From 819894b14db18c98ea0460cbbb28f3ad2a1d1b1b Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Bj=C3=B6rn=20Gustavsson?= Date: Mon, 28 Jan 2013 12:16:32 +0100 Subject: 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 --- lib/compiler/src/beam_type.erl | 23 +++++++++++++++++++---- 1 file 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 -- cgit v1.2.3