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author | Björn Gustavsson <[email protected]> | 2015-09-22 10:40:06 +0200 |
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committer | Björn Gustavsson <[email protected]> | 2015-09-28 10:26:39 +0200 |
commit | 105c5b0071056dc062797e58772e098d2a3a4627 (patch) | |
tree | 4fee14610caff25589ea27bad9b4fc37991681d0 /.gitignore | |
parent | 58a0c1c6c7efdb1f1250edec1b5fcd5eb72e99b9 (diff) | |
download | otp-105c5b0071056dc062797e58772e098d2a3a4627.tar.gz otp-105c5b0071056dc062797e58772e098d2a3a4627.tar.bz2 otp-105c5b0071056dc062797e58772e098d2a3a4627.zip |
beam_dead: Improve optimization of literal binary matching
When the bit syntax is used to match a single binary literal, the bit
syntax instructions will be replaced with a comparison to a binary
literal. The only problem is that the bs_context_to_binary instruction
will not be eliminated.
Example:
f(<<"string">>) ->
ok.
This function would be translated to:
{function, f, 1, 2}.
{label,1}.
{line,...}.
{func_info,...}.
{label,2}.
{test,is_eq_exact,{f,3},[{x,0},{literal,<<"string">>}]}.
{move,{atom,ok},{x,0}}.
return.
{label,3}.
{bs_context_to_binary,{x,0}}.
{jump,{f,1}}.
The bs_context_to_binary instruction serves no useful purpose,
since {x,0} can never be a match context. Eliminating the
instruction, the resulting code will be:
{function, f, 1, 2}.
{label,1}.
{line,...}.
{func_info,...}.
{label,2}.
{test,is_eq_exact,{f,1},[{x,0},{literal,<<"string">>}]}.
{move,{atom,ok},{x,0}}.
return.
Diffstat (limited to '.gitignore')
0 files changed, 0 insertions, 0 deletions