Re: [Mesa-dev] [RFC 10/21] mesa: Remove equality check in helper functions
On Wed, Oct 21, 2015 at 11:43 PM, Erik Faye-Lund wrote: > On Tue, Oct 20, 2015 at 12:44 AM, Nanley Chery > wrote: > > From: Nanley Chery > > > > Since the version numbers being compared are integral and we don't ever > > expect gl_context::Version to be equal to 0, subtract 1 from the rhs of > > the equation and perform the optimization of removing the equality check. > > Is this really an improvement? Changing '>=' to '>' and then making > all versions off-by-one seems like trading less readable and debugable > code for no real upside... > After looking at the assembly generated, I've determined that this is actually not an improvement. I'll drop this patch. I was using .text size as my metric earlier. I now realize that it isn't completely reliable. ___ mesa-dev mailing list mesa-dev@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/mesa-dev
Re: [Mesa-dev] [RFC 10/21] mesa: Remove equality check in helper functions
On Thu 22 Oct 2015, Emil Velikov wrote: > On 22 October 2015 at 07:43, Erik Faye-Lund wrote: > > On Tue, Oct 20, 2015 at 12:44 AM, Nanley Chery > > wrote: > >> From: Nanley Chery > >> > >> Since the version numbers being compared are integral and we don't ever > >> expect gl_context::Version to be equal to 0, subtract 1 from the rhs of > >> the equation and perform the optimization of removing the equality check. > > > > Is this really an improvement? Changing '>=' to '>' and then making > > all versions off-by-one seems like trading less readable and debugable > > code for no real upside... > > Pretty much my line of thinking. Perhaps it was applicable for earlier > iterations of the series ? That's my opinion too. ___ mesa-dev mailing list mesa-dev@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/mesa-dev
Re: [Mesa-dev] [RFC 10/21] mesa: Remove equality check in helper functions
On 22 October 2015 at 07:43, Erik Faye-Lund wrote: > On Tue, Oct 20, 2015 at 12:44 AM, Nanley Chery wrote: >> From: Nanley Chery >> >> Since the version numbers being compared are integral and we don't ever >> expect gl_context::Version to be equal to 0, subtract 1 from the rhs of >> the equation and perform the optimization of removing the equality check. > > Is this really an improvement? Changing '>=' to '>' and then making > all versions off-by-one seems like trading less readable and debugable > code for no real upside... Pretty much my line of thinking. Perhaps it was applicable for earlier iterations of the series ? -Emil ___ mesa-dev mailing list mesa-dev@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/mesa-dev
Re: [Mesa-dev] [RFC 10/21] mesa: Remove equality check in helper functions
On Tue, Oct 20, 2015 at 12:44 AM, Nanley Chery wrote: > From: Nanley Chery > > Since the version numbers being compared are integral and we don't ever > expect gl_context::Version to be equal to 0, subtract 1 from the rhs of > the equation and perform the optimization of removing the equality check. Is this really an improvement? Changing '>=' to '>' and then making all versions off-by-one seems like trading less readable and debugable code for no real upside... ___ mesa-dev mailing list mesa-dev@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/mesa-dev
[Mesa-dev] [RFC 10/21] mesa: Remove equality check in helper functions
From: Nanley Chery
Since the version numbers being compared are integral and we don't ever
expect gl_context::Version to be equal to 0, subtract 1 from the rhs of
the equation and perform the optimization of removing the equality check.
Signed-off-by: Nanley Chery
---
src/mesa/main/extensions.c | 10 +-
src/mesa/main/extensions.h | 2 +-
src/mesa/main/extensions_table.h | 10 +-
3 files changed, 11 insertions(+), 11 deletions(-)
diff --git a/src/mesa/main/extensions.c b/src/mesa/main/extensions.c
index 136313f..365e7ed 100644
--- a/src/mesa/main/extensions.c
+++ b/src/mesa/main/extensions.c
@@ -57,10 +57,10 @@ const struct extension extension_table[] = {
#define EXT(name_str, driver_cap, gll_ver, glc_ver, gles_ver, gles2_ver, )
\
{ .name = "GL_" #name_str, .offset = o(driver_cap), \
.version = { \
-[API_OPENGL_COMPAT] = gll_ver, \
-[API_OPENGL_CORE] = glc_ver, \
-[API_OPENGLES] = gles_ver, \
-[API_OPENGLES2] = gles2_ver, \
+[API_OPENGL_COMPAT] = gll_ver - 1, \
+[API_OPENGL_CORE] = glc_ver - 1, \
+[API_OPENGLES] = gles_ver - 1, \
+[API_OPENGLES2] = gles2_ver - 1, \
}, .year = },
#include "extensions_table.h"
#undef EXT
@@ -399,7 +399,7 @@ _mesa_extension_supported(const struct gl_context *ctx,
extension_index ei)
{
const bool *base = (bool *) &ctx->Extensions;
const struct extension *i = extension_table + ei;
- return (ctx->Version >= i->version[ctx->API]) && base[i->offset];
+ return (ctx->Version > i->version[ctx->API]) && base[i->offset];
}
/**
diff --git a/src/mesa/main/extensions.h b/src/mesa/main/extensions.h
index 24cc04d..50456e98 100644
--- a/src/mesa/main/extensions.h
+++ b/src/mesa/main/extensions.h
@@ -88,7 +88,7 @@ enum {
/** Checks if the context suports a user-facing extension */
#define EXT(name_str, driver_cap, ...) \
static inline bool _mesa_has_##name_str(const struct gl_context *ctx) { \
- return ctx->Extensions.driver_cap && (ctx->Version >= \
+ return ctx->Extensions.driver_cap && (ctx->Version > \
extension_table[MESA_EXTENSION_##name_str].version[ctx->API]); \
}
#include "extensions_table.h"
diff --git a/src/mesa/main/extensions_table.h b/src/mesa/main/extensions_table.h
index ce48b51..b18f4e6 100644
--- a/src/mesa/main/extensions_table.h
+++ b/src/mesa/main/extensions_table.h
@@ -1,8 +1,8 @@
-#define GLL 0
-#define GLC 0
-#define ES1 0
-#define ES2 0
-#define x ~0
+#define GLL 1u
+#define GLC 1u
+#define ES1 1u
+#define ES2 1u
+#define x ~0u
EXT(ARB_ES2_compatibility , ARB_ES2_compatibility
, GLL, GLC, x , x , 2009)
EXT(ARB_ES3_compatibility , ARB_ES3_compatibility
, GLL, GLC, x , x , 2012)
EXT(ARB_arrays_of_arrays, ARB_arrays_of_arrays
, GLL, GLC, x , x , 2012)
--
2.6.1
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