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* [PATCH v2 0/3] Hexagon (target/hexagon) Enable more short-circuit packets
@ 2024-02-01 10:33 Taylor Simpson
  2024-02-01 10:33 ` [PATCH v2 1/3] Hexagon (target/hexagon) Analyze reads before writes Taylor Simpson
                   ` (2 more replies)
  0 siblings, 3 replies; 7+ messages in thread
From: Taylor Simpson @ 2024-02-01 10:33 UTC (permalink / raw)
  To: qemu-devel
  Cc: bcain, quic_mathbern, sidneym, quic_mliebel, richard.henderson,
	philmd, ale, anjo, ltaylorsimpson

This patch series improves the set of packets that can short-circuit
the commit packet logic and write the results directly during the
execution of each instruction in the packet.

The key observation is that checking for overlap between register reads
and writes is different from read-after-write.  For example, this packet
    { R0 = add(R0,R1); R6 = add(R6,R7) }
has an overlap between the reads and writes without doing a read after a
write.  Therefore, it is safe to write directly into the destination
registers during instruction execution.

Another example is a .new register read.  These can read from either the
destination register or a temporary location.

HVX instructions with generated helpers require special handling.
The semantics of the helpers are pass-by-reference, so we still need the
overlap check for these.

***** Changes in v2 *****
Conform to object oriented generators patch
https://lists.gnu.org/archive/html/qemu-devel/2023-12/msg01211.html


Taylor Simpson (3):
  Hexagon (target/hexagon) Analyze reads before writes
  Hexagon (target/hexagon) Enable more short-circuit packets (scalar
    core)
  Hexagon (target/hexagon) Enable more short-circuit packets (HVX)

 target/hexagon/translate.h          | 119 +++++++++++++++++++++++-----
 target/hexagon/translate.c          |  77 ++----------------
 target/hexagon/README               |   9 ++-
 target/hexagon/gen_analyze_funcs.py |  55 ++++++++-----
 target/hexagon/hex_common.py        |  98 +++++++++++++----------
 5 files changed, 200 insertions(+), 158 deletions(-)

-- 
2.34.1



^ permalink raw reply	[flat|nested] 7+ messages in thread

end of thread, other threads:[~2024-03-29  2:06 UTC | newest]

Thread overview: 7+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2024-02-01 10:33 [PATCH v2 0/3] Hexagon (target/hexagon) Enable more short-circuit packets Taylor Simpson
2024-02-01 10:33 ` [PATCH v2 1/3] Hexagon (target/hexagon) Analyze reads before writes Taylor Simpson
2024-03-29  2:05   ` Brian Cain
2024-02-01 10:33 ` [PATCH v2 2/3] Hexagon (target/hexagon) Enable more short-circuit packets (scalar core) Taylor Simpson
2024-03-29  2:02   ` Brian Cain
2024-02-01 10:33 ` [PATCH v2 3/3] Hexagon (target/hexagon) Enable more short-circuit packets (HVX) Taylor Simpson
2024-03-29  2:02   ` Brian Cain

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