[gcc r13-3541] OpenACC: Don't gang-privatize artificial variables [PR90115]
Thomas Schwinge
tschwinge@gcc.gnu.org
Fri Oct 28 08:25:21 GMT 2022
https://gcc.gnu.org/g:11e811d8e2f63667f60f73731bb934273f5882b8
commit r13-3541-g11e811d8e2f63667f60f73731bb934273f5882b8
Author: Julian Brown <julian@codesourcery.com>
Date: Wed Oct 12 20:44:57 2022 +0000
OpenACC: Don't gang-privatize artificial variables [PR90115]
This patch prevents compiler-generated artificial variables from being
treated as privatization candidates for OpenACC.
The rationale is that e.g. "gang-private" variables actually must be
shared by each worker and vector spawned within a particular gang, but
that sharing is not necessary for any compiler-generated variable (at
least at present, but no such need is anticipated either). Variables on
the stack (and machine registers) are already private per-"thread"
(gang, worker and/or vector), and that's fine for artificial variables.
We're restricting this to blocks, as we still need to understand what it
means for a 'DECL_ARTIFICIAL' to appear in a 'private' clause.
Several tests need their scan output patterns adjusted to compensate.
2022-10-14 Julian Brown <julian@codesourcery.com>
PR middle-end/90115
gcc/
* omp-low.cc (oacc_privatization_candidate_p): Artificial vars are not
privatization candidates.
libgomp/
* testsuite/libgomp.oacc-fortran/declare-1.f90: Adjust scan output.
* testsuite/libgomp.oacc-fortran/host_data-5.F90: Likewise.
* testsuite/libgomp.oacc-fortran/if-1.f90: Likewise.
* testsuite/libgomp.oacc-fortran/print-1.f90: Likewise.
* testsuite/libgomp.oacc-fortran/privatized-ref-2.f90: Likewise.
Co-authored-by: Thomas Schwinge <thomas@codesourcery.com>
Diff:
---
gcc/omp-low.cc | 22 ++++++++++++++++++++
.../testsuite/libgomp.oacc-fortran/declare-1.f90 | 2 +-
.../testsuite/libgomp.oacc-fortran/host_data-5.F90 | 24 +++++++++++-----------
libgomp/testsuite/libgomp.oacc-fortran/if-1.f90 | 12 +++++------
libgomp/testsuite/libgomp.oacc-fortran/print-1.f90 | 13 +-----------
.../libgomp.oacc-fortran/privatized-ref-2.f90 | 8 ++------
6 files changed, 44 insertions(+), 37 deletions(-)
diff --git a/gcc/omp-low.cc b/gcc/omp-low.cc
index a8809739001..82a93d00f67 100644
--- a/gcc/omp-low.cc
+++ b/gcc/omp-low.cc
@@ -10710,6 +10710,28 @@ oacc_privatization_candidate_p (const location_t loc, const tree c,
}
}
+ /* If an artificial variable has been added to a bind, e.g.
+ a compiler-generated temporary structure used by the Fortran front-end, do
+ not consider it as a privatization candidate. Note that variables on
+ the stack are private per-thread by default: making them "gang-private"
+ for OpenACC actually means to share a single instance of a variable
+ amongst all workers and threads spawned within each gang.
+ At present, no compiler-generated artificial variables require such
+ sharing semantics, so this is safe. */
+
+ if (res && block && DECL_ARTIFICIAL (decl))
+ {
+ res = false;
+
+ if (dump_enabled_p ())
+ {
+ oacc_privatization_begin_diagnose_var (l_dump_flags, loc, c, decl);
+ dump_printf (l_dump_flags,
+ "isn%'t candidate for adjusting OpenACC privatization "
+ "level: %s\n", "artificial");
+ }
+ }
+
if (res)
{
if (dump_enabled_p ())
diff --git a/libgomp/testsuite/libgomp.oacc-fortran/declare-1.f90 b/libgomp/testsuite/libgomp.oacc-fortran/declare-1.f90
index 51776a1d260..89bd4a2d094 100644
--- a/libgomp/testsuite/libgomp.oacc-fortran/declare-1.f90
+++ b/libgomp/testsuite/libgomp.oacc-fortran/declare-1.f90
@@ -215,7 +215,7 @@ program main
! { dg-note {variable 'C\.[0-9]+' declared in block potentially has improper OpenACC privatization level: 'const_decl'} "TODO" { target *-*-* } .-1 }
! { dg-note {variable 'D\.[0-9]+' declared in block isn't candidate for adjusting OpenACC privatization level: not addressable} "" { target *-*-* } .-2 }
! { dg-note {variable 'S\.[0-9]+' declared in block isn't candidate for adjusting OpenACC privatization level: not addressable} "" { target *-*-* } .-3 }
- ! { dg-note {variable 'desc\.[0-9]+' declared in block is candidate for adjusting OpenACC privatization level} "TODO" { target *-*-* } .-4 }
+ ! { dg-note {variable 'desc\.[0-9]+' declared in block isn't candidate for adjusting OpenACC privatization level: artificial} "" { target *-*-* } .-4 }
use vars
use openacc
implicit none
diff --git a/libgomp/testsuite/libgomp.oacc-fortran/host_data-5.F90 b/libgomp/testsuite/libgomp.oacc-fortran/host_data-5.F90
index 93e9ee09818..c3453a579ae 100644
--- a/libgomp/testsuite/libgomp.oacc-fortran/host_data-5.F90
+++ b/libgomp/testsuite/libgomp.oacc-fortran/host_data-5.F90
@@ -43,7 +43,7 @@ subroutine foo (p2, parr, host_p, host_parr, cond)
! { dg-note {variable 'D\.[0-9]+' declared in block isn't candidate for adjusting OpenACC privatization level: not addressable} "" { target { ! openacc_host_selected } } .-2 }
! { dg-note {variable 'p\.[0-9]+' declared in block isn't candidate for adjusting OpenACC privatization level: not addressable} "" { target *-*-* } .-3 }
! { dg-note {variable 'parr\.[0-9]+' declared in block isn't candidate for adjusting OpenACC privatization level: not addressable} "" { target *-*-* } .-4 }
- ! { dg-note {variable 'parm\.[0-9]+' declared in block is candidate for adjusting OpenACC privatization level} "TODO" { target { ! openacc_host_selected } } .-5 }
+ ! { dg-note {variable 'parm\.[0-9]+' declared in block isn't candidate for adjusting OpenACC privatization level: artificial} "" { target { ! openacc_host_selected } } .-5 }
#if !ACC_MEM_SHARED
if (acc_is_present(p, c_sizeof(p))) stop 5
if (acc_is_present(parr, 1)) stop 6
@@ -54,8 +54,8 @@ subroutine foo (p2, parr, host_p, host_parr, cond)
! { dg-note {variable 'host_p\.[0-9]+' declared in block isn't candidate for adjusting OpenACC privatization level: not addressable} "" { target *-*-* } .-3 }
! { dg-note {variable 'parr\.[0-9]+' declared in block isn't candidate for adjusting OpenACC privatization level: not addressable} "" { target *-*-* } .-4 }
! { dg-note {variable 'host_parr\.[0-9]+' declared in block isn't candidate for adjusting OpenACC privatization level: not addressable} "" { target *-*-* } .-5 }
- ! { dg-note {variable 'D\.[0-9]+' declared in block is candidate for adjusting OpenACC privatization level} "TODO" { target *-*-* } .-6 }
- ! { dg-note {variable 'transfer\.[0-9]+' declared in block is candidate for adjusting OpenACC privatization level} "TODO" { target *-*-* } .-7 }
+ ! { dg-note {variable 'D\.[0-9]+' declared in block isn't candidate for adjusting OpenACC privatization level: artificial} "" { target *-*-* } .-6 }
+ ! { dg-note {variable 'transfer\.[0-9]+' declared in block isn't candidate for adjusting OpenACC privatization level: artificial} "" { target *-*-* } .-7 }
! { dg-note {variable 'parm\.[0-9]+' declared in block isn't candidate for adjusting OpenACC privatization level: not addressable} "" { target *-*-* } .-8 }
! not mapped yet, so it will be equal to the host pointer.
if (transfer(c_loc(p), host_p) /= host_p) stop 7
@@ -74,9 +74,9 @@ subroutine foo (p2, parr, host_p, host_parr, cond)
! { dg-note {variable 'host_p\.[0-9]+' declared in block isn't candidate for adjusting OpenACC privatization level: not addressable} "" { target *-*-* } .-5 }
! { dg-note {variable 'host_parr\.[0-9]+' declared in block isn't candidate for adjusting OpenACC privatization level: not addressable} "" { target *-*-* } .-6 }
! { dg-note {variable 'C\.[0-9]+' declared in block potentially has improper OpenACC privatization level: 'const_decl'} "TODO" { target *-*-* } .-7 }
- ! { dg-note {variable 'parm\.[0-9]+' declared in block is candidate for adjusting OpenACC privatization level} "TODO" { target *-*-* } .-8 }
- ! { dg-note {variable 'D\.[0-9]+' declared in block is candidate for adjusting OpenACC privatization level} "TODO" { target *-*-* } .-9 }
- ! { dg-note {variable 'transfer\.[0-9]+' declared in block is candidate for adjusting OpenACC privatization level} "TODO" { target *-*-* } .-10 }
+ ! { dg-note {variable 'parm\.[0-9]+' declared in block isn't candidate for adjusting OpenACC privatization level: artificial} "" { target *-*-* } .-8 }
+ ! { dg-note {variable 'D\.[0-9]+' declared in block isn't candidate for adjusting OpenACC privatization level: artificial} "" { target *-*-* } .-9 }
+ ! { dg-note {variable 'transfer\.[0-9]+' declared in block isn't candidate for adjusting OpenACC privatization level: artificial} "" { target *-*-* } .-10 }
! { dg-note {variable 'parm\.[0-9]+' declared in block isn't candidate for adjusting OpenACC privatization level: not addressable} "" { target *-*-* } .-11 }
if (.not. acc_is_present(p, c_sizeof(p))) stop 11
if (.not. acc_is_present(parr, 1)) stop 12
@@ -90,8 +90,8 @@ subroutine foo (p2, parr, host_p, host_parr, cond)
! { dg-note {variable 'host_p\.[0-9]+' declared in block isn't candidate for adjusting OpenACC privatization level: not addressable} "" { target *-*-* } .-3 }
! { dg-note {variable 'parr\.[0-9]+' declared in block isn't candidate for adjusting OpenACC privatization level: not addressable} "" { target *-*-* } .-4 }
! { dg-note {variable 'host_parr\.[0-9]+' declared in block isn't candidate for adjusting OpenACC privatization level: not addressable} "" { target *-*-* } .-5 }
- ! { dg-note {variable 'D\.[0-9]+' declared in block is candidate for adjusting OpenACC privatization level} "TODO" { target *-*-* } .-6 }
- ! { dg-note {variable 'transfer\.[0-9]+' declared in block is candidate for adjusting OpenACC privatization level} "TODO" { target *-*-* } .-7 }
+ ! { dg-note {variable 'D\.[0-9]+' declared in block isn't candidate for adjusting OpenACC privatization level: artificial} "" { target *-*-* } .-6 }
+ ! { dg-note {variable 'transfer\.[0-9]+' declared in block isn't candidate for adjusting OpenACC privatization level: artificial} "" { target *-*-* } .-7 }
! { dg-note {variable 'parm\.[0-9]+' declared in block isn't candidate for adjusting OpenACC privatization level: not addressable} "" { target *-*-* } .-8 }
#if ACC_MEM_SHARED
if (transfer(c_loc(p), host_p) /= host_p) stop 15
@@ -110,8 +110,8 @@ subroutine foo (p2, parr, host_p, host_parr, cond)
! { dg-note {variable 'parr\.[0-9]+' declared in block isn't candidate for adjusting OpenACC privatization level: not addressable} "" { target *-*-* } .-4 }
! { dg-note {variable 'host_parr\.[0-9]+' declared in block isn't candidate for adjusting OpenACC privatization level: not addressable} "" { target *-*-* } .-5 }
! { dg-note {variable 'parm\.[0-9]+' declared in block isn't candidate for adjusting OpenACC privatization level: not addressable} "" { target *-*-* } .-6 }
- ! { dg-note {variable 'D\.[0-9]+' declared in block is candidate for adjusting OpenACC privatization level} "TODO" { target *-*-* } .-7 }
- ! { dg-note {variable 'transfer\.[0-9]+' declared in block is candidate for adjusting OpenACC privatization level} "TODO" { target *-*-* } .-8 }
+ ! { dg-note {variable 'D\.[0-9]+' declared in block isn't candidate for adjusting OpenACC privatization level: artificial} "" { target *-*-* } .-7 }
+ ! { dg-note {variable 'transfer\.[0-9]+' declared in block isn't candidate for adjusting OpenACC privatization level: artificial} "" { target *-*-* } .-8 }
#if ACC_MEM_SHARED
if (transfer(c_loc(p), host_p) /= host_p) stop 19
if (transfer(c_loc(parr), host_parr) /= host_parr) stop 20
@@ -129,8 +129,8 @@ subroutine foo (p2, parr, host_p, host_parr, cond)
! { dg-note {variable 'parr\.[0-9]+' declared in block isn't candidate for adjusting OpenACC privatization level: not addressable} "" { target *-*-* } .-4 }
! { dg-note {variable 'host_parr\.[0-9]+' declared in block isn't candidate for adjusting OpenACC privatization level: not addressable} "" { target *-*-* } .-5 }
! { dg-note {variable 'parm\.[0-9]+' declared in block isn't candidate for adjusting OpenACC privatization level: not addressable} "" { target *-*-* } .-6 }
- ! { dg-note {variable 'D\.[0-9]+' declared in block is candidate for adjusting OpenACC privatization level} "TODO" { target *-*-* } .-7 }
- ! { dg-note {variable 'transfer\.[0-9]+' declared in block is candidate for adjusting OpenACC privatization level} "TODO" { target *-*-* } .-8 }
+ ! { dg-note {variable 'D\.[0-9]+' declared in block isn't candidate for adjusting OpenACC privatization level: artificial} "" { target *-*-* } .-7 }
+ ! { dg-note {variable 'transfer\.[0-9]+' declared in block isn't candidate for adjusting OpenACC privatization level: artificial} "" { target *-*-* } .-8 }
#if ACC_MEM_SHARED
if (transfer(c_loc(p), host_p) /= host_p) stop 23
if (transfer(c_loc(parr), host_parr) /= host_parr) stop 24
diff --git a/libgomp/testsuite/libgomp.oacc-fortran/if-1.f90 b/libgomp/testsuite/libgomp.oacc-fortran/if-1.f90
index c6d67647d4a..e0cfd912d0f 100644
--- a/libgomp/testsuite/libgomp.oacc-fortran/if-1.f90
+++ b/libgomp/testsuite/libgomp.oacc-fortran/if-1.f90
@@ -382,7 +382,7 @@ program main
b(:) = 1.0
!$acc data copyin (a(1:N)) copyout (b(1:N)) if (0 == 1)
- ! { dg-note {variable 'parm\.[0-9]+' declared in block is candidate for adjusting OpenACC privatization level} "" { target { ! openacc_host_selected } } .-1 }
+ ! { dg-note {variable 'parm\.[0-9]+' declared in block isn't candidate for adjusting OpenACC privatization level: artificial} "" { target { ! openacc_host_selected } } .-1 }
#if !ACC_MEM_SHARED
if (acc_is_present (a) .eqv. .TRUE.) STOP 21
@@ -396,7 +396,7 @@ program main
!$acc data copyin (a(1:N)) if (1 == 1)
! { dg-note {variable 'parm\.[0-9]+' declared in block isn't candidate for adjusting OpenACC privatization level: not addressable} "" { target *-*-* } .-1 }
- ! { dg-note {variable 'parm\.[0-9]+' declared in block is candidate for adjusting OpenACC privatization level} "" { target { ! openacc_host_selected } } .-2 }
+ ! { dg-note {variable 'parm\.[0-9]+' declared in block isn't candidate for adjusting OpenACC privatization level: artificial} "" { target { ! openacc_host_selected } } .-2 }
#if !ACC_MEM_SHARED
if (acc_is_present (a) .eqv. .FALSE.) STOP 23
@@ -404,7 +404,7 @@ program main
!$acc data copyout (b(1:N)) if (0 == 1)
! { dg-note {variable 'parm\.[0-9]+' declared in block isn't candidate for adjusting OpenACC privatization level: not addressable} "" { target *-*-* } .-1 }
- ! { dg-note {variable 'parm\.[0-9]+' declared in block is candidate for adjusting OpenACC privatization level} "" { target { ! openacc_host_selected } } .-2 }
+ ! { dg-note {variable 'parm\.[0-9]+' declared in block isn't candidate for adjusting OpenACC privatization level: artificial} "" { target { ! openacc_host_selected } } .-2 }
#if !ACC_MEM_SHARED
if (acc_is_present (b) .eqv. .TRUE.) STOP 24
#endif
@@ -877,7 +877,7 @@ program main
b(:) = 1.0
!$acc data copyin (a(1:N)) copyout (b(1:N)) if (0 == 1)
- ! { dg-note {variable 'parm\.[0-9]+' declared in block is candidate for adjusting OpenACC privatization level} "" { target { ! openacc_host_selected } } .-1 }
+ ! { dg-note {variable 'parm\.[0-9]+' declared in block isn't candidate for adjusting OpenACC privatization level: artificial} "" { target { ! openacc_host_selected } } .-1 }
#if !ACC_MEM_SHARED
if (acc_is_present (a) .eqv. .TRUE.) STOP 56
@@ -891,7 +891,7 @@ program main
!$acc data copyin (a(1:N)) if (1 == 1)
! { dg-note {variable 'parm\.[0-9]+' declared in block isn't candidate for adjusting OpenACC privatization level: not addressable} "" { target *-*-* } .-1 }
- ! { dg-note {variable 'parm\.[0-9]+' declared in block is candidate for adjusting OpenACC privatization level} "" { target { ! openacc_host_selected } } .-2 }
+ ! { dg-note {variable 'parm\.[0-9]+' declared in block isn't candidate for adjusting OpenACC privatization level: artificial} "" { target { ! openacc_host_selected } } .-2 }
#if !ACC_MEM_SHARED
if (acc_is_present (a) .eqv. .FALSE.) STOP 58
@@ -899,7 +899,7 @@ program main
!$acc data copyout (b(1:N)) if (0 == 1)
! { dg-note {variable 'parm\.[0-9]+' declared in block isn't candidate for adjusting OpenACC privatization level: not addressable} "" { target *-*-* } .-1 }
- ! { dg-note {variable 'parm\.[0-9]+' declared in block is candidate for adjusting OpenACC privatization level} "" { target { ! openacc_host_selected } } .-2 }
+ ! { dg-note {variable 'parm\.[0-9]+' declared in block isn't candidate for adjusting OpenACC privatization level: artificial} "" { target { ! openacc_host_selected } } .-2 }
#if !ACC_MEM_SHARED
if (acc_is_present (b) .eqv. .TRUE.) STOP 59
#endif
diff --git a/libgomp/testsuite/libgomp.oacc-fortran/print-1.f90 b/libgomp/testsuite/libgomp.oacc-fortran/print-1.f90
index 42a8538e1fb..d2f89d915f8 100644
--- a/libgomp/testsuite/libgomp.oacc-fortran/print-1.f90
+++ b/libgomp/testsuite/libgomp.oacc-fortran/print-1.f90
@@ -6,15 +6,6 @@
! Separate file 'print-1-nvptx.f90' for nvptx offloading.
! { dg-skip-if "separate file" { offload_target_nvptx } }
-! For GCN offloading compilation, when gang-privatizing 'dt_parm.N'
-! (see below), we run into an 'gang-private data-share memory exhausted'
-! error: the default '-mgang-private-size' is too small. Per
-! 'gcc/fortran/trans-io.cc'/'libgfortran/io/io.h', that one is
-! 'struct st_parameter_dt', which indeed is rather big. Instead of
-! working out its exact size (which may vary per GCC configuration),
-! raise '-mgang-private-size' to an arbitrary high value.
-! { dg-additional-options "-foffload-options=amdgcn-amdhsa=-mgang-private-size=13579" { target openacc_radeon_accel_selected } }
-
! { dg-additional-options "-fopt-info-note-omp" }
! { dg-additional-options "-foffload=-fopt-info-note-omp" }
@@ -36,9 +27,7 @@ program main
integer :: var = 42
!$acc parallel ! { dg-line l_compute[incr c_compute] }
- ! { dg-note {variable 'dt_parm\.[0-9]+' declared in block is candidate for adjusting OpenACC privatization level} {} { target *-*-* } l_compute$c_compute }
- ! { dg-note {variable 'dt_parm\.[0-9]+' ought to be adjusted for OpenACC privatization level: 'gang'} {} { target *-*-* } l_compute$c_compute }
- ! { dg-note {variable 'dt_parm\.[0-9]+' adjusted for OpenACC privatization level: 'gang'} {} { target { ! openacc_host_selected } } l_compute$c_compute }
+ ! { dg-note {variable 'dt_parm\.[0-9]+' declared in block isn't candidate for adjusting OpenACC privatization level: artificial} {} { target *-*-* } l_compute$c_compute }
write (0, '("The answer is ", I2)') var
!$acc end parallel
diff --git a/libgomp/testsuite/libgomp.oacc-fortran/privatized-ref-2.f90 b/libgomp/testsuite/libgomp.oacc-fortran/privatized-ref-2.f90
index b31f4066152..498ef70b63a 100644
--- a/libgomp/testsuite/libgomp.oacc-fortran/privatized-ref-2.f90
+++ b/libgomp/testsuite/libgomp.oacc-fortran/privatized-ref-2.f90
@@ -122,9 +122,7 @@ contains
! { dg-note {variable 'str' in 'private' clause is candidate for adjusting OpenACC privatization level} "" { target *-*-* } l_loop$c_loop }
! { dg-note {variable 'str' ought to be adjusted for OpenACC privatization level: 'gang'} "" { target *-*-* } l_loop$c_loop }
! { dg-note {variable 'str' adjusted for OpenACC privatization level: 'gang'} "" { target { ! { openacc_host_selected || { openacc_nvidia_accel_selected && __OPTIMIZE__ } } } } l_loop$c_loop }
- ! { dg-note {variable 'char\.[0-9]+' declared in block is candidate for adjusting OpenACC privatization level} "" { target *-*-* } l_loop$c_loop }
- ! { dg-note {variable 'char\.[0-9]+' ought to be adjusted for OpenACC privatization level: 'gang'} "" { target *-*-* } l_loop$c_loop }
- ! { dg-note {variable 'char\.[0-9]+' adjusted for OpenACC privatization level: 'gang'} "" { target { ! { openacc_host_selected || { openacc_nvidia_accel_selected && __OPTIMIZE__ } } } } l_loop$c_loop }
+ ! { dg-note {variable 'char\.[0-9]+' declared in block isn't candidate for adjusting OpenACC privatization level: artificial} "" { target *-*-* } l_loop$c_loop }
! { dg-message {sorry, unimplemented: target cannot support alloca} PR65181 { target openacc_nvidia_accel_selected } l_loop$c_loop }
do i = 1, 10
str(i:i) = achar(ichar('A') + i)
@@ -167,9 +165,7 @@ contains
! { dg-note {variable 'scalar' in 'private' clause is candidate for adjusting OpenACC privatization level} "" { target *-*-* } l_loop$c_loop }
! { dg-note {variable 'scalar' ought to be adjusted for OpenACC privatization level: 'gang'} "" { target *-*-* } l_loop$c_loop }
! { dg-note {variable 'scalar' adjusted for OpenACC privatization level: 'gang'} "" { target { ! { openacc_host_selected || { openacc_nvidia_accel_selected && __OPTIMIZE__ } } } } l_loop$c_loop }
- ! { dg-note {variable 'char\.[0-9]+' declared in block is candidate for adjusting OpenACC privatization level} "" { target *-*-* } l_loop$c_loop }
- ! { dg-note {variable 'char\.[0-9]+' ought to be adjusted for OpenACC privatization level: 'gang'} "" { target *-*-* } l_loop$c_loop }
- ! { dg-note {variable 'char\.[0-9]+' adjusted for OpenACC privatization level: 'gang'} "" { target { ! { openacc_host_selected || { openacc_nvidia_accel_selected && __OPTIMIZE__ } } } } l_loop$c_loop }
+ ! { dg-note {variable 'char\.[0-9]+' declared in block isn't candidate for adjusting OpenACC privatization level: artificial} "" { target *-*-* } l_loop$c_loop }
do i = 1, 15
scalar(i:i) = achar(ichar('A') + i)
end do
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