C: asm: emulate pblendw using SSE2 instructions

Use a constant mask to blend according to (mask & b) | ((~mask) & a).

 * c/blake3_sse2_x86-64_unix.S: emulate pblendw using SSE2 instructions for x86_64 unix
 * c/blake3_sse2_x86-64_windows_gnu.S: Likewise for x86_64 Windows GNU.
 * c/blake3_sse2_x86-64_windows_msvc.asm: Likewise for x86_64 Windows MSVC.

3 files changed, 216 insertions, 30 deletions

diff --git a/c/blake3_sse2_x86-64_unix.S b/c/blake3_sse2_x86-64_unix.S
index 0d48f08..0ba7183 100644
--- a/c/blake3_sse2_x86-64_unix.S
+++ b/c/blake3_sse2_x86-64_unix.S
@@ -1619,10 +1619,24 @@ blake3_hash_many_sse2:
         pshufd  xmm4, xmm12, 0x39
         movdqa  xmm12, xmm6
         shufps  xmm12, xmm7, 250
-        pblendw xmm13, xmm12, 0xCC
+        movdqa  xmmword ptr [rsp+0x20], xmm2
+        movdqa  xmmword ptr [rsp+0x40], xmm3
+        movdqa  xmm2, xmmword ptr [PBLENDW_0xCC_MASK+rip]
+        movdqa  xmm3, xmm2
+        pandn   xmm2, xmm13
+        pand    xmm3, xmm12
+        movdqa  xmm13, xmm3
+        por     xmm13, xmm2
         movdqa  xmm12, xmm7
         punpcklqdq xmm12, xmm5
-        pblendw xmm12, xmm6, 0xC0
+        movdqa  xmm2, xmmword ptr [PBLENDW_0xC0_MASK+rip]
+        movdqa  xmm3, xmm2
+        pandn   xmm2, xmm12
+        pand    xmm3, xmm6
+        movdqa  xmm12, xmm3
+        por     xmm12, xmm2
+        movdqa  xmm2, xmmword ptr [rsp+0x20]
+        movdqa  xmm3, xmmword ptr [rsp+0x40]
         pshufd  xmm12, xmm12, 0x78
         punpckhdq xmm5, xmm7
         punpckldq xmm6, xmm5
@@ -1636,10 +1650,24 @@ blake3_hash_many_sse2:
         pshufd  xmm12, xmm5, 0x39
         movdqa  xmm5, xmm14
         shufps  xmm5, xmm15, 250
-        pblendw xmm6, xmm5, 0xCC
+        movdqa  xmmword ptr [rsp+0x30], xmm2
+        movdqa  xmmword ptr [rsp+0x50], xmm3
+        movdqa  xmm2, xmmword ptr [PBLENDW_0xCC_MASK+rip]
+        movdqa  xmm3, xmm2
+        pandn   xmm2, xmm6
+        pand    xmm3, xmm5
+        movdqa  xmm6, xmm3
+        por     xmm6, xmm2
         movdqa  xmm5, xmm15
         punpcklqdq xmm5, xmm13
-        pblendw xmm5, xmm14, 0xC0
+        movdqa  xmm2, xmmword ptr [PBLENDW_0xC0_MASK+rip]
+        movdqa  xmm3, xmm2
+        pandn   xmm2, xmm5
+        pand    xmm3, xmm14
+        movdqa  xmm5, xmm3
+        por     xmm5, xmm2
+        movdqa  xmm2, xmmword ptr [rsp+0x30]
+        movdqa  xmm3, xmmword ptr [rsp+0x50]
         pshufd  xmm5, xmm5, 0x78
         punpckhdq xmm13, xmm15
         punpckldq xmm14, xmm13
@@ -1765,10 +1793,20 @@ blake3_hash_many_sse2:
         pshufd  xmm4, xmm8, 0x39
         movdqa  xmm8, xmm6
         shufps  xmm8, xmm7, 250
-        pblendw xmm9, xmm8, 0xCC
+        movdqa  xmm10, xmmword ptr [PBLENDW_0xCC_MASK+rip]
+        movdqa  xmm11, xmm10
+        pandn   xmm10, xmm9
+        pand    xmm11, xmm8
+        movdqa  xmm9, xmm11
+        por     xmm9, xmm10
         movdqa  xmm8, xmm7
         punpcklqdq xmm8, xmm5
-        pblendw xmm8, xmm6, 0xC0
+        movdqa  xmm10, xmmword ptr [PBLENDW_0xC0_MASK+rip]
+        movdqa  xmm11, xmm10
+        pandn   xmm10, xmm8
+        pand    xmm11, xmm6
+        movdqa  xmm8, xmm11
+        por     xmm8, xmm10
         pshufd  xmm8, xmm8, 0x78
         punpckhdq xmm5, xmm7
         punpckldq xmm6, xmm5
@@ -1869,10 +1907,20 @@ _blake3_compress_in_place_sse2:
         pshufd  xmm4, xmm8, 0x39
         movdqa  xmm8, xmm6
         shufps  xmm8, xmm7, 250
-        pblendw xmm9, xmm8, 0xCC
+        movdqa  xmm10, xmmword ptr [PBLENDW_0xCC_MASK+rip]
+        movdqa  xmm11, xmm10
+        pandn   xmm10, xmm9
+        pand    xmm11, xmm8
+        movdqa  xmm9, xmm11
+        por     xmm9, xmm10
         movdqa  xmm8, xmm7
         punpcklqdq xmm8, xmm5
-        pblendw xmm8, xmm6, 0xC0
+        movdqa  xmm10, xmmword ptr [PBLENDW_0xC0_MASK+rip]
+        movdqa  xmm11, xmm10
+        pandn   xmm10, xmm8
+        pand    xmm11, xmm6
+        movdqa  xmm8, xmm11
+        por     xmm8, xmm10
         pshufd  xmm8, xmm8, 0x78
         punpckhdq xmm5, xmm7
         punpckldq xmm6, xmm5
@@ -1972,10 +2020,20 @@ _blake3_compress_xof_sse2:
         pshufd  xmm4, xmm8, 0x39
         movdqa  xmm8, xmm6
         shufps  xmm8, xmm7, 250
-        pblendw xmm9, xmm8, 0xCC
+        movdqa  xmm10, xmmword ptr [PBLENDW_0xCC_MASK+rip]
+        movdqa  xmm11, xmm10
+        pandn   xmm10, xmm9
+        pand    xmm11, xmm8
+        movdqa  xmm9, xmm11
+        por     xmm9, xmm10
         movdqa  xmm8, xmm7
         punpcklqdq xmm8, xmm5
-        pblendw xmm8, xmm6, 0xC0
+        movdqa  xmm10, xmmword ptr [PBLENDW_0xC0_MASK+rip]
+        movdqa  xmm11, xmm10
+        pandn   xmm10, xmm8
+        pand    xmm11, xmm6
+        movdqa  xmm8, xmm11
+        por     xmm8, xmm10
         pshufd  xmm8, xmm8, 0x78
         punpckhdq xmm5, xmm7
         punpckldq xmm6, xmm5
@@ -2026,3 +2084,7 @@ BLAKE3_BLOCK_LEN:
 	.long  64, 64, 64, 64
 CMP_MSB_MASK:
 	.long  0x80000000, 0x80000000, 0x80000000, 0x80000000
+PBLENDW_0xCC_MASK:
+	.long  0x00000000, 0xFFFFFFFF, 0x00000000, 0xFFFFFFFF
+PBLENDW_0xC0_MASK:
+	.long  0x00000000, 0x00000000, 0x00000000, 0xFFFFFFFF
diff --git a/c/blake3_sse2_x86-64_windows_gnu.S b/c/blake3_sse2_x86-64_windows_gnu.S
index 9dcf65f..8092f60 100644
--- a/c/blake3_sse2_x86-64_windows_gnu.S
+++ b/c/blake3_sse2_x86-64_windows_gnu.S
@@ -1630,10 +1630,24 @@ blake3_hash_many_sse2:
         pshufd  xmm4, xmm12, 0x39
         movdqa  xmm12, xmm6
         shufps  xmm12, xmm7, 250
-        pblendw xmm13, xmm12, 0xCC
+        movdqa  xmmword ptr [rsp+0x20], xmm2
+        movdqa  xmmword ptr [rsp+0x40], xmm3
+        movdqa  xmm2, xmmword ptr [PBLENDW_0xCC_MASK+rip]
+        movdqa  xmm3, xmm2
+        pandn   xmm2, xmm13
+        pand    xmm3, xmm12
+        movdqa  xmm13, xmm3
+        por     xmm13, xmm2
         movdqa  xmm12, xmm7
         punpcklqdq xmm12, xmm5
-        pblendw xmm12, xmm6, 0xC0
+        movdqa  xmm2, xmmword ptr [PBLENDW_0xC0_MASK+rip]
+        movdqa  xmm3, xmm2
+        pandn   xmm2, xmm12
+        pand    xmm3, xmm6
+        movdqa  xmm12, xmm3
+        por     xmm12, xmm2
+        movdqa  xmm2, xmmword ptr [rsp+0x20]
+        movdqa  xmm3, xmmword ptr [rsp+0x40]
         pshufd  xmm12, xmm12, 0x78
         punpckhdq xmm5, xmm7
         punpckldq xmm6, xmm5
@@ -1647,10 +1661,24 @@ blake3_hash_many_sse2:
         pshufd  xmm12, xmm5, 0x39
         movdqa  xmm5, xmm14
         shufps  xmm5, xmm15, 250
-        pblendw xmm6, xmm5, 0xCC
+        movdqa  xmmword ptr [rsp+0x30], xmm2
+        movdqa  xmmword ptr [rsp+0x50], xmm3
+        movdqa  xmm2, xmmword ptr [PBLENDW_0xCC_MASK+rip]
+        movdqa  xmm3, xmm2
+        pandn   xmm2, xmm6
+        pand    xmm3, xmm5
+        movdqa  xmm6, xmm3
+        por     xmm6, xmm2
         movdqa  xmm5, xmm15
         punpcklqdq xmm5, xmm13
-        pblendw xmm5, xmm14, 0xC0
+        movdqa  xmm2, xmmword ptr [PBLENDW_0xC0_MASK+rip]
+        movdqa  xmm3, xmm2
+        pandn   xmm2, xmm5
+        pand    xmm3, xmm14
+        movdqa  xmm5, xmm3
+        por     xmm5, xmm2
+        movdqa  xmm2, xmmword ptr [rsp+0x30]
+        movdqa  xmm3, xmmword ptr [rsp+0x50]
         pshufd  xmm5, xmm5, 0x78
         punpckhdq xmm13, xmm15
         punpckldq xmm14, xmm13
@@ -1776,10 +1804,20 @@ blake3_hash_many_sse2:
         pshufd  xmm4, xmm8, 0x39
         movdqa  xmm8, xmm6
         shufps  xmm8, xmm7, 250
-        pblendw xmm9, xmm8, 0xCC
+        movdqa  xmm10, xmmword ptr [PBLENDW_0xCC_MASK+rip]
+        movdqa  xmm11, xmm10
+        pandn   xmm10, xmm9
+        pand    xmm11, xmm8
+        movdqa  xmm9, xmm11
+        por     xmm9, xmm10
         movdqa  xmm8, xmm7
         punpcklqdq xmm8, xmm5
-        pblendw xmm8, xmm6, 0xC0
+        movdqa  xmm10, xmmword ptr [PBLENDW_0xC0_MASK+rip]
+        movdqa  xmm11, xmm10
+        pandn   xmm10, xmm8
+        pand    xmm11, xmm6
+        movdqa  xmm8, xmm11
+        por     xmm8, xmm10
         pshufd  xmm8, xmm8, 0x78
         punpckhdq xmm5, xmm7
         punpckldq xmm6, xmm5
@@ -1889,10 +1927,20 @@ _blake3_compress_in_place_sse2:
         pshufd  xmm4, xmm8, 0x39
         movdqa  xmm8, xmm6
         shufps  xmm8, xmm7, 250
-        pblendw xmm9, xmm8, 0xCC
+        movdqa  xmm10, xmmword ptr [PBLENDW_0xCC_MASK+rip]
+        movdqa  xmm11, xmm10
+        pandn   xmm10, xmm9
+        pand    xmm11, xmm8
+        movdqa  xmm9, xmm11
+        por     xmm9, xmm10
         movdqa  xmm8, xmm7
         punpcklqdq xmm8, xmm5
-        pblendw xmm8, xmm6, 0xC0
+        movdqa  xmm10, xmmword ptr [PBLENDW_0xC0_MASK+rip]
+        movdqa  xmm11, xmm10
+        pandn   xmm10, xmm8
+        pand    xmm11, xmm6
+        movdqa  xmm8, xmm11
+        por     xmm8, xmm10
         pshufd  xmm8, xmm8, 0x78
         punpckhdq xmm5, xmm7
         punpckldq xmm6, xmm5
@@ -2009,10 +2057,20 @@ blake3_compress_xof_sse2:
         pshufd  xmm4, xmm8, 0x39
         movdqa  xmm8, xmm6
         shufps  xmm8, xmm7, 250
-        pblendw xmm9, xmm8, 0xCC
+        movdqa  xmm10, xmmword ptr [PBLENDW_0xCC_MASK+rip]
+        movdqa  xmm11, xmm10
+        pandn   xmm10, xmm9
+        pand    xmm11, xmm8
+        movdqa  xmm9, xmm11
+        por     xmm9, xmm10
         movdqa  xmm8, xmm7
         punpcklqdq xmm8, xmm5
-        pblendw xmm8, xmm6, 0xC0
+        movdqa  xmm10, xmmword ptr [PBLENDW_0xC0_MASK+rip]
+        movdqa  xmm11, xmm10
+        pandn   xmm10, xmm8
+        pand    xmm11, xmm6
+        movdqa  xmm8, xmm11
+        por     xmm8, xmm10
         pshufd  xmm8, xmm8, 0x78
         punpckhdq xmm5, xmm7
         punpckldq xmm6, xmm5
@@ -2067,3 +2125,7 @@ BLAKE3_BLOCK_LEN:
         .long  64, 64, 64, 64
 CMP_MSB_MASK:
         .long  0x80000000, 0x80000000, 0x80000000, 0x80000000
+PBLENDW_0xCC_MASK:
+        .long  0x00000000, 0xFFFFFFFF, 0x00000000, 0xFFFFFFFF
+PBLENDW_0xC0_MASK:
+        .long  0x00000000, 0x00000000, 0x00000000, 0xFFFFFFFF
diff --git a/c/blake3_sse2_x86-64_windows_msvc.asm b/c/blake3_sse2_x86-64_windows_msvc.asm
index 85ba72d..93c6ec3 100644
--- a/c/blake3_sse2_x86-64_windows_msvc.asm
+++ b/c/blake3_sse2_x86-64_windows_msvc.asm
@@ -1631,10 +1631,24 @@ roundloop2:
         pshufd  xmm4, xmm12, 39H
         movdqa  xmm12, xmm6
         shufps  xmm12, xmm7, 250
-        pblendw xmm13, xmm12, 0CCH
+        movdqa  xmmword ptr [rsp+20H], xmm2
+        movdqa  xmmword ptr [rsp+40H], xmm3
+        movdqa  xmm2, xmmword ptr [PBLENDW_0xCC_MASK]
+        movdqa  xmm3, xmm2
+        pandn   xmm2, xmm13
+        pand    xmm3, xmm12
+        movdqa  xmm13, xmm3
+        por     xmm13, xmm2
         movdqa  xmm12, xmm7
         punpcklqdq xmm12, xmm5
-        pblendw xmm12, xmm6, 0C0H
+        movdqa  xmm2, xmmword ptr [PBLENDW_0xC0_MASK]
+        movdqa  xmm3, xmm2
+        pandn   xmm2, xmm12
+        pand    xmm3, xmm6
+        movdqa  xmm12, xmm3
+        por     xmm12, xmm2
+        movdqa  xmm2, xmmword ptr [rsp+20H]
+        movdqa  xmm3, xmmword ptr [rsp+40H]
         pshufd  xmm12, xmm12, 78H
         punpckhdq xmm5, xmm7
         punpckldq xmm6, xmm5
@@ -1648,10 +1662,24 @@ roundloop2:
         pshufd  xmm12, xmm5, 39H
         movdqa  xmm5, xmm14
         shufps  xmm5, xmm15, 250
-        pblendw xmm6, xmm5, 0CCH
+        movdqa  xmmword ptr [rsp+30H], xmm2
+        movdqa  xmmword ptr [rsp+50H], xmm3
+        movdqa  xmm2, xmmword ptr [PBLENDW_0xCC_MASK]
+        movdqa  xmm3, xmm2
+        pandn   xmm2, xmm6
+        pand    xmm3, xmm5
+        movdqa  xmm6, xmm3
+        por     xmm6, xmm2
         movdqa  xmm5, xmm15
         punpcklqdq xmm5, xmm13
-        pblendw xmm5, xmm14, 0C0H
+        movdqa  xmm2, xmmword ptr [PBLENDW_0xC0_MASK]
+        movdqa  xmm3, xmm2
+        pandn   xmm2, xmm5
+        pand    xmm3, xmm14
+        movdqa  xmm5, xmm3
+        por     xmm5, xmm2
+        movdqa  xmm2, xmmword ptr [rsp+30H]
+        movdqa  xmm3, xmmword ptr [rsp+50H]
         pshufd  xmm5, xmm5, 78H
         punpckhdq xmm13, xmm15
         punpckldq xmm14, xmm13
@@ -1777,10 +1805,20 @@ roundloop1:
         pshufd  xmm4, xmm8, 39H
         movdqa  xmm8, xmm6
         shufps  xmm8, xmm7, 250
-        pblendw xmm9, xmm8, 0CCH
+        movdqa  xmm10, xmmword ptr [PBLENDW_0xCC_MASK]
+        movdqa  xmm11, xmm10
+        pandn   xmm10, xmm9
+        pand    xmm11, xmm8
+        movdqa  xmm9, xmm11
+        por     xmm9, xmm10
         movdqa  xmm8, xmm7
         punpcklqdq xmm8, xmm5
-        pblendw xmm8, xmm6, 0C0H
+        movdqa  xmm10, xmmword ptr [PBLENDW_0xC0_MASK]
+        movdqa  xmm11, xmm10
+        pandn   xmm10, xmm8
+        pand    xmm11, xmm6
+        movdqa  xmm8, xmm11
+        por     xmm8, xmm10
         pshufd  xmm8, xmm8, 78H
         punpckhdq xmm5, xmm7
         punpckldq xmm6, xmm5
@@ -1891,10 +1929,20 @@ _blake3_compress_in_place_sse2 PROC
         pshufd  xmm4, xmm8, 39H
         movdqa  xmm8, xmm6
         shufps  xmm8, xmm7, 250
-        pblendw xmm9, xmm8, 0CCH
+        movdqa  xmm10, xmmword ptr [PBLENDW_0xCC_MASK]
+        movdqa  xmm11, xmm10
+        pandn   xmm10, xmm9
+        pand    xmm11, xmm8
+        movdqa  xmm9, xmm11
+        por     xmm9, xmm10
         movdqa  xmm8, xmm7
         punpcklqdq xmm8, xmm5
-        pblendw xmm8, xmm6, 0C0H
+        movdqa  xmm10, xmmword ptr [PBLENDW_0xC0_MASK]
+        movdqa  xmm11, xmm10
+        pandn   xmm10, xmm8
+        pand    xmm11, xmm6
+        movdqa  xmm8, xmm11
+        por     xmm8, xmm10
         pshufd  xmm8, xmm8, 78H
         punpckhdq xmm5, xmm7
         punpckldq xmm6, xmm5
@@ -2012,10 +2060,20 @@ _blake3_compress_xof_sse2 PROC
         pshufd  xmm4, xmm8, 39H
         movdqa  xmm8, xmm6
         shufps  xmm8, xmm7, 250
-        pblendw xmm9, xmm8, 0CCH
+        movdqa  xmm10, xmmword ptr [PBLENDW_0xCC_MASK]
+        movdqa  xmm11, xmm10
+        pandn   xmm10, xmm9
+        pand    xmm11, xmm8
+        movdqa  xmm9, xmm11
+        por     xmm9, xmm10
         movdqa  xmm8, xmm7
         punpcklqdq xmm8, xmm5
-        pblendw xmm8, xmm6, 0C0H
+        movdqa  xmm10, xmmword ptr [PBLENDW_0xC0_MASK]
+        movdqa  xmm11, xmm10
+        pandn   xmm10, xmm8
+        pand    xmm11, xmm6
+        movdqa  xmm8, xmm11
+        por     xmm8, xmm10
         pshufd  xmm8, xmm8, 78H
         punpckhdq xmm5, xmm7
         punpckldq xmm6, xmm5
@@ -2087,3 +2145,7 @@ CMP_MSB_MASK:
 _RDATA ENDS
 END
 
+PBLENDW_0xCC_MASK:
+       dd 00000000H, FFFFFFFFH, 00000000H, FFFFFFFFH
+PBLENDW_0xC0_MASK:
+       dd 00000000H, 00000000H, 00000000H, FFFFFFFFH