auto import from //depot/cupcake/@135843

1 files changed, 1251 insertions, 0 deletions

diff --git a/libpixelflinger/codeflinger/texturing.cpp b/libpixelflinger/codeflinger/texturing.cpp
new file mode 100644
index 0000000..90e6584
--- /dev/null
+++ b/libpixelflinger/codeflinger/texturing.cpp
@@ -0,0 +1,1251 @@
+/* libs/pixelflinger/codeflinger/texturing.cpp
+**
+** Copyright 2006, The Android Open Source Project
+**
+** Licensed under the Apache License, Version 2.0 (the "License"); 
+** you may not use this file except in compliance with the License. 
+** You may obtain a copy of the License at 
+**
+**     http://www.apache.org/licenses/LICENSE-2.0 
+**
+** Unless required by applicable law or agreed to in writing, software 
+** distributed under the License is distributed on an "AS IS" BASIS, 
+** WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 
+** See the License for the specific language governing permissions and 
+** limitations under the License.
+*/
+
+#include <assert.h>
+#include <stdint.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <sys/types.h>
+
+#include <cutils/log.h>
+
+#include "codeflinger/GGLAssembler.h"
+
+
+namespace android {
+
+// ---------------------------------------------------------------------------
+
+// iterators are initialized like this:
+// (intToFixedCenter(x) * dx)>>16 + x0
+// ((x<<16 + 0x8000) * dx)>>16 + x0
+// ((x<<16)*dx + (0x8000*dx))>>16 + x0
+// ( (x*dx) + dx>>1 ) + x0
+// (x*dx) + (dx>>1 + x0)
+
+void GGLAssembler::init_iterated_color(fragment_parts_t& parts, const reg_t& x)
+{
+    context_t const* c = mBuilderContext.c;
+    const needs_t& needs = mBuilderContext.needs;
+
+    if (mSmooth) {
+        // NOTE: we could take this case in the mDithering + !mSmooth case,
+        // but this would use up to 4 more registers for the color components
+        // for only a little added quality.
+        // Currently, this causes the system to run out of registers in
+        // some case (see issue #719496)
+
+        comment("compute initial iterated color (smooth and/or dither case)");
+
+        parts.iterated_packed = 0;
+        parts.packed = 0;
+
+        // 0x1: color component
+        // 0x2: iterators
+        const int optReload = mOptLevel >> 1;
+        if (optReload >= 3)         parts.reload = 0; // reload nothing
+        else if (optReload == 2)    parts.reload = 2; // reload iterators
+        else if (optReload == 1)    parts.reload = 1; // reload colors
+        else if (optReload <= 0)    parts.reload = 3; // reload both
+
+        if (!mSmooth) {
+            // we're not smoothing (just dithering), we never have to 
+            // reload the iterators
+            parts.reload &= ~2;
+        }
+
+        Scratch scratches(registerFile());
+        const int t0 = (parts.reload & 1) ? scratches.obtain() : 0;
+        const int t1 = (parts.reload & 2) ? scratches.obtain() : 0;
+        for (int i=0 ; i<4 ; i++) {
+            if (!mInfo[i].iterated)
+                continue;            
+            
+            // this component exists in the destination and is not replaced
+            // by a texture unit.
+            const int c = (parts.reload & 1) ? t0 : obtainReg();              
+            if (i==0) CONTEXT_LOAD(c, iterators.ydady);
+            if (i==1) CONTEXT_LOAD(c, iterators.ydrdy);
+            if (i==2) CONTEXT_LOAD(c, iterators.ydgdy);
+            if (i==3) CONTEXT_LOAD(c, iterators.ydbdy);
+            parts.argb[i].reg = c;
+
+            if (mInfo[i].smooth) {
+                parts.argb_dx[i].reg = (parts.reload & 2) ? t1 : obtainReg();
+                const int dvdx = parts.argb_dx[i].reg;
+                CONTEXT_LOAD(dvdx, generated_vars.argb[i].dx);
+                MLA(AL, 0, c, x.reg, dvdx, c);
+                
+                // adjust the color iterator to make sure it won't overflow
+                if (!mAA) {
+                    // this is not needed when we're using anti-aliasing
+                    // because we will (have to) clamp the components
+                    // anyway.
+                    int end = scratches.obtain();
+                    MOV(AL, 0, end, reg_imm(parts.count.reg, LSR, 16));
+                    MLA(AL, 1, end, dvdx, end, c);
+                    SUB(MI, 0, c, c, end);
+                    BIC(AL, 0, c, c, reg_imm(c, ASR, 31)); 
+                    scratches.recycle(end);
+                }
+            }
+            
+            if (parts.reload & 1) {
+                CONTEXT_STORE(c, generated_vars.argb[i].c);
+            }
+        }
+    } else {
+        // We're not smoothed, so we can 
+        // just use a packed version of the color and extract the
+        // components as needed (or not at all if we don't blend)
+
+        // figure out if we need the iterated color
+        int load = 0;
+        for (int i=0 ; i<4 ; i++) {
+            component_info_t& info = mInfo[i];
+            if ((info.inDest || info.needed) && !info.replaced)
+                load |= 1;
+        }
+        
+        parts.iterated_packed = 1;
+        parts.packed = (!mTextureMachine.mask && !mBlending
+                && !mFog && !mDithering);
+        parts.reload = 0;
+        if (load || parts.packed) {
+            if (mBlending || mDithering || mInfo[GGLFormat::ALPHA].needed) {
+                comment("load initial iterated color (8888 packed)");
+                parts.iterated.setTo(obtainReg(),
+                        &(c->formats[GGL_PIXEL_FORMAT_RGBA_8888]));
+                CONTEXT_LOAD(parts.iterated.reg, packed8888);
+            } else {
+                comment("load initial iterated color (dest format packed)");
+
+                parts.iterated.setTo(obtainReg(), &mCbFormat);
+
+                // pre-mask the iterated color
+                const int bits = parts.iterated.size();
+                const uint32_t size = ((bits>=32) ? 0 : (1LU << bits)) - 1;
+                uint32_t mask = 0;
+                if (mMasking) {
+                    for (int i=0 ; i<4 ; i++) {
+                        const int component_mask = 1<<i;
+                        const int h = parts.iterated.format.c[i].h;
+                        const int l = parts.iterated.format.c[i].l;
+                        if (h && (!(mMasking & component_mask))) {
+                            mask |= ((1<<(h-l))-1) << l;
+                        }
+                    }
+                }
+
+                if (mMasking && ((mask & size)==0)) {
+                    // none of the components are present in the mask
+                } else {
+                    CONTEXT_LOAD(parts.iterated.reg, packed);
+                    if (mCbFormat.size == 1) {
+                        AND(AL, 0, parts.iterated.reg,
+                                parts.iterated.reg, imm(0xFF));
+                    } else if (mCbFormat.size == 2) {
+                        MOV(AL, 0, parts.iterated.reg,
+                                reg_imm(parts.iterated.reg, LSR, 16));
+                    }
+                }
+
+                // pre-mask the iterated color
+                if (mMasking) {
+                    build_and_immediate(parts.iterated.reg, parts.iterated.reg,
+                            mask, bits);
+                }
+            }
+        }
+    }
+}
+
+void GGLAssembler::build_iterated_color(
+        component_t& fragment,
+        const fragment_parts_t& parts,
+        int component,
+        Scratch& regs)
+{
+    fragment.setTo( regs.obtain(), 0, 32, CORRUPTIBLE); 
+
+    if (!mInfo[component].iterated)
+        return;
+
+    if (parts.iterated_packed) {
+        // iterated colors are packed, extract the one we need
+        extract(fragment, parts.iterated, component);
+    } else {
+        fragment.h = GGL_COLOR_BITS;
+        fragment.l = GGL_COLOR_BITS - 8;
+        fragment.flags |= CLEAR_LO;
+        // iterated colors are held in their own register,
+        // (smooth and/or dithering case)
+        if (parts.reload==3) {
+            // this implies mSmooth
+            Scratch scratches(registerFile());
+            int dx = scratches.obtain();
+            CONTEXT_LOAD(fragment.reg, generated_vars.argb[component].c);
+            CONTEXT_LOAD(dx, generated_vars.argb[component].dx);
+            ADD(AL, 0, dx, fragment.reg, dx);
+            CONTEXT_STORE(dx, generated_vars.argb[component].c);
+        } else if (parts.reload & 1) {
+            CONTEXT_LOAD(fragment.reg, generated_vars.argb[component].c);
+        } else {
+            // we don't reload, so simply rename the register and mark as
+            // non CORRUPTIBLE so that the texture env or blending code
+            // won't modify this (renamed) register
+            regs.recycle(fragment.reg);
+            fragment.reg = parts.argb[component].reg;
+            fragment.flags &= ~CORRUPTIBLE;
+        }
+        if (mInfo[component].smooth && mAA) {
+            // when using smooth shading AND anti-aliasing, we need to clamp
+            // the iterators because there is always an extra pixel on the
+            // edges, which most of the time will cause an overflow
+            // (since technically its outside of the domain).
+            BIC(AL, 0, fragment.reg, fragment.reg,
+                    reg_imm(fragment.reg, ASR, 31));
+            component_sat(fragment);
+        }
+    }
+}
+
+// ---------------------------------------------------------------------------
+
+void GGLAssembler::decodeLogicOpNeeds(const needs_t& needs)
+{
+    // gather some informations about the components we need to process...
+    const int opcode = GGL_READ_NEEDS(LOGIC_OP, needs.n) | GGL_CLEAR;
+    switch(opcode) {
+    case GGL_COPY:
+        mLogicOp = 0;
+        break;
+    case GGL_CLEAR:
+    case GGL_SET:
+        mLogicOp = LOGIC_OP;
+        break;
+    case GGL_AND:
+    case GGL_AND_REVERSE:
+    case GGL_AND_INVERTED:
+    case GGL_XOR:
+    case GGL_OR:
+    case GGL_NOR:
+    case GGL_EQUIV:
+    case GGL_OR_REVERSE:
+    case GGL_OR_INVERTED:
+    case GGL_NAND:
+        mLogicOp = LOGIC_OP|LOGIC_OP_SRC|LOGIC_OP_DST;
+        break;
+    case GGL_NOOP:
+    case GGL_INVERT:
+        mLogicOp = LOGIC_OP|LOGIC_OP_DST;
+        break;        
+    case GGL_COPY_INVERTED:
+        mLogicOp = LOGIC_OP|LOGIC_OP_SRC;
+        break;
+    };        
+}
+
+void GGLAssembler::decodeTMUNeeds(const needs_t& needs, context_t const* c)
+{
+    uint8_t replaced=0;
+    mTextureMachine.mask = 0;
+    mTextureMachine.activeUnits = 0;
+    for (int i=GGL_TEXTURE_UNIT_COUNT-1 ; i>=0 ; i--) {
+        texture_unit_t& tmu = mTextureMachine.tmu[i];
+        if (replaced == 0xF) {
+            // all components are replaced, skip this TMU.
+            tmu.format_idx = 0;
+            tmu.mask = 0;
+            tmu.replaced = replaced;
+            continue;
+        }
+        tmu.format_idx = GGL_READ_NEEDS(T_FORMAT, needs.t[i]);
+        tmu.format = c->formats[tmu.format_idx];
+        tmu.bits = tmu.format.size*8;
+        tmu.swrap = GGL_READ_NEEDS(T_S_WRAP, needs.t[i]);
+        tmu.twrap = GGL_READ_NEEDS(T_T_WRAP, needs.t[i]);
+        tmu.env = ggl_needs_to_env(GGL_READ_NEEDS(T_ENV, needs.t[i]));
+        tmu.pot = GGL_READ_NEEDS(T_POT, needs.t[i]);
+        tmu.linear = GGL_READ_NEEDS(T_LINEAR, needs.t[i])
+                && tmu.format.size!=3; // XXX: only 8, 16 and 32 modes for now
+
+        // 5551 linear filtering is not supported
+        if (tmu.format_idx == GGL_PIXEL_FORMAT_RGBA_5551)
+            tmu.linear = 0;
+        
+        tmu.mask = 0;
+        tmu.replaced = replaced;
+
+        if (tmu.format_idx) {
+            mTextureMachine.activeUnits++;
+            if (tmu.format.c[0].h)    tmu.mask |= 0x1;
+            if (tmu.format.c[1].h)    tmu.mask |= 0x2;
+            if (tmu.format.c[2].h)    tmu.mask |= 0x4;
+            if (tmu.format.c[3].h)    tmu.mask |= 0x8;
+            if (tmu.env == GGL_REPLACE) {
+                replaced |= tmu.mask;
+            } else if (tmu.env == GGL_DECAL) {
+                if (!tmu.format.c[GGLFormat::ALPHA].h) {
+                    // if we don't have alpha, decal does nothing
+                    tmu.mask = 0;
+                } else {
+                    // decal always ignores At
+                    tmu.mask &= ~(1<<GGLFormat::ALPHA);
+                }
+            }
+        }
+        mTextureMachine.mask |= tmu.mask;
+        //printf("%d: mask=%08lx, replaced=%08lx\n",
+        //    i, int(tmu.mask), int(tmu.replaced));
+    }
+    mTextureMachine.replaced = replaced;
+    mTextureMachine.directTexture = 0;
+    //printf("replaced=%08lx\n", mTextureMachine.replaced);
+}
+
+
+void GGLAssembler::init_textures(
+        tex_coord_t* coords,
+        const reg_t& x, const reg_t& y)
+{
+    context_t const* c = mBuilderContext.c;
+    const needs_t& needs = mBuilderContext.needs;
+    int Rctx = mBuilderContext.Rctx;
+    int Rx = x.reg;
+    int Ry = y.reg;
+
+    if (mTextureMachine.mask) {
+        comment("compute texture coordinates");
+    }
+
+    // init texture coordinates for each tmu
+    const int cb_format_idx = GGL_READ_NEEDS(CB_FORMAT, needs.n);
+    const bool multiTexture = mTextureMachine.activeUnits > 1;
+    for (int i=0 ; i<GGL_TEXTURE_UNIT_COUNT; i++) {
+        const texture_unit_t& tmu = mTextureMachine.tmu[i];
+        if (tmu.format_idx == 0)
+            continue;
+        if ((tmu.swrap == GGL_NEEDS_WRAP_11) &&
+            (tmu.twrap == GGL_NEEDS_WRAP_11)) 
+        {
+            // 1:1 texture
+            pointer_t& txPtr = coords[i].ptr;
+            txPtr.setTo(obtainReg(), tmu.bits);
+            CONTEXT_LOAD(txPtr.reg, state.texture[i].iterators.ydsdy);
+            ADD(AL, 0, Rx, Rx, reg_imm(txPtr.reg, ASR, 16));    // x += (s>>16)
+            CONTEXT_LOAD(txPtr.reg, state.texture[i].iterators.ydtdy);
+            ADD(AL, 0, Ry, Ry, reg_imm(txPtr.reg, ASR, 16));    // y += (t>>16)
+            // merge base & offset
+            CONTEXT_LOAD(txPtr.reg, generated_vars.texture[i].stride);
+            SMLABB(AL, Rx, Ry, txPtr.reg, Rx);               // x+y*stride
+            CONTEXT_LOAD(txPtr.reg, generated_vars.texture[i].data);
+            base_offset(txPtr, txPtr, Rx);
+        } else {
+            Scratch scratches(registerFile());
+            reg_t& s = coords[i].s;
+            reg_t& t = coords[i].t;
+            // s = (x * dsdx)>>16 + ydsdy
+            // s = (x * dsdx)>>16 + (y*dsdy)>>16 + s0
+            // t = (x * dtdx)>>16 + ydtdy
+            // t = (x * dtdx)>>16 + (y*dtdy)>>16 + t0
+            s.setTo(obtainReg());
+            t.setTo(obtainReg());
+            const int need_w = GGL_READ_NEEDS(W, needs.n);
+            if (need_w) {
+                CONTEXT_LOAD(s.reg, state.texture[i].iterators.ydsdy);
+                CONTEXT_LOAD(t.reg, state.texture[i].iterators.ydtdy);
+            } else {
+                int ydsdy = scratches.obtain();
+                int ydtdy = scratches.obtain();
+                CONTEXT_LOAD(s.reg, generated_vars.texture[i].dsdx);
+                CONTEXT_LOAD(ydsdy, state.texture[i].iterators.ydsdy);
+                CONTEXT_LOAD(t.reg, generated_vars.texture[i].dtdx);
+                CONTEXT_LOAD(ydtdy, state.texture[i].iterators.ydtdy);
+                MLA(AL, 0, s.reg, Rx, s.reg, ydsdy);
+                MLA(AL, 0, t.reg, Rx, t.reg, ydtdy);
+            }
+            
+            if ((mOptLevel&1)==0) {
+                CONTEXT_STORE(s.reg, generated_vars.texture[i].spill[0]);
+                CONTEXT_STORE(t.reg, generated_vars.texture[i].spill[1]);
+                recycleReg(s.reg);
+                recycleReg(t.reg);
+            }
+        }
+
+        // direct texture?
+        if (!multiTexture && !mBlending && !mDithering && !mFog && 
+            cb_format_idx == tmu.format_idx && !tmu.linear &&
+            mTextureMachine.replaced == tmu.mask) 
+        {
+                mTextureMachine.directTexture = i + 1; 
+        }
+    }
+}
+
+void GGLAssembler::build_textures(  fragment_parts_t& parts,
+                                    Scratch& regs)
+{
+    context_t const* c = mBuilderContext.c;
+    const needs_t& needs = mBuilderContext.needs;
+    int Rctx = mBuilderContext.Rctx;
+
+    // We don't have a way to spill registers automatically
+    // spill depth and AA regs, when we know we may have to.
+    // build the spill list...
+    uint32_t spill_list = 0;
+    for (int i=0 ; i<GGL_TEXTURE_UNIT_COUNT; i++) {
+        const texture_unit_t& tmu = mTextureMachine.tmu[i];
+        if (tmu.format_idx == 0)
+            continue;
+        if (tmu.linear) {
+            // we may run out of register if we have linear filtering
+            // at 1 or 4 bytes / pixel on any texture unit.
+            if (tmu.format.size == 1) {
+                // if depth and AA enabled, we'll run out of 1 register
+                if (parts.z.reg > 0 && parts.covPtr.reg > 0)
+                    spill_list |= 1<<parts.covPtr.reg;
+            }
+            if (tmu.format.size == 4) {
+                // if depth or AA enabled, we'll run out of 1 or 2 registers
+                if (parts.z.reg > 0)
+                    spill_list |= 1<<parts.z.reg;
+                if (parts.covPtr.reg > 0)   
+                    spill_list |= 1<<parts.covPtr.reg;
+            }
+        }
+    }
+
+    Spill spill(registerFile(), *this, spill_list);
+
+    const bool multiTexture = mTextureMachine.activeUnits > 1;
+    for (int i=0 ; i<GGL_TEXTURE_UNIT_COUNT; i++) {
+        const texture_unit_t& tmu = mTextureMachine.tmu[i];
+        if (tmu.format_idx == 0)
+            continue;
+
+        pointer_t& txPtr = parts.coords[i].ptr;
+        pixel_t& texel = parts.texel[i];
+            
+        // repeat...
+        if ((tmu.swrap == GGL_NEEDS_WRAP_11) &&
+            (tmu.twrap == GGL_NEEDS_WRAP_11))
+        { // 1:1 textures
+            comment("fetch texel");
+            texel.setTo(regs.obtain(), &tmu.format);
+            load(txPtr, texel, WRITE_BACK);
+        } else {
+            Scratch scratches(registerFile());
+            reg_t& s = parts.coords[i].s;
+            reg_t& t = parts.coords[i].t;
+            if ((mOptLevel&1)==0) {
+                comment("reload s/t (multitexture or linear filtering)");
+                s.reg = scratches.obtain();
+                t.reg = scratches.obtain();
+                CONTEXT_LOAD(s.reg, generated_vars.texture[i].spill[0]);
+                CONTEXT_LOAD(t.reg, generated_vars.texture[i].spill[1]);
+            }
+
+            comment("compute repeat/clamp");
+            int u       = scratches.obtain();
+            int v       = scratches.obtain();
+            int width   = scratches.obtain();
+            int height  = scratches.obtain();
+            int U = 0;
+            int V = 0;
+
+            CONTEXT_LOAD(width,  generated_vars.texture[i].width);
+            CONTEXT_LOAD(height, generated_vars.texture[i].height);
+
+            int FRAC_BITS = 0;
+            if (tmu.linear) {
+                // linear interpolation
+                if (tmu.format.size == 1) {
+                    // for 8-bits textures, we can afford
+                    // 7 bits of fractional precision at no
+                    // additional cost (we can't do 8 bits
+                    // because filter8 uses signed 16 bits muls)
+                    FRAC_BITS = 7;
+                } else if (tmu.format.size == 2) {
+                    // filter16() is internally limited to 4 bits, so:
+                    // FRAC_BITS=2 generates less instructions,
+                    // FRAC_BITS=3,4,5 creates unpleasant artifacts,
+                    // FRAC_BITS=6+ looks good
+                    FRAC_BITS = 6;
+                } else if (tmu.format.size == 4) {
+                    // filter32() is internally limited to 8 bits, so:
+                    // FRAC_BITS=4 looks good
+                    // FRAC_BITS=5+ looks better, but generates 3 extra ipp
+                    FRAC_BITS = 6;
+                } else {
+                    // for all other cases we use 4 bits.
+                    FRAC_BITS = 4;
+                }
+            }
+            wrapping(u, s.reg, width,  tmu.swrap, FRAC_BITS);
+            wrapping(v, t.reg, height, tmu.twrap, FRAC_BITS);
+
+            if (tmu.linear) {
+                comment("compute linear filtering offsets");
+                // pixel size scale
+                const int shift = 31 - gglClz(tmu.format.size);
+                U = scratches.obtain();
+                V = scratches.obtain();
+
+                // sample the texel center
+                SUB(AL, 0, u, u, imm(1<<(FRAC_BITS-1)));
+                SUB(AL, 0, v, v, imm(1<<(FRAC_BITS-1)));
+
+                // get the fractionnal part of U,V
+                AND(AL, 0, U, u, imm((1<<FRAC_BITS)-1));
+                AND(AL, 0, V, v, imm((1<<FRAC_BITS)-1));
+
+                // compute width-1 and height-1
+                SUB(AL, 0, width,  width,  imm(1));
+                SUB(AL, 0, height, height, imm(1));
+
+                // get the integer part of U,V and clamp/wrap
+                // and compute offset to the next texel
+                if (tmu.swrap == GGL_NEEDS_WRAP_REPEAT) {
+                    // u has already been REPEATed
+                    MOV(AL, 1, u, reg_imm(u, ASR, FRAC_BITS));
+                    MOV(MI, 0, u, width);                    
+                    CMP(AL, u, width);
+                    MOV(LT, 0, width, imm(1 << shift));
+                    if (shift)
+                        MOV(GE, 0, width, reg_imm(width, LSL, shift));
+                    RSB(GE, 0, width, width, imm(0));
+                } else {
+                    // u has not been CLAMPed yet
+                    // algorithm:
+                    // if ((u>>4) >= width)
+                    //      u = width<<4
+                    //      width = 0
+                    // else
+                    //      width = 1<<shift
+                    // u = u>>4; // get integer part
+                    // if (u<0)
+                    //      u = 0
+                    //      width = 0
+                    // generated_vars.rt = width
+                    
+                    CMP(AL, width, reg_imm(u, ASR, FRAC_BITS));
+                    MOV(LE, 0, u, reg_imm(width, LSL, FRAC_BITS));
+                    MOV(LE, 0, width, imm(0));
+                    MOV(GT, 0, width, imm(1 << shift));
+                    MOV(AL, 1, u, reg_imm(u, ASR, FRAC_BITS));
+                    MOV(MI, 0, u, imm(0));
+                    MOV(MI, 0, width, imm(0));
+                }
+                CONTEXT_STORE(width, generated_vars.rt);
+
+                const int stride = width;
+                CONTEXT_LOAD(stride, generated_vars.texture[i].stride);
+                if (tmu.twrap == GGL_NEEDS_WRAP_REPEAT) {
+                    // v has already been REPEATed
+                    MOV(AL, 1, v, reg_imm(v, ASR, FRAC_BITS));
+                    MOV(MI, 0, v, height);
+                    CMP(AL, v, height);
+                    MOV(LT, 0, height, imm(1 << shift));
+                    if (shift)
+                        MOV(GE, 0, height, reg_imm(height, LSL, shift));
+                    RSB(GE, 0, height, height, imm(0));
+                    MUL(AL, 0, height, stride, height);
+                } else {
+                    // u has not been CLAMPed yet
+                    CMP(AL, height, reg_imm(v, ASR, FRAC_BITS));
+                    MOV(LE, 0, v, reg_imm(height, LSL, FRAC_BITS));
+                    MOV(LE, 0, height, imm(0));
+                    if (shift) {
+                        MOV(GT, 0, height, reg_imm(stride, LSL, shift));
+                    } else {
+                        MOV(GT, 0, height, stride);
+                    }
+                    MOV(AL, 1, v, reg_imm(v, ASR, FRAC_BITS));
+                    MOV(MI, 0, v, imm(0));
+                    MOV(MI, 0, height, imm(0));
+                }
+                CONTEXT_STORE(height, generated_vars.lb);
+            }
+    
+            scratches.recycle(width);
+            scratches.recycle(height);
+
+            // iterate texture coordinates...
+            comment("iterate s,t");
+            int dsdx = scratches.obtain();
+            int dtdx = scratches.obtain();
+            CONTEXT_LOAD(dsdx, generated_vars.texture[i].dsdx);
+            CONTEXT_LOAD(dtdx, generated_vars.texture[i].dtdx);
+            ADD(AL, 0, s.reg, s.reg, dsdx);
+            ADD(AL, 0, t.reg, t.reg, dtdx);
+            if ((mOptLevel&1)==0) {
+                CONTEXT_STORE(s.reg, generated_vars.texture[i].spill[0]);
+                CONTEXT_STORE(t.reg, generated_vars.texture[i].spill[1]);
+                scratches.recycle(s.reg);
+                scratches.recycle(t.reg);
+            }
+            scratches.recycle(dsdx);
+            scratches.recycle(dtdx);
+
+            // merge base & offset...
+            comment("merge base & offset");
+            texel.setTo(regs.obtain(), &tmu.format);
+            txPtr.setTo(texel.reg, tmu.bits);
+            int stride = scratches.obtain();
+            CONTEXT_LOAD(stride,    generated_vars.texture[i].stride);
+            CONTEXT_LOAD(txPtr.reg, generated_vars.texture[i].data);
+            SMLABB(AL, u, v, stride, u);    // u+v*stride 
+            base_offset(txPtr, txPtr, u);
+
+            // load texel
+            if (!tmu.linear) {
+                comment("fetch texel");
+                load(txPtr, texel, 0);
+            } else {
+                // recycle registers we don't need anymore
+                scratches.recycle(u);
+                scratches.recycle(v);
+                scratches.recycle(stride);
+
+                comment("fetch texel, bilinear");
+                switch (tmu.format.size) {
+                case 1:  filter8(parts, texel, tmu, U, V, txPtr, FRAC_BITS); break;
+                case 2: filter16(parts, texel, tmu, U, V, txPtr, FRAC_BITS); break;
+                case 3: filter24(parts, texel, tmu, U, V, txPtr, FRAC_BITS); break;
+                case 4: filter32(parts, texel, tmu, U, V, txPtr, FRAC_BITS); break;
+                }
+            }            
+        }
+    }
+}
+
+void GGLAssembler::build_iterate_texture_coordinates(
+    const fragment_parts_t& parts)
+{
+    const bool multiTexture = mTextureMachine.activeUnits > 1;
+    for (int i=0 ; i<GGL_TEXTURE_UNIT_COUNT; i++) {
+        const texture_unit_t& tmu = mTextureMachine.tmu[i];
+        if (tmu.format_idx == 0)
+            continue;
+
+        if ((tmu.swrap == GGL_NEEDS_WRAP_11) &&
+            (tmu.twrap == GGL_NEEDS_WRAP_11))
+        { // 1:1 textures
+            const pointer_t& txPtr = parts.coords[i].ptr;
+            ADD(AL, 0, txPtr.reg, txPtr.reg, imm(txPtr.size>>3));
+        } else {
+            Scratch scratches(registerFile());
+            int s = parts.coords[i].s.reg;
+            int t = parts.coords[i].t.reg;
+            if ((mOptLevel&1)==0) {
+                s = scratches.obtain();
+                t = scratches.obtain();
+                CONTEXT_LOAD(s, generated_vars.texture[i].spill[0]);
+                CONTEXT_LOAD(t, generated_vars.texture[i].spill[1]);
+            }
+            int dsdx = scratches.obtain();
+            int dtdx = scratches.obtain();
+            CONTEXT_LOAD(dsdx, generated_vars.texture[i].dsdx);
+            CONTEXT_LOAD(dtdx, generated_vars.texture[i].dtdx);
+            ADD(AL, 0, s, s, dsdx);
+            ADD(AL, 0, t, t, dtdx);
+            if ((mOptLevel&1)==0) {
+                CONTEXT_STORE(s, generated_vars.texture[i].spill[0]);
+                CONTEXT_STORE(t, generated_vars.texture[i].spill[1]);
+            }
+        }
+    }
+}
+
+void GGLAssembler::filter8(
+        const fragment_parts_t& parts,
+        pixel_t& texel, const texture_unit_t& tmu,
+        int U, int V, pointer_t& txPtr,
+        int FRAC_BITS)
+{
+    if (tmu.format.components != GGL_ALPHA &&
+        tmu.format.components != GGL_LUMINANCE)
+    {
+        // this is a packed format, and we don't support
+        // linear filtering (it's probably RGB 332)
+        // Should not happen with OpenGL|ES
+        LDRB(AL, texel.reg, txPtr.reg);
+        return;
+    }
+
+    // ------------------------
+    // about ~22 cycles / pixel
+    Scratch scratches(registerFile());
+
+    int pixel= scratches.obtain();
+    int d    = scratches.obtain();
+    int u    = scratches.obtain();
+    int k    = scratches.obtain();
+    int rt   = scratches.obtain();
+    int lb   = scratches.obtain();
+
+    // RB -> U * V
+
+    CONTEXT_LOAD(rt, generated_vars.rt);
+    CONTEXT_LOAD(lb, generated_vars.lb);
+
+    int offset = pixel;
+    ADD(AL, 0, offset, lb, rt);
+    LDRB(AL, pixel, txPtr.reg, reg_scale_pre(offset));
+    SMULBB(AL, u, U, V);
+    SMULBB(AL, d, pixel, u);
+    RSB(AL, 0, k, u, imm(1<<(FRAC_BITS*2)));
+    
+    // LB -> (1-U) * V
+    RSB(AL, 0, U, U, imm(1<<FRAC_BITS));
+    LDRB(AL, pixel, txPtr.reg, reg_scale_pre(lb));
+    SMULBB(AL, u, U, V);
+    SMLABB(AL, d, pixel, u, d);
+    SUB(AL, 0, k, k, u);
+    
+    // LT -> (1-U)*(1-V)
+    RSB(AL, 0, V, V, imm(1<<FRAC_BITS));
+    LDRB(AL, pixel, txPtr.reg);
+    SMULBB(AL, u, U, V);
+    SMLABB(AL, d, pixel, u, d);
+
+    // RT -> U*(1-V)
+    LDRB(AL, pixel, txPtr.reg, reg_scale_pre(rt));
+    SUB(AL, 0, u, k, u);
+    SMLABB(AL, texel.reg, pixel, u, d);
+    
+    for (int i=0 ; i<4 ; i++) {
+        if (!texel.format.c[i].h) continue;
+        texel.format.c[i].h = FRAC_BITS*2+8;
+        texel.format.c[i].l = FRAC_BITS*2; // keeping 8 bits in enough
+    }
+    texel.format.size = 4;
+    texel.format.bitsPerPixel = 32;
+    texel.flags |= CLEAR_LO;
+}
+
+void GGLAssembler::filter16(
+        const fragment_parts_t& parts,
+        pixel_t& texel, const texture_unit_t& tmu,
+        int U, int V, pointer_t& txPtr,
+        int FRAC_BITS)
+{    
+    // compute the mask
+    // XXX: it would be nice if the mask below could be computed
+    // automatically.
+    uint32_t mask = 0;
+    int shift = 0;
+    int prec = 0;
+    switch (tmu.format_idx) {
+        case GGL_PIXEL_FORMAT_RGB_565:
+            // source: 00000ggg.ggg00000 | rrrrr000.000bbbbb
+            // result: gggggggg.gggrrrrr | rrrrr0bb.bbbbbbbb
+            mask = 0x07E0F81F;
+            shift = 16;
+            prec = 5;
+            break;
+        case GGL_PIXEL_FORMAT_RGBA_4444:
+            // 0000,1111,0000,1111 | 0000,1111,0000,1111
+            mask = 0x0F0F0F0F;
+            shift = 12;
+            prec = 4;
+            break;
+        case GGL_PIXEL_FORMAT_LA_88:
+            // 0000,0000,1111,1111 | 0000,0000,1111,1111
+            // AALL -> 00AA | 00LL
+            mask = 0x00FF00FF;
+            shift = 8;
+            prec = 8;
+            break;
+        default:
+            // unsupported format, do something sensical...
+            LOGE("Unsupported 16-bits texture format (%d)", tmu.format_idx);
+            LDRH(AL, texel.reg, txPtr.reg);
+            return;
+    }
+
+    const int adjust = FRAC_BITS*2 - prec;
+    const int round  = 0;
+
+    // update the texel format
+    texel.format.size = 4;
+    texel.format.bitsPerPixel = 32;
+    texel.flags |= CLEAR_HI|CLEAR_LO;
+    for (int i=0 ; i<4 ; i++) {
+        if (!texel.format.c[i].h) continue;
+        const uint32_t offset = (mask & tmu.format.mask(i)) ? 0 : shift;
+        texel.format.c[i].h = tmu.format.c[i].h + offset + prec;
+        texel.format.c[i].l = texel.format.c[i].h - (tmu.format.bits(i) + prec);
+    }
+
+    // ------------------------
+    // about ~40 cycles / pixel
+    Scratch scratches(registerFile());
+
+    int pixel= scratches.obtain();
+    int d    = scratches.obtain();
+    int u    = scratches.obtain();
+    int k    = scratches.obtain();
+
+    // RB -> U * V
+    int offset = pixel;
+    CONTEXT_LOAD(offset, generated_vars.rt);
+    CONTEXT_LOAD(u, generated_vars.lb);
+    ADD(AL, 0, offset, offset, u);
+
+    LDRH(AL, pixel, txPtr.reg, reg_pre(offset));
+    SMULBB(AL, u, U, V);
+    ORR(AL, 0, pixel, pixel, reg_imm(pixel, LSL, shift));
+    build_and_immediate(pixel, pixel, mask, 32);
+    if (adjust) {
+        if (round)
+            ADD(AL, 0, u, u, imm(1<<(adjust-1)));
+        MOV(AL, 0, u, reg_imm(u, LSR, adjust));
+    }
+    MUL(AL, 0, d, pixel, u);
+    RSB(AL, 0, k, u, imm(1<<prec));
+    
+    // LB -> (1-U) * V
+    CONTEXT_LOAD(offset, generated_vars.lb);
+    RSB(AL, 0, U, U, imm(1<<FRAC_BITS));
+    LDRH(AL, pixel, txPtr.reg, reg_pre(offset));
+    SMULBB(AL, u, U, V);
+    ORR(AL, 0, pixel, pixel, reg_imm(pixel, LSL, shift));
+    build_and_immediate(pixel, pixel, mask, 32);
+    if (adjust) {
+        if (round)
+            ADD(AL, 0, u, u, imm(1<<(adjust-1)));
+        MOV(AL, 0, u, reg_imm(u, LSR, adjust));
+    }
+    MLA(AL, 0, d, pixel, u, d);
+    SUB(AL, 0, k, k, u);
+    
+    // LT -> (1-U)*(1-V)
+    RSB(AL, 0, V, V, imm(1<<FRAC_BITS));
+    LDRH(AL, pixel, txPtr.reg);
+    SMULBB(AL, u, U, V);
+    ORR(AL, 0, pixel, pixel, reg_imm(pixel, LSL, shift));
+    build_and_immediate(pixel, pixel, mask, 32);
+    if (adjust) {
+        if (round)
+            ADD(AL, 0, u, u, imm(1<<(adjust-1)));
+        MOV(AL, 0, u, reg_imm(u, LSR, adjust));
+    }
+    MLA(AL, 0, d, pixel, u, d);
+
+    // RT -> U*(1-V)            
+    CONTEXT_LOAD(offset, generated_vars.rt);
+    LDRH(AL, pixel, txPtr.reg, reg_pre(offset));
+    SUB(AL, 0, u, k, u);
+    ORR(AL, 0, pixel, pixel, reg_imm(pixel, LSL, shift));
+    build_and_immediate(pixel, pixel, mask, 32);
+    MLA(AL, 0, texel.reg, pixel, u, d);
+}
+
+void GGLAssembler::filter24(
+        const fragment_parts_t& parts,
+        pixel_t& texel, const texture_unit_t& tmu,
+        int U, int V, pointer_t& txPtr,
+        int FRAC_BITS)
+{
+    // not supported yet (currently disabled)
+    load(txPtr, texel, 0);
+}
+
+void GGLAssembler::filter32(
+        const fragment_parts_t& parts,
+        pixel_t& texel, const texture_unit_t& tmu,
+        int U, int V, pointer_t& txPtr,
+        int FRAC_BITS)
+{
+    const int adjust = FRAC_BITS*2 - 8;
+    const int round  = 0;
+
+    // ------------------------
+    // about ~38 cycles / pixel
+    Scratch scratches(registerFile());
+    
+    int pixel= scratches.obtain();
+    int dh   = scratches.obtain();
+    int u    = scratches.obtain();
+    int k    = scratches.obtain();
+
+    int temp = scratches.obtain();
+    int dl   = scratches.obtain();
+    int mask = scratches.obtain();
+
+    MOV(AL, 0, mask, imm(0xFF));
+    ORR(AL, 0, mask, mask, imm(0xFF0000));
+
+    // RB -> U * V
+    int offset = pixel;
+    CONTEXT_LOAD(offset, generated_vars.rt);
+    CONTEXT_LOAD(u, generated_vars.lb);
+    ADD(AL, 0, offset, offset, u);
+
+    LDR(AL, pixel, txPtr.reg, reg_scale_pre(offset));
+    SMULBB(AL, u, U, V);
+    AND(AL, 0, temp, mask, pixel);
+    if (adjust) {
+        if (round)
+            ADD(AL, 0, u, u, imm(1<<(adjust-1)));
+        MOV(AL, 0, u, reg_imm(u, LSR, adjust));
+    }
+    MUL(AL, 0, dh, temp, u);
+    AND(AL, 0, temp, mask, reg_imm(pixel, LSR, 8));
+    MUL(AL, 0, dl, temp, u);
+    RSB(AL, 0, k, u, imm(0x100));
+
+    // LB -> (1-U) * V
+    CONTEXT_LOAD(offset, generated_vars.lb);
+    RSB(AL, 0, U, U, imm(1<<FRAC_BITS));
+    LDR(AL, pixel, txPtr.reg, reg_scale_pre(offset));
+    SMULBB(AL, u, U, V);
+    AND(AL, 0, temp, mask, pixel);
+    if (adjust) {
+        if (round)
+            ADD(AL, 0, u, u, imm(1<<(adjust-1)));
+        MOV(AL, 0, u, reg_imm(u, LSR, adjust));
+    }
+    MLA(AL, 0, dh, temp, u, dh);    
+    AND(AL, 0, temp, mask, reg_imm(pixel, LSR, 8));
+    MLA(AL, 0, dl, temp, u, dl);
+    SUB(AL, 0, k, k, u);
+
+    // LT -> (1-U)*(1-V)
+    RSB(AL, 0, V, V, imm(1<<FRAC_BITS));
+    LDR(AL, pixel, txPtr.reg);
+    SMULBB(AL, u, U, V);
+    AND(AL, 0, temp, mask, pixel);
+    if (adjust) {
+        if (round)
+            ADD(AL, 0, u, u, imm(1<<(adjust-1)));
+        MOV(AL, 0, u, reg_imm(u, LSR, adjust));
+    }
+    MLA(AL, 0, dh, temp, u, dh);    
+    AND(AL, 0, temp, mask, reg_imm(pixel, LSR, 8));
+    MLA(AL, 0, dl, temp, u, dl);
+
+    // RT -> U*(1-V)            
+    CONTEXT_LOAD(offset, generated_vars.rt);
+    LDR(AL, pixel, txPtr.reg, reg_scale_pre(offset));
+    SUB(AL, 0, u, k, u);
+    AND(AL, 0, temp, mask, pixel);
+    MLA(AL, 0, dh, temp, u, dh);    
+    AND(AL, 0, temp, mask, reg_imm(pixel, LSR, 8));
+    MLA(AL, 0, dl, temp, u, dl);
+
+    AND(AL, 0, dh, mask, reg_imm(dh, LSR, 8));
+    AND(AL, 0, dl, dl, reg_imm(mask, LSL, 8));
+    ORR(AL, 0, texel.reg, dh, dl);
+}
+
+void GGLAssembler::build_texture_environment(
+        component_t& fragment,
+        const fragment_parts_t& parts,
+        int component,
+        Scratch& regs)
+{
+    const uint32_t component_mask = 1<<component;
+    const bool multiTexture = mTextureMachine.activeUnits > 1;
+    for (int i=0 ; i<GGL_TEXTURE_UNIT_COUNT ; i++) {
+        texture_unit_t& tmu = mTextureMachine.tmu[i];
+
+        if (tmu.mask & component_mask) {
+            // replace or modulate with this texture
+            if ((tmu.replaced & component_mask) == 0) {
+                // not replaced by a later tmu...
+
+                Scratch scratches(registerFile());
+                pixel_t texel(parts.texel[i]);
+                if (multiTexture && 
+                    tmu.swrap == GGL_NEEDS_WRAP_11 &&
+                    tmu.twrap == GGL_NEEDS_WRAP_11)
+                {
+                    texel.reg = scratches.obtain();
+                    texel.flags |= CORRUPTIBLE;
+                    comment("fetch texel (multitexture 1:1)");
+                    load(parts.coords[i].ptr, texel, WRITE_BACK);
+                 }
+
+                component_t incoming(fragment);
+                modify(fragment, regs);
+                
+                switch (tmu.env) {
+                case GGL_REPLACE:
+                    extract(fragment, texel, component);
+                    break;
+                case GGL_MODULATE:
+                    modulate(fragment, incoming, texel, component);
+                    break;
+                case GGL_DECAL:
+                    decal(fragment, incoming, texel, component);
+                    break;
+                case GGL_BLEND:
+                    blend(fragment, incoming, texel, component, i);
+                    break;
+                case GGL_ADD:
+                    add(fragment, incoming, texel, component);
+                    break;
+                }
+            }
+        }
+    }
+}
+
+// ---------------------------------------------------------------------------
+
+void GGLAssembler::wrapping(
+            int d,
+            int coord, int size,
+            int tx_wrap, int tx_linear)
+{
+    // notes:
+    // if tx_linear is set, we need 4 extra bits of precision on the result
+    // SMULL/UMULL is 3 cycles
+    Scratch scratches(registerFile());
+    int c = coord;
+    if (tx_wrap == GGL_NEEDS_WRAP_REPEAT) {
+        // UMULL takes 4 cycles (interlocked), and we can get away with
+        // 2 cycles using SMULWB, but we're loosing 16 bits of precision
+        // out of 32 (this is not a problem because the iterator keeps
+        // its full precision)
+        // UMULL(AL, 0, size, d, c, size);
+        // note: we can't use SMULTB because it's signed.
+        MOV(AL, 0, d, reg_imm(c, LSR, 16-tx_linear));
+        SMULWB(AL, d, d, size);
+    } else if (tx_wrap == GGL_NEEDS_WRAP_CLAMP_TO_EDGE) {
+        if (tx_linear) {
+            // 1 cycle
+            MOV(AL, 0, d, reg_imm(coord, ASR, 16-tx_linear));
+        } else {
+            // 4 cycles (common case)
+            MOV(AL, 0, d, reg_imm(coord, ASR, 16));
+            BIC(AL, 0, d, d, reg_imm(d, ASR, 31));
+            CMP(AL, d, size);
+            SUB(GE, 0, d, size, imm(1));
+        }
+    }
+}
+
+// ---------------------------------------------------------------------------
+
+void GGLAssembler::modulate(
+        component_t& dest, 
+        const component_t& incoming,
+        const pixel_t& incomingTexel, int component)
+{
+    Scratch locals(registerFile());
+    integer_t texel(locals.obtain(), 32, CORRUPTIBLE);            
+    extract(texel, incomingTexel, component);
+
+    const int Nt = texel.size();
+        // Nt should always be less than 10 bits because it comes
+        // from the TMU.
+
+    int Ni = incoming.size();
+        // Ni could be big because it comes from previous MODULATEs
+
+    if (Nt == 1) {
+        // texel acts as a bit-mask
+        // dest = incoming & ((texel << incoming.h)-texel)
+        RSB(AL, 0, dest.reg, texel.reg, reg_imm(texel.reg, LSL, incoming.h));
+        AND(AL, 0, dest.reg, dest.reg, incoming.reg);
+        dest.l = incoming.l;
+        dest.h = incoming.h;
+        dest.flags |= (incoming.flags & CLEAR_LO);
+    } else if (Ni == 1) {
+        MOV(AL, 0, dest.reg, reg_imm(incoming.reg, LSL, 31-incoming.h));
+        AND(AL, 0, dest.reg, texel.reg, reg_imm(dest.reg, ASR, 31));
+        dest.l = 0;
+        dest.h = Nt;
+    } else {
+        int inReg = incoming.reg;
+        int shift = incoming.l;
+        if ((Nt + Ni) > 32) {
+            // we will overflow, reduce the precision of Ni to 8 bits
+            // (Note Nt cannot be more than 10 bits which happens with 
+            // 565 textures and GGL_LINEAR)
+            shift += Ni-8;
+            Ni = 8;
+        }
+
+        // modulate by the component with the lowest precision
+        if (Nt >= Ni) {
+            if (shift) {
+                // XXX: we should be able to avoid this shift
+                // when shift==16 && Nt<16 && Ni<16, in which
+                // we could use SMULBT below.
+                MOV(AL, 0, dest.reg, reg_imm(inReg, LSR, shift));
+                inReg = dest.reg;
+                shift = 0;
+            }
+            // operation:           (Cf*Ct)/((1<<Ni)-1)
+            // approximated with:   Cf*(Ct + Ct>>(Ni-1))>>Ni
+            // this operation doesn't change texel's size
+            ADD(AL, 0, dest.reg, inReg, reg_imm(inReg, LSR, Ni-1));
+            if (Nt<16 && Ni<16) SMULBB(AL, dest.reg, texel.reg, dest.reg);
+            else                MUL(AL, 0, dest.reg, texel.reg, dest.reg);
+            dest.l = Ni;
+            dest.h = Nt + Ni;            
+        } else {
+            if (shift && (shift != 16)) {
+                // if shift==16, we can use 16-bits mul instructions later
+                MOV(AL, 0, dest.reg, reg_imm(inReg, LSR, shift));
+                inReg = dest.reg;
+                shift = 0;
+            }
+            // operation:           (Cf*Ct)/((1<<Nt)-1)
+            // approximated with:   Ct*(Cf + Cf>>(Nt-1))>>Nt
+            // this operation doesn't change incoming's size
+            Scratch scratches(registerFile());
+            int t = (texel.flags & CORRUPTIBLE) ? texel.reg : dest.reg;
+            if (t == inReg)
+                t = scratches.obtain();
+            ADD(AL, 0, t, texel.reg, reg_imm(texel.reg, LSR, Nt-1));
+            if (Nt<16 && Ni<16) {
+                if (shift==16)  SMULBT(AL, dest.reg, t, inReg);
+                else            SMULBB(AL, dest.reg, t, inReg);
+            } else              MUL(AL, 0, dest.reg, t, inReg);
+            dest.l = Nt;
+            dest.h = Nt + Ni;
+        }
+
+        // low bits are not valid
+        dest.flags |= CLEAR_LO;
+
+        // no need to keep more than 8 bits/component
+        if (dest.size() > 8)
+            dest.l = dest.h-8;
+    }
+}
+
+void GGLAssembler::decal(
+        component_t& dest, 
+        const component_t& incoming,
+        const pixel_t& incomingTexel, int component)
+{
+    // RGBA:
+    // Cv = Cf*(1 - At) + Ct*At = Cf + (Ct - Cf)*At
+    // Av = Af
+    Scratch locals(registerFile());
+    integer_t texel(locals.obtain(), 32, CORRUPTIBLE);            
+    integer_t factor(locals.obtain(), 32, CORRUPTIBLE);
+    extract(texel, incomingTexel, component);
+    extract(factor, incomingTexel, GGLFormat::ALPHA);
+
+    // no need to keep more than 8-bits for decal 
+    int Ni = incoming.size();
+    int shift = incoming.l;
+    if (Ni > 8) {
+        shift += Ni-8;
+        Ni = 8;
+    }
+    integer_t incomingNorm(incoming.reg, Ni, incoming.flags);
+    if (shift) {
+        MOV(AL, 0, dest.reg, reg_imm(incomingNorm.reg, LSR, shift));
+        incomingNorm.reg = dest.reg;
+        incomingNorm.flags |= CORRUPTIBLE;
+    }
+    ADD(AL, 0, factor.reg, factor.reg, reg_imm(factor.reg, LSR, factor.s-1));
+    build_blendOneMinusFF(dest, factor, incomingNorm, texel);
+}
+
+void GGLAssembler::blend(
+        component_t& dest, 
+        const component_t& incoming,
+        const pixel_t& incomingTexel, int component, int tmu)
+{
+    // RGBA:
+    // Cv = (1 - Ct)*Cf + Ct*Cc = Cf + (Cc - Cf)*Ct
+    // Av = At*Af
+
+    if (component == GGLFormat::ALPHA) {
+        modulate(dest, incoming, incomingTexel, component);
+        return;
+    }
+    
+    Scratch locals(registerFile());
+    integer_t color(locals.obtain(), 8, CORRUPTIBLE);            
+    integer_t factor(locals.obtain(), 32, CORRUPTIBLE);
+    LDRB(AL, color.reg, mBuilderContext.Rctx,
+            immed12_pre(GGL_OFFSETOF(state.texture[tmu].env_color[component])));
+    extract(factor, incomingTexel, component);
+
+    // no need to keep more than 8-bits for blend 
+    int Ni = incoming.size();
+    int shift = incoming.l;
+    if (Ni > 8) {
+        shift += Ni-8;
+        Ni = 8;
+    }
+    integer_t incomingNorm(incoming.reg, Ni, incoming.flags);
+    if (shift) {
+        MOV(AL, 0, dest.reg, reg_imm(incomingNorm.reg, LSR, shift));
+        incomingNorm.reg = dest.reg;
+        incomingNorm.flags |= CORRUPTIBLE;
+    }
+    ADD(AL, 0, factor.reg, factor.reg, reg_imm(factor.reg, LSR, factor.s-1));
+    build_blendOneMinusFF(dest, factor, incomingNorm, color);
+}
+
+void GGLAssembler::add(
+        component_t& dest, 
+        const component_t& incoming,
+        const pixel_t& incomingTexel, int component)
+{
+    // RGBA:
+    // Cv = Cf + Ct;
+    Scratch locals(registerFile());
+    
+    component_t incomingTemp(incoming);
+
+    // use "dest" as a temporary for extracting the texel, unless "dest"
+    // overlaps "incoming".
+    integer_t texel(dest.reg, 32, CORRUPTIBLE);
+    if (dest.reg == incomingTemp.reg)
+        texel.reg = locals.obtain();
+    extract(texel, incomingTexel, component);
+
+    if (texel.s < incomingTemp.size()) {
+        expand(texel, texel, incomingTemp.size());
+    } else if (texel.s > incomingTemp.size()) {
+        if (incomingTemp.flags & CORRUPTIBLE) {
+            expand(incomingTemp, incomingTemp, texel.s);
+        } else {
+            incomingTemp.reg = locals.obtain();
+            expand(incomingTemp, incoming, texel.s);
+        }
+    }
+
+    if (incomingTemp.l) {
+        ADD(AL, 0, dest.reg, texel.reg,
+                reg_imm(incomingTemp.reg, LSR, incomingTemp.l));
+    } else {
+        ADD(AL, 0, dest.reg, texel.reg, incomingTemp.reg);
+    }
+    dest.l = 0;
+    dest.h = texel.size();
+    component_sat(dest);
+}
+
+// ----------------------------------------------------------------------------
+
+}; // namespace android
+