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author | Björn Gustavsson <[email protected]> | 2018-01-25 10:09:59 +0100 |
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committer | Björn Gustavsson <[email protected]> | 2018-01-26 15:57:57 +0100 |
commit | fbcff5a137e37edd80aca9c5fe18ce6880648169 (patch) | |
tree | fb846d82599a3e52230f1b028b59f63cb0dd09ec /lib/compiler/src/beam_validator.erl | |
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/beam_validator.erl')
-rw-r--r-- | lib/compiler/src/beam_validator.erl | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/lib/compiler/src/beam_validator.erl b/lib/compiler/src/beam_validator.erl index f8bf935132..7e5d86c177 100644 --- a/lib/compiler/src/beam_validator.erl +++ b/lib/compiler/src/beam_validator.erl @@ -591,6 +591,12 @@ valfun_4({get_list,Src,D1,D2}, Vst0) -> assert_type(cons, Src, Vst0), Vst = set_type_reg(term, D1, Vst0), set_type_reg(term, D2, Vst); +valfun_4({get_hd,Src,Dst}, Vst) -> + assert_type(cons, Src, Vst), + set_type_reg(term, Dst, Vst); +valfun_4({get_tl,Src,Dst}, Vst) -> + assert_type(cons, Src, Vst), + set_type_reg(term, Dst, Vst); valfun_4({get_tuple_element,Src,I,Dst}, Vst) -> assert_type({tuple_element,I+1}, Src, Vst), set_type_reg(term, Dst, Vst); |