> -----Original Message----- > From: Tamar Christina <tamar.christ...@arm.com> > Sent: Wednesday, May 22, 2024 10:29 AM > To: Richard Sandiford <richard.sandif...@arm.com> > Cc: gcc-patches@gcc.gnu.org; nd <n...@arm.com>; Richard Earnshaw > <richard.earns...@arm.com>; Marcus Shawcroft > <marcus.shawcr...@arm.com>; ktkac...@gcc.gnu.org > Subject: RE: [PATCH 2/4]AArch64: add new tuning param and attribute for > enabling conditional early clobber > > > > > Sorry for the bike-shedding, but how about something like "avoid_pred_rmw"? > > (I'm open to other suggestions.) Just looking for something that describes > > either the architecture or the end result that we want to achieve. > > And preferable something fairly short :) > > > > avoid_* would be consistent with the existing "avoid_cross_loop_fma". > > > > > + > > > #undef AARCH64_EXTRA_TUNING_OPTION > > > diff --git a/gcc/config/aarch64/aarch64.h b/gcc/config/aarch64/aarch64.h > > > index > > > bbf11faaf4b4340956094a983f8b0dc2649b2d27..76a18dd511f40ebb58ed12d5 > > 6b46c74084ba7c3c 100644 > > > --- a/gcc/config/aarch64/aarch64.h > > > +++ b/gcc/config/aarch64/aarch64.h > > > @@ -495,6 +495,11 @@ constexpr auto AARCH64_FL_DEFAULT_ISA_MODE = > > AARCH64_FL_SM_OFF; > > > enabled through +gcs. */ > > > #define TARGET_GCS (AARCH64_ISA_GCS) > > > > > > +/* Prefer different predicate registers for the output of a predicated > > > operation > > over > > > + re-using an existing input predicate. */ > > > +#define TARGET_SVE_PRED_CLOBBER (TARGET_SVE \ > > > + && (aarch64_tune_params.extra_tuning_flags \ > > > + & > > AARCH64_EXTRA_TUNE_EARLY_CLOBBER_SVE_PRED_DEST)) > > > > > > /* Standard register usage. */ > > > > > > diff --git a/gcc/config/aarch64/aarch64.md b/gcc/config/aarch64/aarch64.md > > > index > > > dbde066f7478bec51a8703b017ea553aa98be309..1ecd1a2812969504bd5114a > > 53473b478c5ddba82 100644 > > > --- a/gcc/config/aarch64/aarch64.md > > > +++ b/gcc/config/aarch64/aarch64.md > > > @@ -445,6 +445,10 @@ (define_enum_attr "arch" "arches" (const_string > > "any")) > > > ;; target-independent code. > > > (define_attr "is_call" "no,yes" (const_string "no")) > > > > > > +;; Indicates whether we want to enable the pattern with an optional early > > > +;; clobber for SVE predicates. > > > +(define_attr "pred_clobber" "no,yes" (const_string "no")) > > > + > > > ;; [For compatibility with Arm in pipeline models] > > > ;; Attribute that specifies whether or not the instruction touches fp > > > ;; registers. > > > @@ -461,7 +465,8 @@ (define_attr "fp" "no,yes" > > > (define_attr "arch_enabled" "no,yes" > > > (if_then_else > > > (ior > > > - (eq_attr "arch" "any") > > > + (and (eq_attr "arch" "any") > > > + (eq_attr "pred_clobber" "no")) > > > > > > (and (eq_attr "arch" "rcpc8_4") > > > (match_test "AARCH64_ISA_RCPC8_4")) > > > @@ -488,7 +493,10 @@ (define_attr "arch_enabled" "no,yes" > > > (match_test "TARGET_SVE")) > > > > > > (and (eq_attr "arch" "sme") > > > - (match_test "TARGET_SME"))) > > > + (match_test "TARGET_SME")) > > > + > > > + (and (eq_attr "pred_clobber" "yes") > > > + (match_test "TARGET_SVE_PRED_CLOBBER"))) > > > > IMO it'd be bettero handle pred_clobber separately from arch, as a new > > top-level AND: > > > > (and > > (ior > > (eq_attr "pred_clobber" "no") > > (match_test "!TARGET_...")) > > (ior > > ...existing arch tests...)) > > >
Bootstrapped Regtested on aarch64-none-linux-gnu and no issues.
Ok for master?
Thanks,
Tamar
gcc/ChangeLog:
* config/aarch64/aarch64-tuning-flags.def
(AVOID_PRED_RMW): New.
* config/aarch64/aarch64.h (TARGET_SVE_PRED_CLOBBER): New.
* config/aarch64/aarch64.md (pred_clobber): New.
(arch_enabled): Use it.
-- inline copy of patch --
diff --git a/gcc/config/aarch64/aarch64-tuning-flags.def
b/gcc/config/aarch64/aarch64-tuning-flags.def
index
d5bcaebce770f0b217aac783063d39135f754c77..a9f48f5d3d4ea32fbf53086ba21eab4bc65b6dcb
100644
--- a/gcc/config/aarch64/aarch64-tuning-flags.def
+++ b/gcc/config/aarch64/aarch64-tuning-flags.def
@@ -48,4 +48,8 @@ AARCH64_EXTRA_TUNING_OPTION ("avoid_cross_loop_fma",
AVOID_CROSS_LOOP_FMA)
AARCH64_EXTRA_TUNING_OPTION ("fully_pipelined_fma", FULLY_PIPELINED_FMA)
+/* Enable is the target prefers to use a fresh register for predicate outputs
+ rather than re-use an input predicate register. */
+AARCH64_EXTRA_TUNING_OPTION ("avoid_pred_rmw", AVOID_PRED_RMW)
+
#undef AARCH64_EXTRA_TUNING_OPTION
diff --git a/gcc/config/aarch64/aarch64.h b/gcc/config/aarch64/aarch64.h
index
bbf11faaf4b4340956094a983f8b0dc2649b2d27..e7669e65d7dae5df2ba42c265079b1856a5c382b
100644
--- a/gcc/config/aarch64/aarch64.h
+++ b/gcc/config/aarch64/aarch64.h
@@ -495,6 +495,11 @@ constexpr auto AARCH64_FL_DEFAULT_ISA_MODE =
AARCH64_FL_SM_OFF;
enabled through +gcs. */
#define TARGET_GCS (AARCH64_ISA_GCS)
+/* Prefer different predicate registers for the output of a predicated
operation over
+ re-using an existing input predicate. */
+#define TARGET_SVE_PRED_CLOBBER (TARGET_SVE \
+ && (aarch64_tune_params.extra_tuning_flags \
+ & AARCH64_EXTRA_TUNE_AVOID_PRED_RMW))
/* Standard register usage. */
diff --git a/gcc/config/aarch64/aarch64.md b/gcc/config/aarch64/aarch64.md
index
dbde066f7478bec51a8703b017ea553aa98be309..a7da3c01617eb8411029c7d2e32f13fa2cc1c833
100644
--- a/gcc/config/aarch64/aarch64.md
+++ b/gcc/config/aarch64/aarch64.md
@@ -445,6 +445,10 @@ (define_enum_attr "arch" "arches" (const_string "any"))
;; target-independent code.
(define_attr "is_call" "no,yes" (const_string "no"))
+;; Indicates whether we want to enable the pattern with an optional early
+;; clobber for SVE predicates.
+(define_attr "pred_clobber" "any,no,yes" (const_string "any"))
+
;; [For compatibility with Arm in pipeline models]
;; Attribute that specifies whether or not the instruction touches fp
;; registers.
@@ -460,7 +464,17 @@ (define_attr "fp" "no,yes"
(define_attr "arch_enabled" "no,yes"
(if_then_else
- (ior
+ (and
+ (ior
+ (and
+ (eq_attr "pred_clobber" "no")
+ (match_test "!TARGET_SVE_PRED_CLOBBER"))
+ (and
+ (eq_attr "pred_clobber" "yes")
+ (match_test "TARGET_SVE_PRED_CLOBBER"))
+ (eq_attr "pred_clobber" "any"))
+
+ (ior
(eq_attr "arch" "any")
(and (eq_attr "arch" "rcpc8_4")
@@ -488,7 +502,7 @@ (define_attr "arch_enabled" "no,yes"
(match_test "TARGET_SVE"))
(and (eq_attr "arch" "sme")
- (match_test "TARGET_SME")))
+ (match_test "TARGET_SME"))))
(const_string "yes")
(const_string "no")))
rb18355 (1).patch
Description: rb18355 (1).patch
