From: Eric Biggers <[email protected]>
To avoid source code duplication, do the SHA-256 rounds using macros.
This reduces the length of sha256_ni_asm.S by 148 lines while still
producing the exact same object file.
Signed-off-by: Eric Biggers <[email protected]>
---
arch/x86/crypto/sha256_ni_asm.S | 216 +++++---------------------------
1 file changed, 34 insertions(+), 182 deletions(-)
diff --git a/arch/x86/crypto/sha256_ni_asm.S b/arch/x86/crypto/sha256_ni_asm.S
index 537b6dcd7ed8..e485520e3b49 100644
--- a/arch/x86/crypto/sha256_ni_asm.S
+++ b/arch/x86/crypto/sha256_ni_asm.S
@@ -74,23 +74,50 @@
#define SHUF_MASK %xmm8
#define ABEF_SAVE %xmm9
#define CDGH_SAVE %xmm10
+.macro do_4rounds i, m0, m1, m2, m3
+.if \i < 16
+ movdqu \i*4(DATA_PTR), MSG
+ pshufb SHUF_MASK, MSG
+ movdqa MSG, \m0
+.else
+ movdqa \m0, MSG
+.endif
+ paddd \i*4(SHA256CONSTANTS), MSG
+ sha256rnds2 STATE0, STATE1
+.if \i >= 12 && \i < 60
+ movdqa \m0, MSGTMP4
+ palignr $4, \m3, MSGTMP4
+ paddd MSGTMP4, \m1
+ sha256msg2 \m0, \m1
+.endif
+ pshufd $0x0E, MSG, MSG
+ sha256rnds2 STATE1, STATE0
+.if \i >= 4 && \i < 52
+ sha256msg1 \m0, \m3
+.endif
+.endm
+
+.macro do_16rounds i
+ do_4rounds (\i + 0), MSGTMP0, MSGTMP1, MSGTMP2, MSGTMP3
+ do_4rounds (\i + 4), MSGTMP1, MSGTMP2, MSGTMP3, MSGTMP0
+ do_4rounds (\i + 8), MSGTMP2, MSGTMP3, MSGTMP0, MSGTMP1
+ do_4rounds (\i + 12), MSGTMP3, MSGTMP0, MSGTMP1, MSGTMP2
+.endm
+
/*
* Intel SHA Extensions optimized implementation of a SHA-256 update function
*
* The function takes a pointer to the current hash values, a pointer to the
* input data, and a number of 64 byte blocks to process. Once all blocks have
* been processed, the digest pointer is updated with the resulting hash value.
* The function only processes complete blocks, there is no functionality to
* store partial blocks. All message padding and hash value initialization must
* be done outside the update function.
*
- * The indented lines in the loop are instructions related to rounds processing.
- * The non-indented lines are instructions related to the message schedule.
- *
* void sha256_ni_transform(uint32_t *digest, const void *data,
uint32_t numBlocks);
* digest : pointer to digest
* data: pointer to input data
* numBlocks: Number of blocks to process
@@ -123,189 +150,14 @@ SYM_TYPED_FUNC_START(sha256_ni_transform)
.Lloop0:
/* Save hash values for addition after rounds */
movdqa STATE0, ABEF_SAVE
movdqa STATE1, CDGH_SAVE
- /* Rounds 0-3 */
- movdqu 0*16(DATA_PTR), MSG
- pshufb SHUF_MASK, MSG
- movdqa MSG, MSGTMP0
- paddd 0*16(SHA256CONSTANTS), MSG
- sha256rnds2 STATE0, STATE1
- pshufd $0x0E, MSG, MSG
- sha256rnds2 STATE1, STATE0
-
- /* Rounds 4-7 */
- movdqu 1*16(DATA_PTR), MSG
- pshufb SHUF_MASK, MSG
- movdqa MSG, MSGTMP1
- paddd 1*16(SHA256CONSTANTS), MSG
- sha256rnds2 STATE0, STATE1
- pshufd $0x0E, MSG, MSG
- sha256rnds2 STATE1, STATE0
- sha256msg1 MSGTMP1, MSGTMP0
-
- /* Rounds 8-11 */
- movdqu 2*16(DATA_PTR), MSG
- pshufb SHUF_MASK, MSG
- movdqa MSG, MSGTMP2
- paddd 2*16(SHA256CONSTANTS), MSG
- sha256rnds2 STATE0, STATE1
- pshufd $0x0E, MSG, MSG
- sha256rnds2 STATE1, STATE0
- sha256msg1 MSGTMP2, MSGTMP1
-
- /* Rounds 12-15 */
- movdqu 3*16(DATA_PTR), MSG
- pshufb SHUF_MASK, MSG
- movdqa MSG, MSGTMP3
- paddd 3*16(SHA256CONSTANTS), MSG
- sha256rnds2 STATE0, STATE1
- movdqa MSGTMP3, MSGTMP4
- palignr $4, MSGTMP2, MSGTMP4
- paddd MSGTMP4, MSGTMP0
- sha256msg2 MSGTMP3, MSGTMP0
- pshufd $0x0E, MSG, MSG
- sha256rnds2 STATE1, STATE0
- sha256msg1 MSGTMP3, MSGTMP2
-
- /* Rounds 16-19 */
- movdqa MSGTMP0, MSG
- paddd 4*16(SHA256CONSTANTS), MSG
- sha256rnds2 STATE0, STATE1
- movdqa MSGTMP0, MSGTMP4
- palignr $4, MSGTMP3, MSGTMP4
- paddd MSGTMP4, MSGTMP1
- sha256msg2 MSGTMP0, MSGTMP1
- pshufd $0x0E, MSG, MSG
- sha256rnds2 STATE1, STATE0
- sha256msg1 MSGTMP0, MSGTMP3
-
- /* Rounds 20-23 */
- movdqa MSGTMP1, MSG
- paddd 5*16(SHA256CONSTANTS), MSG
- sha256rnds2 STATE0, STATE1
- movdqa MSGTMP1, MSGTMP4
- palignr $4, MSGTMP0, MSGTMP4
- paddd MSGTMP4, MSGTMP2
- sha256msg2 MSGTMP1, MSGTMP2
- pshufd $0x0E, MSG, MSG
- sha256rnds2 STATE1, STATE0
- sha256msg1 MSGTMP1, MSGTMP0
-
- /* Rounds 24-27 */
- movdqa MSGTMP2, MSG
- paddd 6*16(SHA256CONSTANTS), MSG
- sha256rnds2 STATE0, STATE1
- movdqa MSGTMP2, MSGTMP4
- palignr $4, MSGTMP1, MSGTMP4
- paddd MSGTMP4, MSGTMP3
- sha256msg2 MSGTMP2, MSGTMP3
- pshufd $0x0E, MSG, MSG
- sha256rnds2 STATE1, STATE0
- sha256msg1 MSGTMP2, MSGTMP1
-
- /* Rounds 28-31 */
- movdqa MSGTMP3, MSG
- paddd 7*16(SHA256CONSTANTS), MSG
- sha256rnds2 STATE0, STATE1
- movdqa MSGTMP3, MSGTMP4
- palignr $4, MSGTMP2, MSGTMP4
- paddd MSGTMP4, MSGTMP0
- sha256msg2 MSGTMP3, MSGTMP0
- pshufd $0x0E, MSG, MSG
- sha256rnds2 STATE1, STATE0
- sha256msg1 MSGTMP3, MSGTMP2
-
- /* Rounds 32-35 */
- movdqa MSGTMP0, MSG
- paddd 8*16(SHA256CONSTANTS), MSG
- sha256rnds2 STATE0, STATE1
- movdqa MSGTMP0, MSGTMP4
- palignr $4, MSGTMP3, MSGTMP4
- paddd MSGTMP4, MSGTMP1
- sha256msg2 MSGTMP0, MSGTMP1
- pshufd $0x0E, MSG, MSG
- sha256rnds2 STATE1, STATE0
- sha256msg1 MSGTMP0, MSGTMP3
-
- /* Rounds 36-39 */
- movdqa MSGTMP1, MSG
- paddd 9*16(SHA256CONSTANTS), MSG
- sha256rnds2 STATE0, STATE1
- movdqa MSGTMP1, MSGTMP4
- palignr $4, MSGTMP0, MSGTMP4
- paddd MSGTMP4, MSGTMP2
- sha256msg2 MSGTMP1, MSGTMP2
- pshufd $0x0E, MSG, MSG
- sha256rnds2 STATE1, STATE0
- sha256msg1 MSGTMP1, MSGTMP0
-
- /* Rounds 40-43 */
- movdqa MSGTMP2, MSG
- paddd 10*16(SHA256CONSTANTS), MSG
- sha256rnds2 STATE0, STATE1
- movdqa MSGTMP2, MSGTMP4
- palignr $4, MSGTMP1, MSGTMP4
- paddd MSGTMP4, MSGTMP3
- sha256msg2 MSGTMP2, MSGTMP3
- pshufd $0x0E, MSG, MSG
- sha256rnds2 STATE1, STATE0
- sha256msg1 MSGTMP2, MSGTMP1
-
- /* Rounds 44-47 */
- movdqa MSGTMP3, MSG
- paddd 11*16(SHA256CONSTANTS), MSG
- sha256rnds2 STATE0, STATE1
- movdqa MSGTMP3, MSGTMP4
- palignr $4, MSGTMP2, MSGTMP4
- paddd MSGTMP4, MSGTMP0
- sha256msg2 MSGTMP3, MSGTMP0
- pshufd $0x0E, MSG, MSG
- sha256rnds2 STATE1, STATE0
- sha256msg1 MSGTMP3, MSGTMP2
-
- /* Rounds 48-51 */
- movdqa MSGTMP0, MSG
- paddd 12*16(SHA256CONSTANTS), MSG
- sha256rnds2 STATE0, STATE1
- movdqa MSGTMP0, MSGTMP4
- palignr $4, MSGTMP3, MSGTMP4
- paddd MSGTMP4, MSGTMP1
- sha256msg2 MSGTMP0, MSGTMP1
- pshufd $0x0E, MSG, MSG
- sha256rnds2 STATE1, STATE0
- sha256msg1 MSGTMP0, MSGTMP3
-
- /* Rounds 52-55 */
- movdqa MSGTMP1, MSG
- paddd 13*16(SHA256CONSTANTS), MSG
- sha256rnds2 STATE0, STATE1
- movdqa MSGTMP1, MSGTMP4
- palignr $4, MSGTMP0, MSGTMP4
- paddd MSGTMP4, MSGTMP2
- sha256msg2 MSGTMP1, MSGTMP2
- pshufd $0x0E, MSG, MSG
- sha256rnds2 STATE1, STATE0
-
- /* Rounds 56-59 */
- movdqa MSGTMP2, MSG
- paddd 14*16(SHA256CONSTANTS), MSG
- sha256rnds2 STATE0, STATE1
- movdqa MSGTMP2, MSGTMP4
- palignr $4, MSGTMP1, MSGTMP4
- paddd MSGTMP4, MSGTMP3
- sha256msg2 MSGTMP2, MSGTMP3
- pshufd $0x0E, MSG, MSG
- sha256rnds2 STATE1, STATE0
-
- /* Rounds 60-63 */
- movdqa MSGTMP3, MSG
- paddd 15*16(SHA256CONSTANTS), MSG
- sha256rnds2 STATE0, STATE1
- pshufd $0x0E, MSG, MSG
- sha256rnds2 STATE1, STATE0
+ do_16rounds 0
+ do_16rounds 16
+ do_16rounds 32
+ do_16rounds 48
/* Add current hash values with previously saved */
paddd ABEF_SAVE, STATE0
paddd CDGH_SAVE, STATE1
--
2.44.0
"Eric Biggers" <[email protected]> wrote:
> +.macro do_4rounds i, m0, m1, m2, m3
> +.if \i < 16
> + movdqu \i*4(DATA_PTR), MSG
> + pshufb SHUF_MASK, MSG
> + movdqa MSG, \m0
> +.else
> + movdqa \m0, MSG
> +.endif
> + paddd \i*4(SHA256CONSTANTS), MSG
To load the round constant independent from and parallel to the previous
instructions which use \m0 I recommend to change the first lines of the
do_4rounds macro as follows (this might save 1+ cycle per macro invocation,
and most obviously 2 lines):
.macro do_4rounds i, m0, m1, m2, m3
.if \i < 16
movdqu \i*4(DATA_PTR), \m0
pshufb SHUF_MASK, \m0
.endif
movdqa \i*4(SHA256CONSTANTS), MSG
paddd \m0, MSG
...
regards
Stefan
"Eric Biggers" <[email protected]> wrote:
> On Tue, Apr 09, 2024 at 06:52:02PM +0200, Stefan Kanthak wrote:
>> "Eric Biggers" <[email protected]> wrote:
>>
>> > +.macro do_4rounds i, m0, m1, m2, m3
>> > +.if \i < 16
>> > + movdqu \i*4(DATA_PTR), MSG
>> > + pshufb SHUF_MASK, MSG
>> > + movdqa MSG, \m0
>> > +.else
>> > + movdqa \m0, MSG
>> > +.endif
>> > + paddd \i*4(SHA256CONSTANTS), MSG
>>
>> To load the round constant independent from and parallel to the previous
>> instructions which use \m0 I recommend to change the first lines of the
>> do_4rounds macro as follows (this might save 1+ cycle per macro invocation,
>> and most obviously 2 lines):
>>
>> .macro do_4rounds i, m0, m1, m2, m3
>> .if \i < 16
>> movdqu \i*4(DATA_PTR), \m0
>> pshufb SHUF_MASK, \m0
>> .endif
>> movdqa \i*4(SHA256CONSTANTS), MSG
>> paddd \m0, MSG
>> ...
>
> Yes, your suggestion looks good. I don't see any performance difference on
> Ice Lake, but it does shorten the source code. It belongs in a separate patch
> though, since this patch isn't meant to change the output.
Hmmm... the output was already changed: 2 palignr/pblendw and 16 pshufd
have been replaced with punpck?qdq, and 17 displacements changed.
Next simplification, and 5 more lines gone: replace the macro do_16rounds
with a repetition
@@ ...
-.macro do_16rounds i
- do_4rounds (\i + 0), MSGTMP0, MSGTMP1, MSGTMP2, MSGTMP3
- do_4rounds (\i + 4), MSGTMP1, MSGTMP2, MSGTMP3, MSGTMP0
- do_4rounds (\i + 8), MSGTMP2, MSGTMP3, MSGTMP0, MSGTMP1
- do_4rounds (\i + 12), MSGTMP3, MSGTMP0, MSGTMP1, MSGTMP2
-.endm
-
@@ ...
- do_16rounds 0
- do_16rounds 16
- do_16rounds 32
- do_16rounds 48
+.irp i, 0, 16, 32, 48
+ do_4rounds (\i + 0), MSGTMP0, MSGTMP1, MSGTMP2, MSGTMP3
+ do_4rounds (\i + 4), MSGTMP1, MSGTMP2, MSGTMP3, MSGTMP0
+ do_4rounds (\i + 8), MSGTMP2, MSGTMP3, MSGTMP0, MSGTMP1
+ do_4rounds (\i + 12), MSGTMP3, MSGTMP0, MSGTMP1, MSGTMP2
+.endr
This doesn't change the instructions generated, so it belongs to this patch.
The following suggestion changes instructions: AFAIK all processors which
support the SHA extensions support AVX too
@@ ...
+.ifnotdef AVX
movdqa STATE0, MSGTMP4
punpcklqdq STATE1, STATE0 /* FEBA */
punpckhqdq MSGTMP4, STATE1 /* DCHG */
pshufd $0x1B, STATE0, STATE0 /* ABEF */
pshufd $0xB1, STATE1, STATE1 /* CDGH */
+.else
+ vpunpckhqdq STATE0, STATE1, MSGTMP0 /* DCHG */
+ vpunpcklqdq STATE0, STATE1, MSGTMP1 /* BAFE */
+ pshufd $0xB1, MSGTMP0, STATE0 /* CDGH */
+ pshufd $0xB1, MSGTMP1, STATE1 /* ABEF */
+.endif
@@ ...
+.ifnotdef AVX
movdqa \i*4(SHA256CONSTANTS), MSG
paddd \m0, MSG
+.else
+ vpaddd \i*4(SHA256CONSTANTS), \m0, MSG
+.endif
@@ ...
+.ifnotdef AVX
movdqa \m0, MSGTMP4
palignr $4, \m3, MSGTMP4
+.else
+ vpalignr $4, \m3, \m0, MSGTMP4
+.endif
@@ ...
+.ifnotdef AVX
movdqa STATE1, MSGTMP4
punpcklqdq STATE0, STATE1 /* EFGH */
punpckhqdq MSGTMP4, STATE0 /* CDAB */
pshufd $0x1B, STATE0, STATE0 /* DCBA */
pshufd $0xB1, STATE1, STATE1 /* HGFE */
+.else
+ vpunpckhqdq STATE0, STATE1, MSGTMP0 /* ABCD */
+ vpunpcklqdq STATE0, STATE1, MSGTMP1 /* EFGH */
+ pshufd $0x1B, MSGTMP0, STATE0 /* DCBA */
+ pshufd $0x1B, MSGTMP1, STATE1 /* HGFE */
+.endif
And last: are the "#define ... %xmm?" really necessary?
- MSG can't be anything but %xmm0;
- MSGTMP4 is despite its prefix MSG also used to shuffle STATE0 and STATE1,
so it should be named TMP instead (if kept);
- MSGTMP0 to MSGTMP3 are the circular message schedule, they should be named
MSG0 to MSG3 instead (if kept).
I suggest to remove at least those which are now encapsulated in the macro
and the repetition.
regards
Stefan
Hi Stefan,
On Thu, Apr 11, 2024 at 09:42:00AM +0200, Stefan Kanthak wrote:
> "Eric Biggers" <[email protected]> wrote:
>
> > On Tue, Apr 09, 2024 at 06:52:02PM +0200, Stefan Kanthak wrote:
> >> "Eric Biggers" <[email protected]> wrote:
> >>
> >> > +.macro do_4rounds i, m0, m1, m2, m3
> >> > +.if \i < 16
> >> > + movdqu \i*4(DATA_PTR), MSG
> >> > + pshufb SHUF_MASK, MSG
> >> > + movdqa MSG, \m0
> >> > +.else
> >> > + movdqa \m0, MSG
> >> > +.endif
> >> > + paddd \i*4(SHA256CONSTANTS), MSG
> >>
> >> To load the round constant independent from and parallel to the previous
> >> instructions which use \m0 I recommend to change the first lines of the
> >> do_4rounds macro as follows (this might save 1+ cycle per macro invocation,
> >> and most obviously 2 lines):
> >>
> >> .macro do_4rounds i, m0, m1, m2, m3
> >> .if \i < 16
> >> movdqu \i*4(DATA_PTR), \m0
> >> pshufb SHUF_MASK, \m0
> >> .endif
> >> movdqa \i*4(SHA256CONSTANTS), MSG
> >> paddd \m0, MSG
> >> ...
> >
> > Yes, your suggestion looks good. I don't see any performance difference on
> > Ice Lake, but it does shorten the source code. It belongs in a separate patch
> > though, since this patch isn't meant to change the output.
>
> Hmmm... the output was already changed: 2 palignr/pblendw and 16 pshufd
> have been replaced with punpck?qdq, and 17 displacements changed.
Yes, the second patch does that. Your comment is on the first patch, so I
thought you were suggesting changing the first patch. I'll handle your
suggestion in another patch. I'm just trying to keep changes to the actual
output separate from source code only cleanups.
> Next simplification, and 5 more lines gone: replace the macro do_16rounds
> with a repetition
>
> @@ ...
> -.macro do_16rounds i
> - do_4rounds (\i + 0), MSGTMP0, MSGTMP1, MSGTMP2, MSGTMP3
> - do_4rounds (\i + 4), MSGTMP1, MSGTMP2, MSGTMP3, MSGTMP0
> - do_4rounds (\i + 8), MSGTMP2, MSGTMP3, MSGTMP0, MSGTMP1
> - do_4rounds (\i + 12), MSGTMP3, MSGTMP0, MSGTMP1, MSGTMP2
> -.endm
> -
> @@ ...
> - do_16rounds 0
> - do_16rounds 16
> - do_16rounds 32
> - do_16rounds 48
> +.irp i, 0, 16, 32, 48
> + do_4rounds (\i + 0), MSGTMP0, MSGTMP1, MSGTMP2, MSGTMP3
> + do_4rounds (\i + 4), MSGTMP1, MSGTMP2, MSGTMP3, MSGTMP0
> + do_4rounds (\i + 8), MSGTMP2, MSGTMP3, MSGTMP0, MSGTMP1
> + do_4rounds (\i + 12), MSGTMP3, MSGTMP0, MSGTMP1, MSGTMP2
> +.endr
>
> This doesn't change the instructions generated, so it belongs to this patch.
Yes, that makes sense.
> The following suggestion changes instructions: AFAIK all processors which
> support the SHA extensions support AVX too
No (unfortunately). Several generations of Intel's low-power CPUs support SHA
but not AVX. Namely Goldmont, Goldmont Plus, and Tremont.
We could provide two SHA-256 implementations, one with AVX and one without. I
think it's not worthwhile, though.
We ran into this issue with AES-NI too; I was hoping that we could just provide
the new AES-NI + AVX implementation of AES-XTS, and remove the older
implementation that uses AES-NI alone. However, apparently the above-mentioned
low-power CPUs do need the implementation that uses AES-NI alone.
> And last: are the "#define ... %xmm?" really necessary?
>
> - MSG can't be anything but %xmm0;
> - MSGTMP4 is despite its prefix MSG also used to shuffle STATE0 and STATE1,
> so it should be named TMP instead (if kept);
> - MSGTMP0 to MSGTMP3 are the circular message schedule, they should be named
> MSG0 to MSG3 instead (if kept).
>
> I suggest to remove at least those which are now encapsulated in the macro
> and the repetition.
Yes, I noticed the weird naming too. I'll rename MSGTMP[0-3] to MSG[0-3], and
MSGTMP4 to TMP.
You're correct that MSG has to be xmm0 because of how sha256rnds2 uses xmm0 as
an implicit operand. I think I'll leave the '#define' for MSG anyway because
the list of aliases helps make it clear what each register is used for.
Thanks,
- Eric