Mesa (master): glsl: Evaluate constant pack/unpack 4x8 expressions
Matt Turner
mattst88 at kemper.freedesktop.org
Fri Jan 25 22:07:57 UTC 2013
Module: Mesa
Branch: master
Commit: 1ef674f215b10820b94af131b6158d84b89f4e4b
URL: http://cgit.freedesktop.org/mesa/mesa/commit/?id=1ef674f215b10820b94af131b6158d84b89f4e4b
Author: Matt Turner <mattst88 at gmail.com>
Date: Mon Jan 21 14:53:26 2013 -0800
glsl: Evaluate constant pack/unpack 4x8 expressions
That is, evaluate constant expressions for the following functions:
packSnorm4x8, unpackSnorm4x8
packUnorm4x8, unpackUnorm4x8
Reviewed-by: Chad Versace <chad.versace at linux.intel.com>
Reviewed-by: Paul Berry <stereotype441 at gmail.com>
---
src/glsl/ir_constant_expression.cpp | 166 +++++++++++++++++++++++++++++++++++
1 files changed, 166 insertions(+), 0 deletions(-)
diff --git a/src/glsl/ir_constant_expression.cpp b/src/glsl/ir_constant_expression.cpp
index 6f6eeff..86b863f 100644
--- a/src/glsl/ir_constant_expression.cpp
+++ b/src/glsl/ir_constant_expression.cpp
@@ -76,12 +76,24 @@ bitcast_f2u(float f)
}
/**
+ * Evaluate one component of a floating-point 4x8 unpacking function.
+ */
+typedef uint8_t
+(*pack_1x8_func_t)(float);
+
+/**
* 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 4x8 unpacking function.
+ */
+typedef float
+(*unpack_1x8_func_t)(uint8_t);
+
+/**
* Evaluate one component of a floating-point 2x16 unpacking function.
*/
typedef float
@@ -112,6 +124,32 @@ pack_2x16(pack_1x16_func_t pack_1x16,
}
/**
+ * Evaluate a 4x8 floating-point packing function.
+ */
+static uint32_t
+pack_4x8(pack_1x8_func_t pack_1x8,
+ float x, float y, float z, float w)
+{
+ /* From section 8.4 of the GLSL 4.30 spec:
+ *
+ * packSnorm4x8
+ * ------------
+ * 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_1x8(x) << 0);
+ u |= ((uint32_t) pack_1x8(y) << 8);
+ u |= ((uint32_t) pack_1x8(z) << 16);
+ u |= ((uint32_t) pack_1x8(w) << 24);
+ return u;
+}
+
+/**
* Evaluate a 2x16 floating-point unpacking function.
*/
static void
@@ -135,6 +173,52 @@ unpack_2x16(unpack_1x16_func_t unpack_1x16,
}
/**
+ * Evaluate a 4x8 floating-point unpacking function.
+ */
+static void
+unpack_4x8(unpack_1x8_func_t unpack_1x8, uint32_t u,
+ float *x, float *y, float *z, float *w)
+{
+ /* From section 8.4 of the GLSL 4.30 spec:
+ *
+ * unpackSnorm4x8
+ * --------------
+ * 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_1x8((uint8_t) (u & 0xff));
+ *y = unpack_1x8((uint8_t) (u >> 8));
+ *z = unpack_1x8((uint8_t) (u >> 16));
+ *w = unpack_1x8((uint8_t) (u >> 24));
+}
+
+/**
+ * Evaluate one component of packSnorm4x8.
+ */
+static uint8_t
+pack_snorm_1x8(float x)
+{
+ /* From section 8.4 of the GLSL 4.30 spec:
+ *
+ * packSnorm4x8
+ * ------------
+ * The conversion for component c of v to fixed point is done as
+ * follows:
+ *
+ * packSnorm4x8: round(clamp(c, -1, +1) * 127.0)
+ *
+ * We must first cast the float to an int, because casting a negative
+ * float to a uint is undefined.
+ */
+ return (uint8_t) (int8_t)
+ _mesa_round_to_even(CLAMP(x, -1.0f, +1.0f) * 127.0f);
+}
+
+/**
* Evaluate one component of packSnorm2x16.
*/
static uint16_t
@@ -157,6 +241,24 @@ pack_snorm_1x16(float x)
}
/**
+ * Evaluate one component of unpackSnorm4x8.
+ */
+static float
+unpack_snorm_1x8(uint8_t u)
+{
+ /* From section 8.4 of the GLSL 4.30 spec:
+ *
+ * unpackSnorm4x8
+ * --------------
+ * The conversion for unpacked fixed-point value f to floating point is
+ * done as follows:
+ *
+ * unpackSnorm4x8: clamp(f / 127.0, -1, +1)
+ */
+ return CLAMP((int8_t) u / 127.0f, -1.0f, +1.0f);
+}
+
+/**
* Evaluate one component of unpackSnorm2x16.
*/
static float
@@ -175,6 +277,24 @@ unpack_snorm_1x16(uint16_t u)
}
/**
+ * Evaluate one component packUnorm4x8.
+ */
+static uint8_t
+pack_unorm_1x8(float x)
+{
+ /* From section 8.4 of the GLSL 4.30 spec:
+ *
+ * packUnorm4x8
+ * ------------
+ * The conversion for component c of v to fixed point is done as
+ * follows:
+ *
+ * packUnorm4x8: round(clamp(c, 0, +1) * 255.0)
+ */
+ return (uint8_t) _mesa_round_to_even(CLAMP(x, 0.0f, 1.0f) * 255.0f);
+}
+
+/**
* Evaluate one component packUnorm2x16.
*/
static uint16_t
@@ -193,6 +313,24 @@ pack_unorm_1x16(float x)
}
/**
+ * Evaluate one component of unpackUnorm4x8.
+ */
+static float
+unpack_unorm_1x8(uint8_t u)
+{
+ /* From section 8.4 of the GLSL 4.30 spec:
+ *
+ * unpackUnorm4x8
+ * --------------
+ * The conversion for unpacked fixed-point value f to floating point is
+ * done as follows:
+ *
+ * unpackUnorm4x8: f / 255.0
+ */
+ return (float) u / 255.0f;
+}
+
+/**
* Evaluate one component of unpackUnorm2x16.
*/
static float
@@ -599,24 +737,52 @@ ir_expression::constant_expression_value(struct hash_table *variable_context)
op[0]->value.f[0],
op[0]->value.f[1]);
break;
+ case ir_unop_pack_snorm_4x8:
+ assert(op[0]->type == glsl_type::vec4_type);
+ data.u[0] = pack_4x8(pack_snorm_1x8,
+ op[0]->value.f[0],
+ op[0]->value.f[1],
+ op[0]->value.f[2],
+ op[0]->value.f[3]);
+ 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_unpack_snorm_4x8:
+ assert(op[0]->type == glsl_type::uint_type);
+ unpack_4x8(unpack_snorm_1x8,
+ op[0]->value.u[0],
+ &data.f[0], &data.f[1], &data.f[2], &data.f[3]);
+ 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_pack_unorm_4x8:
+ assert(op[0]->type == glsl_type::vec4_type);
+ data.u[0] = pack_4x8(pack_unorm_1x8,
+ op[0]->value.f[0],
+ op[0]->value.f[1],
+ op[0]->value.f[2],
+ op[0]->value.f[3]);
+ 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_unpack_unorm_4x8:
+ assert(op[0]->type == glsl_type::uint_type);
+ unpack_4x8(unpack_unorm_1x8,
+ op[0]->value.u[0],
+ &data.f[0], &data.f[1], &data.f[2], &data.f[3]);
+ break;
case ir_unop_pack_half_2x16:
assert(op[0]->type == glsl_type::vec2_type);
data.u[0] = pack_2x16(pack_half_1x16,
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