In certain cases, we can avoid the overhead of writing to hex_new_value
and write directly to hex_gpr. We add need_commit field to DisasContext
indicating if the end-of-packet commit is needed. If it is not needed,
get_result_gpr() and get_result_gpr_pair() can return hex_gpr.
We pass the ctx->need_commit to helpers when needed.
Finally, we can early-exit from gen_reg_writes during packet commit.
There are a few instructions whose semantics write to the result before
reading all the inputs. Therefore, the idef-parser generated code is
incompatible with short-circuit. We tell idef-parser to skip them.
For debugging purposes, we add a cpu property to turn off short-circuit.
When the short-circuit property is false, we skip the analysis and force
the end-of-packet commit.
Here's a simple example of the TCG generated for
0x004000b4: 0x7800c020 { R0 = #0x1 }
BEFORE:
---- 004000b4
movi_i32 new_r0,$0x1
mov_i32 r0,new_r0
AFTER:
---- 004000b4
movi_i32 r0,$0x1
Signed-off-by: Taylor Simpson<tsimpson@quicinc.com>
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