Do not zero-extend the input to the cas for subword operations;
instead, use the appropriate zero-extending compare insns.
Correct the predicates and constraints for immediate expected operand.
2020-04-16 Andre Vieira <andre.simoesdiasvie...@arm.com>
Backport from mainline.
2018-10-31 Richard Henderson <richard.hender...@linaro.org>
* config/aarch64/aarch64.c (aarch64_gen_compare_reg_maybe_ze): New.
(aarch64_split_compare_and_swap): Use it.
(aarch64_expand_compare_and_swap): Likewise. Remove convert_modes;
test oldval against the proper predicate.
* config/aarch64/atomics.md (atomic_compare_and_swap<ALLI>):
Use nonmemory_operand for expected.
(cas_short_expected_pred): New.
(aarch64_compare_and_swap<SHORT>): Use it; use "rn" not "rI" to match.
(aarch64_compare_and_swap<GPI>): Use "rn" not "rI" for expected.
* config/aarch64/predicates.md (aarch64_plushi_immediate): New.
(aarch64_plushi_operand): New.
diff --git a/gcc/config/aarch64/aarch64.c b/gcc/config/aarch64/aarch64.c
index
c83a9f7ae78d4ed3da6636fce4d1f57c27048756..b6a6e314153ecf4a7ae1b83cfb64e6192197edc5
100644
--- a/gcc/config/aarch64/aarch64.c
+++ b/gcc/config/aarch64/aarch64.c
@@ -1524,6 +1524,33 @@ aarch64_gen_compare_reg (RTX_CODE code, rtx x, rtx y)
return cc_reg;
}
+/* Similarly, but maybe zero-extend Y if Y_MODE < SImode. */
+
+static rtx
+aarch64_gen_compare_reg_maybe_ze (RTX_CODE code, rtx x, rtx y,
+ machine_mode y_mode)
+{
+ if (y_mode == E_QImode || y_mode == E_HImode)
+ {
+ if (CONST_INT_P (y))
+ y = GEN_INT (INTVAL (y) & GET_MODE_MASK (y_mode));
+ else
+ {
+ rtx t, cc_reg;
+ machine_mode cc_mode;
+
+ t = gen_rtx_ZERO_EXTEND (SImode, y);
+ t = gen_rtx_COMPARE (CC_SWPmode, t, x);
+ cc_mode = CC_SWPmode;
+ cc_reg = gen_rtx_REG (cc_mode, CC_REGNUM);
+ emit_set_insn (cc_reg, t);
+ return cc_reg;
+ }
+ }
+
+ return aarch64_gen_compare_reg (code, x, y);
+}
+
/* Build the SYMBOL_REF for __tls_get_addr. */
static GTY(()) rtx tls_get_addr_libfunc;
@@ -14167,20 +14194,11 @@ aarch64_emit_unlikely_jump (rtx insn)
void
aarch64_expand_compare_and_swap (rtx operands[])
{
- rtx bval, rval, mem, oldval, newval, is_weak, mod_s, mod_f, x;
- machine_mode mode, cmp_mode;
- typedef rtx (*gen_split_cas_fn) (rtx, rtx, rtx, rtx, rtx, rtx, rtx);
+ rtx bval, rval, mem, oldval, newval, is_weak, mod_s, mod_f, x, cc_reg;
+ machine_mode mode, r_mode;
typedef rtx (*gen_atomic_cas_fn) (rtx, rtx, rtx, rtx);
int idx;
- gen_split_cas_fn split_gen;
gen_atomic_cas_fn atomic_gen;
- const gen_split_cas_fn split_cas[] =
- {
- gen_aarch64_compare_and_swapqi,
- gen_aarch64_compare_and_swaphi,
- gen_aarch64_compare_and_swapsi,
- gen_aarch64_compare_and_swapdi
- };
const gen_atomic_cas_fn atomic_cas[] =
{
gen_aarch64_compare_and_swapqi_lse,
@@ -14198,36 +14216,19 @@ aarch64_expand_compare_and_swap (rtx operands[])
mod_s = operands[6];
mod_f = operands[7];
mode = GET_MODE (mem);
- cmp_mode = mode;
/* Normally the succ memory model must be stronger than fail, but in the
unlikely event of fail being ACQUIRE and succ being RELEASE we need to
promote succ to ACQ_REL so that we don't lose the acquire semantics. */
-
if (is_mm_acquire (memmodel_from_int (INTVAL (mod_f)))
&& is_mm_release (memmodel_from_int (INTVAL (mod_s))))
mod_s = GEN_INT (MEMMODEL_ACQ_REL);
- switch (mode)
+ r_mode = mode;
+ if (mode == QImode || mode == HImode)
{
- case E_QImode:
- case E_HImode:
- /* For short modes, we're going to perform the comparison in SImode,
- so do the zero-extension now. */
- cmp_mode = SImode;
- rval = gen_reg_rtx (SImode);
- oldval = convert_modes (SImode, mode, oldval, true);
- /* Fall through. */
-
- case E_SImode:
- case E_DImode:
- /* Force the value into a register if needed. */
- if (!aarch64_plus_operand (oldval, mode))
- oldval = force_reg (cmp_mode, oldval);
- break;
-
- default:
- gcc_unreachable ();
+ r_mode = SImode;
+ rval = gen_reg_rtx (r_mode);
}
switch (mode)
@@ -14245,27 +14246,49 @@ aarch64_expand_compare_and_swap (rtx operands[])
/* The CAS insn requires oldval and rval overlap, but we need to
have a copy of oldval saved across the operation to tell if
the operation is successful. */
- if (mode == QImode || mode == HImode)
- rval = copy_to_mode_reg (SImode, gen_lowpart (SImode, oldval));
- else if (reg_overlap_mentioned_p (rval, oldval))
- rval = copy_to_mode_reg (mode, oldval);
+ if (reg_overlap_mentioned_p (rval, oldval))
+ rval = copy_to_mode_reg (r_mode, oldval);
else
- emit_move_insn (rval, oldval);
+ emit_move_insn (rval, gen_lowpart (r_mode, oldval));
+
emit_insn (atomic_gen (rval, mem, newval, mod_s));
- aarch64_gen_compare_reg (EQ, rval, oldval);
+
+ cc_reg = aarch64_gen_compare_reg_maybe_ze (NE, rval, oldval, mode);
}
else
{
- split_gen = split_cas[idx];
- emit_insn (split_gen (rval, mem, oldval, newval, is_weak, mod_s, mod_f));
+ /* The oldval predicate varies by mode. Test it and force to reg. */
+ insn_code code;
+ switch (mode)
+ {
+ case E_QImode:
+ code = CODE_FOR_aarch64_compare_and_swapqi;
+ break;
+ case E_HImode:
+ code = CODE_FOR_aarch64_compare_and_swaphi;
+ break;
+ case E_SImode:
+ code = CODE_FOR_aarch64_compare_and_swapsi;
+ break;
+ case E_DImode:
+ code = CODE_FOR_aarch64_compare_and_swapdi;
+ break;
+ default:
+ gcc_unreachable ();
+ }
+ if (!insn_data[code].operand[2].predicate (oldval, mode))
+ oldval = force_reg (mode, oldval);
+
+ emit_insn (GEN_FCN (code) (rval, mem, oldval, newval,
+ is_weak, mod_s, mod_f));
+ cc_reg = gen_rtx_REG (CCmode, CC_REGNUM);
}
- if (mode == QImode || mode == HImode)
+ if (r_mode != mode)
rval = gen_lowpart (mode, rval);
emit_move_insn (operands[1], rval);
- x = gen_rtx_REG (CCmode, CC_REGNUM);
- x = gen_rtx_EQ (SImode, x, const0_rtx);
+ x = gen_rtx_EQ (SImode, cc_reg, const0_rtx);
emit_insn (gen_rtx_SET (bval, x));
}
@@ -14374,10 +14397,10 @@ aarch64_split_compare_and_swap (rtx operands[])
}
else
{
- cond = aarch64_gen_compare_reg (NE, rval, oldval);
+ cond = aarch64_gen_compare_reg_maybe_ze (NE, rval, oldval, mode);
x = gen_rtx_NE (VOIDmode, cond, const0_rtx);
x = gen_rtx_IF_THEN_ELSE (VOIDmode, x,
- gen_rtx_LABEL_REF (Pmode, label2), pc_rtx);
+ gen_rtx_LABEL_REF (Pmode, label2), pc_rtx);
aarch64_emit_unlikely_jump (gen_rtx_SET (pc_rtx, x));
}
diff --git a/gcc/config/aarch64/atomics.md b/gcc/config/aarch64/atomics.md
index
be970d105ffbe218afb044bef900494454dd8d37..b0e84b8addd809598b3e358a265b86582ce96462
100644
--- a/gcc/config/aarch64/atomics.md
+++ b/gcc/config/aarch64/atomics.md
@@ -24,8 +24,8 @@
[(match_operand:SI 0 "register_operand" "") ;; bool out
(match_operand:ALLI 1 "register_operand" "") ;; val
out
(match_operand:ALLI 2 "aarch64_sync_memory_operand" "") ;; memory
- (match_operand:ALLI 3 "general_operand" "") ;; expected
- (match_operand:ALLI 4 "aarch64_reg_or_zero" "") ;;
desired
+ (match_operand:ALLI 3 "nonmemory_operand" "") ;; expected
+ (match_operand:ALLI 4 "aarch64_reg_or_zero" "") ;; desired
(match_operand:SI 5 "const_int_operand") ;; is_weak
(match_operand:SI 6 "const_int_operand") ;; mod_s
(match_operand:SI 7 "const_int_operand")] ;; mod_f
@@ -36,19 +36,22 @@
}
)
+(define_mode_attr cas_short_expected_pred
+ [(QI "aarch64_reg_or_imm") (HI "aarch64_plushi_operand")])
+
(define_insn_and_split "aarch64_compare_and_swap<mode>"
[(set (reg:CC CC_REGNUM) ;; bool out
(unspec_volatile:CC [(const_int 0)] UNSPECV_ATOMIC_CMPSW))
- (set (match_operand:SI 0 "register_operand" "=&r") ;; val out
+ (set (match_operand:SI 0 "register_operand" "=&r") ;; val out
(zero_extend:SI
(match_operand:SHORT 1 "aarch64_sync_memory_operand" "+Q"))) ;; memory
(set (match_dup 1)
(unspec_volatile:SHORT
- [(match_operand:SI 2 "aarch64_plus_operand" "rI") ;; expected
+ [(match_operand:SHORT 2 "<cas_short_expected_pred>" "rn") ;;
expected
(match_operand:SHORT 3 "aarch64_reg_or_zero" "rZ") ;; desired
- (match_operand:SI 4 "const_int_operand") ;; is_weak
- (match_operand:SI 5 "const_int_operand") ;; mod_s
- (match_operand:SI 6 "const_int_operand")] ;; mod_f
+ (match_operand:SI 4 "const_int_operand") ;;
is_weak
+ (match_operand:SI 5 "const_int_operand") ;; mod_s
+ (match_operand:SI 6 "const_int_operand")] ;; mod_f
UNSPECV_ATOMIC_CMPSW))
(clobber (match_scratch:SI 7 "=&r"))]
""
@@ -68,7 +71,7 @@
(match_operand:GPI 1 "aarch64_sync_memory_operand" "+Q")) ;; memory
(set (match_dup 1)
(unspec_volatile:GPI
- [(match_operand:GPI 2 "aarch64_plus_operand" "rI") ;; expect
+ [(match_operand:GPI 2 "aarch64_plus_operand" "rn") ;; expect
(match_operand:GPI 3 "aarch64_reg_or_zero" "rZ") ;;
desired
(match_operand:SI 4 "const_int_operand") ;;
is_weak
(match_operand:SI 5 "const_int_operand") ;; mod_s
diff --git a/gcc/config/aarch64/predicates.md b/gcc/config/aarch64/predicates.md
index
5d41d4350402b2a9e5941f160c6ab6f933bfff90..7b0565a00b14f17b856c4d2c89335300dfa53e4e
100644
--- a/gcc/config/aarch64/predicates.md
+++ b/gcc/config/aarch64/predicates.md
@@ -110,6 +110,18 @@
(ior (match_operand 0 "register_operand")
(match_operand 0 "aarch64_plus_immediate")))
+(define_predicate "aarch64_plushi_immediate"
+ (match_code "const_int")
+{
+ HOST_WIDE_INT val = INTVAL (op);
+ /* The HImode value must be zero-extendable to an SImode plus_operand. */
+ return ((val & 0xfff) == val || sext_hwi (val & 0xf000, 16) == val);
+})
+
+(define_predicate "aarch64_plushi_operand"
+ (ior (match_operand 0 "register_operand")
+ (match_operand 0 "aarch64_plushi_immediate")))
+
(define_predicate "aarch64_pluslong_immediate"
(and (match_code "const_int")
(match_test "(INTVAL (op) < 0xffffff && INTVAL (op) > -0xffffff)")))
