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* [gcc r12-6125] Improve atomic store implementation on hppa-linux.
@ 2021-12-27 17:56 John David Anglin
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From: John David Anglin @ 2021-12-27 17:56 UTC (permalink / raw)
To: gcc-cvs
https://gcc.gnu.org/g:ea8b5640551ee7cbecf5c3ce30f0268963de3039
commit r12-6125-gea8b5640551ee7cbecf5c3ce30f0268963de3039
Author: John David Anglin <danglin@gcc.gnu.org>
Date: Mon Dec 27 17:56:19 2021 +0000
Improve atomic store implementation on hppa-linux.
2021-12-27 John David Anglin <danglin@gcc.gnu.org>
gcc/ChangeLog:
* config/pa/pa-protos.h: Delete
pa_maybe_emit_compare_and_swap_exchange_loop() declaration.
* config/pa/pa.c (pa_expand_compare_and_swap_loop): Delete.
(pa_maybe_emit_compare_and_swap_exchange_loop): Delete.
* config/pa/pa.md (atomic_storeq): Use __sync_lock_test_and_set
instead of pa_maybe_emit_compare_and_swap_exchange_loop.
(atomic_storehi, atomic_storesi, atomic_storedi): Likewise.
Diff:
---
gcc/config/pa/pa-protos.h | 1 -
gcc/config/pa/pa.c | 76 -----------------------------------------------
gcc/config/pa/pa.md | 40 +++++++++++++++----------
3 files changed, 24 insertions(+), 93 deletions(-)
diff --git a/gcc/config/pa/pa-protos.h b/gcc/config/pa/pa-protos.h
index 5bf6fef4968..69377db45c5 100644
--- a/gcc/config/pa/pa-protos.h
+++ b/gcc/config/pa/pa-protos.h
@@ -73,7 +73,6 @@ extern rtx pa_return_addr_rtx (int, rtx);
extern int pa_insn_refs_are_delayed (rtx_insn *);
extern rtx pa_get_deferred_plabel (rtx);
-extern rtx pa_maybe_emit_compare_and_swap_exchange_loop (rtx, rtx, rtx);
#endif /* RTX_CODE */
extern int pa_and_mask_p (unsigned HOST_WIDE_INT);
diff --git a/gcc/config/pa/pa.c b/gcc/config/pa/pa.c
index 2b10ef34061..895978aea1c 100644
--- a/gcc/config/pa/pa.c
+++ b/gcc/config/pa/pa.c
@@ -11023,82 +11023,6 @@ pa_output_addr_diff_vec (rtx lab, rtx body)
fputs ("\t.end_brtab\n", asm_out_file);
}
-/* This is a helper function for the other atomic operations. This function
- emits a loop that contains SEQ that iterates until a compare-and-swap
- operation at the end succeeds. MEM is the memory to be modified. SEQ is
- a set of instructions that takes a value from OLD_REG as an input and
- produces a value in NEW_REG as an output. Before SEQ, OLD_REG will be
- set to the current contents of MEM. After SEQ, a compare-and-swap will
- attempt to update MEM with NEW_REG. The function returns true when the
- loop was generated successfully. */
-
-static bool
-pa_expand_compare_and_swap_loop (rtx mem, rtx old_reg, rtx new_reg, rtx seq)
-{
- machine_mode mode = GET_MODE (mem);
- rtx_code_label *label;
- rtx cmp_reg, success, oldval;
-
- /* The loop we want to generate looks like
-
- cmp_reg = mem;
- label:
- old_reg = cmp_reg;
- seq;
- (success, cmp_reg) = compare-and-swap(mem, old_reg, new_reg)
- if (success)
- goto label;
-
- Note that we only do the plain load from memory once. Subsequent
- iterations use the value loaded by the compare-and-swap pattern. */
-
- label = gen_label_rtx ();
- cmp_reg = gen_reg_rtx (mode);
-
- emit_move_insn (cmp_reg, mem);
- emit_label (label);
- emit_move_insn (old_reg, cmp_reg);
- if (seq)
- emit_insn (seq);
-
- success = NULL_RTX;
- oldval = cmp_reg;
- if (!expand_atomic_compare_and_swap (&success, &oldval, mem, old_reg,
- new_reg, false, MEMMODEL_SYNC_SEQ_CST,
- MEMMODEL_RELAXED))
- return false;
-
- if (oldval != cmp_reg)
- emit_move_insn (cmp_reg, oldval);
-
- /* Mark this jump predicted not taken. */
- emit_cmp_and_jump_insns (success, const0_rtx, EQ, const0_rtx,
- GET_MODE (success), 1, label,
- profile_probability::guessed_never ());
- return true;
-}
-
-/* This function tries to implement an atomic exchange operation using a
- compare_and_swap loop. VAL is written to *MEM. The previous contents of
- *MEM are returned, using TARGET if possible. No memory model is required
- since a compare_and_swap loop is seq-cst. */
-
-rtx
-pa_maybe_emit_compare_and_swap_exchange_loop (rtx target, rtx mem, rtx val)
-{
- machine_mode mode = GET_MODE (mem);
-
- if (can_compare_and_swap_p (mode, true))
- {
- if (!target || !register_operand (target, mode))
- target = gen_reg_rtx (mode);
- if (pa_expand_compare_and_swap_loop (mem, target, val, NULL_RTX))
- return target;
- }
-
- return NULL_RTX;
-}
-
/* Implement TARGET_CALLEE_COPIES. The callee is responsible for copying
arguments passed by hidden reference in the 32-bit HP runtime. Users
can override this behavior for better compatibility with openmp at the
diff --git a/gcc/config/pa/pa.md b/gcc/config/pa/pa.md
index f124c301b7a..af5449a9ea3 100644
--- a/gcc/config/pa/pa.md
+++ b/gcc/config/pa/pa.md
@@ -10366,10 +10366,12 @@ add,l %2,%3,%3\;bv,n %%r0(%3)"
{
if (TARGET_SYNC_LIBCALL)
{
- rtx mem = operands[0];
- rtx val = operands[1];
- if (pa_maybe_emit_compare_and_swap_exchange_loop (NULL_RTX, mem, val))
- DONE;
+ rtx libfunc = init_one_libfunc ("__sync_lock_test_and_set_1");
+
+ emit_library_call (libfunc, LCT_NORMAL, VOIDmode,
+ XEXP (operands[0], 0), Pmode,
+ operands[1], QImode);
+ DONE;
}
FAIL;
})
@@ -10384,10 +10386,12 @@ add,l %2,%3,%3\;bv,n %%r0(%3)"
{
if (TARGET_SYNC_LIBCALL)
{
- rtx mem = operands[0];
- rtx val = operands[1];
- if (pa_maybe_emit_compare_and_swap_exchange_loop (NULL_RTX, mem, val))
- DONE;
+ rtx libfunc = init_one_libfunc ("__sync_lock_test_and_set_2");
+
+ emit_library_call (libfunc, LCT_NORMAL, VOIDmode,
+ XEXP (operands[0], 0), Pmode,
+ operands[1], HImode);
+ DONE;
}
FAIL;
})
@@ -10402,10 +10406,12 @@ add,l %2,%3,%3\;bv,n %%r0(%3)"
{
if (TARGET_SYNC_LIBCALL)
{
- rtx mem = operands[0];
- rtx val = operands[1];
- if (pa_maybe_emit_compare_and_swap_exchange_loop (NULL_RTX, mem, val))
- DONE;
+ rtx libfunc = init_one_libfunc ("__sync_lock_test_and_set_4");
+
+ emit_library_call (libfunc, LCT_NORMAL, VOIDmode,
+ XEXP (operands[0], 0), Pmode,
+ operands[1], SImode);
+ DONE;
}
FAIL;
})
@@ -10453,10 +10459,12 @@ add,l %2,%3,%3\;bv,n %%r0(%3)"
if (TARGET_SYNC_LIBCALL)
{
- rtx mem = operands[0];
- rtx val = operands[1];
- if (pa_maybe_emit_compare_and_swap_exchange_loop (NULL_RTX, mem, val))
- DONE;
+ rtx libfunc = init_one_libfunc ("__sync_lock_test_and_set_8");
+
+ emit_library_call (libfunc, LCT_NORMAL, VOIDmode,
+ XEXP (operands[0], 0), Pmode,
+ operands[1], DImode);
+ DONE;
}
if (TARGET_64BIT || TARGET_SOFT_FLOAT)
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