 0x1d, 0x20, 0x20, 0x1e, 0x1e, 0x1e, 0x1e
dd 0x1c, 0x1d, 0x1f, 0x20, 0x1c, 0x1d, 0x1f, 0x20
min_write_mask:
dq 0x00, 0x00, 0xff, 0x00
offset_mask:
dq 0x0000000000000007, 0x0000000000000000
dq 0x0000000000000000, 0x0000000000000000
@ -528,3 +542,6 @@ lit_icr_mask:
eb_icr_mask:
dd 0x000000FF, 0x000000FF, 0x000000FF, 0x000000FF
dd 0x000000FF, 0x000000FF, 0x000000FF, 0x000000FF
bytes_mask:
dq 0x00000000000000ff, 0x0000000000000000
dq 0x00000000000000ff, 0x0000000000000000