enable GL_ARB_texture_env_crossbar on r200, separate the enable bits for texture sampling and texture environment, optimize away texture sampling for units if the result is not used, always emit the env instructions in-order and try to eliminate GL_REPLACE env instructions.

5 files changed, 361 insertions, 80 deletions

diff --git a/src/mesa/drivers/dri/r200/r200_context.c b/src/mesa/drivers/dri/r200/r200_context.c
index 77d36e35172..6f8f78ef57a 100644
--- a/src/mesa/drivers/dri/r200/r200_context.c
+++ b/src/mesa/drivers/dri/r200/r200_context.c
@@ -140,6 +140,7 @@ const struct dri_extension card_extensions[] =
     { "GL_ARB_texture_env_add",            NULL },
     { "GL_ARB_texture_env_combine",        NULL },
     { "GL_ARB_texture_env_dot3",           NULL },
+    { "GL_ARB_texture_env_crossbar",       NULL },
     { "GL_ARB_texture_mirrored_repeat",    NULL },
     { "GL_ARB_vertex_buffer_object",       GL_ARB_vertex_buffer_object_functions },
     { "GL_EXT_blend_minmax",               GL_EXT_blend_minmax_functions },
diff --git a/src/mesa/drivers/dri/r200/r200_context.h b/src/mesa/drivers/dri/r200/r200_context.h
index 8169af709b7..89b0b35a8a4 100644
--- a/src/mesa/drivers/dri/r200/r200_context.h
+++ b/src/mesa/drivers/dri/r200/r200_context.h
@@ -172,8 +172,8 @@ struct r200_tex_obj {
 
 struct r200_texture_env_state {
    r200TexObjPtr texobj;
-   GLenum format;
-   GLenum envMode;
+   GLuint outputreg;
+   GLuint unitneeded;
 };
 
 #define R200_MAX_TEXTURE_UNITS 6
@@ -544,6 +544,7 @@ struct r200_state {
    struct r200_stencilbuffer_state stencil;
    struct r200_stipple_state stipple;
    struct r200_texture_state texture;
+   GLuint envneeded;
 };
 
 /* Need refcounting on dma buffers:
diff --git a/src/mesa/drivers/dri/r200/r200_reg.h b/src/mesa/drivers/dri/r200/r200_reg.h
index dd5f17cc366..d19f9dfcdc3 100644
--- a/src/mesa/drivers/dri/r200/r200_reg.h
+++ b/src/mesa/drivers/dri/r200/r200_reg.h
@@ -172,6 +172,8 @@ WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 #define     R200_TEX_BLEND_4_ENABLE                   0x00010000
 #define     R200_TEX_BLEND_5_ENABLE                   0x00020000
 #define     R200_TEX_BLEND_6_ENABLE                   0x00040000
+#define     R200_TEX_BLEND_ENABLE_MASK                0x0007f800
+#define     R200_TEX_BLEND_0_ENABLE_SHIFT             (12)
 #define     R200_MULTI_PASS_ENABLE                    0x00080000
 #define     R200_SPECULAR_ENABLE                      0x00200000
 #define     R200_FOG_ENABLE                           0x00400000
@@ -1146,6 +1148,7 @@ WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 #define     R200_TXC_CLAMP_WRAP                    (0 << 12)
 #define     R200_TXC_CLAMP_0_1                     (1 << 12)
 #define     R200_TXC_CLAMP_8_8                     (2 << 12)
+#define     R200_TXC_OUTPUT_REG_SHIFT              16
 #define     R200_TXC_OUTPUT_REG_MASK               (7 << 16)
 #define     R200_TXC_OUTPUT_REG_NONE               (0 << 16)
 #define     R200_TXC_OUTPUT_REG_R0                 (1 << 16)
@@ -1288,6 +1291,7 @@ WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 #define     R200_TXA_CLAMP_WRAP                    (0 << 12)
 #define     R200_TXA_CLAMP_0_1                     (1 << 12)
 #define     R200_TXA_CLAMP_8_8                     (2 << 12)
+#define     R200_TXA_OUTPUT_REG_SHIFT              16
 #define     R200_TXA_OUTPUT_REG_MASK               (7 << 16)
 #define     R200_TXA_OUTPUT_REG_NONE               (0 << 16)
 #define     R200_TXA_OUTPUT_REG_R0                 (1 << 16)
diff --git a/src/mesa/drivers/dri/r200/r200_state_init.c b/src/mesa/drivers/dri/r200/r200_state_init.c
index f004cf79ce2..30e0dfa4616 100644
--- a/src/mesa/drivers/dri/r200/r200_state_init.c
+++ b/src/mesa/drivers/dri/r200/r200_state_init.c
@@ -118,7 +118,9 @@ static int cmdscl2( int offset, int stride, int count )
 #define CHECK( NM, FLAG )				\
 static GLboolean check_##NM( GLcontext *ctx, int idx )	\
 {							\
+   r200ContextPtr rmesa = R200_CONTEXT(ctx);		\
    (void) idx;						\
+   (void) rmesa;					\
    return FLAG;						\
 }
 
@@ -135,12 +137,13 @@ static GLboolean check_##NM( GLcontext *ctx, int idx )	\
 CHECK( always, GL_TRUE )
 CHECK( never, GL_FALSE )
 CHECK( tex_any, ctx->Texture._EnabledUnits )
-CHECK( tex_pair, (ctx->Texture.Unit[idx]._ReallyEnabled | ctx->Texture.Unit[idx & ~1]._ReallyEnabled))
-CHECK( tex, ctx->Texture.Unit[idx]._ReallyEnabled )
-CHECK( tex_cube, ctx->Texture.Unit[idx]._ReallyEnabled & TEXTURE_CUBE_BIT)
+CHECK( tex_pair, (rmesa->state.texture.unit[idx].unitneeded | rmesa->state.texture.unit[idx & ~1].unitneeded))
+CHECK( tex, rmesa->state.texture.unit[idx].unitneeded )
+CHECK( texenv, rmesa->state.envneeded & (1 << idx) )
+CHECK( tex_cube, rmesa->state.texture.unit[idx].unitneeded & TEXTURE_CUBE_BIT )
 CHECK( fog, ctx->Fog.Enabled )
 TCL_CHECK( tcl, GL_TRUE )
-TCL_CHECK( tcl_tex, ctx->Texture.Unit[idx]._ReallyEnabled )
+TCL_CHECK( tcl_tex, rmesa->state.texture.unit[idx].unitneeded )
 TCL_CHECK( tcl_lighting, ctx->Light.Enabled )
 TCL_CHECK( tcl_light, ctx->Light.Enabled && ctx->Light.Light[idx].Enabled )
 TCL_CHECK( tcl_ucp, (ctx->Transform.ClipPlanesEnabled & (1 << idx)) )
@@ -300,11 +303,11 @@ void r200InitState( r200ContextPtr rmesa )
    ALLOC_STATE( lit[6], tcl_light, LIT_STATE_SIZE, "LIT/light-6", 6 );
    ALLOC_STATE( lit[7], tcl_light, LIT_STATE_SIZE, "LIT/light-7", 7 );
    ALLOC_STATE( pix[0], always, PIX_STATE_SIZE, "PIX/pixstage-0", 0 );
-   ALLOC_STATE( pix[1], tex, PIX_STATE_SIZE, "PIX/pixstage-1", 1 );
-   ALLOC_STATE( pix[2], tex, PIX_STATE_SIZE, "PIX/pixstage-2", 2 );
-   ALLOC_STATE( pix[3], tex, PIX_STATE_SIZE, "PIX/pixstage-3", 3 );
-   ALLOC_STATE( pix[4], tex, PIX_STATE_SIZE, "PIX/pixstage-4", 4 );
-   ALLOC_STATE( pix[5], tex, PIX_STATE_SIZE, "PIX/pixstage-5", 5 );
+   ALLOC_STATE( pix[1], texenv, PIX_STATE_SIZE, "PIX/pixstage-1", 1 );
+   ALLOC_STATE( pix[2], texenv, PIX_STATE_SIZE, "PIX/pixstage-2", 2 );
+   ALLOC_STATE( pix[3], texenv, PIX_STATE_SIZE, "PIX/pixstage-3", 3 );
+   ALLOC_STATE( pix[4], texenv, PIX_STATE_SIZE, "PIX/pixstage-4", 4 );
+   ALLOC_STATE( pix[5], texenv, PIX_STATE_SIZE, "PIX/pixstage-5", 5 );
    if (rmesa->r200Screen->drmSupportsTriPerf) {
       ALLOC_STATE( prf, always, PRF_STATE_SIZE, "PRF/performance-tri", 0 );
    }
diff --git a/src/mesa/drivers/dri/r200/r200_texstate.c b/src/mesa/drivers/dri/r200/r200_texstate.c
index 4a6b285a585..b79f3acc2c1 100644
--- a/src/mesa/drivers/dri/r200/r200_texstate.c
+++ b/src/mesa/drivers/dri/r200/r200_texstate.c
@@ -407,6 +407,14 @@ static GLuint r200_tfactor_color[] =
    R200_TXC_ARG_A_TFACTOR_ALPHA | R200_TXC_COMP_ARG_A
 };
 
+static GLuint r200_tfactor1_color[] =
+{
+   R200_TXC_ARG_A_TFACTOR1_COLOR,
+   R200_TXC_ARG_A_TFACTOR1_COLOR | R200_TXC_COMP_ARG_A,
+   R200_TXC_ARG_A_TFACTOR1_ALPHA,
+   R200_TXC_ARG_A_TFACTOR1_ALPHA | R200_TXC_COMP_ARG_A
+};
+
 static GLuint r200_primary_color[] =
 {
    R200_TXC_ARG_A_DIFFUSE_COLOR,
@@ -455,6 +463,12 @@ static GLuint r200_tfactor_alpha[] =
    R200_TXA_ARG_A_TFACTOR_ALPHA | R200_TXA_COMP_ARG_A
 };
 
+static GLuint r200_tfactor1_alpha[] =
+{
+   R200_TXA_ARG_A_TFACTOR1_ALPHA,
+   R200_TXA_ARG_A_TFACTOR1_ALPHA | R200_TXA_COMP_ARG_A
+};
+
 static GLuint r200_primary_alpha[] =
 {
    R200_TXA_ARG_A_DIFFUSE_ALPHA,
@@ -500,15 +514,17 @@ do {							\
  * Texture unit state management
  */
 
-static GLboolean r200UpdateTextureEnv( GLcontext *ctx, int unit )
+static GLboolean r200UpdateTextureEnv( GLcontext *ctx, int unit, int slot, GLuint replaceargs )
 {
    r200ContextPtr rmesa = R200_CONTEXT(ctx);
    const struct gl_texture_unit *texUnit = &ctx->Texture.Unit[unit];
    GLuint color_combine, alpha_combine;
-   GLuint color_scale = rmesa->hw.pix[unit].cmd[PIX_PP_TXCBLEND2] &
-      ~(R200_TXC_SCALE_MASK);
-   GLuint alpha_scale = rmesa->hw.pix[unit].cmd[PIX_PP_TXABLEND2] &
-      ~(R200_TXA_DOT_ALPHA | R200_TXA_SCALE_MASK);
+   GLuint color_scale = rmesa->hw.pix[slot].cmd[PIX_PP_TXCBLEND2] &
+      ~(R200_TXC_SCALE_MASK | R200_TXC_OUTPUT_REG_MASK | R200_TXC_TFACTOR_SEL_MASK |
+	R200_TXC_TFACTOR1_SEL_MASK);
+   GLuint alpha_scale = rmesa->hw.pix[slot].cmd[PIX_PP_TXABLEND2] &
+      ~(R200_TXA_DOT_ALPHA | R200_TXA_SCALE_MASK | R200_TXA_OUTPUT_REG_MASK |
+	R200_TXA_TFACTOR_SEL_MASK | R200_TXA_TFACTOR1_SEL_MASK);
 
    /* texUnit->_Current can be NULL if and only if the texture unit is
     * not actually enabled.
@@ -526,24 +542,20 @@ static GLboolean r200UpdateTextureEnv( GLcontext *ctx, int unit )
     * reduces the amount of special-casing we have to do, alpha-only
     * textures being a notable exception.
     */
-   /* Don't cache these results.
-    */
-   rmesa->state.texture.unit[unit].format = 0;
-   rmesa->state.texture.unit[unit].envMode = 0;
+
+   color_scale |= ((rmesa->state.texture.unit[unit].outputreg + 1) << R200_TXC_OUTPUT_REG_SHIFT) |
+			(unit << R200_TXC_TFACTOR_SEL_SHIFT) |
+			(replaceargs << R200_TXC_TFACTOR1_SEL_SHIFT);
+   alpha_scale |= ((rmesa->state.texture.unit[unit].outputreg + 1) << R200_TXA_OUTPUT_REG_SHIFT) |
+			(unit << R200_TXA_TFACTOR_SEL_SHIFT) |
+			(replaceargs << R200_TXA_TFACTOR1_SEL_SHIFT);
 
    if ( !texUnit->_ReallyEnabled ) {
-      if ( unit == 0 ) {
-	 color_combine = R200_TXC_ARG_A_ZERO | R200_TXC_ARG_B_ZERO
-	     | R200_TXC_ARG_C_DIFFUSE_COLOR | R200_TXC_OP_MADD;
-	 alpha_combine = R200_TXA_ARG_A_ZERO | R200_TXA_ARG_B_ZERO
-	     | R200_TXA_ARG_C_DIFFUSE_ALPHA | R200_TXA_OP_MADD;
-      }
-      else {
-	 color_combine = R200_TXC_ARG_A_ZERO | R200_TXC_ARG_B_ZERO
-	     | R200_TXC_ARG_C_R0_COLOR | R200_TXC_OP_MADD;
-	 alpha_combine = R200_TXA_ARG_A_ZERO | R200_TXA_ARG_B_ZERO
-	     | R200_TXA_ARG_C_R0_ALPHA | R200_TXA_OP_MADD;
-      }
+      assert( unit == 0);
+      color_combine = R200_TXC_ARG_A_ZERO | R200_TXC_ARG_B_ZERO
+	  | R200_TXC_ARG_C_DIFFUSE_COLOR | R200_TXC_OP_MADD;
+      alpha_combine = R200_TXA_ARG_A_ZERO | R200_TXA_ARG_B_ZERO
+	  | R200_TXA_ARG_C_DIFFUSE_ALPHA | R200_TXA_OP_MADD;
    }
    else {
       GLuint color_arg[3], alpha_arg[3];
@@ -554,14 +566,20 @@ static GLboolean r200UpdateTextureEnv( GLcontext *ctx, int unit )
       GLuint Ashift = texUnit->_CurrentCombine->ScaleShiftA;
 
 
+      const GLint replaceoprgb =
+	 ctx->Texture.Unit[replaceargs]._CurrentCombine->OperandRGB[0] - GL_SRC_COLOR;
+      const GLint replaceopa =
+	 ctx->Texture.Unit[replaceargs]._CurrentCombine->OperandA[0] - GL_SRC_ALPHA;
+
       /* Step 1:
        * Extract the color and alpha combine function arguments.
        */
       for ( i = 0 ; i < numColorArgs ; i++ ) {
-	 const GLint op = texUnit->_CurrentCombine->OperandRGB[i] - GL_SRC_COLOR;
+	 GLint op = texUnit->_CurrentCombine->OperandRGB[i] - GL_SRC_COLOR;
+	 const GLint srcRGBi = texUnit->_CurrentCombine->SourceRGB[i];
 	 assert(op >= 0);
 	 assert(op <= 3);
-	 switch ( texUnit->_CurrentCombine->SourceRGB[i] ) {
+	 switch ( srcRGBi ) {
 	 case GL_TEXTURE:
 	    color_arg[i] = r200_register_color[op][unit];
 	    break;
@@ -572,10 +590,54 @@ static GLboolean r200UpdateTextureEnv( GLcontext *ctx, int unit )
 	    color_arg[i] = r200_primary_color[op];
 	    break;
 	 case GL_PREVIOUS:
-	    if (unit == 0)
-		color_arg[i] = r200_primary_color[op];
-	    else
-		color_arg[i] = r200_register_color[op][0];
+	    if (replaceargs != unit) {
+	       const GLint srcRGBreplace = ctx->Texture.Unit[replaceargs]._CurrentCombine->SourceRGB[0];
+	       if (op >= 2) {
+		  op = op ^ replaceopa;
+	       }
+	       else {
+		  op = op ^ replaceoprgb;
+	       }
+	       switch (srcRGBreplace) {
+	       case GL_TEXTURE:
+		  color_arg[i] = r200_register_color[op][replaceargs];
+		  break;
+	       case GL_CONSTANT:
+		  color_arg[i] = r200_tfactor1_color[op];
+		  break;
+	       case GL_PRIMARY_COLOR:
+		  color_arg[i] = r200_primary_color[op];
+		  break;
+	       case GL_PREVIOUS:
+		  if (slot == 0)
+		     color_arg[i] = r200_primary_color[op];
+		  else
+		     color_arg[i] = r200_register_color[op][rmesa->state.texture.unit[replaceargs - 1].outputreg];
+		  break;
+	       case GL_ZERO:
+		  color_arg[i] = r200_zero_color[op];
+		  break;
+	       case GL_ONE:
+		  color_arg[i] = r200_zero_color[op+1];
+		  break;
+	       case GL_TEXTURE0:
+	       case GL_TEXTURE1:
+	       case GL_TEXTURE2:
+	       case GL_TEXTURE3:
+	       case GL_TEXTURE4:
+	       case GL_TEXTURE5:
+		  color_arg[i] = r200_register_color[op][srcRGBreplace - GL_TEXTURE0];
+		  break;
+	       default:
+	       return GL_FALSE;
+	       }
+	    }
+	    else {
+	       if (slot == 0)
+		  color_arg[i] = r200_primary_color[op];
+	       else
+		  color_arg[i] = r200_register_color[op][rmesa->state.texture.unit[unit - 1].outputreg];
+            }
 	    break;
 	 case GL_ZERO:
 	    color_arg[i] = r200_zero_color[op];
@@ -583,16 +645,25 @@ static GLboolean r200UpdateTextureEnv( GLcontext *ctx, int unit )
 	 case GL_ONE:
 	    color_arg[i] = r200_zero_color[op+1];
 	    break;
+	 case GL_TEXTURE0:
+	 case GL_TEXTURE1:
+	 case GL_TEXTURE2:
+	 case GL_TEXTURE3:
+	 case GL_TEXTURE4:
+	 case GL_TEXTURE5:
+	    color_arg[i] = r200_register_color[op][srcRGBi - GL_TEXTURE0];
+	    break;
 	 default:
 	    return GL_FALSE;
 	 }
       }
 
       for ( i = 0 ; i < numAlphaArgs ; i++ ) {
-	 const GLint op = texUnit->_CurrentCombine->OperandA[i] - GL_SRC_ALPHA;
+	 GLint op = texUnit->_CurrentCombine->OperandA[i] - GL_SRC_ALPHA;
+	 const GLint srcAi = texUnit->_CurrentCombine->SourceA[i];
 	 assert(op >= 0);
 	 assert(op <= 1);
-	 switch ( texUnit->_CurrentCombine->SourceA[i] ) {
+	 switch ( srcAi ) {
 	 case GL_TEXTURE:
 	    alpha_arg[i] = r200_register_alpha[op][unit];
 	    break;
@@ -603,10 +674,49 @@ static GLboolean r200UpdateTextureEnv( GLcontext *ctx, int unit )
 	    alpha_arg[i] = r200_primary_alpha[op];
 	    break;
 	 case GL_PREVIOUS:
-	    if (unit == 0)
-		alpha_arg[i] = r200_primary_alpha[op];
-	    else
-		alpha_arg[i] = r200_register_alpha[op][0];
+	    if (replaceargs != unit) {
+	       const GLint srcAreplace = ctx->Texture.Unit[replaceargs]._CurrentCombine->SourceA[0];
+	       op = op ^ replaceopa;
+	       switch (srcAreplace) {
+	       case GL_TEXTURE:
+		  alpha_arg[i] = r200_register_alpha[op][replaceargs];
+		  break;
+	       case GL_CONSTANT:
+		  alpha_arg[i] = r200_tfactor1_alpha[op];
+		  break;
+	       case GL_PRIMARY_COLOR:
+		  alpha_arg[i] = r200_primary_alpha[op];
+		  break;
+	       case GL_PREVIOUS:
+		  if (slot == 0)
+		     alpha_arg[i] = r200_primary_alpha[op];
+		  else
+		     alpha_arg[i] = r200_register_alpha[op][rmesa->state.texture.unit[replaceargs - 1].outputreg];
+		  break;
+	       case GL_ZERO:
+		  alpha_arg[i] = r200_zero_alpha[op];
+		  break;
+	       case GL_ONE:
+		  alpha_arg[i] = r200_zero_alpha[op+1];
+		  break;
+	       case GL_TEXTURE0:
+	       case GL_TEXTURE1:
+	       case GL_TEXTURE2:
+	       case GL_TEXTURE3:
+	       case GL_TEXTURE4:
+	       case GL_TEXTURE5:
+		  alpha_arg[i] = r200_register_alpha[op][srcAreplace - GL_TEXTURE0];
+		  break;
+	       default:
+	       return GL_FALSE;
+	       }
+	    }
+	    else {
+	       if (slot == 0)
+		  alpha_arg[i] = r200_primary_alpha[op];
+	       else
+		  alpha_arg[i] = r200_register_alpha[op][rmesa->state.texture.unit[unit - 1].outputreg];
+            }
 	    break;
 	 case GL_ZERO:
 	    alpha_arg[i] = r200_zero_alpha[op];
@@ -614,6 +724,14 @@ static GLboolean r200UpdateTextureEnv( GLcontext *ctx, int unit )
 	 case GL_ONE:
 	    alpha_arg[i] = r200_zero_alpha[op+1];
 	    break;
+	 case GL_TEXTURE0:
+	 case GL_TEXTURE1:
+	 case GL_TEXTURE2:
+	 case GL_TEXTURE3:
+	 case GL_TEXTURE4:
+	 case GL_TEXTURE5:
+	    alpha_arg[i] = r200_register_alpha[op][srcAi - GL_TEXTURE0];
+	    break;
 	 default:
 	    return GL_FALSE;
 	 }
@@ -801,20 +919,188 @@ static GLboolean r200UpdateTextureEnv( GLcontext *ctx, int unit )
        */
    }
 
-   if ( rmesa->hw.pix[unit].cmd[PIX_PP_TXCBLEND] != color_combine ||
-	rmesa->hw.pix[unit].cmd[PIX_PP_TXABLEND] != alpha_combine ||
-	rmesa->hw.pix[unit].cmd[PIX_PP_TXCBLEND2] != color_scale ||
-	rmesa->hw.pix[unit].cmd[PIX_PP_TXABLEND2] != alpha_scale) {
-      R200_STATECHANGE( rmesa, pix[unit] );
-      rmesa->hw.pix[unit].cmd[PIX_PP_TXCBLEND] = color_combine;
-      rmesa->hw.pix[unit].cmd[PIX_PP_TXABLEND] = alpha_combine;
-      rmesa->hw.pix[unit].cmd[PIX_PP_TXCBLEND2] = color_scale;
-      rmesa->hw.pix[unit].cmd[PIX_PP_TXABLEND2] = alpha_scale;
+   if ( rmesa->hw.pix[slot].cmd[PIX_PP_TXCBLEND] != color_combine ||
+	rmesa->hw.pix[slot].cmd[PIX_PP_TXABLEND] != alpha_combine ||
+	rmesa->hw.pix[slot].cmd[PIX_PP_TXCBLEND2] != color_scale ||
+	rmesa->hw.pix[slot].cmd[PIX_PP_TXABLEND2] != alpha_scale) {
+      R200_STATECHANGE( rmesa, pix[slot] );
+      rmesa->hw.pix[slot].cmd[PIX_PP_TXCBLEND] = color_combine;
+      rmesa->hw.pix[slot].cmd[PIX_PP_TXABLEND] = alpha_combine;
+      rmesa->hw.pix[slot].cmd[PIX_PP_TXCBLEND2] = color_scale;
+      rmesa->hw.pix[slot].cmd[PIX_PP_TXABLEND2] = alpha_scale;
    }
 
    return GL_TRUE;
 }
 
+#define REF_COLOR 1
+#define REF_ALPHA 2
+
+static GLboolean r200UpdateAllTexEnv( GLcontext *ctx )
+{
+   r200ContextPtr rmesa = R200_CONTEXT(ctx);
+   GLint i, j, currslot;
+   GLint maxunitused = -1;
+   GLboolean texregfree[6] = {GL_TRUE, GL_TRUE, GL_TRUE, GL_TRUE, GL_TRUE, GL_TRUE};
+   GLubyte stageref[7] = {0, 0, 0, 0, 0, 0, 0};
+   GLint nextunit[R200_MAX_TEXTURE_UNITS] = {0, 0, 0, 0, 0, 0};
+   GLint currentnext = -1;
+   GLboolean ok;
+
+   /* find highest used unit */
+   for ( j = 0; j < R200_MAX_TEXTURE_UNITS; j++) {
+      if (ctx->Texture.Unit[j]._ReallyEnabled) {
+	 maxunitused = j;
+      }
+   }
+   stageref[maxunitused + 1] = REF_COLOR | REF_ALPHA;
+
+   for ( j = maxunitused; j >= 0; j-- ) {
+      const struct gl_texture_unit *texUnit = &ctx->Texture.Unit[j];
+
+      rmesa->state.texture.unit[j].outputreg = -1;
+
+      if (stageref[j + 1]) {
+
+	 /* use the lowest available reg. That gets us automatically reg0 for the last stage.
+	    need this even for disabled units, as it may get referenced due to the replace
+	    optimization */
+	 for ( i = 0 ; i < R200_MAX_TEXTURE_UNITS; i++ ) {
+	    if (texregfree[i]) {
+	       rmesa->state.texture.unit[j].outputreg = i;
+	       break;
+	    }
+	 }
+	 if (rmesa->state.texture.unit[j].outputreg == -1) {
+	    /* no more free regs we can use. Need a fallback :-( */
+	    return GL_FALSE;
+         }
+
+         nextunit[j] = currentnext;
+
+         if (!texUnit->_ReallyEnabled) {
+	 /* the not enabled stages are referenced "indirectly",
+            must not cut off the lower stages */
+	    stageref[j] = REF_COLOR | REF_ALPHA;
+	    continue;
+         }
+	 currentnext = j;
+ 
+	 const GLuint numColorArgs = texUnit->_CurrentCombine->_NumArgsRGB;
+	 const GLuint numAlphaArgs = texUnit->_CurrentCombine->_NumArgsA;
+	 const GLboolean isdot3rgba = (texUnit->_CurrentCombine->ModeRGB == GL_DOT3_RGBA) ||
+				      (texUnit->_CurrentCombine->ModeRGB == GL_DOT3_RGBA_EXT);
+
+
+	 /* check if we need the color part, special case for dot3_rgba
+	    as if only the alpha part is referenced later on it still is using the color part */
+	 if ((stageref[j + 1] & REF_COLOR) || isdot3rgba) {
+	    for ( i = 0 ; i < numColorArgs ; i++ ) {
+	       const GLuint srcRGBi = texUnit->_CurrentCombine->SourceRGB[i];
+	       const GLuint op = texUnit->_CurrentCombine->OperandRGB[i];
+	       switch ( srcRGBi ) {
+	       case GL_PREVIOUS:
+		  /* op 0/1 are referencing color, op 2/3 alpha */
+		  stageref[j] |= (op >> 1) + 1;
+	          break;
+	       case GL_TEXTURE:
+		  texregfree[j] = GL_FALSE;
+		  break;
+	       case GL_TEXTURE0:
+	       case GL_TEXTURE1:
+	       case GL_TEXTURE2:
+	       case GL_TEXTURE3:
+	       case GL_TEXTURE4:
+	       case GL_TEXTURE5:
+		  texregfree[srcRGBi - GL_TEXTURE0] = GL_FALSE;
+	          break;
+	       default: /* don't care about other sources here */
+		  break;
+	       }
+	    }
+	 }
+
+	 /* alpha args are ignored for dot3_rgba */
+	 if ((stageref[j + 1] & REF_ALPHA) && !isdot3rgba) {
+
+	    for ( i = 0 ; i < numAlphaArgs ; i++ ) {
+	       const GLuint srcAi = texUnit->_CurrentCombine->SourceA[i];
+	       switch ( srcAi ) {
+	       case GL_PREVIOUS:
+		  stageref[j] |= REF_ALPHA;
+		  break;
+	       case GL_TEXTURE:
+		  texregfree[j] = GL_FALSE;
+		  break;
+	       case GL_TEXTURE0:
+	       case GL_TEXTURE1:
+	       case GL_TEXTURE2:
+	       case GL_TEXTURE3:
+	       case GL_TEXTURE4:
+	       case GL_TEXTURE5:
+		  texregfree[srcAi - GL_TEXTURE0] = GL_FALSE;
+		  break;
+	       default: /* don't care about other sources here */
+		  break;
+	       }
+	    }
+	 }
+      }
+   }
+
+   /* don't enable texture sampling for units if the result is not used */
+   for (i = 0; i < R200_MAX_TEXTURE_UNITS; i++) {
+      if (ctx->Texture.Unit[i]._ReallyEnabled && !texregfree[i])
+	 rmesa->state.texture.unit[i].unitneeded = ctx->Texture.Unit[i]._ReallyEnabled;
+      else rmesa->state.texture.unit[i].unitneeded = 0;
+   }
+
+   ok = GL_TRUE;
+   currslot = 0;
+   rmesa->state.envneeded = 1;
+
+   i = 0;
+   while ((i <= maxunitused) && (i >= 0)) {
+      /* only output instruction if the results are referenced */
+      if (ctx->Texture.Unit[i]._ReallyEnabled && stageref[i+1]) {
+         GLuint replaceunit = i;
+	 /* try to optimize GL_REPLACE away (only one level deep though) */
+	 if (	(ctx->Texture.Unit[i]._CurrentCombine->ModeRGB == GL_REPLACE) &&
+		(ctx->Texture.Unit[i]._CurrentCombine->ModeA == GL_REPLACE) &&
+		(ctx->Texture.Unit[i]._CurrentCombine->ScaleShiftRGB == 0) &&
+		(ctx->Texture.Unit[i]._CurrentCombine->ScaleShiftA == 0) &&
+		(nextunit[i] > 0) ) {
+	    /* yippie! can optimize it away! */
+	    replaceunit = i;
+	    i = nextunit[i];
+	 }
+
+	 /* need env instruction slot */
+	 rmesa->state.envneeded |= 1 << currslot;
+	 ok = r200UpdateTextureEnv( ctx, i, currslot, replaceunit );
+	 if (!ok) return GL_FALSE;
+	 currslot++;
+      }
+      i = i + 1;
+   }
+
+   if (currslot == 0) {
+      /* need one stage at least */
+      rmesa->state.texture.unit[0].outputreg = 0;
+      ok = r200UpdateTextureEnv( ctx, 0, 0, 0 );
+   }
+
+   R200_STATECHANGE( rmesa, ctx );
+   rmesa->hw.ctx.cmd[CTX_PP_CNTL] &= ~R200_TEX_BLEND_ENABLE_MASK;
+   rmesa->hw.ctx.cmd[CTX_PP_CNTL] |= rmesa->state.envneeded << R200_TEX_BLEND_0_ENABLE_SHIFT;
+
+   return ok;
+}
+
+#undef REF_COLOR
+#undef REF_ALPHA
+
+
 #define TEXOBJ_TXFILTER_MASK (R200_MAX_MIP_LEVEL_MASK |		\
 			      R200_MIN_FILTER_MASK | 		\
 			      R200_MAG_FILTER_MASK |		\
@@ -1063,9 +1349,7 @@ static void disable_tex( GLcontext *ctx, int unit )
       }
 
       R200_STATECHANGE( rmesa, ctx );
-      rmesa->hw.ctx.cmd[CTX_PP_CNTL] &= ~((R200_TEX_0_ENABLE |
-					   R200_TEX_BLEND_0_ENABLE) << unit);
-      rmesa->hw.ctx.cmd[CTX_PP_CNTL] |= R200_TEX_BLEND_0_ENABLE; 
+      rmesa->hw.ctx.cmd[CTX_PP_CNTL] &= ~(R200_TEX_0_ENABLE << unit);
 	 
       R200_STATECHANGE( rmesa, vtx );
       rmesa->hw.vtx.cmd[VTX_TCL_OUTPUT_VTXFMT_1] &= ~(7 << (unit * 3));
@@ -1077,10 +1361,6 @@ static void disable_tex( GLcontext *ctx, int unit )
       /* Actually want to keep all units less than max active texture
        * enabled, right?  Fix this for >2 texunits.
        */
-      /* FIXME: What should happen here if r200UpdateTextureEnv fails? */
-      if (unit == 0) 
-	 r200UpdateTextureEnv( ctx, unit ); 
-
 
       {
 	 GLuint tmp = rmesa->TexGenEnabled;
@@ -1258,7 +1538,6 @@ static GLboolean update_tex_common( GLcontext *ctx, int unit )
    struct gl_texture_unit *texUnit = &ctx->Texture.Unit[unit];
    struct gl_texture_object *tObj = texUnit->_Current;
    r200TexObjPtr t = (r200TexObjPtr) tObj->DriverData;
-   GLenum format;
 
    /* Fallback if there's a texture border */
    if ( tObj->Image[0][tObj->BaseLevel]->Border > 0 )
@@ -1288,8 +1567,7 @@ static GLboolean update_tex_common( GLcontext *ctx, int unit )
     */
    if ( 1|| !(rmesa->hw.ctx.cmd[CTX_PP_CNTL] & (R200_TEX_0_ENABLE<<unit))) {
       R200_STATECHANGE( rmesa, ctx );
-      rmesa->hw.ctx.cmd[CTX_PP_CNTL] |= (R200_TEX_0_ENABLE | 
-					 R200_TEX_BLEND_0_ENABLE) << unit;
+      rmesa->hw.ctx.cmd[CTX_PP_CNTL] |= R200_TEX_0_ENABLE << unit;
 
       R200_STATECHANGE( rmesa, vtx );
       rmesa->hw.vtx.cmd[VTX_TCL_OUTPUT_VTXFMT_1] &= ~(7 << (unit * 3));
@@ -1309,16 +1587,6 @@ static GLboolean update_tex_common( GLcontext *ctx, int unit )
       rmesa->NewGLState |= _NEW_TEXTURE_MATRIX;
    }
 
-   format = tObj->Image[0][tObj->BaseLevel]->Format;
-   if ( rmesa->state.texture.unit[unit].format != format ||
-	rmesa->state.texture.unit[unit].envMode != texUnit->EnvMode ) {
-      rmesa->state.texture.unit[unit].format = format;
-      rmesa->state.texture.unit[unit].envMode = texUnit->EnvMode;
-      if ( ! r200UpdateTextureEnv( ctx, unit ) ) {
-	 return GL_FALSE;
-      }
-   }
-
    FALLBACK( rmesa, R200_FALLBACK_BORDER_MODE, t->border_fallback );
    return !t->border_fallback;
 }
@@ -1327,27 +1595,27 @@ static GLboolean update_tex_common( GLcontext *ctx, int unit )
 
 static GLboolean r200UpdateTextureUnit( GLcontext *ctx, int unit )
 {
-   struct gl_texture_unit *texUnit = &ctx->Texture.Unit[unit];
+   r200ContextPtr rmesa = R200_CONTEXT(ctx);
 
-   if ( texUnit->_ReallyEnabled & (TEXTURE_RECT_BIT) ) {
+   if ( rmesa->state.texture.unit[unit].unitneeded & (TEXTURE_RECT_BIT) ) {
       return (enable_tex_rect( ctx, unit ) &&
 	      update_tex_common( ctx, unit ));
    }
-   else if ( texUnit->_ReallyEnabled & (TEXTURE_1D_BIT | TEXTURE_2D_BIT) ) {
+   else if (  rmesa->state.texture.unit[unit].unitneeded & (TEXTURE_1D_BIT | TEXTURE_2D_BIT) ) {
       return (enable_tex_2d( ctx, unit ) &&
 	      update_tex_common( ctx, unit ));
    }
 #if ENABLE_HW_3D_TEXTURE
-   else if ( texUnit->_ReallyEnabled & (TEXTURE_3D_BIT) ) {
+   else if ( rmesa->state.texture.unit[unit].unitneeded & (TEXTURE_3D_BIT) ) {
       return (enable_tex_3d( ctx, unit ) &&
 	      update_tex_common( ctx, unit ));
    }
 #endif
-   else if ( texUnit->_ReallyEnabled & (TEXTURE_CUBE_BIT) ) {
+   else if ( rmesa->state.texture.unit[unit].unitneeded & (TEXTURE_CUBE_BIT) ) {
       return (enable_tex_cube( ctx, unit ) &&
 	      update_tex_common( ctx, unit ));
    }
-   else if ( texUnit->_ReallyEnabled ) {
+   else if ( rmesa->state.texture.unit[unit].unitneeded ) {
       return GL_FALSE;
    }
    else {
@@ -1363,12 +1631,16 @@ void r200UpdateTextureState( GLcontext *ctx )
    GLboolean ok;
    GLuint dbg;
 
-   ok = (r200UpdateTextureUnit( ctx, 0 ) &&
+   ok = r200UpdateAllTexEnv( ctx );
+
+   if (ok) {
+      ok = (r200UpdateTextureUnit( ctx, 0 ) &&
 	 r200UpdateTextureUnit( ctx, 1 ) &&
 	 r200UpdateTextureUnit( ctx, 2 ) &&
 	 r200UpdateTextureUnit( ctx, 3 ) &&
 	 r200UpdateTextureUnit( ctx, 4 ) &&
 	 r200UpdateTextureUnit( ctx, 5 ));
+   }
 
    FALLBACK( rmesa, R200_FALLBACK_TEXTURE, !ok );