Re: [PATCH] nvptx: bump default to PTX 4.1
On 1/5/22 11:33, Andrew Stubbs wrote:
On 05/01/2022 10:24, Tom de Vries wrote:
On 12/21/21 12:33, Andrew Stubbs wrote:
On 20/12/2021 15:58, Andrew Stubbs wrote:
In order to support the %dynamic_smem_size PTX feature is is
necessary to bump the minimum supported PTX version from 3.1 (~2013)
to 4.1 (~2014).
Tobias has pointed out, privately, that the default version is both
documented and encoded in the -mptx option, so I need to fix that too.
This patch adds -mptx=4.1, sets it as the default, and updates the
documentation accordingly.
The -mptx=3.1 option is kept for backwards compatibility as an alias
for 4.1. There's no point in actually allowing 3.1 as any program
linked against libgomp will fail (and that's all offloading programs).
OK for stage 1?
Just keep -mptx=3.1 as is, and add -mptx=4.1.
AFAIU, there's actually only one file required to have -mptx=4.1, the
one using %dynamic_smem_size. Since it's somewhat cumbersome to add
flags for a single file, how about:
...
diff --git a/libgomp/configure.tgt b/libgomp/configure.tgt
index d4f1e741b5a..92242697f24 100644
--- a/libgomp/configure.tgt
+++ b/libgomp/configure.tgt
@@ -162,6 +162,7 @@ case "${target}" in
nvptx*-*-*)
config_path="nvptx accel"
+ XCFLAGS="$XCFLAGS -mptx=4.1"
;;
*-*-rtems*)
...
?
There shouldn't be any need for that as long as the default is correct.
There is no need to change the default, as long as we use this.
In any case, I'm no expert but doesn't the deferred assembly thing mean
that the whole project needs to have the correct minimum setting?
If your question is whether ptx modules with .version 3.1 and 4.1 can be
linked together, then the answer seems to be yes.
If the NVPTX maintainer prefers I can leave the 3.1 meaning actually
3.1, but that will break any makefiles or build scripts that exist in
the wild and happen to specify 3.1 explicitly (not that I know any
reason why they would).
I think you're trying to support a scenario we shouldn't support, by
making things unclear.
Thanks,
- Tom
Re: [PATCH] nvptx: bump default to PTX 4.1
On 05/01/2022 10:24, Tom de Vries wrote:
On 12/21/21 12:33, Andrew Stubbs wrote:
On 20/12/2021 15:58, Andrew Stubbs wrote:
In order to support the %dynamic_smem_size PTX feature is is
necessary to bump the minimum supported PTX version from 3.1 (~2013)
to 4.1 (~2014).
Tobias has pointed out, privately, that the default version is both
documented and encoded in the -mptx option, so I need to fix that too.
This patch adds -mptx=4.1, sets it as the default, and updates the
documentation accordingly.
The -mptx=3.1 option is kept for backwards compatibility as an alias
for 4.1. There's no point in actually allowing 3.1 as any program
linked against libgomp will fail (and that's all offloading programs).
OK for stage 1?
Just keep -mptx=3.1 as is, and add -mptx=4.1.
AFAIU, there's actually only one file required to have -mptx=4.1, the
one using %dynamic_smem_size. Since it's somewhat cumbersome to add
flags for a single file, how about:
...
diff --git a/libgomp/configure.tgt b/libgomp/configure.tgt
index d4f1e741b5a..92242697f24 100644
--- a/libgomp/configure.tgt
+++ b/libgomp/configure.tgt
@@ -162,6 +162,7 @@ case "${target}" in
nvptx*-*-*)
config_path="nvptx accel"
+ XCFLAGS="$XCFLAGS -mptx=4.1"
;;
*-*-rtems*)
...
?
There shouldn't be any need for that as long as the default is correct.
In any case, I'm no expert but doesn't the deferred assembly thing mean
that the whole project needs to have the correct minimum setting?
If the NVPTX maintainer prefers I can leave the 3.1 meaning actually
3.1, but that will break any makefiles or build scripts that exist in
the wild and happen to specify 3.1 explicitly (not that I know any
reason why they would).
Andrew
Re: [PATCH] nvptx: bump default to PTX 4.1
On 12/21/21 12:33, Andrew Stubbs wrote:
On 20/12/2021 15:58, Andrew Stubbs wrote:
In order to support the %dynamic_smem_size PTX feature is is necessary
to bump the minimum supported PTX version from 3.1 (~2013) to 4.1
(~2014).
Tobias has pointed out, privately, that the default version is both
documented and encoded in the -mptx option, so I need to fix that too.
This patch adds -mptx=4.1, sets it as the default, and updates the
documentation accordingly.
The -mptx=3.1 option is kept for backwards compatibility as an alias for
4.1. There's no point in actually allowing 3.1 as any program linked
against libgomp will fail (and that's all offloading programs).
OK for stage 1?
Just keep -mptx=3.1 as is, and add -mptx=4.1.
AFAIU, there's actually only one file required to have -mptx=4.1, the
one using %dynamic_smem_size. Since it's somewhat cumbersome to add
flags for a single file, how about:
...
diff --git a/libgomp/configure.tgt b/libgomp/configure.tgt
index d4f1e741b5a..92242697f24 100644
--- a/libgomp/configure.tgt
+++ b/libgomp/configure.tgt
@@ -162,6 +162,7 @@ case "${target}" in
nvptx*-*-*)
config_path="nvptx accel"
+ XCFLAGS="$XCFLAGS -mptx=4.1"
;;
*-*-rtems*)
...
?
Thanks,
- Tom
[PATCH] nvptx: bump default to PTX 4.1
On 20/12/2021 15:58, Andrew Stubbs wrote:
In order to support the %dynamic_smem_size PTX feature is is necessary
to bump the minimum supported PTX version from 3.1 (~2013) to 4.1 (~2014).
Tobias has pointed out, privately, that the default version is both
documented and encoded in the -mptx option, so I need to fix that too.
This patch adds -mptx=4.1, sets it as the default, and updates the
documentation accordingly.
The -mptx=3.1 option is kept for backwards compatibility as an alias for
4.1. There's no point in actually allowing 3.1 as any program linked
against libgomp will fail (and that's all offloading programs).
OK for stage 1?
Andrew
nvptx: bump default to PTX 4.1
gcc/ChangeLog:
* config/nvptx/nvptx-opts.h (ptx_version): Change PTX_VERSION_3_1 to
PTX_VERSION_4_1.
* config/nvptx/nvptx.c (nvptx_file_start): Bump minimum PTX version
to 4.1.
* config/nvptx/nvptx.opt (ptx_version): Add 4.1. Change default.
doc/invoke.texi: -mptx default is now 4.1.
diff --git a/gcc/config/nvptx/nvptx-opts.h b/gcc/config/nvptx/nvptx-opts.h
index 7b6ecd42fed..c7fcf1c8cd4 100644
--- a/gcc/config/nvptx/nvptx-opts.h
+++ b/gcc/config/nvptx/nvptx-opts.h
@@ -31,7 +31,7 @@ enum ptx_isa
enum ptx_version
{
- PTX_VERSION_3_1,
+ PTX_VERSION_4_1,
PTX_VERSION_6_3,
PTX_VERSION_7_0
};
diff --git a/gcc/config/nvptx/nvptx.c b/gcc/config/nvptx/nvptx.c
index ff44d9fdbef..9bc26d7de0c 100644
--- a/gcc/config/nvptx/nvptx.c
+++ b/gcc/config/nvptx/nvptx.c
@@ -5409,7 +5409,7 @@ nvptx_file_start (void)
else if (TARGET_PTX_6_3)
fputs ("\t.version\t6.3\n", asm_out_file);
else
-fputs ("\t.version\t3.1\n", asm_out_file);
+fputs ("\t.version\t4.1\n", asm_out_file);
if (TARGET_SM80)
fputs ("\t.target\tsm_80\n", asm_out_file);
else if (TARGET_SM75)
diff --git a/gcc/config/nvptx/nvptx.opt b/gcc/config/nvptx/nvptx.opt
index 1d88ef18d04..9e6a6a7fbff 100644
--- a/gcc/config/nvptx/nvptx.opt
+++ b/gcc/config/nvptx/nvptx.opt
@@ -79,8 +79,12 @@ Enum
Name(ptx_version) Type(int)
Known PTX versions (for use with the -mptx= option):
+; Keep 3.1 for backwards compatibility only
EnumValue
-Enum(ptx_version) String(3.1) Value(PTX_VERSION_3_1)
+Enum(ptx_version) String(3.1) Value(PTX_VERSION_4_1)
+
+EnumValue
+Enum(ptx_version) String(4.1) Value(PTX_VERSION_4_1)
EnumValue
Enum(ptx_version) String(6.3) Value(PTX_VERSION_6_3)
@@ -89,5 +93,5 @@ EnumValue
Enum(ptx_version) String(7.0) Value(PTX_VERSION_7_0)
mptx=
-Target RejectNegative ToLower Joined Enum(ptx_version) Var(ptx_version_option)
Init(PTX_VERSION_3_1)
+Target RejectNegative ToLower Joined Enum(ptx_version) Var(ptx_version_option)
Init(PTX_VERSION_4_1)
Specify the version of the ptx version to use.
diff --git a/gcc/doc/invoke.texi b/gcc/doc/invoke.texi
index 37836a7d614..92f0da62a2b 100644
--- a/gcc/doc/invoke.texi
+++ b/gcc/doc/invoke.texi
@@ -27056,8 +27056,8 @@ strings must be lower-case. Valid ISA strings include
@samp{sm_30} and
@item -mptx=@var{version-string}
@opindex mptx
Generate code for given the specified PTX version (e.g.@: @samp{6.3}).
-Valid version strings include @samp{3.1} and @samp{6.3}. The default PTX
-version is 3.1.
+Valid version strings include @samp{4.1} and @samp{6.3}. The default PTX
+version is 4.1.
@item -mmainkernel
@opindex mmainkernel
