https://gcc.gnu.org/g:d8403076bc4a5bdeb36fe0c5a3b6a6c71f3cfa84
commit d8403076bc4a5bdeb36fe0c5a3b6a6c71f3cfa84
Author: Thomas Schwinge <tschwi...@baylibre.com>
Date: Fri Dec 13 15:09:49 2024 +0100
nvptx: Handle '__builtin_stack_save()' in a well-behaved way for PTX
"native" stacks [PR65181]
PR target/65181
gcc/
* config/nvptx/nvptx.md [!TARGET_SOFT_STACK] (save_stack_block):
'define_expand'.
gcc/testsuite/
* gcc.target/nvptx/__builtin_stack_save___builtin_stack_restore-1.c:
Adjust.
Diff:
---
gcc/ChangeLog.omp | 4 ++++
gcc/config/nvptx/nvptx.md | 17 ++++++++++++++++-
gcc/testsuite/ChangeLog.omp | 4 ++++
.../__builtin_stack_save___builtin_stack_restore-1.c | 17 ++++++-----------
4 files changed, 30 insertions(+), 12 deletions(-)
diff --git a/gcc/ChangeLog.omp b/gcc/ChangeLog.omp
index ce600d235f66..95c0ca220ec8 100644
--- a/gcc/ChangeLog.omp
+++ b/gcc/ChangeLog.omp
@@ -1,5 +1,9 @@
2024-12-18 Thomas Schwinge <tschwi...@baylibre.com>
+ PR target/65181
+ * config/nvptx/nvptx.md [!TARGET_SOFT_STACK] (save_stack_block):
+ 'define_expand'.
+
Backported from trunk:
2024-08-09 Andrew Stubbs <a...@baylibre.com>
diff --git a/gcc/config/nvptx/nvptx.md b/gcc/config/nvptx/nvptx.md
index 18033bef699d..816d09f35102 100644
--- a/gcc/config/nvptx/nvptx.md
+++ b/gcc/config/nvptx/nvptx.md
@@ -1708,12 +1708,27 @@
return nvptx_output_set_softstack (REGNO (operands[0]));
})
+(define_expand "save_stack_block"
+ [(match_operand 0 "register_operand" "")
+ (match_operand 1 "register_operand" "")]
+ "!TARGET_SOFT_STACK"
+{
+ /* The concept of a '%stack' pointer doesn't apply to PTX like this.
+ However, GCC occasionally synthesize '__builtin_stack_save ()',
+ '__builtin_stack_restore ()', and isn't able to optimize them all away.
+ Just submit a dummy -- user code shouldn't be able to observe this. */
+ emit_move_insn (operands[0], GEN_INT (0xdeadbeef));
+ DONE;
+})
+
(define_expand "restore_stack_block"
[(match_operand 0 "register_operand" "")
(match_operand 1 "register_operand" "")]
""
{
- if (TARGET_SOFT_STACK)
+ if (!TARGET_SOFT_STACK)
+ ; /* See 'save_stack_block'. */
+ else
{
emit_move_insn (operands[0], operands[1]);
emit_insn (gen_set_softstack (Pmode, operands[0]));
diff --git a/gcc/testsuite/ChangeLog.omp b/gcc/testsuite/ChangeLog.omp
index 76c302c02430..0f933749b622 100644
--- a/gcc/testsuite/ChangeLog.omp
+++ b/gcc/testsuite/ChangeLog.omp
@@ -1,5 +1,9 @@
2024-12-18 Thomas Schwinge <tschwi...@baylibre.com>
+ PR target/65181
+ * gcc.target/nvptx/__builtin_stack_save___builtin_stack_restore-1.c:
+ Adjust.
+
PR target/65181
* gcc.target/nvptx/__builtin_stack_save___builtin_stack_restore-1.c:
Add.
diff --git
a/gcc/testsuite/gcc.target/nvptx/__builtin_stack_save___builtin_stack_restore-1.c
b/gcc/testsuite/gcc.target/nvptx/__builtin_stack_save___builtin_stack_restore-1.c
index 294014dae1db..35a879fd5973 100644
---
a/gcc/testsuite/gcc.target/nvptx/__builtin_stack_save___builtin_stack_restore-1.c
+++
b/gcc/testsuite/gcc.target/nvptx/__builtin_stack_save___builtin_stack_restore-1.c
@@ -1,7 +1,6 @@
/* Document what we do for '__builtin_stack_save()',
'__builtin_stack_restore()'. */
-/* { dg-do compile }
- TODO We can't 'assemble' this -- it's invalid PTX code. */
+/* { dg-do assemble } */
/* { dg-options {-O3 -mno-soft-stack} } */
/* { dg-additional-options -save-temps } */
/* { dg-final { check-function-bodies {** } {} } } */
@@ -10,8 +9,10 @@ void *p;
void f(void)
{
+ // 0xdeadbeef
p = __builtin_stack_save();
asm volatile ("" : : : "memory");
+ // no-op
__builtin_stack_restore(p);
asm volatile ("" : : : "memory");
}
@@ -19,14 +20,8 @@ void f(void)
** f:
** \.visible \.func f
** {
-** st\.global\.u64 \[p\], %stack;
+** \.reg\.u64 (%r[0-9]+);
+** mov\.u64 \1, 3735928559;
+** st\.global\.u64 \[p\], \1;
** ret;
*/
-
-/* The concept of a '%stack' pointer doesn't apply like this for
- '-mno-soft-stack': PTX "native" stacks (TODO).
-
- { dg-final { scan-assembler-not {%stack} { xfail *-*-* } } } */
-
-/* As these are an internal-use built-in function, we don't bother with
- emitting proper error diagnostics. */
