Mesa (master): cell: combine eval_z(), eval_w() functions

[Brian Paul]

Module: Mesa
Branch: master
Commit: 96b19195ecf25d2fd54031befba431515075494a
URL:    http://cgit.freedesktop.org/mesa/mesa/commit/?id=96b19195ecf25d2fd54031befba431515075494a

Author: Brian Paul <brianp at vmware.com>
Date:   Sun Feb 15 09:25:22 2009 -0700

cell: combine eval_z(), eval_w() functions

---

 src/gallium/drivers/cell/spu/spu_tri.c |   47 ++++++++++++++++++-------------
 1 files changed, 27 insertions(+), 20 deletions(-)

diff --git a/src/gallium/drivers/cell/spu/spu_tri.c b/src/gallium/drivers/cell/spu/spu_tri.c
index 0d9fcb9..9ccae22 100644
--- a/src/gallium/drivers/cell/spu/spu_tri.c
+++ b/src/gallium/drivers/cell/spu/spu_tri.c
@@ -212,31 +212,37 @@ eval_coeff_soa(uint slot, float x, float y, vector float w, vector float result[
 }
 
 
-/** Evalute coefficients to get Z for four pixels in a quad */
 static INLINE vector float
-eval_z(float x, float y)
+splatz(vector float v)
 {
-   const uint slot = 0;
-   const float dzdx = spu_extract(setup.coef[slot].dadx, 2);
-   const float dzdy = spu_extract(setup.coef[slot].dady, 2);
-   const float topLeft = spu_extract(setup.coef[slot].a0, 2) + x * dzdx + y * dzdy;
-   const vector float topLeftv = spu_splats(topLeft);
-   const vector float derivs = (vector float) { 0.0, dzdx, dzdy, dzdx + dzdy };
-   return spu_add(topLeftv, derivs);
+   return spu_splats(spu_extract(v, 2));
 }
 
 
-/** Evalute coefficients to get W for four pixels in a quad */
 static INLINE vector float
-eval_w(float x, float y)
+splatw(vector float v)
 {
-   const uint slot = 0;
-   const float dwdx = spu_extract(setup.coef[slot].dadx, 3);
-   const float dwdy = spu_extract(setup.coef[slot].dady, 3);
-   const float topLeft = spu_extract(setup.coef[slot].a0, 3) + x * dwdx + y * dwdy;
-   const vector float topLeftv = spu_splats(topLeft);
-   const vector float derivs = (vector float) { 0.0, dwdx, dwdy, dwdx + dwdy };
-   return spu_add(topLeftv, derivs);
+   return spu_splats(spu_extract(v, 3));
+}
+
+
+/**
+ * Compute quad's Z and W vectors for the quad at (x,y).
+ */
+static INLINE void
+eval_zw(float x, float y, vector float *zOut, vector float *wOut)
+{
+   static const vector float fragX = (const vector float) { 0.0, 1.0, 0.0, 1.0 };
+   static const vector float fragY = (const vector float) { 0.0, 0.0, 1.0, 1.0 };
+   const uint slot = 0;  /* vertex position attribute */
+   const vector float pos = setup.coef[slot].a0;
+   const vector float dposdx = setup.coef[slot].dadx;
+   const vector float dposdy = setup.coef[slot].dady;
+   const vector float xVec = spu_splats(x) + fragX;
+   const vector float yVec = spu_splats(y) + fragY;
+
+   *zOut = splatz(pos) + xVec * splatz(dposdx) + yVec * splatz(dposdy);
+   *wOut = splatw(pos) + xVec * splatw(dposdx) + yVec * splatw(dposdy);
 }
 
 
@@ -262,10 +268,11 @@ emit_quad( int x, int y, mask_t mask)
           * Run fragment shader, execute per-fragment ops, update fb/tile.
           */
          vector float inputs[4*4], outputs[2*4];
-         vector float fragZ = eval_z((float) x, (float) y);
-         vector float fragW = eval_w((float) x, (float) y);
+         vector float fragZ, fragW;
          vector unsigned int kill_mask;
 
+         eval_zw((float) x, (float) y, &fragZ, &fragW);
+
          /* setup inputs */
 #if 0
          eval_coeff_soa(1, (float) x, (float) y, fragW, inputs);