<div dir="ltr">On 21 January 2013 00:49, Chad Versace <<a href="mailto:chad.versace@linux.intel.com" target="_blank">chad.versace@linux.intel.com</a>> wrote: <div class="gmail_extra"><div class="gmail_quote"> <blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex">That is, evaluate constant expressions of the following functions: packSnorm2x16 unpackSnorm2x16 packUnorm2x16 unpackUnorm2x16 packHalf2x16 unpackHalf2x16 v2: Reuse _mesa_pack_float_to_half and its inverse to evaluate pack/unpackHalf2x16 [for idr]. Signed-off-by: Chad Versace <<a href="mailto:chad.versace@linux.intel.com" target="_blank">chad.versace@linux.intel.com</a>> --- src/glsl/ir_constant_expression.cpp | 187 ++++++++++++++++++++++++++++++++++++ 1 file changed, 187 insertions(+) diff --git a/src/glsl/ir_constant_expression.cpp b/src/glsl/ir_constant_expression.cpp index 7678090..b34c6e8 100644 --- a/src/glsl/ir_constant_expression.cpp +++ b/src/glsl/ir_constant_expression.cpp @@ -75,6 +75,157 @@ bitcast_f2u(float f) return u; } +/** + * Evaluate one component of a floating-point 2x16 unpacking function. + */ +typedef uint16_t +(*pack_1x16_func_t)(float); + +/** + * Evaluate one component of a floating-point 2x16 unpacking function. + */ +typedef float +(*unpack_1x16_func_t)(uint16_t); + +/** + * Evaluate a 2x16 floating-point packing function. + */ +static uint32_t +pack_2x16(pack_1x16_func_t pack_1x16, + float x, float y) +{ + /* From section 8.4 of the GLSL ES 3.00 spec: + * + * packSnorm2x16 + * ------------- + * The first component of the vector will be written to the least + * significant bits of the output; the last component will be written to + * the most significant bits. + * + * The specifications for the other packing functions contain similar + * language. + */ + uint32_t u = 0; + u |= ((uint32_t) pack_1x16(x) << 0); + u |= ((uint32_t) pack_1x16(y) << 16); + return u; +} + +/** + * Evaluate a 2x16 floating-point unpacking function. + */ +static void +unpack_2x16(unpack_1x16_func_t unpack_1x16, + uint32_t u, + float *x, float *y) +{ + /* From section 8.4 of the GLSL ES 3.00 spec: + * + * unpackSnorm2x16 + * --------------- + * The first component of the returned vector will be extracted from + * the least significant bits of the input; the last component will be + * extracted from the most significant bits. + * + * The specifications for the other unpacking functions contain similar + * language. + */ + *x = unpack_1x16((uint16_t) (u & 0xffff)); + *y = unpack_1x16((uint16_t) (u >> 16)); +} + +/** + * Evaluate one component of packSnorm2x16. + */ +static uint16_t +pack_snorm_1x16(float x) +{ + /* From section 8.4 of the GLSL ES 3.00 spec: + * + * packSnorm2x16 + * --------------- + * The conversion for component c of v to fixed point is done as + * follows: + * + * packSnorm2x16: round(clamp(c, -1, +1) * 32767.0) + */ + return (uint16_t) _mesa_round_to_even(CLAMP(x, -1.0f, +1.0f) * 32767.0f); </blockquote><div> </div><div>Brian Paul has a patch out on the list to change the return type of _mesa_round_to_even() to float, to placate some VStudio compiler warnings ("[Mesa-dev] [PATCH 10/11] glsl: make round_to_even() return float"). When that patch lands, this expression will be typecasting a float to a uint16_t, which is undefined for negative floats. To be on the safe side, can we do something like this instead? </div><div>/* Note: we need to cast to int before casting to uint16_t, since casting a negative float directly to uint16_t is undefined */ </div><div>return (uint16_t) (int) _mesa_round_to_even(...); </div> <div>With that change, this patch is: Reviewed-by: Paul Berry <<a href="mailto:stereotype441@gmail.com">stereotype441@gmail.com</a>> </div><div> </div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex"> +} + +/** + * Evaluate one component of unpackSnorm2x16. + */ +static float +unpack_snorm_1x16(uint16_t u) +{ + /* From section 8.4 of the GLSL ES 3.00 spec: + * + * unpackSnorm2x16 + * --------------- + * The conversion for unpacked fixed-point value f to floating point is + * done as follows: + * + * unpackSnorm2x16: clamp(f / 32767.0, -1,+1) + */ + return CLAMP((int16_t) u / 32767.0f, -1.0f, +1.0f); +} + +/** + * Evaluate one component packUnorm2x16. + */ +static uint16_t +pack_unorm_1x16(float x) +{ + /* From section 8.4 of the GLSL ES 3.00 spec: + * + * packUnorm2x16 + * --------------- + * The conversion for component c of v to fixed point is done as + * follows: + * + * packUnorm2x16: round(clamp(c, 0, +1) * 65535.0) + */ + return (uint16_t) _mesa_round_to_even(CLAMP(x, 0.0f, 1.0f) * 65535.0f); +} + + +/** + * Evaluate one component of unpackUnorm2x16. + */ +static float +unpack_unorm_1x16(uint16_t u) +{ + /* From section 8.4 of the GLSL ES 3.00 spec: + * + * unpackUnorm2x16 + * --------------- + * The conversion for unpacked fixed-point value f to floating point is + * done as follows: + * + * unpackUnorm2x16: f / 65535.0 + */ + return (float) u / 65535.0f; +} + + +/** + * Evaluate one component of packHalf2x16. + */ +static uint16_t +pack_half_1x16(float x) +{ + return _mesa_float_to_half(x); +} + +/** + * Evaluate one component of unpackHalf2x16. + */ +static float +unpack_half_1x16(uint16_t u) +{ + return _mesa_half_to_float(u); +} + ir_constant * ir_rvalue::constant_expression_value(struct hash_table *variable_context) { @@ -440,6 +591,42 @@ ir_expression::constant_expression_value(struct hash_table *variable_context) } break; + case ir_unop_pack_snorm_2x16: + assert(op[0]->type == glsl_type::vec2_type); + data.u[0] = pack_2x16(pack_snorm_1x16, + op[0]->value.f[0], + op[0]->value.f[1]); + break; + case ir_unop_unpack_snorm_2x16: + assert(op[0]->type == glsl_type::uint_type); + unpack_2x16(unpack_snorm_1x16, + op[0]->value.u[0], + &data.f[0], &data.f[1]); + break; + case ir_unop_pack_unorm_2x16: + assert(op[0]->type == glsl_type::vec2_type); + data.u[0] = pack_2x16(pack_unorm_1x16, + op[0]->value.f[0], + op[0]->value.f[1]); + break; + case ir_unop_unpack_unorm_2x16: + assert(op[0]->type == glsl_type::uint_type); + unpack_2x16(unpack_unorm_1x16, + op[0]->value.u[0], + &data.f[0], &data.f[1]); + break; + case ir_unop_pack_half_2x16: + assert(op[0]->type == glsl_type::vec2_type); + data.u[0] = pack_2x16(pack_half_1x16, + op[0]->value.f[0], + op[0]->value.f[1]); + break; + case ir_unop_unpack_half_2x16: + assert(op[0]->type == glsl_type::uint_type); + unpack_2x16(unpack_half_1x16, + op[0]->value.u[0], + &data.f[0], &data.f[1]); + break; case ir_binop_pow: assert(op[0]->type->base_type == GLSL_TYPE_FLOAT); for (unsigned c = 0; c < op[0]->type->components(); c++) { -- 1.8.1.1 _______________________________________________ mesa-dev mailing list <a href="mailto:mesa-dev@lists.freedesktop.org" target="_blank">mesa-dev@lists.freedesktop.org</a> <a href="http://lists.freedesktop.org/mailman/listinfo/mesa-dev" target="_blank">http://lists.freedesktop.org/mailman/listinfo/mesa-dev</a> </blockquote></div> </div></div>