Пример #1
0
/**
 * Build a manual selection sequence for cube face sc/tc coordinates and
 * major axis vector (multiplied by 2 for consistency) for the given
 * vec3 \p coords, for the face implied by \p selcoords.
 *
 * For the major axis, we always adjust the sign to be in the direction of
 * selcoords.ma; i.e., a positive out_ma means that coords is pointed towards
 * the selcoords major axis.
 */
static void build_cube_select(LLVMBuilderRef builder,
			      const struct cube_selection_coords *selcoords,
			      const LLVMValueRef *coords,
			      LLVMValueRef *out_st,
			      LLVMValueRef *out_ma)
{
	LLVMTypeRef f32 = LLVMTypeOf(coords[0]);
	LLVMValueRef is_ma_positive;
	LLVMValueRef sgn_ma;
	LLVMValueRef is_ma_z, is_not_ma_z;
	LLVMValueRef is_ma_y;
	LLVMValueRef is_ma_x;
	LLVMValueRef sgn;
	LLVMValueRef tmp;

	is_ma_positive = LLVMBuildFCmp(builder, LLVMRealUGE,
		selcoords->ma, LLVMConstReal(f32, 0.0), "");
	sgn_ma = LLVMBuildSelect(builder, is_ma_positive,
		LLVMConstReal(f32, 1.0), LLVMConstReal(f32, -1.0), "");

	is_ma_z = LLVMBuildFCmp(builder, LLVMRealUGE, selcoords->id, LLVMConstReal(f32, 4.0), "");
	is_not_ma_z = LLVMBuildNot(builder, is_ma_z, "");
	is_ma_y = LLVMBuildAnd(builder, is_not_ma_z,
		LLVMBuildFCmp(builder, LLVMRealUGE, selcoords->id, LLVMConstReal(f32, 2.0), ""), "");
	is_ma_x = LLVMBuildAnd(builder, is_not_ma_z, LLVMBuildNot(builder, is_ma_y, ""), "");

	/* Select sc */
	tmp = LLVMBuildSelect(builder, is_ma_z, coords[2], coords[0], "");
	sgn = LLVMBuildSelect(builder, is_ma_y, LLVMConstReal(f32, 1.0),
		LLVMBuildSelect(builder, is_ma_x, sgn_ma,
			LLVMBuildFNeg(builder, sgn_ma, ""), ""), "");
	out_st[0] = LLVMBuildFMul(builder, tmp, sgn, "");

	/* Select tc */
	tmp = LLVMBuildSelect(builder, is_ma_y, coords[2], coords[1], "");
	sgn = LLVMBuildSelect(builder, is_ma_y, LLVMBuildFNeg(builder, sgn_ma, ""),
		LLVMConstReal(f32, -1.0), "");
	out_st[1] = LLVMBuildFMul(builder, tmp, sgn, "");

	/* Select ma */
	tmp = LLVMBuildSelect(builder, is_ma_z, coords[2],
		LLVMBuildSelect(builder, is_ma_y, coords[1], coords[0], ""), "");
	sgn = LLVMBuildSelect(builder, is_ma_positive,
		LLVMConstReal(f32, 2.0), LLVMConstReal(f32, -2.0), "");
	*out_ma = LLVMBuildFMul(builder, tmp, sgn, "");
}
Пример #2
0
/* Perform front/back face culling and return true if the primitive is accepted. */
static LLVMValueRef ac_cull_face(struct ac_llvm_context *ctx,
				 LLVMValueRef pos[3][4],
				 struct ac_position_w_info *w,
				 bool cull_front,
				 bool cull_back,
				 bool cull_zero_area)
{
	LLVMBuilderRef builder = ctx->builder;

	if (cull_front && cull_back)
		return ctx->i1false;

	if (!cull_front && !cull_back && !cull_zero_area)
		return ctx->i1true;

	/* Front/back face culling. Also if the determinant == 0, the triangle
	 * area is 0.
	 */
	LLVMValueRef det_t0 = LLVMBuildFSub(builder, pos[2][0], pos[0][0], "");
	LLVMValueRef det_t1 = LLVMBuildFSub(builder, pos[1][1], pos[0][1], "");
	LLVMValueRef det_t2 = LLVMBuildFSub(builder, pos[0][0], pos[1][0], "");
	LLVMValueRef det_t3 = LLVMBuildFSub(builder, pos[0][1], pos[2][1], "");
	LLVMValueRef det_p0 = LLVMBuildFMul(builder, det_t0, det_t1, "");
	LLVMValueRef det_p1 = LLVMBuildFMul(builder, det_t2, det_t3, "");
	LLVMValueRef det = LLVMBuildFSub(builder, det_p0, det_p1, "");

	/* Negative W negates the determinant. */
	det = LLVMBuildSelect(builder, w->w_reflection,
			      LLVMBuildFNeg(builder, det, ""),
			      det, "");

	LLVMValueRef accepted = NULL;
	if (cull_front) {
		LLVMRealPredicate cond = cull_zero_area ? LLVMRealOGT : LLVMRealOGE;
		accepted = LLVMBuildFCmp(builder, cond, det, ctx->f32_0, "");
	} else if (cull_back) {
		LLVMRealPredicate cond = cull_zero_area ? LLVMRealOLT : LLVMRealOLE;
		accepted = LLVMBuildFCmp(builder, cond, det, ctx->f32_0, "");
	} else if (cull_zero_area) {
		accepted = LLVMBuildFCmp(builder, LLVMRealONE, det, ctx->f32_0, "");
	}
	return accepted;
}
Пример #3
0
/**
 * Inverse of lp_build_clamped_float_to_unsigned_norm above.
 * Ex: src = { i32, i32, i32, i32 } with values in range [0, 2^src_width-1]
 * return {float, float, float, float} with values in range [0, 1].
 */
LLVMValueRef
lp_build_unsigned_norm_to_float(LLVMBuilderRef builder,
                                unsigned src_width,
                                struct lp_type dst_type,
                                LLVMValueRef src)
{
   LLVMTypeRef vec_type = lp_build_vec_type(dst_type);
   LLVMTypeRef int_vec_type = lp_build_int_vec_type(dst_type);
   LLVMValueRef bias_;
   LLVMValueRef res;
   unsigned mantissa;
   unsigned n;
   unsigned long long ubound;
   unsigned long long mask;
   double scale;
   double bias;

   assert(dst_type.floating);

   mantissa = lp_mantissa(dst_type);

   n = MIN2(mantissa, src_width);

   ubound = ((unsigned long long)1 << n);
   mask = ubound - 1;
   scale = (double)ubound/mask;
   bias = (double)((unsigned long long)1 << (mantissa - n));

   res = src;

   if(src_width > mantissa) {
      int shift = src_width - mantissa;
      res = LLVMBuildLShr(builder, res, lp_build_const_int_vec(dst_type, shift), "");
   }

   bias_ = lp_build_const_vec(dst_type, bias);

   res = LLVMBuildOr(builder,
                     res,
                     LLVMBuildBitCast(builder, bias_, int_vec_type, ""), "");

   res = LLVMBuildBitCast(builder, res, vec_type, "");

   res = LLVMBuildFSub(builder, res, bias_, "");
   res = LLVMBuildFMul(builder, res, lp_build_const_vec(dst_type, scale), "");

   return res;
}
Пример #4
0
static LLVMValueRef
translateFloatBinOp(NodeKind Op, LLVMValueRef ValueE1, LLVMValueRef ValueE2) {
  switch (Op) {
    case SumOp:  return LLVMBuildFAdd(Builder, ValueE1, ValueE2, ""); 
    case SubOp:  return LLVMBuildFSub(Builder, ValueE1, ValueE2, ""); 
    case MultOp: return LLVMBuildFMul(Builder, ValueE1, ValueE2, ""); 
    case DivOp:  return LLVMBuildFDiv(Builder, ValueE1, ValueE2, ""); 
    case LtOp:   return LLVMBuildFCmp(Builder, LLVMRealOLT, ValueE1, ValueE2, ""); 
    case LeOp:   return LLVMBuildFCmp(Builder, LLVMRealOLE, ValueE1, ValueE2, ""); 
    case GtOp:   return LLVMBuildFCmp(Builder, LLVMRealOGT, ValueE1, ValueE2, ""); 
    case GeOp:   return LLVMBuildFCmp(Builder, LLVMRealOGE, ValueE1, ValueE2, ""); 
    case EqOp:   return LLVMBuildFCmp(Builder, LLVMRealOEQ, ValueE1, ValueE2, ""); 
    case DiffOp: return LLVMBuildFCmp(Builder, LLVMRealONE, ValueE1, ValueE2, ""); 
    default:     return NULL;
  }
}
Пример #5
0
/**
 * Converts int16 half-float to float32
 * Note this can be performed in 1 instruction if vcvtph2ps exists (sse5 i think?)
 * [llvm.x86.vcvtph2ps / _mm_cvtph_ps]
 *
 * @param src_type      <vector> type of int16
 * @param src           value to convert
 *
 * ref http://fgiesen.wordpress.com/2012/03/28/half-to-float-done-quic/
 */
LLVMValueRef
lp_build_half_to_float(struct gallivm_state *gallivm,
                       struct lp_type src_type,
                       LLVMValueRef src)
{
    struct lp_type f32_type = lp_type_float_vec(32, 32 * src_type.length);
    struct lp_type i32_type = lp_type_int_vec(32, 32 * src_type.length);

    LLVMBuilderRef builder = gallivm->builder;
    LLVMTypeRef int_vec_type = lp_build_vec_type(gallivm, i32_type);
    LLVMTypeRef float_vec_type = lp_build_vec_type(gallivm, f32_type);

    /* Constants */
    LLVMValueRef i32_13          = lp_build_const_int_vec(gallivm, i32_type, 13);
    LLVMValueRef i32_16          = lp_build_const_int_vec(gallivm, i32_type, 16);
    LLVMValueRef i32_mask_nosign = lp_build_const_int_vec(gallivm, i32_type, 0x7fff);
    LLVMValueRef i32_was_infnan  = lp_build_const_int_vec(gallivm, i32_type, 0x7bff);
    LLVMValueRef i32_exp_infnan  = lp_build_const_int_vec(gallivm, i32_type, 0xff << 23);
    LLVMValueRef f32_magic       = LLVMBuildBitCast(builder,
                                   lp_build_const_int_vec(gallivm, i32_type, (254 - 15) << 23),
                                   float_vec_type, "");

    /* Convert int16 vector to int32 vector by zero ext */
    LLVMValueRef h             = LLVMBuildZExt(builder, src, int_vec_type, "");

    /* Exponent / mantissa bits */
    LLVMValueRef expmant       = LLVMBuildAnd(builder, i32_mask_nosign, h, "");
    LLVMValueRef shifted       = LLVMBuildBitCast(builder, LLVMBuildShl(builder, expmant, i32_13, ""), float_vec_type, "");

    /* Exponent adjust */
    LLVMValueRef scaled        = LLVMBuildBitCast(builder, LLVMBuildFMul(builder, shifted, f32_magic, ""), int_vec_type, "");

    /* Make sure Inf/NaN survive */
    LLVMValueRef b_wasinfnan   = lp_build_compare(gallivm, i32_type, PIPE_FUNC_GREATER, expmant, i32_was_infnan);
    LLVMValueRef infnanexp     = LLVMBuildAnd(builder, b_wasinfnan, i32_exp_infnan, "");

    /* Sign bit */
    LLVMValueRef justsign      = LLVMBuildXor(builder, h, expmant, "");
    LLVMValueRef sign          = LLVMBuildShl(builder, justsign, i32_16, "");

    /* Combine result */
    LLVMValueRef sign_inf      = LLVMBuildOr(builder, sign, infnanexp, "");
    LLVMValueRef final         = LLVMBuildOr(builder, scaled, sign_inf, "");

    /* Cast from int32 vector to float32 vector */
    return LLVMBuildBitCast(builder, final, float_vec_type, "");
}
Пример #6
0
/**
 * Unpack several pixels in SoA.
 *
 * It takes a vector of packed pixels:
 *
 *   packed = {P0, P1, P2, P3, ..., Pn}
 *
 * And will produce four vectors:
 *
 *   red    = {R0, R1, R2, R3, ..., Rn}
 *   green  = {G0, G1, G2, G3, ..., Gn}
 *   blue   = {B0, B1, B2, B3, ..., Bn}
 *   alpha  = {A0, A1, A2, A3, ..., An}
 *
 * It requires that a packed pixel fits into an element of the output
 * channels. The common case is when converting pixel with a depth of 32 bit or
 * less into floats.
 *
 * \param format_desc  the format of the 'packed' incoming pixel vector
 * \param type  the desired type for rgba_out (type.length = n, above)
 * \param packed  the incoming vector of packed pixels
 * \param rgba_out  returns the SoA R,G,B,A vectors
 */
void
lp_build_unpack_rgba_soa(struct gallivm_state *gallivm,
                         const struct util_format_description *format_desc,
                         struct lp_type type,
                         LLVMValueRef packed,
                         LLVMValueRef rgba_out[4])
{
   LLVMBuilderRef builder = gallivm->builder;
   struct lp_build_context bld;
   LLVMValueRef inputs[4];
   unsigned chan;

   assert(format_desc->layout == UTIL_FORMAT_LAYOUT_PLAIN);
   assert(format_desc->block.width == 1);
   assert(format_desc->block.height == 1);
   assert(format_desc->block.bits <= type.width);
   /* FIXME: Support more output types */
   assert(type.width == 32);

   lp_build_context_init(&bld, gallivm, type);

   /* Decode the input vector components */
   for (chan = 0; chan < format_desc->nr_channels; ++chan) {
      const unsigned width = format_desc->channel[chan].size;
      const unsigned start = format_desc->channel[chan].shift;
      const unsigned stop = start + width;
      LLVMValueRef input;

      input = packed;

      switch(format_desc->channel[chan].type) {
      case UTIL_FORMAT_TYPE_VOID:
         input = lp_build_undef(gallivm, type);
         break;

      case UTIL_FORMAT_TYPE_UNSIGNED:
         /*
          * Align the LSB
          */

         if (start) {
            input = LLVMBuildLShr(builder, input, lp_build_const_int_vec(gallivm, type, start), "");
         }

         /*
          * Zero the MSBs
          */

         if (stop < format_desc->block.bits) {
            unsigned mask = ((unsigned long long)1 << width) - 1;
            input = LLVMBuildAnd(builder, input, lp_build_const_int_vec(gallivm, type, mask), "");
         }

         /*
          * Type conversion
          */

         if (type.floating) {
            if (format_desc->colorspace == UTIL_FORMAT_COLORSPACE_SRGB) {
               assert(width == 8);
               if (format_desc->swizzle[3] == chan) {
                  input = lp_build_unsigned_norm_to_float(gallivm, width, type, input);
               }
               else {
                  struct lp_type conv_type = lp_uint_type(type);
                  input = lp_build_srgb_to_linear(gallivm, conv_type, input);
               }
            }
            else {
               if(format_desc->channel[chan].normalized)
                  input = lp_build_unsigned_norm_to_float(gallivm, width, type, input);
               else
                  input = LLVMBuildSIToFP(builder, input,
                                          lp_build_vec_type(gallivm, type), "");
            }
         }
         else if (format_desc->channel[chan].pure_integer) {
            /* Nothing to do */
         } else {
             /* FIXME */
             assert(0);
         }

         break;

      case UTIL_FORMAT_TYPE_SIGNED:
         /*
          * Align the sign bit first.
          */

         if (stop < type.width) {
            unsigned bits = type.width - stop;
            LLVMValueRef bits_val = lp_build_const_int_vec(gallivm, type, bits);
            input = LLVMBuildShl(builder, input, bits_val, "");
         }

         /*
          * Align the LSB (with an arithmetic shift to preserve the sign)
          */

         if (format_desc->channel[chan].size < type.width) {
            unsigned bits = type.width - format_desc->channel[chan].size;
            LLVMValueRef bits_val = lp_build_const_int_vec(gallivm, type, bits);
            input = LLVMBuildAShr(builder, input, bits_val, "");
         }

         /*
          * Type conversion
          */

         if (type.floating) {
            input = LLVMBuildSIToFP(builder, input, lp_build_vec_type(gallivm, type), "");
            if (format_desc->channel[chan].normalized) {
               double scale = 1.0 / ((1 << (format_desc->channel[chan].size - 1)) - 1);
               LLVMValueRef scale_val = lp_build_const_vec(gallivm, type, scale);
               input = LLVMBuildFMul(builder, input, scale_val, "");
               /* the formula above will produce value below -1.0 for most negative
                * value but everything seems happy with that hence disable for now */
               if (0)
                  input = lp_build_max(&bld, input,
                                       lp_build_const_vec(gallivm, type, -1.0f));
            }
         }
         else if (format_desc->channel[chan].pure_integer) {
            /* Nothing to do */
         } else {
             /* FIXME */
             assert(0);
         }

         break;

      case UTIL_FORMAT_TYPE_FLOAT:
         if (type.floating) {
            assert(start == 0);
            assert(stop == 32);
            assert(type.width == 32);
            input = LLVMBuildBitCast(builder, input, lp_build_vec_type(gallivm, type), "");
         }
         else {
            /* FIXME */
            assert(0);
            input = lp_build_undef(gallivm, type);
         }
         break;

      case UTIL_FORMAT_TYPE_FIXED:
         if (type.floating) {
            double scale = 1.0 / ((1 << (format_desc->channel[chan].size/2)) - 1);
            LLVMValueRef scale_val = lp_build_const_vec(gallivm, type, scale);
            input = LLVMBuildSIToFP(builder, input, lp_build_vec_type(gallivm, type), "");
            input = LLVMBuildFMul(builder, input, scale_val, "");
         }
         else {
            /* FIXME */
            assert(0);
            input = lp_build_undef(gallivm, type);
         }
         break;

      default:
         assert(0);
         input = lp_build_undef(gallivm, type);
         break;
      }

      inputs[chan] = input;
   }

   lp_build_format_swizzle_soa(format_desc, &bld, inputs, rgba_out);
}
Пример #7
0
/**
 * Generic type conversion.
 *
 * TODO: Take a precision argument, or even better, add a new precision member
 * to the lp_type union.
 */
void
lp_build_conv(struct gallivm_state *gallivm,
              struct lp_type src_type,
              struct lp_type dst_type,
              const LLVMValueRef *src, unsigned num_srcs,
              LLVMValueRef *dst, unsigned num_dsts)
{
    LLVMBuilderRef builder = gallivm->builder;
    struct lp_type tmp_type;
    LLVMValueRef tmp[LP_MAX_VECTOR_LENGTH];
    unsigned num_tmps;
    unsigned i;

    /* We must not loose or gain channels. Only precision */
    assert(src_type.length * num_srcs == dst_type.length * num_dsts);

    assert(src_type.length <= LP_MAX_VECTOR_LENGTH);
    assert(dst_type.length <= LP_MAX_VECTOR_LENGTH);
    assert(num_srcs <= LP_MAX_VECTOR_LENGTH);
    assert(num_dsts <= LP_MAX_VECTOR_LENGTH);

    tmp_type = src_type;
    for(i = 0; i < num_srcs; ++i) {
        assert(lp_check_value(src_type, src[i]));
        tmp[i] = src[i];
    }
    num_tmps = num_srcs;


    /* Special case 4x4f --> 1x16ub
     */
    if (src_type.floating == 1 &&
            src_type.fixed    == 0 &&
            src_type.sign     == 1 &&
            src_type.norm     == 0 &&
            src_type.width    == 32 &&
            src_type.length   == 4 &&

            dst_type.floating == 0 &&
            dst_type.fixed    == 0 &&
            dst_type.sign     == 0 &&
            dst_type.norm     == 1 &&
            dst_type.width    == 8 &&
            dst_type.length   == 16 &&

            4 * num_dsts      == num_srcs &&

            util_cpu_caps.has_sse2)
    {
        struct lp_build_context bld;
        struct lp_type int16_type = dst_type;
        struct lp_type int32_type = dst_type;
        LLVMValueRef const_255f;
        unsigned i, j;

        lp_build_context_init(&bld, gallivm, src_type);

        int16_type.width *= 2;
        int16_type.length /= 2;
        int16_type.sign = 1;

        int32_type.width *= 4;
        int32_type.length /= 4;
        int32_type.sign = 1;

        const_255f = lp_build_const_vec(gallivm, src_type, 255.0f);

        for (i = 0; i < num_dsts; ++i, src += 4) {
            LLVMValueRef lo, hi;

            for (j = 0; j < 4; ++j) {
                tmp[j] = LLVMBuildFMul(builder, src[j], const_255f, "");
                tmp[j] = lp_build_iround(&bld, tmp[j]);
            }

            /* relying on clamping behavior of sse2 intrinsics here */
            lo = lp_build_pack2(gallivm, int32_type, int16_type, tmp[0], tmp[1]);
            hi = lp_build_pack2(gallivm, int32_type, int16_type, tmp[2], tmp[3]);
            dst[i] = lp_build_pack2(gallivm, int16_type, dst_type, lo, hi);
        }

        return;
    }

    /* Special case 2x8f --> 1x16ub
     */
    else if (src_type.floating == 1 &&
             src_type.fixed    == 0 &&
             src_type.sign     == 1 &&
             src_type.norm     == 0 &&
             src_type.width    == 32 &&
             src_type.length   == 8 &&

             dst_type.floating == 0 &&
             dst_type.fixed    == 0 &&
             dst_type.sign     == 0 &&
             dst_type.norm     == 1 &&
             dst_type.width    == 8 &&
             dst_type.length   == 16 &&

             2 * num_dsts      == num_srcs &&

             util_cpu_caps.has_avx) {

        struct lp_build_context bld;
        struct lp_type int16_type = dst_type;
        struct lp_type int32_type = dst_type;
        LLVMValueRef const_255f;
        unsigned i;

        lp_build_context_init(&bld, gallivm, src_type);

        int16_type.width *= 2;
        int16_type.length /= 2;
        int16_type.sign = 1;

        int32_type.width *= 4;
        int32_type.length /= 4;
        int32_type.sign = 1;

        const_255f = lp_build_const_vec(gallivm, src_type, 255.0f);

        for (i = 0; i < num_dsts; ++i, src += 2) {
            LLVMValueRef lo, hi, a, b;

            a = LLVMBuildFMul(builder, src[0], const_255f, "");
            b = LLVMBuildFMul(builder, src[1], const_255f, "");

            a = lp_build_iround(&bld, a);
            b = lp_build_iround(&bld, b);

            tmp[0] = lp_build_extract_range(gallivm, a, 0, 4);
            tmp[1] = lp_build_extract_range(gallivm, a, 4, 4);
            tmp[2] = lp_build_extract_range(gallivm, b, 0, 4);
            tmp[3] = lp_build_extract_range(gallivm, b, 4, 4);

            /* relying on clamping behavior of sse2 intrinsics here */
            lo = lp_build_pack2(gallivm, int32_type, int16_type, tmp[0], tmp[1]);
            hi = lp_build_pack2(gallivm, int32_type, int16_type, tmp[2], tmp[3]);
            dst[i] = lp_build_pack2(gallivm, int16_type, dst_type, lo, hi);
        }
        return;
    }

    /* Pre convert half-floats to floats
     */
    else if (src_type.floating && src_type.width == 16)
    {
        for(i = 0; i < num_tmps; ++i)
            tmp[i] = lp_build_half_to_float(gallivm, src_type, tmp[i]);

        tmp_type.width = 32;
    }

    /*
     * Clamp if necessary
     */

    if(memcmp(&src_type, &dst_type, sizeof src_type) != 0) {
        struct lp_build_context bld;
        double src_min = lp_const_min(src_type);
        double dst_min = lp_const_min(dst_type);
        double src_max = lp_const_max(src_type);
        double dst_max = lp_const_max(dst_type);
        LLVMValueRef thres;

        lp_build_context_init(&bld, gallivm, tmp_type);

        if(src_min < dst_min) {
            if(dst_min == 0.0)
                thres = bld.zero;
            else
                thres = lp_build_const_vec(gallivm, src_type, dst_min);
            for(i = 0; i < num_tmps; ++i)
                tmp[i] = lp_build_max(&bld, tmp[i], thres);
        }

        if(src_max > dst_max) {
            if(dst_max == 1.0)
                thres = bld.one;
            else
                thres = lp_build_const_vec(gallivm, src_type, dst_max);
            for(i = 0; i < num_tmps; ++i)
                tmp[i] = lp_build_min(&bld, tmp[i], thres);
        }
    }

    /*
     * Scale to the narrowest range
     */

    if(dst_type.floating) {
        /* Nothing to do */
    }
    else if(tmp_type.floating) {
        if(!dst_type.fixed && !dst_type.sign && dst_type.norm) {
            for(i = 0; i < num_tmps; ++i) {
                tmp[i] = lp_build_clamped_float_to_unsigned_norm(gallivm,
                         tmp_type,
                         dst_type.width,
                         tmp[i]);
            }
            tmp_type.floating = FALSE;
        }
        else {
            double dst_scale = lp_const_scale(dst_type);
            LLVMTypeRef tmp_vec_type;

            if (dst_scale != 1.0) {
                LLVMValueRef scale = lp_build_const_vec(gallivm, tmp_type, dst_scale);
                for(i = 0; i < num_tmps; ++i)
                    tmp[i] = LLVMBuildFMul(builder, tmp[i], scale, "");
            }

            /* Use an equally sized integer for intermediate computations */
            tmp_type.floating = FALSE;
            tmp_vec_type = lp_build_vec_type(gallivm, tmp_type);
            for(i = 0; i < num_tmps; ++i) {
#if 0
                if(dst_type.sign)
                    tmp[i] = LLVMBuildFPToSI(builder, tmp[i], tmp_vec_type, "");
                else
                    tmp[i] = LLVMBuildFPToUI(builder, tmp[i], tmp_vec_type, "");
#else
                /* FIXME: there is no SSE counterpart for LLVMBuildFPToUI */
                tmp[i] = LLVMBuildFPToSI(builder, tmp[i], tmp_vec_type, "");
#endif
            }
        }
    }
    else {
        unsigned src_shift = lp_const_shift(src_type);
        unsigned dst_shift = lp_const_shift(dst_type);
        unsigned src_offset = lp_const_offset(src_type);
        unsigned dst_offset = lp_const_offset(dst_type);

        /* Compensate for different offsets */
        if (dst_offset > src_offset && src_type.width > dst_type.width) {
            for (i = 0; i < num_tmps; ++i) {
                LLVMValueRef shifted;
                LLVMValueRef shift = lp_build_const_int_vec(gallivm, tmp_type, src_shift - 1);
                if(src_type.sign)
                    shifted = LLVMBuildAShr(builder, tmp[i], shift, "");
                else
                    shifted = LLVMBuildLShr(builder, tmp[i], shift, "");

                tmp[i] = LLVMBuildSub(builder, tmp[i], shifted, "");
            }
        }

        if(src_shift > dst_shift) {
            LLVMValueRef shift = lp_build_const_int_vec(gallivm, tmp_type,
                                 src_shift - dst_shift);
            for(i = 0; i < num_tmps; ++i)
                if(src_type.sign)
                    tmp[i] = LLVMBuildAShr(builder, tmp[i], shift, "");
                else
                    tmp[i] = LLVMBuildLShr(builder, tmp[i], shift, "");
        }
    }

    /*
     * Truncate or expand bit width
     *
     * No data conversion should happen here, although the sign bits are
     * crucial to avoid bad clamping.
     */

    {
        struct lp_type new_type;

        new_type = tmp_type;
        new_type.sign   = dst_type.sign;
        new_type.width  = dst_type.width;
        new_type.length = dst_type.length;

        lp_build_resize(gallivm, tmp_type, new_type, tmp, num_srcs, tmp, num_dsts);

        tmp_type = new_type;
        num_tmps = num_dsts;
    }

    /*
     * Scale to the widest range
     */

    if(src_type.floating) {
        /* Nothing to do */
    }
    else if(!src_type.floating && dst_type.floating) {
        if(!src_type.fixed && !src_type.sign && src_type.norm) {
            for(i = 0; i < num_tmps; ++i) {
                tmp[i] = lp_build_unsigned_norm_to_float(gallivm,
                         src_type.width,
                         dst_type,
                         tmp[i]);
            }
            tmp_type.floating = TRUE;
        }
        else {
            double src_scale = lp_const_scale(src_type);
            LLVMTypeRef tmp_vec_type;

            /* Use an equally sized integer for intermediate computations */
            tmp_type.floating = TRUE;
            tmp_type.sign = TRUE;
            tmp_vec_type = lp_build_vec_type(gallivm, tmp_type);
            for(i = 0; i < num_tmps; ++i) {
#if 0
                if(dst_type.sign)
                    tmp[i] = LLVMBuildSIToFP(builder, tmp[i], tmp_vec_type, "");
                else
                    tmp[i] = LLVMBuildUIToFP(builder, tmp[i], tmp_vec_type, "");
#else
                /* FIXME: there is no SSE counterpart for LLVMBuildUIToFP */
                tmp[i] = LLVMBuildSIToFP(builder, tmp[i], tmp_vec_type, "");
#endif
            }

            if (src_scale != 1.0) {
                LLVMValueRef scale = lp_build_const_vec(gallivm, tmp_type, 1.0/src_scale);
                for(i = 0; i < num_tmps; ++i)
                    tmp[i] = LLVMBuildFMul(builder, tmp[i], scale, "");
            }
        }
    }
    else {
        unsigned src_shift = lp_const_shift(src_type);
        unsigned dst_shift = lp_const_shift(dst_type);
        unsigned src_offset = lp_const_offset(src_type);
        unsigned dst_offset = lp_const_offset(dst_type);

        if (src_shift < dst_shift) {
            LLVMValueRef pre_shift[LP_MAX_VECTOR_LENGTH];
            LLVMValueRef shift = lp_build_const_int_vec(gallivm, tmp_type, dst_shift - src_shift);

            for (i = 0; i < num_tmps; ++i) {
                pre_shift[i] = tmp[i];
                tmp[i] = LLVMBuildShl(builder, tmp[i], shift, "");
            }

            /* Compensate for different offsets */
            if (dst_offset > src_offset) {
                for (i = 0; i < num_tmps; ++i) {
                    tmp[i] = LLVMBuildSub(builder, tmp[i], pre_shift[i], "");
                }
            }
        }
    }

    for(i = 0; i < num_dsts; ++i) {
        dst[i] = tmp[i];
        assert(lp_check_value(dst_type, dst[i]));
    }
}
Пример #8
0
/**
 * Inverse of lp_build_clamped_float_to_unsigned_norm above.
 * Ex: src = { i32, i32, i32, i32 } with values in range [0, 2^src_width-1]
 * return {float, float, float, float} with values in range [0, 1].
 */
LLVMValueRef
lp_build_unsigned_norm_to_float(struct gallivm_state *gallivm,
                                unsigned src_width,
                                struct lp_type dst_type,
                                LLVMValueRef src)
{
    LLVMBuilderRef builder = gallivm->builder;
    LLVMTypeRef vec_type = lp_build_vec_type(gallivm, dst_type);
    LLVMTypeRef int_vec_type = lp_build_int_vec_type(gallivm, dst_type);
    LLVMValueRef bias_;
    LLVMValueRef res;
    unsigned mantissa;
    unsigned n;
    unsigned long long ubound;
    unsigned long long mask;
    double scale;
    double bias;

    assert(dst_type.floating);

    mantissa = lp_mantissa(dst_type);

    if (src_width <= (mantissa + 1)) {
        /*
         * The source width matches fits what can be represented in floating
         * point (i.e., mantissa + 1 bits). So do a straight multiplication
         * followed by casting. No further rounding is necessary.
         */

        scale = 1.0/(double)((1ULL << src_width) - 1);
        res = LLVMBuildSIToFP(builder, src, vec_type, "");
        res = LLVMBuildFMul(builder, res,
                            lp_build_const_vec(gallivm, dst_type, scale), "");
        return res;
    }
    else {
        /*
         * The source width exceeds what can be represented in floating
         * point. So truncate the incoming values.
         */

        n = MIN2(mantissa, src_width);

        ubound = ((unsigned long long)1 << n);
        mask = ubound - 1;
        scale = (double)ubound/mask;
        bias = (double)((unsigned long long)1 << (mantissa - n));

        res = src;

        if (src_width > mantissa) {
            int shift = src_width - mantissa;
            res = LLVMBuildLShr(builder, res,
                                lp_build_const_int_vec(gallivm, dst_type, shift), "");
        }

        bias_ = lp_build_const_vec(gallivm, dst_type, bias);

        res = LLVMBuildOr(builder,
                          res,
                          LLVMBuildBitCast(builder, bias_, int_vec_type, ""), "");

        res = LLVMBuildBitCast(builder, res, vec_type, "");

        res = LLVMBuildFSub(builder, res, bias_, "");
        res = LLVMBuildFMul(builder, res, lp_build_const_vec(gallivm, dst_type, scale), "");
    }

    return res;
}
Пример #9
0
/**
 * Special case for converting clamped IEEE-754 floats to unsigned norms.
 *
 * The mathematical voodoo below may seem excessive but it is actually
 * paramount we do it this way for several reasons. First, there is no single
 * precision FP to unsigned integer conversion Intel SSE instruction. Second,
 * secondly, even if there was, since the FP's mantissa takes only a fraction
 * of register bits the typically scale and cast approach would require double
 * precision for accurate results, and therefore half the throughput
 *
 * Although the result values can be scaled to an arbitrary bit width specified
 * by dst_width, the actual result type will have the same width.
 *
 * Ex: src = { float, float, float, float }
 * return { i32, i32, i32, i32 } where each value is in [0, 2^dst_width-1].
 */
LLVMValueRef
lp_build_clamped_float_to_unsigned_norm(struct gallivm_state *gallivm,
                                        struct lp_type src_type,
                                        unsigned dst_width,
                                        LLVMValueRef src)
{
    LLVMBuilderRef builder = gallivm->builder;
    LLVMTypeRef int_vec_type = lp_build_int_vec_type(gallivm, src_type);
    LLVMValueRef res;
    unsigned mantissa;

    assert(src_type.floating);
    assert(dst_width <= src_type.width);
    src_type.sign = FALSE;

    mantissa = lp_mantissa(src_type);

    if (dst_width <= mantissa) {
        /*
         * Apply magic coefficients that will make the desired result to appear
         * in the lowest significant bits of the mantissa, with correct rounding.
         *
         * This only works if the destination width fits in the mantissa.
         */

        unsigned long long ubound;
        unsigned long long mask;
        double scale;
        double bias;

        ubound = (1ULL << dst_width);
        mask = ubound - 1;
        scale = (double)mask/ubound;
        bias = (double)(1ULL << (mantissa - dst_width));

        res = LLVMBuildFMul(builder, src, lp_build_const_vec(gallivm, src_type, scale), "");
        res = LLVMBuildFAdd(builder, res, lp_build_const_vec(gallivm, src_type, bias), "");
        res = LLVMBuildBitCast(builder, res, int_vec_type, "");
        res = LLVMBuildAnd(builder, res,
                           lp_build_const_int_vec(gallivm, src_type, mask), "");
    }
    else if (dst_width == (mantissa + 1)) {
        /*
         * The destination width matches exactly what can be represented in
         * floating point (i.e., mantissa + 1 bits). So do a straight
         * multiplication followed by casting. No further rounding is necessary.
         */

        double scale;

        scale = (double)((1ULL << dst_width) - 1);

        res = LLVMBuildFMul(builder, src,
                            lp_build_const_vec(gallivm, src_type, scale), "");
        res = LLVMBuildFPToSI(builder, res, int_vec_type, "");
    }
    else {
        /*
         * The destination exceeds what can be represented in the floating point.
         * So multiply by the largest power two we get away with, and when
         * subtract the most significant bit to rescale to normalized values.
         *
         * The largest power of two factor we can get away is
         * (1 << (src_type.width - 1)), because we need to use signed . In theory it
         * should be (1 << (src_type.width - 2)), but IEEE 754 rules states
         * INT_MIN should be returned in FPToSI, which is the correct result for
         * values near 1.0!
         *
         * This means we get (src_type.width - 1) correct bits for values near 0.0,
         * and (mantissa + 1) correct bits for values near 1.0. Equally or more
         * important, we also get exact results for 0.0 and 1.0.
         */

        unsigned n = MIN2(src_type.width - 1, dst_width);

        double scale = (double)(1ULL << n);
        unsigned lshift = dst_width - n;
        unsigned rshift = n;
        LLVMValueRef lshifted;
        LLVMValueRef rshifted;

        res = LLVMBuildFMul(builder, src,
                            lp_build_const_vec(gallivm, src_type, scale), "");
        res = LLVMBuildFPToSI(builder, res, int_vec_type, "");

        /*
         * Align the most significant bit to its final place.
         *
         * This will cause 1.0 to overflow to 0, but the later adjustment will
         * get it right.
         */
        if (lshift) {
            lshifted = LLVMBuildShl(builder, res,
                                    lp_build_const_int_vec(gallivm, src_type,
                                            lshift), "");
        } else {
            lshifted = res;
        }

        /*
         * Align the most significant bit to the right.
         */
        rshifted =  LLVMBuildLShr(builder, res,
                                  lp_build_const_int_vec(gallivm, src_type, rshift),
                                  "");

        /*
         * Subtract the MSB to the LSB, therefore re-scaling from
         * (1 << dst_width) to ((1 << dst_width) - 1).
         */

        res = LLVMBuildSub(builder, lshifted, rshifted, "");
    }

    return res;
}
Пример #10
0
/**
 * Initialize the bld->a, dadq fields.  This involves fetching
 * those values from the arrays which are passed into the JIT function.
 */
static void
coeffs_init(struct lp_build_interp_soa_context *bld,
            LLVMValueRef a0_ptr,
            LLVMValueRef dadx_ptr,
            LLVMValueRef dady_ptr)
{
   struct lp_build_context *coeff_bld = &bld->coeff_bld;
   struct lp_build_context *setup_bld = &bld->setup_bld;
   struct gallivm_state *gallivm = coeff_bld->gallivm;
   LLVMBuilderRef builder = gallivm->builder;
   LLVMValueRef pixoffx, pixoffy;
   unsigned attrib;
   unsigned chan;
   unsigned i;

   pixoffx = coeff_bld->undef;
   pixoffy = coeff_bld->undef;
   for (i = 0; i < coeff_bld->type.length; i++) {
      LLVMValueRef nr = lp_build_const_int32(gallivm, i);
      LLVMValueRef pixxf = lp_build_const_float(gallivm, quad_offset_x[i]);
      LLVMValueRef pixyf = lp_build_const_float(gallivm, quad_offset_y[i]);
      pixoffx = LLVMBuildInsertElement(builder, pixoffx, pixxf, nr, "");
      pixoffy = LLVMBuildInsertElement(builder, pixoffy, pixyf, nr, "");
   }


   for (attrib = 0; attrib < bld->num_attribs; ++attrib) {
      const unsigned mask = bld->mask[attrib];
      const unsigned interp = bld->interp[attrib];
      LLVMValueRef index = lp_build_const_int32(gallivm,
                                attrib * TGSI_NUM_CHANNELS);
      LLVMValueRef ptr;
      LLVMValueRef dadxaos = setup_bld->zero;
      LLVMValueRef dadyaos = setup_bld->zero;
      LLVMValueRef a0aos = setup_bld->zero;

      /* always fetch all 4 values for performance/simplicity */
      switch (interp) {
      case LP_INTERP_PERSPECTIVE:
         /* fall-through */

      case LP_INTERP_LINEAR:
         ptr = LLVMBuildGEP(builder, dadx_ptr, &index, 1, "");
         ptr = LLVMBuildBitCast(builder, ptr,
               LLVMPointerType(setup_bld->vec_type, 0), "");
         dadxaos = LLVMBuildLoad(builder, ptr, "");

         ptr = LLVMBuildGEP(builder, dady_ptr, &index, 1, "");
         ptr = LLVMBuildBitCast(builder, ptr,
               LLVMPointerType(setup_bld->vec_type, 0), "");
         dadyaos = LLVMBuildLoad(builder, ptr, "");

         attrib_name(dadxaos, attrib, 0, ".dadxaos");
         attrib_name(dadyaos, attrib, 0, ".dadyaos");
         /* fall-through */

      case LP_INTERP_CONSTANT:
      case LP_INTERP_FACING:
         ptr = LLVMBuildGEP(builder, a0_ptr, &index, 1, "");
         ptr = LLVMBuildBitCast(builder, ptr,
               LLVMPointerType(setup_bld->vec_type, 0), "");
         a0aos = LLVMBuildLoad(builder, ptr, "");
         attrib_name(a0aos, attrib, 0, ".a0aos");
         break;

      case LP_INTERP_POSITION:
         /* Nothing to do as the position coeffs are already setup in slot 0 */
         continue;

      default:
         assert(0);
         break;
      }

      /*
       * a = a0 + (x * dadx + y * dady)
       * a0aos is the attrib value at top left corner of stamp
       */
      if (interp != LP_INTERP_CONSTANT &&
          interp != LP_INTERP_FACING) {
         LLVMValueRef x = lp_build_broadcast_scalar(setup_bld, bld->x);
         LLVMValueRef y = lp_build_broadcast_scalar(setup_bld, bld->y);
         a0aos = lp_build_fmuladd(builder, x, dadxaos, a0aos);
         a0aos = lp_build_fmuladd(builder, y, dadyaos, a0aos);
      }

      /*
       * dadq = {0, dadx, dady, dadx + dady}
       * for two quads (side by side) this is:
       * {0, dadx, dady, dadx+dady, 2*dadx, 2*dadx+dady, 3*dadx+dady}
       */
      for (chan = 0; chan < TGSI_NUM_CHANNELS; ++chan) {
         /* this generates a CRAPLOAD of shuffles... */
         if (mask & (1 << chan)) {
            LLVMValueRef dadx, dady;
            LLVMValueRef dadq, dadq2;
            LLVMValueRef a;
            LLVMValueRef chan_index = lp_build_const_int32(gallivm, chan);

            if (attrib == 0 && chan == 0) {
               a = bld->x;
               if (bld->pos_offset) {
                  a = LLVMBuildFAdd(builder, a, lp_build_const_float(gallivm, bld->pos_offset), "");
               }
               a = lp_build_broadcast_scalar(coeff_bld, a);
               dadx = coeff_bld->one;
               dady = coeff_bld->zero;
            }
            else if (attrib == 0 && chan == 1) {
               a = bld->y;
               if (bld->pos_offset) {
                  a = LLVMBuildFAdd(builder, a, lp_build_const_float(gallivm, bld->pos_offset), "");
               }
               a = lp_build_broadcast_scalar(coeff_bld, a);
               dady = coeff_bld->one;
               dadx = coeff_bld->zero;
            }
            else {
               dadx = lp_build_extract_broadcast(gallivm, setup_bld->type,
                                              coeff_bld->type, dadxaos, chan_index);
               dady = lp_build_extract_broadcast(gallivm, setup_bld->type,
                                              coeff_bld->type, dadyaos, chan_index);

               /*
                * a = {a, a, a, a}
                */
               a = lp_build_extract_broadcast(gallivm, setup_bld->type,
                                              coeff_bld->type, a0aos, chan_index);
            }

            dadx = LLVMBuildFMul(builder, dadx, pixoffx, "");
            dady = LLVMBuildFMul(builder, dady, pixoffy, "");
            dadq = LLVMBuildFAdd(builder, dadx, dady, "");

            /*
             * Compute the attrib values on the upper-left corner of each
             * group of quads.
             * Note that if we process 2 quads at once this doesn't
             * really exactly to what we want.
             * We need to access elem 0 and 2 respectively later if we process
             * 2 quads at once.
             */

            if (interp != LP_INTERP_CONSTANT &&
                interp != LP_INTERP_FACING) {
               dadq2 = LLVMBuildFAdd(builder, dadq, dadq, "");
               a = LLVMBuildFAdd(builder, a, dadq2, "");
	    }

#if PERSPECTIVE_DIVIDE_PER_QUAD
            /*
             * a *= 1 / w
             */

            /*
             * XXX since we're only going to access elements 0,2 out of 8
             * if we have 8-wide vectors we should do the division only 4-wide.
             * a is really a 2-elements in a 4-wide vector disguised as 8-wide
             * in this case.
             */
            if (interp == LP_INTERP_PERSPECTIVE) {
               LLVMValueRef w = bld->a[0][3];
               assert(attrib != 0);
               assert(bld->mask[0] & TGSI_WRITEMASK_W);
               if (!bld->oow) {
                  bld->oow = lp_build_rcp(coeff_bld, w);
                  lp_build_name(bld->oow, "oow");
               }
               a = lp_build_mul(coeff_bld, a, bld->oow);
            }
#endif

            attrib_name(a, attrib, chan, ".a");
            attrib_name(dadq, attrib, chan, ".dadq");

            bld->a[attrib][chan] = lp_build_alloca(gallivm,
                                                   LLVMTypeOf(a), "");
            LLVMBuildStore(builder, a, bld->a[attrib][chan]);
            bld->dadq[attrib][chan] = dadq;
         }
      }
   }
}
Пример #11
0
/**
 * Sample the texture/mipmap using given image filter and mip filter.
 * data0_ptr and data1_ptr point to the two mipmap levels to sample
 * from.  width0/1_vec, height0/1_vec, depth0/1_vec indicate their sizes.
 * If we're using nearest miplevel sampling the '1' values will be null/unused.
 */
static void
lp_build_sample_mipmap(struct lp_build_sample_context *bld,
                       unsigned img_filter,
                       unsigned mip_filter,
                       LLVMValueRef s,
                       LLVMValueRef t,
                       LLVMValueRef r,
                       LLVMValueRef ilevel0,
                       LLVMValueRef ilevel1,
                       LLVMValueRef lod_fpart,
                       LLVMValueRef colors_lo_var,
                       LLVMValueRef colors_hi_var)
{
   LLVMBuilderRef builder = bld->gallivm->builder;
   LLVMValueRef size0;
   LLVMValueRef size1;
   LLVMValueRef row_stride0_vec;
   LLVMValueRef row_stride1_vec;
   LLVMValueRef img_stride0_vec;
   LLVMValueRef img_stride1_vec;
   LLVMValueRef data_ptr0;
   LLVMValueRef data_ptr1;
   LLVMValueRef colors0_lo, colors0_hi;
   LLVMValueRef colors1_lo, colors1_hi;

   /* sample the first mipmap level */
   lp_build_mipmap_level_sizes(bld, ilevel0,
                               &size0,
                               &row_stride0_vec, &img_stride0_vec);
   data_ptr0 = lp_build_get_mipmap_level(bld, ilevel0);
   if (img_filter == PIPE_TEX_FILTER_NEAREST) {
      lp_build_sample_image_nearest(bld,
                                    size0,
                                    row_stride0_vec, img_stride0_vec,
                                    data_ptr0, s, t, r,
                                    &colors0_lo, &colors0_hi);
   }
   else {
      assert(img_filter == PIPE_TEX_FILTER_LINEAR);
      lp_build_sample_image_linear(bld,
                                   size0,
                                   row_stride0_vec, img_stride0_vec,
                                   data_ptr0, s, t, r,
                                   &colors0_lo, &colors0_hi);
   }

   /* Store the first level's colors in the output variables */
   LLVMBuildStore(builder, colors0_lo, colors_lo_var);
   LLVMBuildStore(builder, colors0_hi, colors_hi_var);

   if (mip_filter == PIPE_TEX_MIPFILTER_LINEAR) {
      LLVMValueRef h16_scale = lp_build_const_float(bld->gallivm, 256.0);
      LLVMTypeRef i32_type = LLVMIntTypeInContext(bld->gallivm->context, 32);
      struct lp_build_if_state if_ctx;
      LLVMValueRef need_lerp;

      lod_fpart = LLVMBuildFMul(builder, lod_fpart, h16_scale, "");
      lod_fpart = LLVMBuildFPToSI(builder, lod_fpart, i32_type, "lod_fpart.fixed16");

      /* need_lerp = lod_fpart > 0 */
      need_lerp = LLVMBuildICmp(builder, LLVMIntSGT,
                                lod_fpart, LLVMConstNull(i32_type),
                                "need_lerp");

      lp_build_if(&if_ctx, bld->gallivm, need_lerp);
      {
         struct lp_build_context h16_bld;

         lp_build_context_init(&h16_bld, bld->gallivm, lp_type_ufixed(16));

         /* sample the second mipmap level */
         lp_build_mipmap_level_sizes(bld, ilevel1,
                                     &size1,
                                     &row_stride1_vec, &img_stride1_vec);
         data_ptr1 = lp_build_get_mipmap_level(bld, ilevel1);
         if (img_filter == PIPE_TEX_FILTER_NEAREST) {
            lp_build_sample_image_nearest(bld,
                                          size1,
                                          row_stride1_vec, img_stride1_vec,
                                          data_ptr1, s, t, r,
                                          &colors1_lo, &colors1_hi);
         }
         else {
            lp_build_sample_image_linear(bld,
                                         size1,
                                         row_stride1_vec, img_stride1_vec,
                                         data_ptr1, s, t, r,
                                         &colors1_lo, &colors1_hi);
         }

         /* interpolate samples from the two mipmap levels */

         lod_fpart = LLVMBuildTrunc(builder, lod_fpart, h16_bld.elem_type, "");
         lod_fpart = lp_build_broadcast_scalar(&h16_bld, lod_fpart);

#if HAVE_LLVM == 0x208
         /* This is a work-around for a bug in LLVM 2.8.
          * Evidently, something goes wrong in the construction of the
          * lod_fpart short[8] vector.  Adding this no-effect shuffle seems
          * to force the vector to be properly constructed.
          * Tested with mesa-demos/src/tests/mipmap_limits.c (press t, f).
          */
         {
            LLVMValueRef shuffles[8], shuffle;
            int i;
            assert(h16_bld.type.length <= Elements(shuffles));
            for (i = 0; i < h16_bld.type.length; i++)
               shuffles[i] = lp_build_const_int32(bld->gallivm, 2 * (i & 1));
            shuffle = LLVMConstVector(shuffles, h16_bld.type.length);
            lod_fpart = LLVMBuildShuffleVector(builder,
                                               lod_fpart, lod_fpart,
                                               shuffle, "");
         }
#endif

         colors0_lo = lp_build_lerp(&h16_bld, lod_fpart,
                                    colors0_lo, colors1_lo);
         colors0_hi = lp_build_lerp(&h16_bld, lod_fpart,
                                    colors0_hi, colors1_hi);

         LLVMBuildStore(builder, colors0_lo, colors_lo_var);
         LLVMBuildStore(builder, colors0_hi, colors_hi_var);
      }
      lp_build_endif(&if_ctx);
   }
}
Пример #12
0
/**
 * Special case for converting clamped IEEE-754 floats to unsigned norms.
 *
 * The mathematical voodoo below may seem excessive but it is actually
 * paramount we do it this way for several reasons. First, there is no single
 * precision FP to unsigned integer conversion Intel SSE instruction. Second,
 * secondly, even if there was, since the FP's mantissa takes only a fraction
 * of register bits the typically scale and cast approach would require double
 * precision for accurate results, and therefore half the throughput
 *
 * Although the result values can be scaled to an arbitrary bit width specified
 * by dst_width, the actual result type will have the same width.
 *
 * Ex: src = { float, float, float, float }
 * return { i32, i32, i32, i32 } where each value is in [0, 2^dst_width-1].
 */
LLVMValueRef
lp_build_clamped_float_to_unsigned_norm(LLVMBuilderRef builder,
                                        struct lp_type src_type,
                                        unsigned dst_width,
                                        LLVMValueRef src)
{
   LLVMTypeRef int_vec_type = lp_build_int_vec_type(src_type);
   LLVMValueRef res;
   unsigned mantissa;
   unsigned n;
   unsigned long long ubound;
   unsigned long long mask;
   double scale;
   double bias;

   assert(src_type.floating);

   mantissa = lp_mantissa(src_type);

   /* We cannot carry more bits than the mantissa */
   n = MIN2(mantissa, dst_width);

   /* This magic coefficients will make the desired result to appear in the
    * lowest significant bits of the mantissa.
    */
   ubound = ((unsigned long long)1 << n);
   mask = ubound - 1;
   scale = (double)mask/ubound;
   bias = (double)((unsigned long long)1 << (mantissa - n));

   res = LLVMBuildFMul(builder, src, lp_build_const_vec(src_type, scale), "");
   res = LLVMBuildFAdd(builder, res, lp_build_const_vec(src_type, bias), "");
   res = LLVMBuildBitCast(builder, res, int_vec_type, "");

   if(dst_width > n) {
      int shift = dst_width - n;
      res = LLVMBuildShl(builder, res, lp_build_const_int_vec(src_type, shift), "");

      /* TODO: Fill in the empty lower bits for additional precision? */
      /* YES: this fixes progs/trivial/tri-z-eq.c.
       * Otherwise vertex Z=1.0 values get converted to something like
       * 0xfffffb00 and the test for equality with 0xffffffff fails.
       */
#if 0
      {
         LLVMValueRef msb;
         msb = LLVMBuildLShr(builder, res, lp_build_const_int_vec(src_type, dst_width - 1), "");
         msb = LLVMBuildShl(builder, msb, lp_build_const_int_vec(src_type, shift), "");
         msb = LLVMBuildSub(builder, msb, lp_build_const_int_vec(src_type, 1), "");
         res = LLVMBuildOr(builder, res, msb, "");
      }
#elif 0
      while(shift > 0) {
         res = LLVMBuildOr(builder, res, LLVMBuildLShr(builder, res, lp_build_const_int_vec(src_type, n), ""), "");
         shift -= n;
         n *= 2;
      }
#endif
   }
   else
      res = LLVMBuildAnd(builder, res, lp_build_const_int_vec(src_type, mask), "");

   return res;
}
Пример #13
0
/**
 * Generic type conversion.
 *
 * TODO: Take a precision argument, or even better, add a new precision member
 * to the lp_type union.
 */
void
lp_build_conv(LLVMBuilderRef builder,
              struct lp_type src_type,
              struct lp_type dst_type,
              const LLVMValueRef *src, unsigned num_srcs,
              LLVMValueRef *dst, unsigned num_dsts)
{
   struct lp_type tmp_type;
   LLVMValueRef tmp[LP_MAX_VECTOR_LENGTH];
   unsigned num_tmps;
   unsigned i;

   /* We must not loose or gain channels. Only precision */
   assert(src_type.length * num_srcs == dst_type.length * num_dsts);

   assert(src_type.length <= LP_MAX_VECTOR_LENGTH);
   assert(dst_type.length <= LP_MAX_VECTOR_LENGTH);
   assert(num_srcs <= LP_MAX_VECTOR_LENGTH);
   assert(num_dsts <= LP_MAX_VECTOR_LENGTH);

   tmp_type = src_type;
   for(i = 0; i < num_srcs; ++i) {
      assert(lp_check_value(src_type, src[i]));
      tmp[i] = src[i];
   }
   num_tmps = num_srcs;

   /*
    * Clamp if necessary
    */

   if(memcmp(&src_type, &dst_type, sizeof src_type) != 0) {
      struct lp_build_context bld;
      double src_min = lp_const_min(src_type);
      double dst_min = lp_const_min(dst_type);
      double src_max = lp_const_max(src_type);
      double dst_max = lp_const_max(dst_type);
      LLVMValueRef thres;

      lp_build_context_init(&bld, builder, tmp_type);

      if(src_min < dst_min) {
         if(dst_min == 0.0)
            thres = bld.zero;
         else
            thres = lp_build_const_vec(src_type, dst_min);
         for(i = 0; i < num_tmps; ++i)
            tmp[i] = lp_build_max(&bld, tmp[i], thres);
      }

      if(src_max > dst_max) {
         if(dst_max == 1.0)
            thres = bld.one;
         else
            thres = lp_build_const_vec(src_type, dst_max);
         for(i = 0; i < num_tmps; ++i)
            tmp[i] = lp_build_min(&bld, tmp[i], thres);
      }
   }

   /*
    * Scale to the narrowest range
    */

   if(dst_type.floating) {
      /* Nothing to do */
   }
   else if(tmp_type.floating) {
      if(!dst_type.fixed && !dst_type.sign && dst_type.norm) {
         for(i = 0; i < num_tmps; ++i) {
            tmp[i] = lp_build_clamped_float_to_unsigned_norm(builder,
                                                             tmp_type,
                                                             dst_type.width,
                                                             tmp[i]);
         }
         tmp_type.floating = FALSE;
      }
      else {
         double dst_scale = lp_const_scale(dst_type);
         LLVMTypeRef tmp_vec_type;

         if (dst_scale != 1.0) {
            LLVMValueRef scale = lp_build_const_vec(tmp_type, dst_scale);
            for(i = 0; i < num_tmps; ++i)
               tmp[i] = LLVMBuildFMul(builder, tmp[i], scale, "");
         }

         /* Use an equally sized integer for intermediate computations */
         tmp_type.floating = FALSE;
         tmp_vec_type = lp_build_vec_type(tmp_type);
         for(i = 0; i < num_tmps; ++i) {
#if 0
            if(dst_type.sign)
               tmp[i] = LLVMBuildFPToSI(builder, tmp[i], tmp_vec_type, "");
            else
               tmp[i] = LLVMBuildFPToUI(builder, tmp[i], tmp_vec_type, "");
#else
           /* FIXME: there is no SSE counterpart for LLVMBuildFPToUI */
            tmp[i] = LLVMBuildFPToSI(builder, tmp[i], tmp_vec_type, "");
#endif
         }
      }
   }
   else {
      unsigned src_shift = lp_const_shift(src_type);
      unsigned dst_shift = lp_const_shift(dst_type);

      /* FIXME: compensate different offsets too */
      if(src_shift > dst_shift) {
         LLVMValueRef shift = lp_build_const_int_vec(tmp_type, src_shift - dst_shift);
         for(i = 0; i < num_tmps; ++i)
            if(src_type.sign)
               tmp[i] = LLVMBuildAShr(builder, tmp[i], shift, "");
            else
               tmp[i] = LLVMBuildLShr(builder, tmp[i], shift, "");
      }
   }

   /*
    * Truncate or expand bit width
    *
    * No data conversion should happen here, although the sign bits are
    * crucial to avoid bad clamping.
    */

   {
      struct lp_type new_type;

      new_type = tmp_type;
      new_type.sign   = dst_type.sign;
      new_type.width  = dst_type.width;
      new_type.length = dst_type.length;

      lp_build_resize(builder, tmp_type, new_type, tmp, num_srcs, tmp, num_dsts);

      tmp_type = new_type;
      num_tmps = num_dsts;
   }

   /*
    * Scale to the widest range
    */

   if(src_type.floating) {
      /* Nothing to do */
   }
   else if(!src_type.floating && dst_type.floating) {
      if(!src_type.fixed && !src_type.sign && src_type.norm) {
         for(i = 0; i < num_tmps; ++i) {
            tmp[i] = lp_build_unsigned_norm_to_float(builder,
                                                     src_type.width,
                                                     dst_type,
                                                     tmp[i]);
         }
         tmp_type.floating = TRUE;
      }
      else {
         double src_scale = lp_const_scale(src_type);
         LLVMTypeRef tmp_vec_type;

         /* Use an equally sized integer for intermediate computations */
         tmp_type.floating = TRUE;
         tmp_type.sign = TRUE;
         tmp_vec_type = lp_build_vec_type(tmp_type);
         for(i = 0; i < num_tmps; ++i) {
#if 0
            if(dst_type.sign)
               tmp[i] = LLVMBuildSIToFP(builder, tmp[i], tmp_vec_type, "");
            else
               tmp[i] = LLVMBuildUIToFP(builder, tmp[i], tmp_vec_type, "");
#else
            /* FIXME: there is no SSE counterpart for LLVMBuildUIToFP */
            tmp[i] = LLVMBuildSIToFP(builder, tmp[i], tmp_vec_type, "");
#endif
          }

          if (src_scale != 1.0) {
             LLVMValueRef scale = lp_build_const_vec(tmp_type, 1.0/src_scale);
             for(i = 0; i < num_tmps; ++i)
                tmp[i] = LLVMBuildFMul(builder, tmp[i], scale, "");
          }
      }
    }
    else {
       unsigned src_shift = lp_const_shift(src_type);
       unsigned dst_shift = lp_const_shift(dst_type);

       /* FIXME: compensate different offsets too */
       if(src_shift < dst_shift) {
          LLVMValueRef shift = lp_build_const_int_vec(tmp_type, dst_shift - src_shift);
          for(i = 0; i < num_tmps; ++i)
             tmp[i] = LLVMBuildShl(builder, tmp[i], shift, "");
       }
    }

   for(i = 0; i < num_dsts; ++i) {
      dst[i] = tmp[i];
      assert(lp_check_value(dst_type, dst[i]));
   }
}
Пример #14
0
void
ac_prepare_cube_coords(struct ac_llvm_context *ctx,
		       bool is_deriv, bool is_array,
		       LLVMValueRef *coords_arg,
		       LLVMValueRef *derivs_arg)
{

	LLVMBuilderRef builder = ctx->builder;
	struct cube_selection_coords selcoords;
	LLVMValueRef coords[3];
	LLVMValueRef invma;

	build_cube_intrinsic(ctx, coords_arg, &selcoords);

	invma = ac_build_intrinsic(ctx, "llvm.fabs.f32",
			ctx->f32, &selcoords.ma, 1, AC_FUNC_ATTR_READNONE);
	invma = ac_build_fdiv(ctx, LLVMConstReal(ctx->f32, 1.0), invma);

	for (int i = 0; i < 2; ++i)
		coords[i] = LLVMBuildFMul(builder, selcoords.stc[i], invma, "");

	coords[2] = selcoords.id;

	if (is_deriv && derivs_arg) {
		LLVMValueRef derivs[4];
		int axis;

		/* Convert cube derivatives to 2D derivatives. */
		for (axis = 0; axis < 2; axis++) {
			LLVMValueRef deriv_st[2];
			LLVMValueRef deriv_ma;

			/* Transform the derivative alongside the texture
			 * coordinate. Mathematically, the correct formula is
			 * as follows. Assume we're projecting onto the +Z face
			 * and denote by dx/dh the derivative of the (original)
			 * X texture coordinate with respect to horizontal
			 * window coordinates. The projection onto the +Z face
			 * plane is:
			 *
			 *   f(x,z) = x/z
			 *
			 * Then df/dh = df/dx * dx/dh + df/dz * dz/dh
			 *            = 1/z * dx/dh - x/z * 1/z * dz/dh.
			 *
			 * This motivatives the implementation below.
			 *
			 * Whether this actually gives the expected results for
			 * apps that might feed in derivatives obtained via
			 * finite differences is anyone's guess. The OpenGL spec
			 * seems awfully quiet about how textureGrad for cube
			 * maps should be handled.
			 */
			build_cube_select(builder, &selcoords, &derivs_arg[axis * 3],
					  deriv_st, &deriv_ma);

			deriv_ma = LLVMBuildFMul(builder, deriv_ma, invma, "");

			for (int i = 0; i < 2; ++i)
				derivs[axis * 2 + i] =
					LLVMBuildFSub(builder,
						LLVMBuildFMul(builder, deriv_st[i], invma, ""),
						LLVMBuildFMul(builder, deriv_ma, coords[i], ""), "");
		}

		memcpy(derivs_arg, derivs, sizeof(derivs));
	}

	/* Shift the texture coordinate. This must be applied after the
	 * derivative calculation.
	 */
	for (int i = 0; i < 2; ++i)
		coords[i] = LLVMBuildFAdd(builder, coords[i], LLVMConstReal(ctx->f32, 1.5), "");

	if (is_array) {
		/* for cube arrays coord.z = coord.w(array_index) * 8 + face */
		/* coords_arg.w component - array_index for cube arrays */
		LLVMValueRef tmp = LLVMBuildFMul(ctx->builder, coords_arg[3], LLVMConstReal(ctx->f32, 8.0), "");
		coords[2] = LLVMBuildFAdd(ctx->builder, tmp, coords[2], "");
	}

	memcpy(coords_arg, coords, sizeof(coords));
}
Пример #15
0
/**
 * Unpack a single pixel into its RGBA components.
 *
 * @param desc  the pixel format for the packed pixel value
 * @param packed integer pixel in a format such as PIPE_FORMAT_B8G8R8A8_UNORM
 *
 * @return RGBA in a float[4] or ubyte[4] or ushort[4] vector.
 */
static INLINE LLVMValueRef
lp_build_unpack_arith_rgba_aos(struct gallivm_state *gallivm,
                               const struct util_format_description *desc,
                               LLVMValueRef packed)
{
   LLVMBuilderRef builder = gallivm->builder;
   LLVMValueRef shifted, casted, scaled, masked;
   LLVMValueRef shifts[4];
   LLVMValueRef masks[4];
   LLVMValueRef scales[4];

   boolean normalized;
   boolean needs_uitofp;
   unsigned shift;
   unsigned i;

   /* TODO: Support more formats */
   assert(desc->layout == UTIL_FORMAT_LAYOUT_PLAIN);
   assert(desc->block.width == 1);
   assert(desc->block.height == 1);
   assert(desc->block.bits <= 32);

   /* Do the intermediate integer computations with 32bit integers since it
    * matches floating point size */
   assert (LLVMTypeOf(packed) == LLVMInt32TypeInContext(gallivm->context));

   /* Broadcast the packed value to all four channels
    * before: packed = BGRA
    * after: packed = {BGRA, BGRA, BGRA, BGRA}
    */
   packed = LLVMBuildInsertElement(builder,
                                   LLVMGetUndef(LLVMVectorType(LLVMInt32TypeInContext(gallivm->context), 4)),
                                   packed,
                                   LLVMConstNull(LLVMInt32TypeInContext(gallivm->context)),
                                   "");
   packed = LLVMBuildShuffleVector(builder,
                                   packed,
                                   LLVMGetUndef(LLVMVectorType(LLVMInt32TypeInContext(gallivm->context), 4)),
                                   LLVMConstNull(LLVMVectorType(LLVMInt32TypeInContext(gallivm->context), 4)),
                                   "");

   /* Initialize vector constants */
   normalized = FALSE;
   needs_uitofp = FALSE;
   shift = 0;

   /* Loop over 4 color components */
   for (i = 0; i < 4; ++i) {
      unsigned bits = desc->channel[i].size;

      if (desc->channel[i].type == UTIL_FORMAT_TYPE_VOID) {
         shifts[i] = LLVMGetUndef(LLVMInt32TypeInContext(gallivm->context));
         masks[i] = LLVMConstNull(LLVMInt32TypeInContext(gallivm->context));
         scales[i] =  LLVMConstNull(LLVMFloatTypeInContext(gallivm->context));
      }
      else {
         unsigned long long mask = (1ULL << bits) - 1;

         assert(desc->channel[i].type == UTIL_FORMAT_TYPE_UNSIGNED);

         if (bits == 32) {
            needs_uitofp = TRUE;
         }

         shifts[i] = lp_build_const_int32(gallivm, shift);
         masks[i] = lp_build_const_int32(gallivm, mask);

         if (desc->channel[i].normalized) {
            scales[i] = lp_build_const_float(gallivm, 1.0 / mask);
            normalized = TRUE;
         }
         else
            scales[i] =  lp_build_const_float(gallivm, 1.0);
      }

      shift += bits;
   }

   /* Ex: convert packed = {BGRA, BGRA, BGRA, BGRA}
    * into masked = {B, G, R, A}
    */
   shifted = LLVMBuildLShr(builder, packed, LLVMConstVector(shifts, 4), "");
   masked = LLVMBuildAnd(builder, shifted, LLVMConstVector(masks, 4), "");


   if (!needs_uitofp) {
      /* UIToFP can't be expressed in SSE2 */
      casted = LLVMBuildSIToFP(builder, masked, LLVMVectorType(LLVMFloatTypeInContext(gallivm->context), 4), "");
   } else {
      casted = LLVMBuildUIToFP(builder, masked, LLVMVectorType(LLVMFloatTypeInContext(gallivm->context), 4), "");
   }

   /* At this point 'casted' may be a vector of floats such as
    * {255.0, 255.0, 255.0, 255.0}.  Next, if the pixel values are normalized
    * we'll scale this to {1.0, 1.0, 1.0, 1.0}.
    */

   if (normalized)
      scaled = LLVMBuildFMul(builder, casted, LLVMConstVector(scales, 4), "");
   else
      scaled = casted;

   return scaled;
}
Пример #16
0
/**
 * Pack a single pixel.
 *
 * @param rgba 4 float vector with the unpacked components.
 *
 * XXX: This is mostly for reference and testing -- operating a single pixel at
 * a time is rarely if ever needed.
 */
LLVMValueRef
lp_build_pack_rgba_aos(struct gallivm_state *gallivm,
                       const struct util_format_description *desc,
                       LLVMValueRef rgba)
{
   LLVMBuilderRef builder = gallivm->builder;
   LLVMTypeRef type;
   LLVMValueRef packed = NULL;
   LLVMValueRef swizzles[4];
   LLVMValueRef shifted, casted, scaled, unswizzled;
   LLVMValueRef shifts[4];
   LLVMValueRef scales[4];
   boolean normalized;
   unsigned shift;
   unsigned i, j;

   assert(desc->layout == UTIL_FORMAT_LAYOUT_PLAIN);
   assert(desc->block.width == 1);
   assert(desc->block.height == 1);

   type = LLVMIntTypeInContext(gallivm->context, desc->block.bits);

   /* Unswizzle the color components into the source vector. */
   for (i = 0; i < 4; ++i) {
      for (j = 0; j < 4; ++j) {
         if (desc->swizzle[j] == i)
            break;
      }
      if (j < 4)
         swizzles[i] = lp_build_const_int32(gallivm, j);
      else
         swizzles[i] = LLVMGetUndef(LLVMInt32TypeInContext(gallivm->context));
   }

   unswizzled = LLVMBuildShuffleVector(builder, rgba,
                                       LLVMGetUndef(LLVMVectorType(LLVMFloatTypeInContext(gallivm->context), 4)),
                                       LLVMConstVector(swizzles, 4), "");

   normalized = FALSE;
   shift = 0;
   for (i = 0; i < 4; ++i) {
      unsigned bits = desc->channel[i].size;

      if (desc->channel[i].type == UTIL_FORMAT_TYPE_VOID) {
         shifts[i] = LLVMGetUndef(LLVMInt32TypeInContext(gallivm->context));
         scales[i] =  LLVMGetUndef(LLVMFloatTypeInContext(gallivm->context));
      }
      else {
         unsigned mask = (1 << bits) - 1;

         assert(desc->channel[i].type == UTIL_FORMAT_TYPE_UNSIGNED);
         assert(bits < 32);

         shifts[i] = lp_build_const_int32(gallivm, shift);

         if (desc->channel[i].normalized) {
            scales[i] = lp_build_const_float(gallivm, mask);
            normalized = TRUE;
         }
         else
            scales[i] = lp_build_const_float(gallivm, 1.0);
      }

      shift += bits;
   }

   if (normalized)
      scaled = LLVMBuildFMul(builder, unswizzled, LLVMConstVector(scales, 4), "");
   else
      scaled = unswizzled;

   casted = LLVMBuildFPToSI(builder, scaled, LLVMVectorType(LLVMInt32TypeInContext(gallivm->context), 4), "");

   shifted = LLVMBuildShl(builder, casted, LLVMConstVector(shifts, 4), "");
   
   /* Bitwise or all components */
   for (i = 0; i < 4; ++i) {
      if (desc->channel[i].type == UTIL_FORMAT_TYPE_UNSIGNED) {
         LLVMValueRef component = LLVMBuildExtractElement(builder, shifted,
                                               lp_build_const_int32(gallivm, i), "");
         if (packed)
            packed = LLVMBuildOr(builder, packed, component, "");
         else
            packed = component;
      }
   }

   if (!packed)
      packed = LLVMGetUndef(LLVMInt32TypeInContext(gallivm->context));

   if (desc->block.bits < 32)
      packed = LLVMBuildTrunc(builder, packed, type, "");

   return packed;
}
Пример #17
0
static LLVMValueRef
lp_build_extract_soa_chan(struct lp_build_context *bld,
                          unsigned blockbits,
                          boolean srgb_chan,
                          struct util_format_channel_description chan_desc,
                          LLVMValueRef packed)
{
   struct gallivm_state *gallivm = bld->gallivm;
   LLVMBuilderRef builder = gallivm->builder;
   struct lp_type type = bld->type;
   LLVMValueRef input = packed;
   const unsigned width = chan_desc.size;
   const unsigned start = chan_desc.shift;
   const unsigned stop = start + width;

   /* Decode the input vector component */

   switch(chan_desc.type) {
   case UTIL_FORMAT_TYPE_VOID:
      input = bld->undef;
      break;

   case UTIL_FORMAT_TYPE_UNSIGNED:
      /*
       * Align the LSB
       */
      if (start) {
         input = LLVMBuildLShr(builder, input,
                               lp_build_const_int_vec(gallivm, type, start), "");
      }

      /*
       * Zero the MSBs
       */
      if (stop < blockbits) {
         unsigned mask = ((unsigned long long)1 << width) - 1;
         input = LLVMBuildAnd(builder, input,
                              lp_build_const_int_vec(gallivm, type, mask), "");
      }

      /*
       * Type conversion
       */
      if (type.floating) {
         if (srgb_chan) {
            struct lp_type conv_type = lp_uint_type(type);
            input = lp_build_srgb_to_linear(gallivm, conv_type, width, input);
         }
         else {
            if(chan_desc.normalized)
               input = lp_build_unsigned_norm_to_float(gallivm, width, type, input);
            else
               input = LLVMBuildSIToFP(builder, input, bld->vec_type, "");
         }
      }
      else if (chan_desc.pure_integer) {
         /* Nothing to do */
      } else {
          /* FIXME */
          assert(0);
      }
      break;

   case UTIL_FORMAT_TYPE_SIGNED:
      /*
       * Align the sign bit first.
       */
      if (stop < type.width) {
         unsigned bits = type.width - stop;
         LLVMValueRef bits_val = lp_build_const_int_vec(gallivm, type, bits);
         input = LLVMBuildShl(builder, input, bits_val, "");
      }

      /*
       * Align the LSB (with an arithmetic shift to preserve the sign)
       */
      if (chan_desc.size < type.width) {
         unsigned bits = type.width - chan_desc.size;
         LLVMValueRef bits_val = lp_build_const_int_vec(gallivm, type, bits);
         input = LLVMBuildAShr(builder, input, bits_val, "");
      }

      /*
       * Type conversion
       */
      if (type.floating) {
         input = LLVMBuildSIToFP(builder, input, bld->vec_type, "");
         if (chan_desc.normalized) {
            double scale = 1.0 / ((1 << (chan_desc.size - 1)) - 1);
            LLVMValueRef scale_val = lp_build_const_vec(gallivm, type, scale);
            input = LLVMBuildFMul(builder, input, scale_val, "");
            /*
             * The formula above will produce value below -1.0 for most negative
             * value but everything seems happy with that hence disable for now.
             */
            if (0)
               input = lp_build_max(bld, input,
                                    lp_build_const_vec(gallivm, type, -1.0f));
         }
      }
      else if (chan_desc.pure_integer) {
         /* Nothing to do */
      } else {
          /* FIXME */
          assert(0);
      }
      break;

   case UTIL_FORMAT_TYPE_FLOAT:
      if (type.floating) {
         if (chan_desc.size == 16) {
            struct lp_type f16i_type = type;
            f16i_type.width /= 2;
            f16i_type.floating = 0;
            if (start) {
               input = LLVMBuildLShr(builder, input,
                                     lp_build_const_int_vec(gallivm, type, start), "");
            }
            input = LLVMBuildTrunc(builder, input,
                                   lp_build_vec_type(gallivm, f16i_type), "");
            input = lp_build_half_to_float(gallivm, input);
         } else {
            assert(start == 0);
            assert(stop == 32);
            assert(type.width == 32);
         }
         input = LLVMBuildBitCast(builder, input, bld->vec_type, "");
      }
      else {
         /* FIXME */
         assert(0);
         input = bld->undef;
      }
      break;

   case UTIL_FORMAT_TYPE_FIXED:
      if (type.floating) {
         double scale = 1.0 / ((1 << (chan_desc.size/2)) - 1);
         LLVMValueRef scale_val = lp_build_const_vec(gallivm, type, scale);
         input = LLVMBuildSIToFP(builder, input, bld->vec_type, "");
         input = LLVMBuildFMul(builder, input, scale_val, "");
      }
      else {
         /* FIXME */
         assert(0);
         input = bld->undef;
      }
      break;

   default:
      assert(0);
      input = bld->undef;
      break;
   }

   return input;
}