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-rw-r--r--src/glsl/ir_constant_expression.cpp18
-rw-r--r--src/glsl/nir/nir_constant_expressions.py15
-rw-r--r--src/glsl/nir/nir_opcodes.py2
-rw-r--r--src/mesa/main/imports.c25
-rw-r--r--src/mesa/main/imports.h3
-rw-r--r--src/util/Makefile.sources1
-rw-r--r--src/util/rounding.h58
7 files changed, 82 insertions, 40 deletions
diff --git a/src/glsl/ir_constant_expression.cpp b/src/glsl/ir_constant_expression.cpp
index 388c4c28683..ecebc3cdc3b 100644
--- a/src/glsl/ir_constant_expression.cpp
+++ b/src/glsl/ir_constant_expression.cpp
@@ -35,6 +35,7 @@
#include <math.h>
#include "main/core.h" /* for MAX2, MIN2, CLAMP */
+#include "util/rounding.h" /* for _mesa_roundeven */
#include "ir.h"
#include "glsl_types.h"
#include "program/hash_table.h"
@@ -245,8 +246,8 @@ pack_snorm_1x8(float x)
* 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);
+ return (uint8_t) (int)
+ _mesa_roundevenf(CLAMP(x, -1.0f, +1.0f) * 127.0f);
}
/**
@@ -267,8 +268,8 @@ pack_snorm_1x16(float x)
* We must first cast the float to an int, because casting a negative
* float to a uint is undefined.
*/
- return (uint16_t) (int16_t)
- _mesa_round_to_even(CLAMP(x, -1.0f, +1.0f) * 32767.0f);
+ return (uint16_t) (int)
+ _mesa_roundevenf(CLAMP(x, -1.0f, +1.0f) * 32767.0f);
}
/**
@@ -322,7 +323,7 @@ pack_unorm_1x8(float x)
*
* packUnorm4x8: round(clamp(c, 0, +1) * 255.0)
*/
- return (uint8_t) _mesa_round_to_even(CLAMP(x, 0.0f, 1.0f) * 255.0f);
+ return (uint8_t) (int) _mesa_roundevenf(CLAMP(x, 0.0f, 1.0f) * 255.0f);
}
/**
@@ -340,7 +341,8 @@ pack_unorm_1x16(float x)
*
* packUnorm2x16: round(clamp(c, 0, +1) * 65535.0)
*/
- return (uint16_t) _mesa_round_to_even(CLAMP(x, 0.0f, 1.0f) * 65535.0f);
+ return (uint16_t) (int)
+ _mesa_roundevenf(CLAMP(x, 0.0f, 1.0f) * 65535.0f);
}
/**
@@ -733,9 +735,9 @@ ir_expression::constant_expression_value(struct hash_table *variable_context)
case ir_unop_round_even:
for (unsigned c = 0; c < op[0]->type->components(); c++) {
if (op[0]->type->base_type == GLSL_TYPE_DOUBLE)
- data.d[c] = _mesa_round_to_even(op[0]->value.d[c]);
+ data.d[c] = _mesa_roundeven(op[0]->value.d[c]);
else
- data.f[c] = _mesa_round_to_even(op[0]->value.f[c]);
+ data.f[c] = _mesa_roundevenf(op[0]->value.f[c]);
}
break;
diff --git a/src/glsl/nir/nir_constant_expressions.py b/src/glsl/nir/nir_constant_expressions.py
index 22bc4f09583..bf82fe533d6 100644
--- a/src/glsl/nir/nir_constant_expressions.py
+++ b/src/glsl/nir/nir_constant_expressions.py
@@ -28,6 +28,7 @@ template = """\
#include <math.h>
#include "main/core.h"
+#include "util/rounding.h" /* for _mesa_roundeven */
#include "nir_constant_expressions.h"
#if defined(_MSC_VER) && (_MSC_VER < 1800)
@@ -68,8 +69,8 @@ pack_snorm_1x8(float x)
* 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);
+ return (uint8_t) (int)
+ _mesa_roundevenf(CLAMP(x, -1.0f, +1.0f) * 127.0f);
}
/**
@@ -90,8 +91,8 @@ pack_snorm_1x16(float x)
* We must first cast the float to an int, because casting a negative
* float to a uint is undefined.
*/
- return (uint16_t) (int16_t)
- _mesa_round_to_even(CLAMP(x, -1.0f, +1.0f) * 32767.0f);
+ return (uint16_t) (int)
+ _mesa_roundevenf(CLAMP(x, -1.0f, +1.0f) * 32767.0f);
}
/**
@@ -145,7 +146,8 @@ pack_unorm_1x8(float x)
*
* packUnorm4x8: round(clamp(c, 0, +1) * 255.0)
*/
- return (uint8_t) _mesa_round_to_even(CLAMP(x, 0.0f, 1.0f) * 255.0f);
+ return (uint8_t) (int)
+ _mesa_roundevenf(CLAMP(x, 0.0f, 1.0f) * 255.0f);
}
/**
@@ -163,7 +165,8 @@ pack_unorm_1x16(float x)
*
* packUnorm2x16: round(clamp(c, 0, +1) * 65535.0)
*/
- return (uint16_t) _mesa_round_to_even(CLAMP(x, 0.0f, 1.0f) * 65535.0f);
+ return (uint16_t) (int)
+ _mesa_roundevenf(CLAMP(x, 0.0f, 1.0f) * 65535.0f);
}
/**
diff --git a/src/glsl/nir/nir_opcodes.py b/src/glsl/nir/nir_opcodes.py
index 77f3bb8266d..062cd628b8d 100644
--- a/src/glsl/nir/nir_opcodes.py
+++ b/src/glsl/nir/nir_opcodes.py
@@ -183,7 +183,7 @@ unop("ftrunc", tfloat, "truncf(src0)")
unop("fceil", tfloat, "ceilf(src0)")
unop("ffloor", tfloat, "floorf(src0)")
unop("ffract", tfloat, "src0 - floorf(src0)")
-unop("fround_even", tfloat, "_mesa_round_to_even(src0)")
+unop("fround_even", tfloat, "_mesa_roundevenf(src0)")
# Trigonometric operations.
diff --git a/src/mesa/main/imports.c b/src/mesa/main/imports.c
index ac8deeb97c9..68c7316575c 100644
--- a/src/mesa/main/imports.c
+++ b/src/mesa/main/imports.c
@@ -45,6 +45,7 @@
#include <stdio.h>
#include <stdarg.h>
#include "c99_math.h"
+#include "util/rounding.h" /* for _mesa_roundeven */
#include "imports.h"
#include "context.h"
#include "mtypes.h"
@@ -307,26 +308,6 @@ _mesa_bitcount_64(uint64_t n)
#endif
-/* Using C99 rounding functions for roundToEven() implementation is
- * difficult, because round(), rint, and nearbyint() are affected by
- * fesetenv(), which the application may have done for its own
- * purposes. Mesa's IROUND macro is close to what we want, but it
- * rounds away from 0 on n + 0.5.
- */
-int
-_mesa_round_to_even(float val)
-{
- int rounded = IROUND(val);
-
- if (val - floor(val) == 0.5) {
- if (rounded % 2 != 0)
- rounded += val > 0 ? -1 : 1;
- }
-
- return rounded;
-}
-
-
/**
* Convert a 4-byte float to a 2-byte half float.
*
@@ -388,7 +369,7 @@ _mesa_float_to_half(float val)
* or normal.
*/
e = 0;
- m = _mesa_round_to_even((1 << 24) * fabsf(fi.f));
+ m = (int) _mesa_roundevenf((1 << 24) * fabsf(fi.f));
}
else if (new_exp > 15) {
/* map this value to infinity */
@@ -402,7 +383,7 @@ _mesa_float_to_half(float val)
* either normal or infinite.
*/
e = new_exp + 15;
- m = _mesa_round_to_even(flt_m / (float) (1 << 13));
+ m = (int) _mesa_roundevenf(flt_m / (float) (1 << 13));
}
}
diff --git a/src/mesa/main/imports.h b/src/mesa/main/imports.h
index ee6b39945a3..29f249980a0 100644
--- a/src/mesa/main/imports.h
+++ b/src/mesa/main/imports.h
@@ -433,9 +433,6 @@ _mesa_fls(unsigned int n)
#endif
}
-extern int
-_mesa_round_to_even(float val);
-
extern GLhalfARB
_mesa_float_to_half(float f);
diff --git a/src/util/Makefile.sources b/src/util/Makefile.sources
index 560ea836aa1..3e0d02bad1e 100644
--- a/src/util/Makefile.sources
+++ b/src/util/Makefile.sources
@@ -14,6 +14,7 @@ MESA_UTIL_FILES := \
register_allocate.h \
rgtc.c \
rgtc.h \
+ rounding.h \
set.c \
set.h \
simple_list.h \
diff --git a/src/util/rounding.h b/src/util/rounding.h
new file mode 100644
index 00000000000..c8be45057b6
--- /dev/null
+++ b/src/util/rounding.h
@@ -0,0 +1,58 @@
+/*
+ * Copyright © 2015 Intel Corporation
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice (including the next
+ * paragraph) shall be included in all copies or substantial portions of the
+ * Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
+ * IN THE SOFTWARE.
+ */
+
+#include <math.h>
+
+/* The C standard library has functions round()/rint()/nearbyint() that round
+ * their arguments according to the rounding mode set in the floating-point
+ * control register. While there are trunc()/ceil()/floor() functions that do
+ * a specific operation without modifying the rounding mode, there is no
+ * roundeven() in any version of C.
+ *
+ * Technical Specification 18661 (ISO/IEC TS 18661-1:2014) adds roundeven(),
+ * but it's unfortunately not implemented by glibc.
+ *
+ * This implementation differs in that it does not raise the inexact exception.
+ *
+ * We use rint() to implement these functions, with the assumption that the
+ * floating-point rounding mode has not been changed from the default Round
+ * to Nearest.
+ */
+
+/**
+ * \brief Rounds \c x to the nearest integer, with ties to the even integer.
+ */
+static inline float
+_mesa_roundevenf(float x)
+{
+ return rintf(x);
+}
+
+/**
+ * \brief Rounds \c x to the nearest integer, with ties to the even integer.
+ */
+static inline double
+_mesa_roundeven(double x)
+{
+ return rint(x);
+}