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* [PATCH 00/16] tcg: Better handling of constants
@ 2020-04-18 16:18 Richard Henderson
  2020-04-18 16:18 ` [PATCH 01/16] tcg: Add temp_readonly Richard Henderson
                   ` (16 more replies)
  0 siblings, 17 replies; 21+ messages in thread
From: Richard Henderson @ 2020-04-18 16:18 UTC (permalink / raw)
  To: qemu-devel

This promotes constants to full-fledged temporaries, which are then
hashed so we have only a single copy across the TB.  If an opcode
requires forcing one into a register, then we will only do this
once -- at least until the register is killed, e.g. by a function call.

While this is probably an modest improvement for integer code, it is
significant for SVE vector code.  In particular, where a generator function
loads a constant for the operation, and then the generator function is
called N times for the N x 128-bit vector.  Previously we'd be loading
up the same constant N times and now we do so only once.

The existing tcg_const_{type}() functions are unchanged, allocating
a new temporary and initializing it.  The constant propagation pass
of the optimizer will generally remove the temporary when it turns
out not to be modified further.

This adds new tcg_constant_{type}() functions which produce a read-only
temporary containing the constant which need not be freed.  I have
updated the generic expanders to take advantage of this, but have not
touched the target front ends.

This also, in the end, allows the complete removal of the tcg opcodes
that create a constant: INDEX_op_movi_{i32,i64} and INDEX_op_dupi_vec.
Loading of constants into hard registers is completely controlled by
the register allocator.


r~


Richard Henderson (16):
  tcg: Add temp_readonly
  tcg: Introduce TYPE_CONST temporaries
  tcg: Use tcg_constant_i32 with icount expander
  tcg: Use tcg_constant_{i32,i64} with tcg int expanders
  tcg: Use tcg_constant_{i32,vec} with tcg vec expanders
  tcg: Use tcg_constant_{i32,i64} with tcg plugins
  tcg: Rename struct tcg_temp_info to TempOptInfo
  tcg/optimize: Adjust TempOptInfo allocation
  tcg/optimize: Use tcg_constant_internal with constant folding
  tcg/tci: Add special tci_movi_{i32,i64} opcodes
  tcg: Remove movi and dupi opcodes
  tcg: Use tcg_out_dupi_vec from temp_load
  tcg: Increase tcg_out_dupi_vec immediate to int64_t
  tcg: Add tcg_reg_alloc_dup2
  tcg/i386: Use tcg_constant_vec with tcg vec expanders
  tcg: Remove tcg_gen_dup{8,16,32,64}i_vec

 include/exec/gen-icount.h    |  25 ++--
 include/tcg/tcg-op.h         |  17 +--
 include/tcg/tcg-opc.h        |  11 +-
 include/tcg/tcg.h            |  30 +++++
 accel/tcg/plugin-gen.c       |  49 ++++---
 tcg/aarch64/tcg-target.inc.c |  12 +-
 tcg/arm/tcg-target.inc.c     |   1 -
 tcg/i386/tcg-target.inc.c    | 110 +++++++++-------
 tcg/mips/tcg-target.inc.c    |   2 -
 tcg/optimize.c               | 204 ++++++++++++++---------------
 tcg/ppc/tcg-target.inc.c     |  24 ++--
 tcg/riscv/tcg-target.inc.c   |   2 -
 tcg/s390/tcg-target.inc.c    |   2 -
 tcg/sparc/tcg-target.inc.c   |   2 -
 tcg/tcg-op-vec.c             |  83 ++++++------
 tcg/tcg-op.c                 | 216 ++++++++++++++----------------
 tcg/tcg.c                    | 246 +++++++++++++++++++++++++++++------
 tcg/tci.c                    |   4 +-
 tcg/tci/tcg-target.inc.c     |   6 +-
 19 files changed, 602 insertions(+), 444 deletions(-)

-- 
2.20.1



^ permalink raw reply	[flat|nested] 21+ messages in thread

end of thread, other threads:[~2020-04-20 18:07 UTC | newest]

Thread overview: 21+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2020-04-18 16:18 [PATCH 00/16] tcg: Better handling of constants Richard Henderson
2020-04-18 16:18 ` [PATCH 01/16] tcg: Add temp_readonly Richard Henderson
2020-04-20  6:57   ` Philippe Mathieu-Daudé
2020-04-18 16:19 ` [PATCH 02/16] tcg: Introduce TYPE_CONST temporaries Richard Henderson
2020-04-18 16:19 ` [PATCH 03/16] tcg: Use tcg_constant_i32 with icount expander Richard Henderson
2020-04-18 16:19 ` [PATCH 04/16] tcg: Use tcg_constant_{i32,i64} with tcg int expanders Richard Henderson
2020-04-18 16:19 ` [PATCH 05/16] tcg: Use tcg_constant_{i32,vec} with tcg vec expanders Richard Henderson
2020-04-18 16:19 ` [PATCH 06/16] tcg: Use tcg_constant_{i32,i64} with tcg plugins Richard Henderson
2020-04-18 16:19 ` [PATCH 07/16] tcg: Rename struct tcg_temp_info to TempOptInfo Richard Henderson
2020-04-20  7:00   ` Philippe Mathieu-Daudé
2020-04-18 16:19 ` [PATCH 08/16] tcg/optimize: Adjust TempOptInfo allocation Richard Henderson
2020-04-18 16:19 ` [PATCH 09/16] tcg/optimize: Use tcg_constant_internal with constant folding Richard Henderson
2020-04-18 16:19 ` [PATCH 10/16] tcg/tci: Add special tci_movi_{i32,i64} opcodes Richard Henderson
2020-04-18 16:19 ` [PATCH 11/16] tcg: Remove movi and dupi opcodes Richard Henderson
2020-04-18 16:19 ` [PATCH 12/16] tcg: Use tcg_out_dupi_vec from temp_load Richard Henderson
2020-04-18 16:19 ` [PATCH 13/16] tcg: Increase tcg_out_dupi_vec immediate to int64_t Richard Henderson
2020-04-18 16:19 ` [PATCH 14/16] tcg: Add tcg_reg_alloc_dup2 Richard Henderson
2020-04-18 16:19 ` [PATCH 15/16] tcg/i386: Use tcg_constant_vec with tcg vec expanders Richard Henderson
2020-04-18 16:19 ` [PATCH 16/16] tcg: Remove tcg_gen_dup{8,16,32,64}i_vec Richard Henderson
2020-04-20 15:39 ` [PATCH 00/16] tcg: Better handling of constants Alex Bennée
2020-04-20 18:06   ` Richard Henderson

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