With later changes to RDFFR to use subregisters for HSSR cases,
forward prop begins to duplicate FFR reads as the cost penalties of
reading the FFR register is lost.
This change prevents that incorrect optimization.
Splits the sve_ffr sve_type instruction attibute into sve_ffr_write
and sve_ffr_read to avoid penalizing sve_ffr_read's.
gcc/ChangeLog:
* config/aarch64/aarch64-sve.md:
(aarch64_wrffr): Change sve_type attribute from sve_ffr to
sve_ffr_write.
(aarch64_rdffr): Change sve_type attribute from sve_ffr to
sve_ffr_read.
(aarch64_rdffr_z): Likewise.
(aarch64_rdffr_z_ptest): Likewise.
(aarch64_rdffr_ptest): Likewise.
(aarch64_rdffr_z_cc): Likewise.
(aarch64_rdffr_cc): Likewise.
* config/aarch64/aarch64.cc (aarch64_insn_cost): Add logic
to make sve_ffr_read's more expensive.
* config/aarch64/aarch64.md (sve_type): Replace sve_ffr with
sve_ffr_write and sve_ffr_read.
* config/aarch64/neoversev2.md (neoversev2_dispatch): Replace
sve_ffr with sve_ffr_read or sve_ffr_write.
* config/aarch64/olympus.md (olympus_dispatch): Likewise.
---
gcc/config/aarch64/aarch64-sve.md | 14 +++++++-------
gcc/config/aarch64/aarch64.cc | 16 +++++++++++++---
gcc/config/aarch64/aarch64.md | 2 +-
gcc/config/aarch64/neoversev2.md | 4 ++--
gcc/config/aarch64/olympus.md | 4 ++--
5 files changed, 25 insertions(+), 15 deletions(-)
diff --git a/gcc/config/aarch64/aarch64-sve.md
b/gcc/config/aarch64/aarch64-sve.md
index 4b6d466b824..e7fe0b87978 100644
--- a/gcc/config/aarch64/aarch64-sve.md
+++ b/gcc/config/aarch64/aarch64-sve.md
@@ -1141,7 +1141,7 @@ (define_insn "aarch64_wrffr"
[ Dm ] setffr
[ Upa ] wrffr\t%0.b
}
- [(set_attr "sve_type" "sve_ffr")]
+ [(set_attr "sve_type" "sve_ffr_write")]
)
;; [L2 in the block comment above about FFR handling]
@@ -1184,7 +1184,7 @@ (define_insn "aarch64_rdffr"
(reg:VNx16BI FFRT_REGNUM))]
"TARGET_SVE && TARGET_NON_STREAMING"
"rdffr\t%0.b"
- [(set_attr "sve_type" "sve_ffr")]
+ [(set_attr "sve_type" "sve_ffr_read")]
)
;; Likewise with zero predication.
@@ -1199,7 +1199,7 @@ (define_insn "aarch64_rdffr_z"
[ ?Upa , 0Upa; yes ] ^
[ Upa , Upa ; no ] ^
}
- [(set_attr "sve_type" "sve_ffr")]
+ [(set_attr "sve_type" "sve_ffr_read")]
)
;; Read the FFR to test for a fault, without using the predicate result.
@@ -1220,7 +1220,7 @@ (define_insn "*aarch64_rdffr_z_ptest"
[ ?Upa , 0Upa; yes ] ^
[ Upa , Upa ; no ] ^
}
- [(set_attr "sve_type" "sve_ffr")]
+ [(set_attr "sve_type" "sve_ffr_read")]
)
;; Same for unpredicated RDFFR when tested with a known PTRUE.
@@ -1239,7 +1239,7 @@ (define_insn "*aarch64_rdffr_ptest"
[ ?Upa , 0Upa; yes ] ^
[ Upa , Upa ; no ] ^
}
- [(set_attr "sve_type" "sve_ffr")]
+ [(set_attr "sve_type" "sve_ffr_read")]
)
;; Read the FFR with zero predication and test the result.
@@ -1263,7 +1263,7 @@ (define_insn "*aarch64_rdffr_z_cc"
[ ?Upa , 0Upa; yes ] ^
[ Upa , Upa ; no ] ^
}
- [(set_attr "sve_type" "sve_ffr")]
+ [(set_attr "sve_type" "sve_ffr_read")]
)
;; Same for unpredicated RDFFR when tested with a known PTRUE.
@@ -1283,7 +1283,7 @@ (define_insn "*aarch64_rdffr_cc"
[ ?Upa , 0Upa; yes ] ^
[ Upa , Upa ; no ] ^
}
- [(set_attr "sve_type" "sve_ffr")]
+ [(set_attr "sve_type" "sve_ffr_read")]
)
;; [R3 in the block comment above about FFR handling]
diff --git a/gcc/config/aarch64/aarch64.cc b/gcc/config/aarch64/aarch64.cc
index 00df040c8dc..51c72624bfe 100644
--- a/gcc/config/aarch64/aarch64.cc
+++ b/gcc/config/aarch64/aarch64.cc
@@ -17004,8 +17004,18 @@ aarch64_frame_allocation_cost (frame_cost_type,
static int
aarch64_insn_cost (rtx_insn *insn, bool speed)
{
+ int extra_cost = 0;
+
+ const sve_vec_cost *sve_costs = aarch64_tune_params.vec_costs->sve;
+
+ /* Reads and sets to FFR are expensive. Mark them as such to prevent
+ duplication. */
+ if (recog_memoized (insn) != -1
+ && get_attr_sve_type (insn) == SVE_TYPE_SVE_FFR_WRITE)
+ extra_cost = sve_costs->read_ffr_cost;
+
if (rtx set = single_set (insn))
- return set_rtx_cost (set, speed);
+ return set_rtx_cost (set, speed) + extra_cost;
/* If the instruction does multiple sets in parallel, use the cost
of the most expensive set. This copes with instructions that set
@@ -17020,10 +17030,10 @@ aarch64_insn_cost (rtx_insn *insn, bool speed)
if (GET_CODE (x) == SET)
max_cost = std::max (max_cost, set_rtx_cost (x, speed));
}
- return max_cost;
+ return max_cost + extra_cost;
}
- return pattern_cost (pat, speed);
+ return pattern_cost (pat, speed) + extra_cost;
}
/* Implement TARGET_INIT_BUILTINS. */
diff --git a/gcc/config/aarch64/aarch64.md b/gcc/config/aarch64/aarch64.md
index 302658c970d..932fec20f8c 100644
--- a/gcc/config/aarch64/aarch64.md
+++ b/gcc/config/aarch64/aarch64.md
@@ -700,7 +700,7 @@ (define_attr "sve_type"
sve_gatherload_32,sve_gatherload_64,\
sve_store_pred,sve_store_1reg,sve_store_2reg,sve_store_3reg,sve_store_4reg,\
sve_scatterstore_32,sve_scatterstore_64,\
- sve_ffr,\
+ sve_ffr_write, sve_ffr_read,\
sve_crypto_sha3"
(const_string "none"))
diff --git a/gcc/config/aarch64/neoversev2.md b/gcc/config/aarch64/neoversev2.md
index 8dc9b098d09..2cfa39a72fe 100644
--- a/gcc/config/aarch64/neoversev2.md
+++ b/gcc/config/aarch64/neoversev2.md
@@ -49,7 +49,7 @@ (define_attr "neoversev2_dispatch"
(ior
(eq_attr "type" "crc,f_cvti2f,mla,neon_from_gp,neon_from_gp_q,\
sdiv,smlal,udiv,umlal")
- (eq_attr "sve_type" "sve_ffr,sve_pred_logical"))
+ (eq_attr "sve_type" "sve_ffr_read,sve_ffr_write,sve_pred_logical"))
(const_string "m0")
(ior
(eq_attr "type"
@@ -189,4 +189,4 @@ (define_attr "neoversev2_dispatch"
(eq_attr "sve_type" "sve_scatterstore_32,sve_scatterstore_64,\
sve_store_1reg,sve_store_2reg,sve_store_3reg,sve_store_4reg"))
(const_string "l01_v")]
- (const_string "none")))
\ No newline at end of file
+ (const_string "none")))
diff --git a/gcc/config/aarch64/olympus.md b/gcc/config/aarch64/olympus.md
index 22b12016ffd..9c1390deef7 100644
--- a/gcc/config/aarch64/olympus.md
+++ b/gcc/config/aarch64/olympus.md
@@ -46,7 +46,7 @@ (define_attr "olympus_dispatch"
(eq_attr "sve_type" "sve_pred_cnt_ctrl,sve_pred_cnt_scalar,\
sve_pred_logical,sve_pred_misc"))
(const_string "m")
- (eq_attr "sve_type" "sve_ffr")
+ (eq_attr "sve_type" "sve_ffr_write,sve_ffr_read")
(const_string "m0")
(ior
(eq_attr "type" "f_loadd,f_loads,load_4,load_8,load_16,\
@@ -196,4 +196,4 @@ (define_attr "olympus_dispatch"
(eq_attr "sve_type" "sve_store_2reg,sve_store_3reg,sve_store_4reg,\
sve_scatterstore_32,sve_scatterstore_64"))
(const_string "sa_v_v0123")]
- (const_string "none")))
\ No newline at end of file
+ (const_string "none")))
--
2.43.0
