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| author | Björn Gustavsson <[email protected]> | 2017-11-29 15:13:05 +0100 |
|---|---|---|
| committer | Björn Gustavsson <[email protected]> | 2017-11-30 12:43:22 +0100 |
| commit | 67fd015394185302f769378c2c5e47bddbdc22ea (patch) | |
| tree | 51957138935856b761194837d7e0f7b5c67f8485 /erts | |
| parent | 93fde6744a0c94c2d31f99cb1f9019ff6e98f83d (diff) | |
| download | otp-67fd015394185302f769378c2c5e47bddbdc22ea.tar.gz otp-67fd015394185302f769378c2c5e47bddbdc22ea.tar.bz2 otp-67fd015394185302f769378c2c5e47bddbdc22ea.zip | |
Stop trying to maximize the use of x(0)
X register 0 used to be mapped to a hardware register, and therefore
faster than the other registers. Because of that, the compiler
tried to use x(0) as much as possible as a temporary register.
That was changed a few releases ago. X register 0 is now placed
in the array of all X registers and has no special speed
advantage compared to the other registers.
Remove the code in the compiler that attempts to use x(0) as
much as possible. As a result, the following type of instruction
will be much less frequent:
{put_list,Src,{x,0},{x,0}}
Instead, the following type of instruction will be more frequent:
{put_list,Src,{x,X},{x,X}}
(Where X is an arbitrary X register.)
Update the runtime system to specialize that kind of put_list
instruction.
Diffstat (limited to 'erts')
| -rw-r--r-- | erts/emulator/beam/instrs.tab | 7 | ||||
| -rw-r--r-- | erts/emulator/beam/ops.tab | 7 |
2 files changed, 12 insertions, 2 deletions
diff --git a/erts/emulator/beam/instrs.tab b/erts/emulator/beam/instrs.tab index c17d1a8f69..d934abb217 100644 --- a/erts/emulator/beam/instrs.tab +++ b/erts/emulator/beam/instrs.tab @@ -542,6 +542,13 @@ put_list(Hd, Tl, Dst) { HTOP += 2; } +update_list(Hd, Dst) { + HTOP[0] = $Hd; + HTOP[1] = $Dst; + $Dst = make_list(HTOP); + HTOP += 2; +} + i_put_tuple := i_put_tuple.make.fill; i_put_tuple.make(Dst) { diff --git a/erts/emulator/beam/ops.tab b/erts/emulator/beam/ops.tab index 3df91056cb..c30af029ce 100644 --- a/erts/emulator/beam/ops.tab +++ b/erts/emulator/beam/ops.tab @@ -503,6 +503,10 @@ i_put_tuple xy I # put_list Const=c n Dst => move Const x | put_list x n Dst +put_list Src Dst=x Dst => update_list Src Dst + +update_list xyc x + put_list x n x put_list y n x put_list x x x @@ -525,8 +529,6 @@ put_list c y x # The following put_list instructions using x(0) are frequently used. -put_list y r r -put_list x r r put_list r n r put_list r n x put_list r x x @@ -537,6 +539,7 @@ put_list x x r put_list s s d %hot + # # Some more only used by the emulator # |