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| author | Björn Gustavsson <[email protected]> | 2010-12-08 15:27:37 +0100 |
|---|---|---|
| committer | Björn Gustavsson <[email protected]> | 2011-01-17 15:23:46 +0100 |
| commit | 74d7bd100b742a803c8de82c9c997308cf871038 (patch) | |
| tree | 8230b273d29b0c2f60950c9c7a0db747d217d18d /erts/emulator/beam/ops.tab | |
| parent | b166f8975387d7ef07409e841d45c2cd74c2282e (diff) | |
| download | otp-74d7bd100b742a803c8de82c9c997308cf871038.tar.gz otp-74d7bd100b742a803c8de82c9c997308cf871038.tar.bz2 otp-74d7bd100b742a803c8de82c9c997308cf871038.zip | |
Optimize addition of a small integer to a variable
Introduce a new i_increment/4 to optimize the addition of
a register and a small integer. This instruction saves two
instruction words compared to the standard instructions
(an i_fetch/2 instruction followed by a i_plus/3 instruction)
and will also be slightly faster.
Diffstat (limited to 'erts/emulator/beam/ops.tab')
| -rw-r--r-- | erts/emulator/beam/ops.tab | 20 |
1 files changed, 19 insertions, 1 deletions
diff --git a/erts/emulator/beam/ops.tab b/erts/emulator/beam/ops.tab index 6db55e1402..029d7b512c 100644 --- a/erts/emulator/beam/ops.tab +++ b/erts/emulator/beam/ops.tab @@ -1371,7 +1371,21 @@ apply I apply_last I P # -# New GCing arithmetic instructions. +# Optimize addition and subtraction of small literals using +# the i_increment/4 instruction (in bodies, not in guards). +# + +gc_bif2 p Live u$bif:erlang:splus/2 Int=i Reg=d Dst => \ + gen_increment(Reg, Int, Live, Dst) +gc_bif2 p Live u$bif:erlang:splus/2 Reg=d Int=i Dst => \ + gen_increment(Reg, Int, Live, Dst) + +gc_bif2 p Live u$bif:erlang:sminus/2 Reg=d Int=i Dst | \ + negation_is_small(Int) => \ + gen_increment_from_minus(Reg, Int, Live, Dst) + +# +# GCing arithmetic instructions. # gc_bif2 Fail I u$bif:erlang:splus/2 S1 S2 Dst=d => i_fetch S1 S2 | i_plus Fail I Dst @@ -1394,6 +1408,10 @@ gc_bif1 Fail I u$bif:erlang:bnot/1 Src Dst=d => i_int_bnot Fail Src I Dst gc_bif1 Fail I u$bif:erlang:sminus/1 Src Dst=d => i_fetch i Src | i_minus Fail I Dst gc_bif1 Fail I u$bif:erlang:splus/1 Src Dst=d => i_fetch i Src | i_plus Fail I Dst +i_increment r I I d +i_increment x I I d +i_increment y I I d + i_plus j I d i_minus j I d i_times j I d |