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Re: [PATCH] [aarch64] Fix falkor pipeline description for dup<q>
- From: Kyrill Tkachov <kyrylo dot tkachov at foss dot arm dot com>
- To: Siddhesh Poyarekar <siddhesh at sourceware dot org>, "gcc-patches at gcc dot gnu dot org" <gcc-patches at gcc dot gnu dot org>
- Cc: James Greenhalgh <James dot Greenhalgh at arm dot com>
- Date: Thu, 02 Aug 2018 11:49:43 +0100
- Subject: Re: [PATCH] [aarch64] Fix falkor pipeline description for dup<q>
- References: <20180802102303.22423-1-siddhesh@sourceware.org>
Hi Siddhesh,
On 02/08/18 11:23, Siddhesh Poyarekar wrote:
There was a typo in the pipeline description where DUP was assigned to
the vector pipes for quad mode ops when it really only uses the VTOG
pipes. Fixing this does not show any noticeable difference in
performance (there's a very small bump of 1.7% in x264 but that's
about it) in my tests but is the more precise description of operations
for falkor.
You know the microarchitecture better, so I'm assuming that's correct for Falkor.
I assume this has been tested with a bootstrap and test.
* gcc/config/aarch64/falkor.md (falkor_am_1_vxvy_vxvy): Move
neon_dup_q to...
(falkor_am_1_gtov_gtov): ... a new insn reservation.
No gcc/ prefix in the ChangeLog path.
CC: james.greenhalgh@arm.com
CC: kyrylo.tkachov@foss.arm.com
---
gcc/config/aarch64/falkor.md | 8 +++++++-
1 file changed, 7 insertions(+), 1 deletion(-)
diff --git a/gcc/config/aarch64/falkor.md b/gcc/config/aarch64/falkor.md
index 5cbc5150ef3..83b4b14b7f4 100644
--- a/gcc/config/aarch64/falkor.md
+++ b/gcc/config/aarch64/falkor.md
@@ -322,6 +322,12 @@
(eq_attr "type" "neon_from_gp_q"))
"falkor_gtov,falkor_gtov")
+;; DUP does not use vector pipes in Q mode, only gtov+gtov.
+(define_insn_reservation "falkor_am_1_gtov_gtov" 1
+ (and (eq_attr "tune" "falkor")
+ (eq_attr "type" "neon_dup_q"))
+ "falkor_gtov,falkor_gtov")
You should be able to use the "*" construct here like this:
falkor_gtov*2
Otherwise looks ok to me (but you'll need a maintainer to approve)
Thanks,
Kyrill
+
;; neon_to_gp_q is used for 32-bit ARM instructions that move 64-bits of data
;; so no use needed here.
@@ -337,7 +343,7 @@
(define_insn_reservation "falkor_am_1_vxvy_vxvy" 1
(and (eq_attr "tune" "falkor")
- (eq_attr "type" "neon_bsl_q,neon_dup_q,neon_ext_q,neon_move_q,neon_rev_q,neon_tbl1_q,neon_permute_q"))
+ (eq_attr "type" "neon_bsl_q,neon_ext_q,neon_move_q,neon_rev_q,neon_tbl1_q,neon_permute_q"))
"falkor_vxvy+falkor_vxvy")
(define_insn_reservation "falkor_am_2_vxvy" 2
--
2.17.1