Re: [Mesa-dev] [PATCH v4] Fixing an x86 FPU bug.
Looks better, just a bunch of nit-picks...
First, I think the summary/subject line can be improved. How about
mesa: use fi_type in vertex attribute code
On 02/18/2015 10:00 AM, marius.pre...@intel.com wrote:
From: Marius Predut marius.pre...@intel.com
On 32-bit, for floating point operations is used x86 FPU registers
instead SSE, reason for when reinterprets an integer as a float
result is unexpected (modify floats when they are written to memory).
How about this:
For 32-bit builds, floating point operations use x86 FPU registers,
not SSE registers. If we're actually storing an integer in a float
variable, the value might get modified when written to memory. This
patch changes the VBO code to use the fi_type (float/int union) to
store/copy vertex attributes.
The patch was checked with and without -O3 compiler flag.
Also, it add performace improvement because treat GLfloats as GLint.
On x86 systems, moving a float as a int (thereby using integer registers
instead of FP registers) is a performance win.
Maybe:
Also, this can improve performance on x86 because moving floats with
integer registers instead of FP registers is faster.
Neil Roberts review:
-include changes on all places that are storing attribute values.
Brian Paul review:
- use fi_type type instead gl_constant_value
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=82668
Signed-off-by: Marius Predut marius.pre...@intel.com
---
src/mesa/main/context.c |3 ++-
src/mesa/main/macros.h| 32
src/mesa/vbo/vbo_attrib_tmp.h | 20
src/mesa/vbo/vbo_context.h| 14 +++---
src/mesa/vbo/vbo_exec.h | 11 ++-
src/mesa/vbo/vbo_exec_api.c | 35 +--
src/mesa/vbo/vbo_exec_draw.c |6 +++---
src/mesa/vbo/vbo_exec_eval.c | 22 +++---
src/mesa/vbo/vbo_save.h | 16
src/mesa/vbo/vbo_save_api.c | 34 +-
src/mesa/vbo/vbo_save_draw.c |4 ++--
11 files changed, 105 insertions(+), 92 deletions(-)
diff --git a/src/mesa/main/context.c b/src/mesa/main/context.c
index 63d30a2..f0597e2 100644
--- a/src/mesa/main/context.c
+++ b/src/mesa/main/context.c
@@ -134,6 +134,7 @@
#include math/m_matrix.h
#include main/dispatch.h /* for _gloffset_COUNT */
#include uniforms.h
+#include macros.h
#ifdef USE_SPARC_ASM
#include sparc/sparc.h
@@ -656,7 +657,7 @@ _mesa_init_constants(struct gl_constants *consts, gl_api
api)
consts-MaxSamples = 0;
/* GLSL default if NativeIntegers == FALSE */
- consts-UniformBooleanTrue = FLT_AS_UINT(1.0f);
+ consts-UniformBooleanTrue = FLOAT_AS_UNION(1.0f).u;
/* GL_ARB_sync */
consts-MaxServerWaitTimeout = 0x1fff7fffULL;
diff --git a/src/mesa/main/macros.h b/src/mesa/main/macros.h
index 2d59c6f..9ca3460 100644
--- a/src/mesa/main/macros.h
+++ b/src/mesa/main/macros.h
@@ -170,25 +170,25 @@ extern GLfloat _mesa_ubyte_to_float_color_tab[256];
ub = ((GLubyte) F_TO_I((f) * 255.0F))
#endif
-static inline GLfloat INT_AS_FLT(GLint i)
+static fi_type UINT_AS_UNION(GLuint u)
{
fi_type tmp;
- tmp.i = i;
- return tmp.f;
+ tmp.u = u;
+ return tmp;
}
-static inline GLfloat UINT_AS_FLT(GLuint u)
+static inline fi_type INT_AS_UNION(GLint i)
{
fi_type tmp;
- tmp.u = u;
- return tmp.f;
+ tmp.i = i;
+ return tmp;
}
-static inline unsigned FLT_AS_UINT(float f)
+static inline fi_type FLOAT_AS_UNION(GLfloat f)
{
fi_type tmp;
tmp.f = f;
- return tmp.u;
+ return tmp;
}
/**
@@ -620,24 +620,24 @@ do { \
* The default values are chosen based on \p type.
*/
static inline void
-COPY_CLEAN_4V_TYPE_AS_FLOAT(GLfloat dst[4], int sz, const GLfloat src[4],
+COPY_CLEAN_4V_TYPE_AS_UNION(fi_type dst[4], int sz, const fi_type src[4],
GLenum type)
{
switch (type) {
case GL_FLOAT:
- ASSIGN_4V(dst, 0, 0, 0, 1);
+ ASSIGN_4V(dst, FLOAT_AS_UNION(0), FLOAT_AS_UNION(0), FLOAT_AS_UNION(0),
FLOAT_AS_UNION(1));
Wrap to = 78 columns.
break;
case GL_INT:
- ASSIGN_4V(dst, INT_AS_FLT(0), INT_AS_FLT(0),
- INT_AS_FLT(0), INT_AS_FLT(1));
+ ASSIGN_4V(dst, INT_AS_UNION(0), INT_AS_UNION(0),
+INT_AS_UNION(0), INT_AS_UNION(1));
break;
case GL_UNSIGNED_INT:
- ASSIGN_4V(dst, UINT_AS_FLT(0), UINT_AS_FLT(0),
- UINT_AS_FLT(0), UINT_AS_FLT(1));
+ ASSIGN_4V(dst, UINT_AS_UNION(0), UINT_AS_UNION(0),
+UINT_AS_UNION(0), UINT_AS_UNION(1));
break;
default:
- ASSIGN_4V(dst, 0.0f, 0.0f, 0.0f, 1.0f); /* silence warnings */
- ASSERT(!Unexpected type in COPY_CLEAN_4V_TYPE_AS_FLOAT macro);
+ ASSIGN_4V(dst, FLOAT_AS_UNION(0), FLOAT_AS_UNION(0), FLOAT_AS_UNION(0),
FLOAT_AS_UNION(1)); /* silence warnings */
Line wrap.
+
[Mesa-dev] [PATCH v4] Fixing an x86 FPU bug.
From: Marius Predut marius.pre...@intel.com
On 32-bit, for floating point operations is used x86 FPU registers
instead SSE, reason for when reinterprets an integer as a float
result is unexpected (modify floats when they are written to memory).
The patch was checked with and without -O3 compiler flag.
Also, it add performace improvement because treat GLfloats as GLint.
On x86 systems, moving a float as a int (thereby using integer registers
instead of FP registers) is a performance win.
Neil Roberts review:
-include changes on all places that are storing attribute values.
Brian Paul review:
- use fi_type type instead gl_constant_value
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=82668
Signed-off-by: Marius Predut marius.pre...@intel.com
---
src/mesa/main/context.c |3 ++-
src/mesa/main/macros.h| 32
src/mesa/vbo/vbo_attrib_tmp.h | 20
src/mesa/vbo/vbo_context.h| 14 +++---
src/mesa/vbo/vbo_exec.h | 11 ++-
src/mesa/vbo/vbo_exec_api.c | 35 +--
src/mesa/vbo/vbo_exec_draw.c |6 +++---
src/mesa/vbo/vbo_exec_eval.c | 22 +++---
src/mesa/vbo/vbo_save.h | 16
src/mesa/vbo/vbo_save_api.c | 34 +-
src/mesa/vbo/vbo_save_draw.c |4 ++--
11 files changed, 105 insertions(+), 92 deletions(-)
diff --git a/src/mesa/main/context.c b/src/mesa/main/context.c
index 63d30a2..f0597e2 100644
--- a/src/mesa/main/context.c
+++ b/src/mesa/main/context.c
@@ -134,6 +134,7 @@
#include math/m_matrix.h
#include main/dispatch.h /* for _gloffset_COUNT */
#include uniforms.h
+#include macros.h
#ifdef USE_SPARC_ASM
#include sparc/sparc.h
@@ -656,7 +657,7 @@ _mesa_init_constants(struct gl_constants *consts, gl_api
api)
consts-MaxSamples = 0;
/* GLSL default if NativeIntegers == FALSE */
- consts-UniformBooleanTrue = FLT_AS_UINT(1.0f);
+ consts-UniformBooleanTrue = FLOAT_AS_UNION(1.0f).u;
/* GL_ARB_sync */
consts-MaxServerWaitTimeout = 0x1fff7fffULL;
diff --git a/src/mesa/main/macros.h b/src/mesa/main/macros.h
index 2d59c6f..9ca3460 100644
--- a/src/mesa/main/macros.h
+++ b/src/mesa/main/macros.h
@@ -170,25 +170,25 @@ extern GLfloat _mesa_ubyte_to_float_color_tab[256];
ub = ((GLubyte) F_TO_I((f) * 255.0F))
#endif
-static inline GLfloat INT_AS_FLT(GLint i)
+static fi_type UINT_AS_UNION(GLuint u)
{
fi_type tmp;
- tmp.i = i;
- return tmp.f;
+ tmp.u = u;
+ return tmp;
}
-static inline GLfloat UINT_AS_FLT(GLuint u)
+static inline fi_type INT_AS_UNION(GLint i)
{
fi_type tmp;
- tmp.u = u;
- return tmp.f;
+ tmp.i = i;
+ return tmp;
}
-static inline unsigned FLT_AS_UINT(float f)
+static inline fi_type FLOAT_AS_UNION(GLfloat f)
{
fi_type tmp;
tmp.f = f;
- return tmp.u;
+ return tmp;
}
/**
@@ -620,24 +620,24 @@ do { \
* The default values are chosen based on \p type.
*/
static inline void
-COPY_CLEAN_4V_TYPE_AS_FLOAT(GLfloat dst[4], int sz, const GLfloat src[4],
+COPY_CLEAN_4V_TYPE_AS_UNION(fi_type dst[4], int sz, const fi_type src[4],
GLenum type)
{
switch (type) {
case GL_FLOAT:
- ASSIGN_4V(dst, 0, 0, 0, 1);
+ ASSIGN_4V(dst, FLOAT_AS_UNION(0), FLOAT_AS_UNION(0), FLOAT_AS_UNION(0),
FLOAT_AS_UNION(1));
break;
case GL_INT:
- ASSIGN_4V(dst, INT_AS_FLT(0), INT_AS_FLT(0),
- INT_AS_FLT(0), INT_AS_FLT(1));
+ ASSIGN_4V(dst, INT_AS_UNION(0), INT_AS_UNION(0),
+INT_AS_UNION(0), INT_AS_UNION(1));
break;
case GL_UNSIGNED_INT:
- ASSIGN_4V(dst, UINT_AS_FLT(0), UINT_AS_FLT(0),
- UINT_AS_FLT(0), UINT_AS_FLT(1));
+ ASSIGN_4V(dst, UINT_AS_UNION(0), UINT_AS_UNION(0),
+UINT_AS_UNION(0), UINT_AS_UNION(1));
break;
default:
- ASSIGN_4V(dst, 0.0f, 0.0f, 0.0f, 1.0f); /* silence warnings */
- ASSERT(!Unexpected type in COPY_CLEAN_4V_TYPE_AS_FLOAT macro);
+ ASSIGN_4V(dst, FLOAT_AS_UNION(0), FLOAT_AS_UNION(0), FLOAT_AS_UNION(0),
FLOAT_AS_UNION(1)); /* silence warnings */
+ ASSERT(!Unexpected type in COPY_CLEAN_4V_TYPE_AS_UNION macro);
}
COPY_SZ_4V(dst, sz, src);
}
diff --git a/src/mesa/vbo/vbo_attrib_tmp.h b/src/mesa/vbo/vbo_attrib_tmp.h
index ec66934..17a0a10 100644
--- a/src/mesa/vbo/vbo_attrib_tmp.h
+++ b/src/mesa/vbo/vbo_attrib_tmp.h
@@ -28,6 +28,18 @@ USE OR OTHER DEALINGS IN THE SOFTWARE.
#include util/u_format_r11g11b10f.h
#include main/varray.h
+
+/* ATTR */
+#define ATTR( A, N, T, V0, V1, V2, V3 ) ATTR_##T((A), (N), (T), (V0),
(V1), (V2), (V3))
+
+#define ATTR_GL_UNSIGNED_INT( A, N, T, V0, V1, V2, V3 ) \
+ATTR_UNION(A, N, T, UINT_AS_UNION(V0), UINT_AS_UNION(V1),
UINT_AS_UNION(V2), UINT_AS_UNION(V3))
+#define ATTR_GL_INT( A, N, T, V0, V1, V2, V3 ) \
+ATTR_UNION(A, N, T,
