[Mesa-dev] [PATCH 5/8] glsl: Add support for lowering 4x8 pack/unpack operations
Matt Turner
mattst88 at gmail.com
Thu Jan 24 19:47:30 PST 2013
Lower them to arithmetic and bit manipulation expressions.
---
src/glsl/ir_optimization.h | 6 +
src/glsl/lower_packing_builtins.cpp | 279 +++++++++++++++++++++++++++++++++++
2 files changed, 285 insertions(+), 0 deletions(-)
diff --git a/src/glsl/ir_optimization.h b/src/glsl/ir_optimization.h
index ac90b87..8f33018 100644
--- a/src/glsl/ir_optimization.h
+++ b/src/glsl/ir_optimization.h
@@ -54,6 +54,12 @@ enum lower_packing_builtins_op {
LOWER_PACK_HALF_2x16_TO_SPLIT = 0x0040,
LOWER_UNPACK_HALF_2x16_TO_SPLIT = 0x0080,
+
+ LOWER_PACK_SNORM_4x8 = 0x0100,
+ LOWER_UNPACK_SNORM_4x8 = 0x0200,
+
+ LOWER_PACK_UNORM_4x8 = 0x0400,
+ LOWER_UNPACK_UNORM_4x8 = 0x0800,
};
bool do_common_optimization(exec_list *ir, bool linked,
diff --git a/src/glsl/lower_packing_builtins.cpp b/src/glsl/lower_packing_builtins.cpp
index 49176cc..aa6765f 100644
--- a/src/glsl/lower_packing_builtins.cpp
+++ b/src/glsl/lower_packing_builtins.cpp
@@ -85,9 +85,15 @@ public:
case LOWER_PACK_SNORM_2x16:
*rvalue = lower_pack_snorm_2x16(op0);
break;
+ case LOWER_PACK_SNORM_4x8:
+ *rvalue = lower_pack_snorm_4x8(op0);
+ break;
case LOWER_PACK_UNORM_2x16:
*rvalue = lower_pack_unorm_2x16(op0);
break;
+ case LOWER_PACK_UNORM_4x8:
+ *rvalue = lower_pack_unorm_4x8(op0);
+ break;
case LOWER_PACK_HALF_2x16:
*rvalue = lower_pack_half_2x16(op0);
break;
@@ -97,9 +103,15 @@ public:
case LOWER_UNPACK_SNORM_2x16:
*rvalue = lower_unpack_snorm_2x16(op0);
break;
+ case LOWER_UNPACK_SNORM_4x8:
+ *rvalue = lower_unpack_snorm_4x8(op0);
+ break;
case LOWER_UNPACK_UNORM_2x16:
*rvalue = lower_unpack_unorm_2x16(op0);
break;
+ case LOWER_UNPACK_UNORM_4x8:
+ *rvalue = lower_unpack_unorm_4x8(op0);
+ break;
case LOWER_UNPACK_HALF_2x16:
*rvalue = lower_unpack_half_2x16(op0);
break;
@@ -137,18 +149,30 @@ private:
case ir_unop_pack_snorm_2x16:
result = op_mask & LOWER_PACK_SNORM_2x16;
break;
+ case ir_unop_pack_snorm_4x8:
+ result = op_mask & LOWER_PACK_SNORM_4x8;
+ break;
case ir_unop_pack_unorm_2x16:
result = op_mask & LOWER_PACK_UNORM_2x16;
break;
+ case ir_unop_pack_unorm_4x8:
+ result = op_mask & LOWER_PACK_UNORM_4x8;
+ break;
case ir_unop_pack_half_2x16:
result = op_mask & (LOWER_PACK_HALF_2x16 | LOWER_PACK_HALF_2x16_TO_SPLIT);
break;
case ir_unop_unpack_snorm_2x16:
result = op_mask & LOWER_UNPACK_SNORM_2x16;
break;
+ case ir_unop_unpack_snorm_4x8:
+ result = op_mask & LOWER_UNPACK_SNORM_4x8;
+ break;
case ir_unop_unpack_unorm_2x16:
result = op_mask & LOWER_UNPACK_UNORM_2x16;
break;
+ case ir_unop_unpack_unorm_4x8:
+ result = op_mask & LOWER_UNPACK_UNORM_4x8;
+ break;
case ir_unop_unpack_half_2x16:
result = op_mask & (LOWER_UNPACK_HALF_2x16 | LOWER_UNPACK_HALF_2x16_TO_SPLIT);
break;
@@ -214,6 +238,30 @@ private:
}
/**
+ * \brief Pack four uint8's into a single uint32.
+ *
+ * Interpret the given uvec4 as a uint32 quad. Pack the quad into a uint32
+ * where the least significant bits specify the first element of the quad.
+ * Return the uint32.
+ */
+ ir_rvalue*
+ pack_uvec4_to_uint(ir_rvalue *uvec4_rval)
+ {
+ assert(uvec4_rval->type == glsl_type::uvec4_type);
+
+ /* uvec4 u = UVEC4_RVAL; */
+ ir_variable *u = factory.make_temp(glsl_type::uvec4_type,
+ "tmp_pack_uvec4_to_uint");
+ factory.emit(assign(u, uvec4_rval));
+
+ /* return ((u.w 0xff) << 24) | ((u.z & 0xff) << 16) | ((u.y & 0xff) << 8) | (u.x & 0xff); */
+ return bit_or(bit_or(lshift(bit_and(swizzle_w(u), constant(0xffu)), constant(24u)),
+ lshift(bit_and(swizzle_z(u), constant(0xffu)), constant(16u))),
+ bit_or(lshift(bit_and(swizzle_y(u), constant(0xffu)), constant(8u)),
+ bit_and(swizzle_x(u), constant(0xffu))));
+ }
+
+ /**
* \brief Unpack a uint32 into two uint16's.
*
* Interpret the given uint32 as a uint16 pair where the uint32's least
@@ -244,6 +292,44 @@ private:
}
/**
+ * \brief Unpack a uint32 into four uint8's.
+ *
+ * Interpret the given uint32 as a uint8 quad where the uint32's least
+ * significant bits specify the quad's first element. Return the uint8
+ * quad as a uvec4.
+ */
+ ir_rvalue*
+ unpack_uint_to_uvec4(ir_rvalue *uint_rval)
+ {
+ assert(uint_rval->type == glsl_type::uint_type);
+
+ /* uint u = UINT_RVAL; */
+ ir_variable *u = factory.make_temp(glsl_type::uint_type,
+ "tmp_unpack_uint_to_uvec4_u");
+ factory.emit(assign(u, uint_rval));
+
+ /* uvec4 u4; */
+ ir_variable *u4 = factory.make_temp(glsl_type::uvec4_type,
+ "tmp_unpack_uint_to_uvec4_u4");
+
+ /* u4.x = u & 0xffu; */
+ factory.emit(assign(u4, bit_and(u, constant(0xffu)), WRITEMASK_X));
+
+ /* u4.y = (u >> 8u) & 0xffu; */
+ factory.emit(assign(u4, bit_and(rshift(u, constant(8u)),
+ constant(0xffu)), WRITEMASK_Y));
+
+ /* u4.z = (u >> 16u) & 0xffu; */
+ factory.emit(assign(u4, bit_and(rshift(u, constant(16u)),
+ constant(0xffu)), WRITEMASK_Z));
+
+ /* u4.w = (u >> 24u) */
+ factory.emit(assign(u4, rshift(u, constant(24u)), WRITEMASK_W));
+
+ return deref(u4).val;
+ }
+
+ /**
* \brief Lower a packSnorm2x16 expression.
*
* \param vec2_rval is packSnorm2x16's input
@@ -293,6 +379,55 @@ private:
}
/**
+ * \brief Lower a packSnorm4x8 expression.
+ *
+ * \param vec4_rval is packSnorm4x8's input
+ * \return packSnorm4x8's output as a uint rvalue
+ */
+ ir_rvalue*
+ lower_pack_snorm_4x8(ir_rvalue *vec4_rval)
+ {
+ /* From page 137 (143 of pdf) of the GLSL 4.30 spec:
+ *
+ * highp uint packSnorm4x8(vec4 v)
+ * -------------------------------
+ * First, converts each component of the normalized floating-point value
+ * v into 8-bit integer values. Then, the results are packed into the
+ * returned 32-bit unsigned integer.
+ *
+ * The conversion for component c of v to fixed point is done as
+ * follows:
+ *
+ * packSnorm4x8: round(clamp(c, -1, +1) * 127.0)
+ *
+ * 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.
+ *
+ * This function generates IR that approximates the following pseudo-GLSL:
+ *
+ * return pack_uvec4_to_uint(
+ * uvec4(ivec4(
+ * round(clamp(VEC4_RVALUE, -1.0f, 1.0f) * 127.0f))));
+ *
+ * It is necessary to first convert the vec4 to ivec4 rather than directly
+ * converting vec4 to uvec4 because the latter conversion is undefined.
+ * From page 87 (93 of pdf) of the GLSL 4.30 spec: "It is undefined to
+ * convert a negative floating point value to an uint".
+ */
+ assert(vec4_rval->type == glsl_type::vec4_type);
+
+ ir_rvalue *result = pack_uvec4_to_uint(
+ i2u(f2i(round_even(mul(clamp(vec4_rval,
+ constant(-1.0f),
+ constant(1.0f)),
+ constant(127.0f))))));
+
+ assert(result->type == glsl_type::uint_type);
+ return result;
+ }
+
+ /**
* \brief Lower an unpackSnorm2x16 expression.
*
* \param uint_rval is unpackSnorm2x16's input
@@ -352,6 +487,65 @@ private:
}
/**
+ * \brief Lower an unpackSnorm4x8 expression.
+ *
+ * \param uint_rval is unpackSnorm4x8's input
+ * \return unpackSnorm4x8's output as a vec4 rvalue
+ */
+ ir_rvalue*
+ lower_unpack_snorm_4x8(ir_rvalue *uint_rval)
+ {
+ /* From page 137 (143 of pdf) of the GLSL 4.30 spec:
+ *
+ * highp vec4 unpackSnorm4x8 (highp uint p)
+ * ----------------------------------------
+ * First, unpacks a single 32-bit unsigned integer p into four
+ * 8-bit unsigned integers. Then, each component is converted to
+ * a normalized floating-point value to generate the returned
+ * four-component vector.
+ *
+ * The conversion for unpacked fixed-point value f to floating point is
+ * done as follows:
+ *
+ * unpackSnorm4x8: clamp(f / 127.0, -1, +1)
+ *
+ * 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.
+ *
+ * This function generates IR that approximates the following pseudo-GLSL:
+ *
+ * return clamp(
+ * ((ivec4(unpack_uint_to_uvec4(UINT_RVALUE)) << 24) >> 24) / 127.0f,
+ * -1.0f, 1.0f);
+ *
+ * The above IR may appear unnecessarily complex, but the intermediate
+ * conversion to ivec4 and the bit shifts are necessary to correctly unpack
+ * negative floats.
+ *
+ * To see why, consider packing and then unpacking vec4(-1.0, 0.0, 0.0,
+ * 0.0). packSnorm4x8 encodes -1.0 as the int8 0xff. During unpacking, we
+ * place that int8 into an int32, which results in the *positive* integer
+ * 0x000000ff. The int8's sign bit becomes, in the int32, the rather
+ * unimportant bit 8. We must now extend the int8's sign bit into bits
+ * 9-32, which is accomplished by left-shifting then right-shifting.
+ */
+
+ assert(uint_rval->type == glsl_type::uint_type);
+
+ ir_rvalue *result =
+ clamp(div(i2f(rshift(lshift(u2i(unpack_uint_to_uvec4(uint_rval)),
+ constant(24u)),
+ constant(24u))),
+ constant(127.0f)),
+ constant(-1.0f),
+ constant(1.0f));
+
+ assert(result->type == glsl_type::vec4_type);
+ return result;
+ }
+
+ /**
* \brief Lower a packUnorm2x16 expression.
*
* \param vec2_rval is packUnorm2x16's input
@@ -396,6 +590,50 @@ private:
}
/**
+ * \brief Lower a packUnorm4x8 expression.
+ *
+ * \param vec4_rval is packUnorm4x8's input
+ * \return packUnorm4x8's output as a uint rvalue
+ */
+ ir_rvalue*
+ lower_pack_unorm_4x8(ir_rvalue *vec4_rval)
+ {
+ /* From page 137 (143 of pdf) of the GLSL 4.30 spec:
+ *
+ * highp uint packUnorm4x8 (vec4 v)
+ * --------------------------------
+ * First, converts each component of the normalized floating-point value
+ * v into 16-bit integer values. Then, the results are packed into the
+ * returned 32-bit unsigned integer.
+ *
+ * The conversion for component c of v to fixed point is done as
+ * follows:
+ *
+ * packUnorm4x8: round(clamp(c, 0, +1) * 65535.0)
+ *
+ * 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.
+ *
+ * This function generates IR that approximates the following pseudo-GLSL:
+ *
+ * return pack_uvec4_to_uint(uvec4(
+ * round(clamp(VEC2_RVALUE, 0.0f, 1.0f) * 255.0f)));
+ *
+ * Here it is safe to directly convert the vec4 to uvec4 because the the
+ * vec4 has been clamped to a non-negative range.
+ */
+
+ assert(vec4_rval->type == glsl_type::vec4_type);
+
+ ir_rvalue *result = pack_uvec4_to_uint(
+ f2u(round_even(mul(saturate(vec4_rval), constant(255.0f)))));
+
+ assert(result->type == glsl_type::uint_type);
+ return result;
+ }
+
+ /**
* \brief Lower an unpackUnorm2x16 expression.
*
* \param uint_rval is unpackUnorm2x16's input
@@ -437,6 +675,47 @@ private:
}
/**
+ * \brief Lower an unpackUnorm4x8 expression.
+ *
+ * \param uint_rval is unpackUnorm4x8's input
+ * \return unpackUnorm4x8's output as a vec4 rvalue
+ */
+ ir_rvalue*
+ lower_unpack_unorm_4x8(ir_rvalue *uint_rval)
+ {
+ /* From page 137 (143 of pdf) of the GLSL 4.30 spec:
+ *
+ * highp vec4 unpackUnorm4x8 (highp uint p)
+ * ----------------------------------------
+ * First, unpacks a single 32-bit unsigned integer p into four
+ * 8-bit unsigned integers. Then, each component is converted to
+ * a normalized floating-point value to generate the returned
+ * two-component vector.
+ *
+ * The conversion for unpacked fixed-point value f to floating point is
+ * done as follows:
+ *
+ * unpackUnorm4x8: f / 255.0
+ *
+ * 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.
+ *
+ * This function generates IR that approximates the following pseudo-GLSL:
+ *
+ * return vec4(unpack_uint_to_uvec4(UINT_RVALUE)) / 255.0;
+ */
+
+ assert(uint_rval->type == glsl_type::uint_type);
+
+ ir_rvalue *result = div(u2f(unpack_uint_to_uvec4(uint_rval)),
+ constant(255.0f));
+
+ assert(result->type == glsl_type::vec4_type);
+ return result;
+ }
+
+ /**
* \brief Lower the component-wise calculation of packHalf2x16.
*
* \param f_rval is one component of packHafl2x16's input
--
1.7.8.6
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