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nvptx: Emit DECL and DEF linker markers for aliases [PR104957] (was: Add 'g++.target/nvptx/alias-g++.dg_init_dtor2-1.C' (was: Enhance 'gcc.target/nvptx/alias-*.c' assembler scanning (was: [committed][nvptx] Use .alias directive for mptx >= 6.3)))

Message ID 87wmjqz2vr.fsf@euler.schwinge.ddns.net
State New
Headers show
Series nvptx: Emit DECL and DEF linker markers for aliases [PR104957] (was: Add 'g++.target/nvptx/alias-g++.dg_init_dtor2-1.C' (was: Enhance 'gcc.target/nvptx/alias-*.c' assembler scanning (was: [committed][nvptx] Use .alias directive for mptx >= 6.3))) | expand

Commit Message

Thomas Schwinge Sept. 5, 2024, 12:44 p.m. UTC 
Hi!

On 2024-09-05T14:42:00+0200, I wrote:
> On 2024-09-05T14:39:46+0200, I wrote:
>> On 2024-09-05T14:36:54+0200, I wrote:
>>> On 2022-03-22T14:41:46+0100, Tom de Vries via Gcc-patches <gcc-patches@gcc.gnu.org> wrote:
>>>> [nvptx] Use .alias directive for mptx >= 6.3
>>>
>>>> --- a/gcc/config/nvptx/nvptx.cc
>>>> +++ b/gcc/config/nvptx/nvptx.cc
>>>
>>>> @@ -968,7 +969,8 @@ static void
>>>>  write_fn_proto_1 (std::stringstream &s, bool is_defn,
>>>>  		  const char *name, const_tree decl)
>>>>  {
>>>> -  write_fn_marker (s, is_defn, TREE_PUBLIC (decl), name);
>>>> +  if (lookup_attribute ("alias", DECL_ATTRIBUTES (decl)) == NULL)
>>>> +    write_fn_marker (s, is_defn, TREE_PUBLIC (decl), name);
>>>
>>> This non-emitting of DECL and DEF linker markers for aliases is
>>> problematic, as I'll discuss in the following.
>>
>> First, to show what currently is (not) happening, I've pushed to trunk
>> branch commit d0f02538494ded78cac12c63f5708a53f5a77bda
>> "Enhance 'gcc.target/nvptx/alias-*.c' assembler scanning", see attached.
>
> Then, commit a1865fd33897bc6c6e0109df0a12ee73ce386315
> "Add 'g++.target/nvptx/alias-g++.dg_init_dtor2-1.C'", see attached, as
> one representative example of C++ code where the current behavior is an
> actual problem.

Finally, commit 8f5aade15e595b288a2c4ec60ddde8dc80df1a80
"nvptx: Emit DECL and DEF linker markers for aliases [PR104957]", see
attached, to address this issue.


Grüße
 Thomas
diff mbox series

Patch

From 8f5aade15e595b288a2c4ec60ddde8dc80df1a80 Mon Sep 17 00:00:00 2001
From: Thomas Schwinge <tschwinge@baylibre.com>
Date: Wed, 17 Jul 2024 23:56:25 +0200
Subject: [PATCH] nvptx: Emit DECL and DEF linker markers for aliases
 [PR104957]

With nvptx '-malias' enabled (as implemented in
commit f8b15e177155960017ac0c5daef8780d1127f91c
"[nvptx] Use .alias directive for mptx >= 6.3"), the C++ front end in certain
cases does 'write_fn_proto' before an eventual 'alias' attribute has been
added.  In that case, we do emit (via 'write_fn_marker') a DECL linker marker,
but then never emit a corresponding DEF linker marker for the alias.  This
causes hundreds of instances of link-time 'unresolved symbol [alias]' across
the C++ test suite, which are regressions compared to a test run with (default)
'-mno-alias' (in which case the respective functions get duplicated).

	PR target/104957
	gcc/
	* config/nvptx/nvptx.cc (write_fn_proto_1): Revert 2022-03-22
	change; 'write_fn_marker' also for alias DECL.
	(nvptx_asm_output_def_from_decls): 'write_fn_marker' for alias
	DEF.
	gcc/testsuite/
	* g++.target/nvptx/alias-g++.dg_init_dtor2-1.C: Un-XFAIL.
	* gcc.target/nvptx/alias-1.c: Likewise.
	* gcc.target/nvptx/alias-3.c: Likewise.
	* gcc.target/nvptx/alias-to-alias-1.c: Likewise.
---
 gcc/config/nvptx/nvptx.cc                                 | 6 ++++--
 .../g++.target/nvptx/alias-g++.dg_init_dtor2-1.C          | 4 ++--
 gcc/testsuite/gcc.target/nvptx/alias-1.c                  | 4 ++--
 gcc/testsuite/gcc.target/nvptx/alias-3.c                  | 4 ++--
 gcc/testsuite/gcc.target/nvptx/alias-to-alias-1.c         | 8 ++++----
 5 files changed, 14 insertions(+), 12 deletions(-)

diff --git a/gcc/config/nvptx/nvptx.cc b/gcc/config/nvptx/nvptx.cc
index 144b8d0c874..4a7c64f05eb 100644
--- a/gcc/config/nvptx/nvptx.cc
+++ b/gcc/config/nvptx/nvptx.cc
@@ -997,8 +997,7 @@  static void
 write_fn_proto_1 (std::stringstream &s, bool is_defn,
 		  const char *name, const_tree decl, bool force_public)
 {
-  if (lookup_attribute ("alias", DECL_ATTRIBUTES (decl)) == NULL)
-    write_fn_marker (s, is_defn, TREE_PUBLIC (decl) || force_public, name);
+  write_fn_marker (s, is_defn, TREE_PUBLIC (decl) || force_public, name);
 
   /* PTX declaration.  */
   if (DECL_EXTERNAL (decl))
@@ -7627,6 +7626,9 @@  nvptx_asm_output_def_from_decls (FILE *stream, tree name, tree value)
   fputs (s.str ().c_str (), stream);
 
   tree id = DECL_ASSEMBLER_NAME (name);
+  std::stringstream s_def;
+  write_fn_marker (s_def, true, TREE_PUBLIC (name), IDENTIFIER_POINTER (id));
+  fputs (s_def.str ().c_str (), stream);
   NVPTX_ASM_OUTPUT_DEF (stream, IDENTIFIER_POINTER (id),
 			IDENTIFIER_POINTER (value));
 }
diff --git a/gcc/testsuite/g++.target/nvptx/alias-g++.dg_init_dtor2-1.C b/gcc/testsuite/g++.target/nvptx/alias-g++.dg_init_dtor2-1.C
index 747656d51d6..a30f99af308 100644
--- a/gcc/testsuite/g++.target/nvptx/alias-g++.dg_init_dtor2-1.C
+++ b/gcc/testsuite/g++.target/nvptx/alias-g++.dg_init_dtor2-1.C
@@ -1,6 +1,6 @@ 
 /* Reduced from 'g++.dg/init/dtor2.C'.  */
 
-/* { dg-do compile } */
+/* { dg-do link } */
 /* { dg-add-options nvptx_alias_ptx } */
 /* { dg-additional-options -save-temps } */
 /* Via the magic string "-std=*++" indicate that testing one (the default) C++ standard is sufficient.  */
@@ -26,7 +26,7 @@  int main()
 
 /* { dg-final { scan-assembler-times {(?n)^// BEGIN GLOBAL FUNCTION DECL: _ZN1BD1Ev$} 1 } }
    { dg-final { scan-assembler-times {(?n)^\.visible \.func _ZN1BD1Ev \(\.param\.u64 %in_ar0\);$} 1 } }
-   { dg-final { scan-assembler-times {(?n)^// BEGIN GLOBAL FUNCTION DEF: _ZN1BD1Ev$} 1 { xfail *-*-* } } }
+   { dg-final { scan-assembler-times {(?n)^// BEGIN GLOBAL FUNCTION DEF: _ZN1BD1Ev$} 1 } }
    { dg-final { scan-assembler-times {(?n)^\.alias _ZN1BD1Ev,_ZN1BD2Ev;$} 1 } } */
 
 /* { dg-final { scan-assembler-times {(?n)\tcall _ZN1BD1Ev, \(} 1 } }
diff --git a/gcc/testsuite/gcc.target/nvptx/alias-1.c b/gcc/testsuite/gcc.target/nvptx/alias-1.c
index 0fb06495f67..f2aeff36e69 100644
--- a/gcc/testsuite/gcc.target/nvptx/alias-1.c
+++ b/gcc/testsuite/gcc.target/nvptx/alias-1.c
@@ -28,9 +28,9 @@  main (void)
    { dg-final { scan-assembler-times {(?n)^// BEGIN GLOBAL FUNCTION DEF: __f$} 1 } }
    { dg-final { scan-assembler-times {(?n)^\.visible \.func __f$} 1 } } */
 
-/* { dg-final { scan-assembler-times {(?n)^// BEGIN GLOBAL FUNCTION DECL: f$} 1 { xfail *-*-* } } }
+/* { dg-final { scan-assembler-times {(?n)^// BEGIN GLOBAL FUNCTION DECL: f$} 1 } }
    { dg-final { scan-assembler-times {(?n)^\.visible \.func f;$} 1 } }
-   { dg-final { scan-assembler-times {(?n)^// BEGIN GLOBAL FUNCTION DEF: f$} 1 { xfail *-*-* } } }
+   { dg-final { scan-assembler-times {(?n)^// BEGIN GLOBAL FUNCTION DEF: f$} 1 } }
    { dg-final { scan-assembler-times {(?n)^\.alias f,__f;$} 1 } } */
 
 /* { dg-final { scan-assembler-times {(?n)\tcall __f;$} 0 } }
diff --git a/gcc/testsuite/gcc.target/nvptx/alias-3.c b/gcc/testsuite/gcc.target/nvptx/alias-3.c
index 1906607f95f..01a44e2e424 100644
--- a/gcc/testsuite/gcc.target/nvptx/alias-3.c
+++ b/gcc/testsuite/gcc.target/nvptx/alias-3.c
@@ -30,9 +30,9 @@  main (void)
    { dg-final { scan-assembler-times {(?n)^// BEGIN FUNCTION DEF: __f$} 1 } }
    { dg-final { scan-assembler-times {(?n)^\.func __f$} 1 } } */
 
-/* { dg-final { scan-assembler-times {(?n)^// BEGIN FUNCTION DECL: f$} 1 { xfail *-*-* } } }
+/* { dg-final { scan-assembler-times {(?n)^// BEGIN FUNCTION DECL: f$} 1 } }
    { dg-final { scan-assembler-times {(?n)^\.func f;$} 1 } }
-   { dg-final { scan-assembler-times {(?n)^// BEGIN FUNCTION DEF: f$} 1 { xfail *-*-* } } }
+   { dg-final { scan-assembler-times {(?n)^// BEGIN FUNCTION DEF: f$} 1 } }
    { dg-final { scan-assembler-times {(?n)^\.alias f,__f;$} 1 } } */
 
 /* { dg-final { scan-assembler-times {(?n)\tcall __f;$} 0 } }
diff --git a/gcc/testsuite/gcc.target/nvptx/alias-to-alias-1.c b/gcc/testsuite/gcc.target/nvptx/alias-to-alias-1.c
index ebd62e11964..7bce7a358c7 100644
--- a/gcc/testsuite/gcc.target/nvptx/alias-to-alias-1.c
+++ b/gcc/testsuite/gcc.target/nvptx/alias-to-alias-1.c
@@ -24,14 +24,14 @@  main (void)
    { dg-final { scan-assembler-times {(?n)^// BEGIN GLOBAL FUNCTION DEF: foo$} 1 } }
    { dg-final { scan-assembler-times {(?n)^\.visible \.func foo$} 1 } } */
 
-/* { dg-final { scan-assembler-times {(?n)^// BEGIN GLOBAL FUNCTION DECL: bar$} 1 { xfail *-*-* } } }
+/* { dg-final { scan-assembler-times {(?n)^// BEGIN GLOBAL FUNCTION DECL: bar$} 1 } }
    { dg-final { scan-assembler-times {(?n)^\.visible \.func bar;$} 1 } }
-   { dg-final { scan-assembler-times {(?n)^// BEGIN GLOBAL FUNCTION DEF: bar$} 1 { xfail *-*-* } } }
+   { dg-final { scan-assembler-times {(?n)^// BEGIN GLOBAL FUNCTION DEF: bar$} 1 } }
    { dg-final { scan-assembler-times {(?n)^\.alias bar,foo;$} 1 } } */
 
-/* { dg-final { scan-assembler-times {(?n)^// BEGIN GLOBAL FUNCTION DECL: baz$} 1 { xfail *-*-* } } }
+/* { dg-final { scan-assembler-times {(?n)^// BEGIN GLOBAL FUNCTION DECL: baz$} 1 } }
    { dg-final { scan-assembler-times {(?n)^\.visible \.func baz;$} 1 } }
-   { dg-final { scan-assembler-times {(?n)^// BEGIN GLOBAL FUNCTION DEF: baz$} 1 { xfail *-*-* } } }
+   { dg-final { scan-assembler-times {(?n)^// BEGIN GLOBAL FUNCTION DEF: baz$} 1 } }
    { dg-final { scan-assembler-times {(?n)^\.alias baz,bar;$} 1 } } */
 
 /* { dg-final { scan-assembler-times {(?n)\tcall foo;$} 0 } }
-- 
2.34.1