planar blend use signed images

source/row_win.cc

 /*
  *  Copyright 2011 The LibYuv Project Authors. All rights reserved.
  *
  *  Use of this source code is governed by a BSD-style license
  *  that can be found in the LICENSE file in the root of the source
  *  tree. An additional intellectual property rights grant can be found
  *  in the file PATENTS. All contributing project authors may
  *  be found in the AUTHORS file in the root of the source tree.
  */
 
@@ skipping 4045 matching lines @@
     lea        edx, [edx + 8]
     sub        ecx, 16
     jg         convertloop
 
     pop        edi
     ret
   }
 }
 #endif  // HAS_YUY2TOYROW_SSE2
 
+#ifdef HAS_BLENDPLANEROW_SSSE3
+// Blend 8 pixels at a time.
+// =((G2*C2)+(H2*(D2))+32768+127)/256

[jzern, 2015/12/02 00:31:33]

(D2) could be D2 to match the other side of the addition

+__declspec(naked)
+void BlendPlaneRow_SSSE3(const uint8* src0, const uint8* src1,
+                         const uint8* alpha, uint8* dst, int width) {
+  __asm {
+    push       esi
+    push       edi
+    pcmpeqb    xmm5, xmm5       // generate mask 0xff00ff00
+    psllw      xmm5, 8
+    mov        eax, 0x80808080  // 128 for biasing image to signed.
+    movd       xmm6, eax
+    pshufd     xmm6, xmm6, 0x00
+    mov        eax, 0x807f807f  // 32768 + 127 for unbias and round.
+    movd       xmm7, eax
+    pshufd     xmm7, xmm7, 0x00
+    mov        eax, [esp + 8 + 4]   // src0
+    mov        edx, [esp + 8 + 8]   // src1
+    mov        esi, [esp + 8 + 12]  // alpha
+    mov        edi, [esp + 8 + 16]  // dst
+    mov        ecx, [esp + 8 + 20]  // width
+    sub        eax, esi
+    sub        edx, esi
+    sub        edi, esi
+
+    // 8 pixel loop.
+  convertloop8:
+    movq       xmm0, qword ptr [esi]        // alpha
+    punpcklbw  xmm0, xmm0
+    pxor       xmm0, xmm5         // a, 255-a
+    movq       xmm1, qword ptr [eax + esi]  // src0
+    movq       xmm2, qword ptr [edx + esi]  // src1
+    punpcklbw  xmm1, xmm2
+    psubb      xmm1, xmm6         // bias src0/1 - 128
+    pmaddubsw  xmm0, xmm1
+    paddw      xmm0, xmm7         // unbias result - 32768 and round.
+    psrlw      xmm0, 8
+    packuswb   xmm0, xmm0
+    movq       qword ptr [edi + esi], xmm0
+    lea        esi, [esi + 8]
+    sub        ecx, 8
+    jge        convertloop8
+
+    pop        edi
+    pop        esi
+    ret
+  }
+}
+#endif  // HAS_BLENDPLANEROW_SSSE3
+
 #ifdef HAS_ARGBBLENDROW_SSSE3
 // Shuffle table for isolating alpha.
 static const uvec8 kShuffleAlpha = {
   3u, 0x80, 3u, 0x80, 7u, 0x80, 7u, 0x80,
   11u, 0x80, 11u, 0x80, 15u, 0x80, 15u, 0x80
 };
 
 // Blend 8 pixels at a time.
 __declspec(naked)
 void ARGBBlendRow_SSSE3(const uint8* src_argb0, const uint8* src_argb1,
@@ skipping 2174 matching lines @@
 }
 #endif  // HAS_ARGBLUMACOLORTABLEROW_SSSE3
 
 #endif  // defined(_M_X64)
 #endif  // !defined(LIBYUV_DISABLE_X86) && (defined(_M_IX86) || defined(_M_X64))
 
 #ifdef __cplusplus
 }  // extern "C"
 }  // namespace libyuv
 #endif