Ping for the 9 patches lacking review.
r~
On 1/30/23 10:59, Richard Henderson wrote:
Based-on: 20230126043824.54819-1-richard.hender...@linaro.org
("[PATCH v5 00/36] tcg: Support for Int128 with helpers")
The biggest pitfall for new users of TCG is the fact that "normal"
temporaries die at branches, and we must therefore use a different
"local" temporary in that case.
The following patch set changes that, so that the "normal" temporary
is the one that lives across branches, and there is a special temporary
that dies at the end of the extended basic block, and this special
case is reserved for tcg internals.
TEMP_LOCAL is renamed TEMP_TB, which I believe to be more explicit and
less confusing. TEMP_NORMAL is removed entirely.
I thought about putting in a proper full-power liveness analysis pass.
This would have eliminated the differences between all non-global
temporaries, and would have noticed when TEMP_LOCAL finally dies
within a translation and avoid any final writeback.
But I came to the conclusion that it was too expensive in runtime,
and so retaining some distinction in the types was required.
In addition, I found that the usage of temps within plugin-gen.c
(9 per guest memory operation) meant that we *must* have some form
of temp that can be re-used. (There is one x86 instruction which
generates 62 memory operations; 62 * 9 == 558, which is larger than
our current TCG_MAX_TEMPS.)
However I did add a new liveness pass which, with a single pass over
the opcode stream, can see that a TEMP_LOCAL is only live within a
single extended basic block, and thus may be transformed to TEMP_EBB.
With this, and by not recycling TEMP_LOCAL, we can get identical code
out of the backend even when changing the front end translators are
adjusted to use TEMP_LOCAL for everything.
Benchmarking one test case, qemu-arm linux-test, the new liveness pass
comes in at about 1.6% on perf, but I can't see any difference in
wall clock time before and after the patch set.
r~
Richard Henderson (27):
tcg: Adjust TCGContext.temps_in_use check
accel/tcg: Pass max_insn to gen_intermediate_code by pointer
accel/tcg: Use more accurate max_insns for tb_overflow
tcg: Remove branch-to-next regardless of reference count
tcg: Rename TEMP_LOCAL to TEMP_TB
tcg: Add liveness_pass_0
tcg: Remove TEMP_NORMAL
tcg: Pass TCGTempKind to tcg_temp_new_internal
tcg: Add tcg_temp_ebb_new_{i32,i64,ptr}
tcg: Add tcg_gen_movi_ptr
tcg: Use tcg_temp_ebb_new_* in tcg/
accel/tcg/plugin: Use tcg_temp_ebb_*
accel/tcg/plugin: Tidy plugin_gen_disable_mem_helpers
tcg: Don't re-use TEMP_TB temporaries
tcg: Change default temp lifetime to TEMP_TB
target/arm: Drop copies in gen_sve_{ldr,str}
target/arm: Don't use tcg_temp_local_new_*
target/cris: Don't use tcg_temp_local_new
target/hexagon: Don't use tcg_temp_local_new_*
target/hppa: Don't use tcg_temp_local_new
target/i386: Don't use tcg_temp_local_new
target/mips: Don't use tcg_temp_local_new
target/ppc: Don't use tcg_temp_local_new
target/xtensa: Don't use tcg_temp_local_new_*
exec/gen-icount: Don't use tcg_temp_local_new_i32
tcg: Remove tcg_temp_local_new_*, tcg_const_local_*
tcg: Update docs/devel/tcg-ops.rst for temporary changes
docs/devel/tcg-ops.rst | 103 ++++----
target/hexagon/idef-parser/README.rst | 4 +-
include/exec/gen-icount.h | 8 +-
include/exec/translator.h | 4 +-
include/tcg/tcg-op.h | 7 +-
include/tcg/tcg.h | 64 ++---
target/arm/translate-a64.h | 1 -
target/hexagon/gen_tcg.h | 4 +-
accel/tcg/plugin-gen.c | 33 +--
accel/tcg/translate-all.c | 2 +-
accel/tcg/translator.c | 6 +-
target/alpha/translate.c | 2 +-
target/arm/translate-a64.c | 6 -
target/arm/translate-sve.c | 38 +--
target/arm/translate.c | 8 +-
target/avr/translate.c | 2 +-
target/cris/translate.c | 8 +-
target/hexagon/genptr.c | 16 +-
target/hexagon/idef-parser/parser-helpers.c | 4 +-
target/hexagon/translate.c | 4 +-
target/hppa/translate.c | 5 +-
target/i386/tcg/translate.c | 29 +--
target/loongarch/translate.c | 2 +-
target/m68k/translate.c | 2 +-
target/microblaze/translate.c | 2 +-
target/mips/tcg/translate.c | 59 ++---
target/nios2/translate.c | 2 +-
target/openrisc/translate.c | 2 +-
target/ppc/translate.c | 8 +-
target/riscv/translate.c | 2 +-
target/rx/translate.c | 2 +-
target/s390x/tcg/translate.c | 2 +-
target/sh4/translate.c | 2 +-
target/sparc/translate.c | 2 +-
target/tricore/translate.c | 2 +-
target/xtensa/translate.c | 18 +-
tcg/optimize.c | 2 +-
tcg/tcg-op-gvec.c | 270 ++++++++++----------
tcg/tcg-op.c | 258 +++++++++----------
tcg/tcg.c | 270 +++++++++++---------
target/cris/translate_v10.c.inc | 10 +-
target/mips/tcg/nanomips_translate.c.inc | 4 +-
target/ppc/translate/spe-impl.c.inc | 8 +-
target/ppc/translate/vmx-impl.c.inc | 4 +-
target/hexagon/README | 8 +-
target/hexagon/gen_tcg_funcs.py | 18 +-
46 files changed, 640 insertions(+), 677 deletions(-)
