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authorBjörn Gustavsson <[email protected]>2013-01-28 12:16:32 +0100
committerBjörn Gustavsson <[email protected]>2013-01-31 11:11:36 +0100
commit819894b14db18c98ea0460cbbb28f3ad2a1d1b1b (patch)
tree7d9c1e7e2f60c8ede62dbfa040ae4346887afa77 /lib/compiler/src
parent9cfd4261240fffc51ca5aa7d1df5a29a30f42a38 (diff)
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beam_type: Convert integer to float at compile time
In code such as: X / 2 the following code would be output from beam_type for the division: {fconv,{x,0},{fr,0}}. {fconv,{integer,2},{fr,1}}. fclearerror. {bif,fdiv,{f,0},[{fr,0},{fr,1}],{fr,0}}. That is, the integer 2 would be converted to the float 2.0 at run-time by "{fconv,{integer,2},{fr,1}}". Make sure that we do the conversion at compile time. Noticed-by: Richard O'Keefe
Diffstat (limited to 'lib/compiler/src')
-rw-r--r--lib/compiler/src/beam_type.erl23
1 files changed, 19 insertions, 4 deletions
diff --git a/lib/compiler/src/beam_type.erl b/lib/compiler/src/beam_type.erl
index 7392f99fb6..372923a5cf 100644
--- a/lib/compiler/src/beam_type.erl
+++ b/lib/compiler/src/beam_type.erl
@@ -142,9 +142,11 @@ simplify_float(Is0, Ts0) ->
throw:not_possible -> not_possible
end.
-simplify_float_1([{set,[D0],[A],{alloc,_,{gc_bif,'-',{f,0}}}}=I|Is]=Is0, Ts0, Rs0, Acc0) ->
- case tdb_find(A, Ts0) of
+simplify_float_1([{set,[D0],[A0],{alloc,_,{gc_bif,'-',{f,0}}}}=I|Is]=Is0,
+ Ts0, Rs0, Acc0) ->
+ case tdb_find(A0, Ts0) of
float ->
+ A = coerce_to_float(A0),
{Rs1,Acc1} = load_reg(A, Ts0, Rs0, Acc0),
{D,Rs} = find_dest(D0, Rs1),
Areg = fetch_reg(A, Rs),
@@ -156,13 +158,16 @@ simplify_float_1([{set,[D0],[A],{alloc,_,{gc_bif,'-',{f,0}}}}=I|Is]=Is0, Ts0, Rs
{Rs,Acc} = flush(Rs0, Is0, Acc0),
simplify_float_1(Is, Ts, Rs, [I|checkerror(Acc)])
end;
-simplify_float_1([{set,[D0],[A,B],{alloc,_,{gc_bif,Op0,{f,0}}}}=I|Is]=Is0, Ts0, Rs0, Acc0) ->
- case float_op(Op0, A, B, Ts0) of
+simplify_float_1([{set,[D0],[A0,B0],{alloc,_,{gc_bif,Op0,{f,0}}}}=I|Is]=Is0,
+ Ts0, Rs0, Acc0) ->
+ case float_op(Op0, A0, B0, Ts0) of
no ->
Ts = update(I, Ts0),
{Rs,Acc} = flush(Rs0, Is0, Acc0),
simplify_float_1(Is, Ts, Rs, [I|checkerror(Acc)]);
{yes,Op} ->
+ A = coerce_to_float(A0),
+ B = coerce_to_float(B0),
{Rs1,Acc1} = load_reg(A, Ts0, Rs0, Acc0),
{Rs2,Acc2} = load_reg(B, Ts0, Rs1, Acc1),
{D,Rs} = find_dest(D0, Rs2),
@@ -187,6 +192,16 @@ simplify_float_1([], Ts, Rs, Acc0) ->
Is = opt_fmoves(Is0, []),
{Is,Ts}.
+coerce_to_float({integer,I}=Int) ->
+ try float(I) of
+ F ->
+ {float,F}
+ catch _:_ ->
+ %% Let the overflow happen at run-time.
+ Int
+ end;
+coerce_to_float(Other) -> Other.
+
opt_fmoves([{set,[{x,_}=R],[{fr,_}]=Src,fmove}=I1,
{set,[_]=Dst,[{x,_}=R],move}=I2|Is], Acc) ->
case beam_utils:is_killed_block(R, Is) of