gallivm: rework and implement more texture wrap modes

All the texture wrap modes are now implemented for linear and nearest
sampling.

However, texture border color is not yet supported so some wrap modes
will produce int coords outside the texture bounds.  We'll get garbage
values insted of the texture border color for now.

1 files changed, 448 insertions, 60 deletions

diff --git a/src/gallium/auxiliary/gallivm/lp_bld_sample_soa.c b/src/gallium/auxiliary/gallivm/lp_bld_sample_soa.c
index 64698c660e4..1ba139c6cd4 100644
--- a/src/gallium/auxiliary/gallivm/lp_bld_sample_soa.c
+++ b/src/gallium/auxiliary/gallivm/lp_bld_sample_soa.c
@@ -69,10 +69,14 @@ struct lp_build_sample_context
    struct lp_type coord_type;
    struct lp_build_context coord_bld;
 
-   /** Integer coordinates */
+   /** Unsigned integer coordinates */
    struct lp_type uint_coord_type;
    struct lp_build_context uint_coord_bld;
 
+   /** Signed integer coordinates */
+   struct lp_type int_coord_type;
+   struct lp_build_context int_coord_bld;
+
    /** Output texels type and build context */
    struct lp_type texel_type;
    struct lp_build_context texel_bld;
@@ -138,14 +142,74 @@ lp_build_sample_packed(struct lp_build_sample_context *bld,
 }
 
 
+/**
+ * Helper to compute the mirror function for the PIPE_WRAP_MIRROR modes.
+ */
+static LLVMValueRef
+lp_build_coord_mirror(struct lp_build_sample_context *bld,
+                      LLVMValueRef coord)
+{
+   struct lp_build_context *coord_bld = &bld->coord_bld;
+   struct lp_build_context *int_coord_bld = &bld->int_coord_bld;
+   LLVMValueRef fract, flr, isOdd;
+
+   /* fract = coord - floor(coord) */
+   fract = lp_build_sub(coord_bld, coord, lp_build_floor(coord_bld, coord));
+
+   /* flr = ifloor(coord); */
+   flr = lp_build_ifloor(coord_bld, coord);
+
+   /* isOdd = flr & 1 */
+   isOdd = LLVMBuildAnd(bld->builder, flr, int_coord_bld->one, "");
+
+   /* make coord positive or negative depending on isOdd */
+   coord = lp_build_set_sign(coord_bld, fract, isOdd);
+
+   /* convert isOdd to float */
+   isOdd = lp_build_int_to_float(coord_bld, isOdd);
+
+   /* add isOdd to coord */
+   coord = lp_build_add(coord_bld, coord, isOdd);
+
+   return coord;
+}
+
+
+/**
+ * We only support a few wrap modes in lp_build_sample_wrap_int() at this time.
+ * Return whether the given mode is supported by that function.
+ */
+static boolean
+is_simple_wrap_mode(int mode)
+{
+   switch (mode) {
+   case PIPE_TEX_WRAP_REPEAT:
+   case PIPE_TEX_WRAP_CLAMP:
+   case PIPE_TEX_WRAP_CLAMP_TO_EDGE:
+   case PIPE_TEX_WRAP_CLAMP_TO_BORDER:
+      return TRUE;
+   default:
+      return FALSE;
+   }
+}
+
+
+/**
+ * Build LLVM code for texture wrap mode, for scaled integer texcoords.
+ * \param coord  the incoming texcoord (s,t,r or q) scaled to the texture size
+ * \param length  the texture size along one dimension
+ * \param is_pot  if TRUE, length is a power of two
+ * \param wrap_mode  one of PIPE_TEX_WRAP_x
+ */
 static LLVMValueRef
-lp_build_sample_wrap(struct lp_build_sample_context *bld,
-                     LLVMValueRef coord,
-                     LLVMValueRef length,
-                     boolean is_pot,
-                     unsigned wrap_mode)
+lp_build_sample_wrap_int(struct lp_build_sample_context *bld,
+                         LLVMValueRef coord,
+                         LLVMValueRef length,
+                         boolean is_pot,
+                         unsigned wrap_mode)
 {
    struct lp_build_context *uint_coord_bld = &bld->uint_coord_bld;
+   struct lp_build_context *int_coord_bld = &bld->int_coord_bld;
    LLVMValueRef length_minus_one;
 
    length_minus_one = lp_build_sub(uint_coord_bld, length, uint_coord_bld->one);
@@ -161,12 +225,12 @@ lp_build_sample_wrap(struct lp_build_sample_context *bld,
       break;
 
    case PIPE_TEX_WRAP_CLAMP:
-      coord = lp_build_max(uint_coord_bld, coord, uint_coord_bld->zero);
-      coord = lp_build_min(uint_coord_bld, coord, length_minus_one);
-      break;
-
    case PIPE_TEX_WRAP_CLAMP_TO_EDGE:
    case PIPE_TEX_WRAP_CLAMP_TO_BORDER:
+      coord = lp_build_max(int_coord_bld, coord, int_coord_bld->zero);
+      coord = lp_build_min(int_coord_bld, coord, length_minus_one);
+      break;
+
    case PIPE_TEX_WRAP_MIRROR_REPEAT:
    case PIPE_TEX_WRAP_MIRROR_CLAMP:
    case PIPE_TEX_WRAP_MIRROR_CLAMP_TO_EDGE:
@@ -186,6 +250,332 @@ lp_build_sample_wrap(struct lp_build_sample_context *bld,
 }
 
 
+/**
+ * Build LLVM code for texture wrap mode for linear filtering.
+ * \param x0_out  returns first integer texcoord
+ * \param x1_out  returns second integer texcoord
+ * \param weight_out  returns linear interpolation weight
+ */
+static void
+lp_build_sample_wrap_linear(struct lp_build_sample_context *bld,
+                            LLVMValueRef coord,
+                            LLVMValueRef length,
+                            boolean is_pot,
+                            unsigned wrap_mode,
+                            LLVMValueRef *x0_out,
+                            LLVMValueRef *x1_out,
+                            LLVMValueRef *weight_out)
+{
+   struct lp_build_context *coord_bld = &bld->coord_bld;
+   struct lp_build_context *int_coord_bld = &bld->int_coord_bld;
+   struct lp_build_context *uint_coord_bld = &bld->uint_coord_bld;
+   LLVMValueRef two = lp_build_const_scalar(coord_bld->type, 2.0);
+   LLVMValueRef half = lp_build_const_scalar(coord_bld->type, 0.5);
+   LLVMValueRef length_f = lp_build_int_to_float(coord_bld, length);
+   LLVMValueRef length_minus_one;
+   LLVMValueRef length_f_minus_one;
+   LLVMValueRef coord0, coord1, weight;
+
+   /* XXX check for normalized vs. unnormalized coords */
+
+   length_minus_one = lp_build_sub(uint_coord_bld, length, uint_coord_bld->one);
+   length_f_minus_one = lp_build_sub(coord_bld, length_f, coord_bld->one);
+
+   switch(wrap_mode) {
+   case PIPE_TEX_WRAP_REPEAT:
+      /* mul by size and subtract 0.5 */
+      coord = lp_build_mul(coord_bld, coord, length_f);
+      coord = lp_build_sub(coord_bld, coord, half);
+      /* convert to int */
+      coord0 = lp_build_ifloor(coord_bld, coord);
+      coord1 = lp_build_add(uint_coord_bld, coord0, uint_coord_bld->one);
+      /* compute lerp weight */
+      weight = lp_build_fract(coord_bld, coord);
+      /* repeat wrap */
+      if (is_pot) {
+         coord0 = LLVMBuildAnd(bld->builder, coord0, length_minus_one, "");
+         coord1 = LLVMBuildAnd(bld->builder, coord1, length_minus_one, "");
+      }
+      else {
+         /* Signed remainder won't give the right results for negative
+          * dividends but unsigned remainder does.*/
+         coord0 = LLVMBuildURem(bld->builder, coord0, length, "");
+         coord1 = LLVMBuildURem(bld->builder, coord1, length, "");
+      }
+      break;
+
+   case PIPE_TEX_WRAP_CLAMP:
+      coord = lp_build_mul(coord_bld, coord, length_f);
+      weight = lp_build_fract(coord_bld, coord);
+      coord0 = lp_build_clamp(coord_bld, coord, coord_bld->zero,
+                              length_f_minus_one);
+      coord1 = lp_build_add(coord_bld, coord, coord_bld->one);
+      coord1 = lp_build_clamp(coord_bld, coord1, coord_bld->zero,
+                              length_f_minus_one);
+      coord0 = lp_build_ifloor(coord_bld, coord0);
+      coord1 = lp_build_ifloor(coord_bld, coord1);
+      break;
+
+   case PIPE_TEX_WRAP_CLAMP_TO_EDGE:
+      /* clamp to [0,1] */
+      coord = lp_build_clamp(coord_bld, coord, coord_bld->zero, coord_bld->one);
+      /* mul by tex size and subtract 0.5 */
+      coord = lp_build_mul(coord_bld, coord, length_f);
+      coord = lp_build_sub(coord_bld, coord, half);
+      /* compute lerp weight */
+      weight = lp_build_fract(coord_bld, coord);
+      /* coord0 = floor(coord); */
+      coord0 = lp_build_ifloor(coord_bld, coord);
+      coord1 = lp_build_add(int_coord_bld, coord0, int_coord_bld->one);
+      /* coord0 = max(coord0, 0) */
+      coord0 = lp_build_max(int_coord_bld, coord0, int_coord_bld->zero);
+      /* coord1 = min(coord1, length-1) */
+      coord1 = lp_build_min(int_coord_bld, coord1, length_minus_one);
+      break;
+
+   case PIPE_TEX_WRAP_CLAMP_TO_BORDER:
+      {
+         LLVMValueRef min, max;
+         /* min = -1.0 / (2 * length) */
+         min = lp_build_rcp(coord_bld, lp_build_mul(coord_bld, two, length_f));
+         min = lp_build_negate(coord_bld, min);
+         /* max = length - min */
+         max = lp_build_sub(coord_bld, length_f, min);
+         /* scale coord to length (and sub 0.5?) */
+         coord = lp_build_mul(coord_bld, coord, length_f);
+         /* compute lerp weight */
+         weight = lp_build_fract(coord_bld, coord);
+         /* coord = clamp(coord, min, max) */
+         coord = lp_build_clamp(coord_bld, coord, min, max);
+         /* convert to int */
+         coord0 = lp_build_ifloor(coord_bld, coord);
+         coord1 = lp_build_add(int_coord_bld, coord0, int_coord_bld->one);
+      }
+      break;
+
+   case PIPE_TEX_WRAP_MIRROR_REPEAT:
+      /* compute mirror function */
+      coord = lp_build_coord_mirror(bld, coord);
+
+      /* scale coord to length */
+      coord = lp_build_mul(coord_bld, coord, length_f);
+      coord = lp_build_sub(coord_bld, coord, half);
+
+      /* compute lerp weight */
+      weight = lp_build_fract(coord_bld, coord);
+
+      /* convert to int coords */
+      coord0 = lp_build_ifloor(coord_bld, coord);
+      coord1 = lp_build_add(int_coord_bld, coord0, int_coord_bld->one);
+
+      /* coord0 = max(coord0, 0) */
+      coord0 = lp_build_max(int_coord_bld, coord0, int_coord_bld->zero);
+      /* coord1 = min(coord1, length-1) */
+      coord1 = lp_build_min(int_coord_bld, coord1, length_minus_one);
+      break;
+
+   case PIPE_TEX_WRAP_MIRROR_CLAMP:
+      coord = lp_build_abs(coord_bld, coord);
+      coord = lp_build_mul(coord_bld, coord, length_f);
+      weight = lp_build_fract(coord_bld, coord);
+      coord = lp_build_clamp(coord_bld, coord, coord_bld->zero, length_f_minus_one);
+      coord0 = lp_build_ifloor(coord_bld, coord);
+      coord1 = lp_build_add(int_coord_bld, coord0, int_coord_bld->one);
+      break;
+
+   case PIPE_TEX_WRAP_MIRROR_CLAMP_TO_EDGE:
+      {
+         LLVMValueRef min, max;
+         /* min = 1.0 / (2 * length) */
+         min = lp_build_rcp(coord_bld, lp_build_mul(coord_bld, two, length_f));
+         /* max = length - min */
+         max = lp_build_sub(coord_bld, length_f, min);
+
+         coord = lp_build_abs(coord_bld, coord);
+         coord = lp_build_mul(coord_bld, coord, length_f);
+         weight = lp_build_fract(coord_bld, coord);
+         coord = lp_build_clamp(coord_bld, coord, min, max);
+         coord0 = lp_build_ifloor(coord_bld, coord);
+         coord1 = lp_build_add(int_coord_bld, coord0, int_coord_bld->one);
+      }
+      break;
+
+   case PIPE_TEX_WRAP_MIRROR_CLAMP_TO_BORDER:
+      {
+         LLVMValueRef min, max;
+         /* min = -1.0 / (2 * length) */
+         min = lp_build_rcp(coord_bld, lp_build_mul(coord_bld, two, length_f));
+         min = lp_build_negate(coord_bld, min);
+         /* max = length - min */
+         max = lp_build_sub(coord_bld, length_f, min);
+
+         coord = lp_build_abs(coord_bld, coord);
+         coord = lp_build_mul(coord_bld, coord, length_f);
+         weight = lp_build_fract(coord_bld, coord);
+         coord = lp_build_clamp(coord_bld, coord, min, max);
+         coord0 = lp_build_ifloor(coord_bld, coord);
+         coord1 = lp_build_add(int_coord_bld, coord0, int_coord_bld->one);
+      }
+      break;
+
+   default:
+      assert(0);
+   }
+
+   *x0_out = coord0;
+   *x1_out = coord1;
+   *weight_out = weight;
+}
+
+
+/**
+ * Build LLVM code for texture wrap mode for nearest filtering.
+ * \param coord  the incoming texcoord (nominally in [0,1])
+ * \param length  the texture size along one dimension, as int
+ * \param is_pot  if TRUE, length is a power of two
+ * \param wrap_mode  one of PIPE_TEX_WRAP_x
+ */
+static LLVMValueRef
+lp_build_sample_wrap_nearest(struct lp_build_sample_context *bld,
+                             LLVMValueRef coord,
+                             LLVMValueRef length,
+                             boolean is_pot,
+                             unsigned wrap_mode)
+{
+   struct lp_build_context *coord_bld = &bld->coord_bld;
+   struct lp_build_context *int_coord_bld = &bld->int_coord_bld;
+   struct lp_build_context *uint_coord_bld = &bld->uint_coord_bld;
+   LLVMValueRef two = lp_build_const_scalar(coord_bld->type, 2.0);
+   LLVMValueRef length_f = lp_build_int_to_float(coord_bld, length);
+   LLVMValueRef length_minus_one = lp_build_sub(uint_coord_bld, length, uint_coord_bld->one);
+   LLVMValueRef length_f_minus_one = lp_build_sub(coord_bld, length_f, coord_bld->one);
+   LLVMValueRef icoord;
+   
+   /* XXX check for normalized vs. unnormalized coords */
+
+   switch(wrap_mode) {
+   case PIPE_TEX_WRAP_REPEAT:
+      coord = lp_build_mul(coord_bld, coord, length_f);
+      icoord = lp_build_ifloor(coord_bld, coord);
+      if (is_pot)
+         icoord = LLVMBuildAnd(bld->builder, icoord, length_minus_one, "");
+      else
+         /* Signed remainder won't give the right results for negative
+          * dividends but unsigned remainder does.*/
+         icoord = LLVMBuildURem(bld->builder, icoord, length, "");
+      break;
+
+   case PIPE_TEX_WRAP_CLAMP:
+      /* mul by size */
+      coord = lp_build_mul(coord_bld, coord, length_f);
+      /* floor */
+      icoord = lp_build_ifloor(coord_bld, coord);
+      /* clamp to [0, size-1].  Note: int coord builder type */
+      icoord = lp_build_clamp(int_coord_bld, icoord, int_coord_bld->zero,
+                              length_minus_one);
+      break;
+
+   case PIPE_TEX_WRAP_CLAMP_TO_EDGE:
+      {
+         LLVMValueRef min, max;
+         /* min = 1.0 / (2 * length) */
+         min = lp_build_rcp(coord_bld, lp_build_mul(coord_bld, two, length_f));
+         /* max = length - min */
+         max = lp_build_sub(coord_bld, length_f, min);
+         /* scale coord to length */
+         coord = lp_build_mul(coord_bld, coord, length_f);
+         /* coord = clamp(coord, min, max) */
+         coord = lp_build_clamp(coord_bld, coord, min, max);
+         icoord = lp_build_ifloor(coord_bld, coord);
+      }
+      break;
+
+   case PIPE_TEX_WRAP_CLAMP_TO_BORDER:
+      /* Note: this is the same as CLAMP_TO_EDGE, except min = -min */
+      {
+         LLVMValueRef min, max;
+         /* min = -1.0 / (2 * length) */
+         min = lp_build_rcp(coord_bld, lp_build_mul(coord_bld, two, length_f));
+         min = lp_build_negate(coord_bld, min);
+         /* max = length - min */
+         max = lp_build_sub(coord_bld, length_f, min);
+         /* scale coord to length */
+         coord = lp_build_mul(coord_bld, coord, length_f);
+         /* coord = clamp(coord, min, max) */
+         coord = lp_build_clamp(coord_bld, coord, min, max);
+         icoord = lp_build_ifloor(coord_bld, coord);
+      }
+      break;
+
+   case PIPE_TEX_WRAP_MIRROR_REPEAT:
+      {
+         LLVMValueRef min, max;
+         /* min = 1.0 / (2 * length) */
+         min = lp_build_rcp(coord_bld, lp_build_mul(coord_bld, two, length_f));
+         /* max = length - min */
+         max = lp_build_sub(coord_bld, length_f, min);
+
+         /* compute mirror function */
+         coord = lp_build_coord_mirror(bld, coord);
+
+         /* scale coord to length */
+         coord = lp_build_mul(coord_bld, coord, length_f);
+
+         /* coord = clamp(coord, min, max) */
+         coord = lp_build_clamp(coord_bld, coord, min, max);
+         icoord = lp_build_ifloor(coord_bld, coord);
+      }
+      break;
+
+   case PIPE_TEX_WRAP_MIRROR_CLAMP:
+      coord = lp_build_abs(coord_bld, coord);
+      coord = lp_build_mul(coord_bld, coord, length_f);
+      coord = lp_build_clamp(coord_bld, coord, coord_bld->zero, length_f_minus_one);
+      icoord = lp_build_ifloor(coord_bld, coord);
+      break;
+
+   case PIPE_TEX_WRAP_MIRROR_CLAMP_TO_EDGE:
+      {
+         LLVMValueRef min, max;
+         /* min = 1.0 / (2 * length) */
+         min = lp_build_rcp(coord_bld, lp_build_mul(coord_bld, two, length_f));
+         /* max = length - min */
+         max = lp_build_sub(coord_bld, length_f, min);
+
+         coord = lp_build_abs(coord_bld, coord);
+         coord = lp_build_mul(coord_bld, coord, length_f);
+         coord = lp_build_clamp(coord_bld, coord, min, max);
+         icoord = lp_build_ifloor(coord_bld, coord);
+      }
+      break;
+
+   case PIPE_TEX_WRAP_MIRROR_CLAMP_TO_BORDER:
+      {
+         LLVMValueRef min, max;
+         /* min = 1.0 / (2 * length) */
+         min = lp_build_rcp(coord_bld, lp_build_mul(coord_bld, two, length_f));
+         min = lp_build_negate(coord_bld, min);
+         /* max = length - min */
+         max = lp_build_sub(coord_bld, length_f, min);
+
+         coord = lp_build_abs(coord_bld, coord);
+         coord = lp_build_mul(coord_bld, coord, length_f);
+         coord = lp_build_clamp(coord_bld, coord, min, max);
+         icoord = lp_build_ifloor(coord_bld, coord);
+      }
+      break;
+
+   default:
+      assert(0);
+   }
+
+   return icoord;
+}
+
+
+/**
+ * Sample 2D texture with nearest filtering.
+ */
 static void
 lp_build_sample_2d_nearest_soa(struct lp_build_sample_context *bld,
                                LLVMValueRef s,
@@ -196,16 +586,15 @@ lp_build_sample_2d_nearest_soa(struct lp_build_sample_context *bld,
                                LLVMValueRef data_ptr,
                                LLVMValueRef *texel)
 {
-   LLVMValueRef x;
-   LLVMValueRef y;
+   LLVMValueRef x, y;
 
-   x = lp_build_ifloor(&bld->coord_bld, s);
-   y = lp_build_ifloor(&bld->coord_bld, t);
-   lp_build_name(x, "tex.x.floor");
-   lp_build_name(y, "tex.y.floor");
+   x = lp_build_sample_wrap_nearest(bld, s, width,
+                                    bld->static_state->pot_width,
+                                    bld->static_state->wrap_s);
+   y = lp_build_sample_wrap_nearest(bld, t, height,
+                                    bld->static_state->pot_height,
+                                    bld->static_state->wrap_t);
 
-   x = lp_build_sample_wrap(bld, x, width,  bld->static_state->pot_width,  bld->static_state->wrap_s);
-   y = lp_build_sample_wrap(bld, y, height, bld->static_state->pot_height, bld->static_state->wrap_t);
    lp_build_name(x, "tex.x.wrapped");
    lp_build_name(y, "tex.y.wrapped");
 
@@ -213,6 +602,9 @@ lp_build_sample_2d_nearest_soa(struct lp_build_sample_context *bld,
 }
 
 
+/**
+ * Sample 2D texture with bilinear filtering.
+ */
 static void
 lp_build_sample_2d_linear_soa(struct lp_build_sample_context *bld,
                               LLVMValueRef s,
@@ -223,9 +615,6 @@ lp_build_sample_2d_linear_soa(struct lp_build_sample_context *bld,
                               LLVMValueRef data_ptr,
                               LLVMValueRef *texel)
 {
-   LLVMValueRef half;
-   LLVMValueRef s_ipart;
-   LLVMValueRef t_ipart;
    LLVMValueRef s_fpart;
    LLVMValueRef t_fpart;
    LLVMValueRef x0, x1;
@@ -233,27 +622,10 @@ lp_build_sample_2d_linear_soa(struct lp_build_sample_context *bld,
    LLVMValueRef neighbors[2][2][4];
    unsigned chan;
 
-   half = lp_build_const_scalar(bld->coord_type, 0.5);
-   s = lp_build_sub(&bld->coord_bld, s, half);
-   t = lp_build_sub(&bld->coord_bld, t, half);
-
-   s_ipart = lp_build_floor(&bld->coord_bld, s);
-   t_ipart = lp_build_floor(&bld->coord_bld, t);
-
-   s_fpart = lp_build_sub(&bld->coord_bld, s, s_ipart);
-   t_fpart = lp_build_sub(&bld->coord_bld, t, t_ipart);
-
-   x0 = lp_build_itrunc(&bld->coord_bld, s_ipart);
-   y0 = lp_build_itrunc(&bld->coord_bld, t_ipart);
-
-   x0 = lp_build_sample_wrap(bld, x0, width,  bld->static_state->pot_width,  bld->static_state->wrap_s);
-   y0 = lp_build_sample_wrap(bld, y0, height, bld->static_state->pot_height, bld->static_state->wrap_t);
-
-   x1 = lp_build_add(&bld->uint_coord_bld, x0, bld->uint_coord_bld.one);
-   y1 = lp_build_add(&bld->uint_coord_bld, y0, bld->uint_coord_bld.one);
-
-   x1 = lp_build_sample_wrap(bld, x1, width,  bld->static_state->pot_width,  bld->static_state->wrap_s);
-   y1 = lp_build_sample_wrap(bld, y1, height, bld->static_state->pot_height, bld->static_state->wrap_t);
+   lp_build_sample_wrap_linear(bld, s, width, bld->static_state->pot_width,
+                               bld->static_state->wrap_s, &x0, &x1, &s_fpart);
+   lp_build_sample_wrap_linear(bld, t, height, bld->static_state->pot_height,
+                               bld->static_state->wrap_t, &y0, &y1, &t_fpart);
 
    lp_build_sample_texel_soa(bld, x0, y0, stride, data_ptr, neighbors[0][0]);
    lp_build_sample_texel_soa(bld, x1, y0, stride, data_ptr, neighbors[0][1]);
@@ -334,20 +706,33 @@ lp_build_sample_2d_linear_aos(struct lp_build_sample_context *bld,
    h16_vec_type = lp_build_vec_type(h16.type);
    u8n_vec_type = lp_build_vec_type(u8n.type);
 
+   if (bld->static_state->normalized_coords) {
+      LLVMTypeRef coord_vec_type = lp_build_vec_type(bld->coord_type);
+      LLVMValueRef fp_width = LLVMBuildSIToFP(bld->builder, width, coord_vec_type, "");
+      LLVMValueRef fp_height = LLVMBuildSIToFP(bld->builder, height, coord_vec_type, "");
+      s = lp_build_mul(&bld->coord_bld, s, fp_width);
+      t = lp_build_mul(&bld->coord_bld, t, fp_height);
+   }
+
+   /* scale coords by 256 (8 fractional bits) */
    s = lp_build_mul_imm(&bld->coord_bld, s, 256);
    t = lp_build_mul_imm(&bld->coord_bld, t, 256);
 
+   /* convert float to int */
    s = LLVMBuildFPToSI(builder, s, i32_vec_type, "");
    t = LLVMBuildFPToSI(builder, t, i32_vec_type, "");
 
+   /* subtract 0.5 (add -128) */
    i32_c128 = lp_build_int_const_scalar(i32.type, -128);
    s = LLVMBuildAdd(builder, s, i32_c128, "");
    t = LLVMBuildAdd(builder, t, i32_c128, "");
 
+   /* compute floor (shift right 8) */
    i32_c8 = lp_build_int_const_scalar(i32.type, 8);
    s_ipart = LLVMBuildAShr(builder, s, i32_c8, "");
    t_ipart = LLVMBuildAShr(builder, t, i32_c8, "");
 
+   /* compute fractional part (AND with 0xff) */
    i32_c255 = lp_build_int_const_scalar(i32.type, 255);
    s_fpart = LLVMBuildAnd(builder, s, i32_c255, "");
    t_fpart = LLVMBuildAnd(builder, t, i32_c255, "");
@@ -355,14 +740,18 @@ lp_build_sample_2d_linear_aos(struct lp_build_sample_context *bld,
    x0 = s_ipart;
    y0 = t_ipart;
 
-   x0 = lp_build_sample_wrap(bld, x0, width,  bld->static_state->pot_width,  bld->static_state->wrap_s);
-   y0 = lp_build_sample_wrap(bld, y0, height, bld->static_state->pot_height, bld->static_state->wrap_t);
+   x1 = lp_build_add(&bld->int_coord_bld, x0, bld->int_coord_bld.one);
+   y1 = lp_build_add(&bld->int_coord_bld, y0, bld->int_coord_bld.one);
 
-   x1 = lp_build_add(&bld->uint_coord_bld, x0, bld->uint_coord_bld.one);
-   y1 = lp_build_add(&bld->uint_coord_bld, y0, bld->uint_coord_bld.one);
+   x0 = lp_build_sample_wrap_int(bld, x0, width,  bld->static_state->pot_width,
+                                 bld->static_state->wrap_s);
+   y0 = lp_build_sample_wrap_int(bld, y0, height, bld->static_state->pot_height,
+                                 bld->static_state->wrap_t);
 
-   x1 = lp_build_sample_wrap(bld, x1, width,  bld->static_state->pot_width,  bld->static_state->wrap_s);
-   y1 = lp_build_sample_wrap(bld, y1, height, bld->static_state->pot_height, bld->static_state->wrap_t);
+   x1 = lp_build_sample_wrap_int(bld, x1, width,  bld->static_state->pot_width,
+                                 bld->static_state->wrap_s);
+   y1 = lp_build_sample_wrap_int(bld, y1, height, bld->static_state->pot_height,
+                                 bld->static_state->wrap_t);
 
    /*
     * Transform 4 x i32 in
@@ -546,9 +935,11 @@ lp_build_sample_soa(LLVMBuilderRef builder,
    bld.format_desc = util_format_description(static_state->format);
    bld.coord_type = type;
    bld.uint_coord_type = lp_uint_type(type);
+   bld.int_coord_type = lp_int_type(type);
    bld.texel_type = type;
    lp_build_context_init(&bld.coord_bld, builder, bld.coord_type);
    lp_build_context_init(&bld.uint_coord_bld, builder, bld.uint_coord_type);
+   lp_build_context_init(&bld.int_coord_bld, builder, bld.int_coord_type);
    lp_build_context_init(&bld.texel_bld, builder, bld.texel_type);
 
    /* Get the dynamic state */
@@ -568,23 +959,20 @@ lp_build_sample_soa(LLVMBuilderRef builder,
    if(static_state->target == PIPE_TEXTURE_1D)
       t = bld.coord_bld.zero;
 
-   if(static_state->normalized_coords) {
-      LLVMTypeRef coord_vec_type = lp_build_vec_type(bld.coord_type);
-      LLVMValueRef fp_width = LLVMBuildSIToFP(builder, width, coord_vec_type, "");
-      LLVMValueRef fp_height = LLVMBuildSIToFP(builder, height, coord_vec_type, "");
-      s = lp_build_mul(&bld.coord_bld, s, fp_width);
-      t = lp_build_mul(&bld.coord_bld, t, fp_height);
-   }
-
    switch (static_state->min_img_filter) {
    case PIPE_TEX_FILTER_NEAREST:
-      lp_build_sample_2d_nearest_soa(&bld, s, t, width, height, stride, data_ptr, texel);
+      lp_build_sample_2d_nearest_soa(&bld, s, t, width, height,
+                                     stride, data_ptr, texel);
       break;
    case PIPE_TEX_FILTER_LINEAR:
-      if(lp_format_is_rgba8(bld.format_desc))
-         lp_build_sample_2d_linear_aos(&bld, s, t, width, height, stride, data_ptr, texel);
+      if(lp_format_is_rgba8(bld.format_desc) &&
+         is_simple_wrap_mode(static_state->wrap_s) &&
+         is_simple_wrap_mode(static_state->wrap_t))
+         lp_build_sample_2d_linear_aos(&bld, s, t, width, height,
+                                       stride, data_ptr, texel);
       else
-         lp_build_sample_2d_linear_soa(&bld, s, t, width, height, stride, data_ptr, texel);
+         lp_build_sample_2d_linear_soa(&bld, s, t, width, height,
+                                       stride, data_ptr, texel);
       break;
    default:
       assert(0);