[Openmp-commits] [openmp] [OpenMP][AIX]Define struct kmp_base_tas_lock with the order of two members swapped for big-endian (PR #79188)
Xing Xue via Openmp-commits
openmp-commits at lists.llvm.org
Tue Jan 23 10:21:35 PST 2024
https://github.com/xingxue-ibm created https://github.com/llvm/llvm-project/pull/79188
The direct lock data structure has bit `0` (the least significant bit) of the first 32-bit word set to `1` to indicate it is a direct lock. On the other hand, the first word (in 32-bit mode) or first two words (in 64-bit mode) of an indirect lock are the address of the entry allocated from the indirect lock table. The runtime checks bit `0` of the first 32-bit word to tell if this is a direct or an indirect lock. This works fine for 32-bit and 64-bit little-endian because its memory layout of a 64-bit address is (`low word`, `high word`). However, this causes problems for big-endian where the memory layout of a 64-bit address is (`high word`, `low word`). If an address of the indirect lock table entry is something like `0x110035300`, i.e., (`0x1`, `0x10035300`), it is treated as a direct lock. This patch defines `struct kmp_base_tas_lock` with the ordering of the two 32-bit members flipped for big-endian PPC64 so that when checking/setting tags in member `poll`, the second word (the low word) is used. This patch also changes places where `poll` is not already explicitly specified for checking/setting tags.
>From 52fa82c062786fd6dfd8b2c055ff59d8eb85bee0 Mon Sep 17 00:00:00 2001
From: Xing Xue <xingxue at outlook.com>
Date: Tue, 23 Jan 2024 09:53:18 -0500
Subject: [PATCH] Define struct kmp_base_tas_lock with the order of two members
swapped for big-endian.
---
openmp/runtime/src/kmp_csupport.cpp | 5 +++--
openmp/runtime/src/kmp_gsupport.cpp | 2 +-
openmp/runtime/src/kmp_lock.cpp | 6 +++---
openmp/runtime/src/kmp_lock.h | 17 +++++++++++++----
4 files changed, 20 insertions(+), 10 deletions(-)
diff --git a/openmp/runtime/src/kmp_csupport.cpp b/openmp/runtime/src/kmp_csupport.cpp
index 9eeaeb88fb9ec73..878e78b5c7ad2de 100644
--- a/openmp/runtime/src/kmp_csupport.cpp
+++ b/openmp/runtime/src/kmp_csupport.cpp
@@ -1533,8 +1533,9 @@ void __kmpc_critical_with_hint(ident_t *loc, kmp_int32 global_tid,
kmp_dyna_lockseq_t lockseq = __kmp_map_hint_to_lock(hint);
if (*lk == 0) {
if (KMP_IS_D_LOCK(lockseq)) {
- KMP_COMPARE_AND_STORE_ACQ32((volatile kmp_int32 *)crit, 0,
- KMP_GET_D_TAG(lockseq));
+ KMP_COMPARE_AND_STORE_ACQ32(
+ (volatile kmp_int32 *)&((kmp_base_tas_lock_t *)crit)->poll, 0,
+ KMP_GET_D_TAG(lockseq));
} else {
__kmp_init_indirect_csptr(crit, loc, global_tid, KMP_GET_I_TAG(lockseq));
}
diff --git a/openmp/runtime/src/kmp_gsupport.cpp b/openmp/runtime/src/kmp_gsupport.cpp
index 88189659a234163..4dc8a90f83b4eab 100644
--- a/openmp/runtime/src/kmp_gsupport.cpp
+++ b/openmp/runtime/src/kmp_gsupport.cpp
@@ -144,7 +144,7 @@ void KMP_EXPAND_NAME(KMP_API_NAME_GOMP_BARRIER)(void) {
// Mutual exclusion
-// The symbol that icc/ifort generates for unnamed for unnamed critical sections
+// The symbol that icc/ifort generates for unnamed critical sections
// - .gomp_critical_user_ - is defined using .comm in any objects reference it.
// We can't reference it directly here in C code, as the symbol contains a ".".
//
diff --git a/openmp/runtime/src/kmp_lock.cpp b/openmp/runtime/src/kmp_lock.cpp
index 85c54f4cdc7e965..0ad14f862bcb9b7 100644
--- a/openmp/runtime/src/kmp_lock.cpp
+++ b/openmp/runtime/src/kmp_lock.cpp
@@ -2689,7 +2689,7 @@ void __kmp_spin_backoff(kmp_backoff_t *boff) {
// lock word.
static void __kmp_init_direct_lock(kmp_dyna_lock_t *lck,
kmp_dyna_lockseq_t seq) {
- TCW_4(*lck, KMP_GET_D_TAG(seq));
+ TCW_4(((kmp_base_tas_lock_t *)lck)->poll, KMP_GET_D_TAG(seq));
KA_TRACE(
20,
("__kmp_init_direct_lock: initialized direct lock with type#%d\n", seq));
@@ -3180,8 +3180,8 @@ kmp_indirect_lock_t *__kmp_allocate_indirect_lock(void **user_lock,
lck->type = tag;
if (OMP_LOCK_T_SIZE < sizeof(void *)) {
- *((kmp_lock_index_t *)user_lock) = idx
- << 1; // indirect lock word must be even
+ *(kmp_lock_index_t *)&(((kmp_base_tas_lock_t *)user_lock)->poll) =
+ idx << 1; // indirect lock word must be even
} else {
*((kmp_indirect_lock_t **)user_lock) = lck;
}
diff --git a/openmp/runtime/src/kmp_lock.h b/openmp/runtime/src/kmp_lock.h
index f21179b4eb68a15..5dbb325e2e38315 100644
--- a/openmp/runtime/src/kmp_lock.h
+++ b/openmp/runtime/src/kmp_lock.h
@@ -50,7 +50,7 @@ typedef struct ident ident_t;
// recent versions), but we are bounded by the pointer-sized chunks that
// the Intel compiler allocates.
-#if KMP_OS_LINUX && defined(KMP_GOMP_COMPAT)
+#if (KMP_OS_LINUX || KMP_OS_AIX) && defined(KMP_GOMP_COMPAT)
#define OMP_LOCK_T_SIZE sizeof(int)
#define OMP_NEST_LOCK_T_SIZE sizeof(void *)
#else
@@ -120,8 +120,15 @@ extern void __kmp_validate_locks(void);
struct kmp_base_tas_lock {
// KMP_LOCK_FREE(tas) => unlocked; locked: (gtid+1) of owning thread
+#if __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__ && KMP_ARCH_PPC64
+ // Swap the high and low 32-bit words to be consistent with the layout of
+ // a 64-bit address in big-endian.
+ kmp_int32 depth_locked; // depth locked, for nested locks only
+ std::atomic<kmp_int32> poll;
+#else
std::atomic<kmp_int32> poll;
kmp_int32 depth_locked; // depth locked, for nested locks only
+#endif
};
typedef struct kmp_base_tas_lock kmp_base_tas_lock_t;
@@ -1138,11 +1145,13 @@ extern int (**__kmp_indirect_test)(kmp_user_lock_p, kmp_int32);
// Extracts direct lock tag from a user lock pointer
#define KMP_EXTRACT_D_TAG(l) \
- (*((kmp_dyna_lock_t *)(l)) & ((1 << KMP_LOCK_SHIFT) - 1) & \
- -(*((kmp_dyna_lock_t *)(l)) & 1))
+ ((kmp_dyna_lock_t)((kmp_base_tas_lock_t *)(l))->poll & \
+ ((1 << KMP_LOCK_SHIFT) - 1) & \
+ -((kmp_dyna_lock_t)((kmp_tas_lock_t *)(l))->lk.poll & 1))
// Extracts indirect lock index from a user lock pointer
-#define KMP_EXTRACT_I_INDEX(l) (*(kmp_lock_index_t *)(l) >> 1)
+#define KMP_EXTRACT_I_INDEX(l) \
+ ((kmp_lock_index_t)((kmp_base_tas_lock_t *)(l))->poll >> 1)
// Returns function pointer to the direct lock function with l (kmp_dyna_lock_t
// *) and op (operation type).
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