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| author | Björn Gustavsson <[email protected]> | 2018-01-25 10:09:59 +0100 |
|---|---|---|
| committer | Björn Gustavsson <[email protected]> | 2018-01-26 15:57:57 +0100 |
| commit | fbcff5a137e37edd80aca9c5fe18ce6880648169 (patch) | |
| tree | fb846d82599a3e52230f1b028b59f63cb0dd09ec /lib/compiler/src/genop.tab | |
| parent | 5b58d9e2d3262160b7f10d8b6798f89f0618c5f6 (diff) | |
| download | otp-fbcff5a137e37edd80aca9c5fe18ce6880648169.tar.gz otp-fbcff5a137e37edd80aca9c5fe18ce6880648169.tar.bz2 otp-fbcff5a137e37edd80aca9c5fe18ce6880648169.zip | |
Eliminate get_list/3 internally in the compiler
Instructions that produce more than one result complicate
optimizations. get_list/3 is one of two instructions that
produce multiple results (get_map_elements/3 is the other).
Introduce the get_hd/2 and get_tl/2 instructions
that return the head and tail of a cons cell, respectively,
and use it internally in all optimization passes.
For efficiency, we still want to use get_list/3 if both
head and tail are used, so we will translate matching pairs
of get_hd and get_tl back to get_list instructions.
Diffstat (limited to 'lib/compiler/src/genop.tab')
| -rwxr-xr-x | lib/compiler/src/genop.tab | 10 |
1 files changed, 10 insertions, 0 deletions
diff --git a/lib/compiler/src/genop.tab b/lib/compiler/src/genop.tab index d59bb241a8..a47d4e8cf7 100755 --- a/lib/compiler/src/genop.tab +++ b/lib/compiler/src/genop.tab @@ -564,3 +564,13 @@ BEAM_FORMAT_NUMBER=0 ## exception, but store the atom 'badarg' in x(0) and execute the ## next instruction. 161: raw_raise/0 + +## @spec get_hd Source Head +## @doc Get the head (or car) part of a list (a cons cell) from Source and +## put it into the register Head. +162: get_hd/2 + +## @spec get_tl Source Tail +## @doc Get the tail (or cdr) part of a list (a cons cell) from Source and +## put it into the register Tail. +163: get_tl/2 |