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sparc: Add errata workaround to membar patterns

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LEON now uses the standard V8 membar patterns that contains an ldstub
instruction. This instruction needs to be aligned properly when the
GR712RC errata workaround is enabled.

gcc/ChangeLog:

	* config/sparc/sparc.cc (atomic_insn_for_leon3_p): Treat membar_storeload as atomic
	* config/sparc/sync.md (membar_storeload): Turn into named insn
	and add GR712RC errata workaround.
	(membar_v8): Add GR712RC errata workaround.
This commit is contained in:
Daniel Cederman 2024-01-04 14:56:06 +01:00 committed by Daniel Hellstrom
parent 13db80cb88
commit af59861398
2 changed files with 19 additions and 5 deletions
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1
gcc/config/sparc/sparc.cc
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@ -1052,6 +1052,7 @@ atomic_insn_for_leon3_p (rtx_insn *insn)
{
switch (INSN_CODE (insn))
{
case CODE_FOR_membar_storeload:
case CODE_FOR_swapsi:
case CODE_FOR_ldstub:
case CODE_FOR_atomic_compare_and_swap_leon3_1:

23
gcc/config/sparc/sync.md
View File

@ -65,12 +65,19 @@
[(set_attr "type" "multi")])
;; For V8, LDSTUB has the effect of membar #StoreLoad.
(define_insn "*membar_storeload"
(define_insn "membar_storeload"
[(set (match_operand:BLK 0 "" "")
(unspec:BLK [(match_dup 0) (const_int 2)] UNSPEC_MEMBAR))]
"TARGET_V8"
"ldstub\t[%%sp-1], %%g0"
[(set_attr "type" "multi")])
{
if (sparc_fix_gr712rc)
return ".align\t16\n\tldstub\t[%%sp-1], %%g0";
else
return "ldstub\t[%%sp-1], %%g0";
}
[(set_attr "type" "multi")
(set (attr "length") (if_then_else (eq_attr "fix_gr712rc" "true")
(const_int 4) (const_int 1)))])
;; Put the two together, in combination with the fact that V8 implements PSO
;; as its weakest memory model, means a full barrier. Match all remaining
@ -80,9 +87,15 @@
(unspec:BLK [(match_dup 0) (match_operand:SI 1 "const_int_operand")]
UNSPEC_MEMBAR))]
"TARGET_V8"
"stbar\n\tldstub\t[%%sp-1], %%g0"
{
if (sparc_fix_gr712rc)
return "stbar\n.align\t16\n\tldstub\t[%%sp-1], %%g0";
else
return "stbar\n\tldstub\t[%%sp-1], %%g0";
}
[(set_attr "type" "multi")
(set_attr "length" "2")])
(set (attr "length") (if_then_else (eq_attr "fix_gr712rc" "true")
(const_int 5) (const_int 2)))])
;; For V9, we have the full membar instruction.
(define_insn "*membar"