Re: [Mesa-dev] [PATCH] mesa: Ensure stack is realigned on x86.
On 02/12/14 21:10, Brian Paul wrote:
On 12/02/2014 01:27 PM, Jose Fonseca wrote:
From: José Fonseca
Nowadays GCC assumes stack pointer is 16-byte aligned even on 32-bits,
but that is an assumption OpenGL drivers (or any dynamic library for
that matter) can affort to make as there are many closed- and open-
can or cannot?
Oops. "cannot".
affort -> afford
Thanks.
source application binaries out there that only assume 4-byte stack
alignment.
This fix uses force_align_arg_pointer GCC attribute, and is only a
stop-gap measure.
The right fix would be to pass -mstackrealign or
-mincoming-stack-boundary=2 to all source fails that use any -msse*
option, as there is no way to guarantee if/when GCC will decide to spill
SSE registers to the stack.
https://bugs.freedesktop.org/show_bug.cgi?id=86788
---
src/mesa/main/sse_minmax.c | 3 +++
1 file changed, 3 insertions(+)
diff --git a/src/mesa/main/sse_minmax.c b/src/mesa/main/sse_minmax.c
index 222ac14..93cf2a6 100644
--- a/src/mesa/main/sse_minmax.c
+++ b/src/mesa/main/sse_minmax.c
@@ -31,6 +31,9 @@
#include
void
+#if !defined(__x86_64__)
+ __attribute__((force_align_arg_pointer))
+#endif
_mesa_uint_array_min_max(const unsigned *ui_indices, unsigned
*min_index,
unsigned *max_index, const unsigned count)
{
I don't remember if this code is compiled with MSVC. If so, do you also
need a gcc check for the __attribute__ part?
No, it doesn't compile on MSVC yet -- there are a few non-standard GCC
"__attribute__" below already, plus MSVC doesn't define __SSE4_1__, so
the whole thing would be no-oped.
Getting this to compile on MSVC/MinGW is something I rather leave to
another time, as it will involve updating scons to set -msse4.1
correctly, and port a few defines from
src/gallium/include/pipe/p_config.h and
src/gallium/auxiliary/util/u_sse.h for portability.
Jose
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Re: [Mesa-dev] [PATCH] mesa: Ensure stack is realigned on x86.
On 12/02/2014 01:27 PM, Jose Fonseca wrote:
From: José Fonseca
Nowadays GCC assumes stack pointer is 16-byte aligned even on 32-bits,
but that is an assumption OpenGL drivers (or any dynamic library for
that matter) can affort to make as there are many closed- and open-
can or cannot?
affort -> afford
source application binaries out there that only assume 4-byte stack
alignment.
This fix uses force_align_arg_pointer GCC attribute, and is only a
stop-gap measure.
The right fix would be to pass -mstackrealign or
-mincoming-stack-boundary=2 to all source fails that use any -msse*
option, as there is no way to guarantee if/when GCC will decide to spill
SSE registers to the stack.
https://bugs.freedesktop.org/show_bug.cgi?id=86788
---
src/mesa/main/sse_minmax.c | 3 +++
1 file changed, 3 insertions(+)
diff --git a/src/mesa/main/sse_minmax.c b/src/mesa/main/sse_minmax.c
index 222ac14..93cf2a6 100644
--- a/src/mesa/main/sse_minmax.c
+++ b/src/mesa/main/sse_minmax.c
@@ -31,6 +31,9 @@
#include
void
+#if !defined(__x86_64__)
+ __attribute__((force_align_arg_pointer))
+#endif
_mesa_uint_array_min_max(const unsigned *ui_indices, unsigned *min_index,
unsigned *max_index, const unsigned count)
{
I don't remember if this code is compiled with MSVC. If so, do you also
need a gcc check for the __attribute__ part?
-Brian
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[Mesa-dev] [PATCH] mesa: Ensure stack is realigned on x86.
From: José Fonseca
Nowadays GCC assumes stack pointer is 16-byte aligned even on 32-bits,
but that is an assumption OpenGL drivers (or any dynamic library for
that matter) can affort to make as there are many closed- and open-
source application binaries out there that only assume 4-byte stack
alignment.
This fix uses force_align_arg_pointer GCC attribute, and is only a
stop-gap measure.
The right fix would be to pass -mstackrealign or
-mincoming-stack-boundary=2 to all source fails that use any -msse*
option, as there is no way to guarantee if/when GCC will decide to spill
SSE registers to the stack.
https://bugs.freedesktop.org/show_bug.cgi?id=86788
---
src/mesa/main/sse_minmax.c | 3 +++
1 file changed, 3 insertions(+)
diff --git a/src/mesa/main/sse_minmax.c b/src/mesa/main/sse_minmax.c
index 222ac14..93cf2a6 100644
--- a/src/mesa/main/sse_minmax.c
+++ b/src/mesa/main/sse_minmax.c
@@ -31,6 +31,9 @@
#include
void
+#if !defined(__x86_64__)
+ __attribute__((force_align_arg_pointer))
+#endif
_mesa_uint_array_min_max(const unsigned *ui_indices, unsigned *min_index,
unsigned *max_index, const unsigned count)
{
--
2.1.3
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