Merge branch 'bjorn/compiler/float/OTP-10788'

* bjorn/compiler/float/OTP-10788:
  beam_type: Convert integer to float at compile time
  compiler: Use the literal pool for floating point constants

4 files changed, 30 insertions, 7 deletions

diff --git a/erts/emulator/beam/beam_load.c b/erts/emulator/beam/beam_load.c
index f57fa2bfbb..81c1ea749a 100644
--- a/erts/emulator/beam/beam_load.c
+++ b/erts/emulator/beam/beam_load.c
@@ -1853,7 +1853,10 @@ load_code(LoaderState* stp)
 		    unsigned tag;
 
 		    switch (last_op->a[arg].val) {
-		    case 0:	/* Floating point number */
+		    case 0:
+			/* Floating point number.
+			 * Not generated by the compiler in R16B and later.
+			 */
 			{
 			    Eterm* hp;
 /* XXX:PaN - Halfword should use ARCH_64 variant instead */
diff --git a/lib/compiler/src/beam_asm.erl b/lib/compiler/src/beam_asm.erl
index a7c8508321..98967e651f 100644
--- a/lib/compiler/src/beam_asm.erl
+++ b/lib/compiler/src/beam_asm.erl
@@ -387,7 +387,7 @@ encode_arg({list, List}, Dict0) ->
     {L, Dict} = encode_list(List, Dict0, []),
     {[encode(?tag_z, 1), encode(?tag_u, length(List))|L], Dict};
 encode_arg({float, Float}, Dict) when is_float(Float) ->
-    {[encode(?tag_z, 0),<<Float:64/float>>], Dict};
+    encode_arg({literal,Float}, Dict);
 encode_arg({fr,Fr}, Dict) ->
     {[encode(?tag_z, 2),encode(?tag_u, Fr)], Dict};
 encode_arg({field_flags,Flags0}, Dict) ->
diff --git a/lib/compiler/src/beam_disasm.erl b/lib/compiler/src/beam_disasm.erl
index 62bdc74cc8..67d756c45c 100644
--- a/lib/compiler/src/beam_disasm.erl
+++ b/lib/compiler/src/beam_disasm.erl
@@ -512,7 +512,12 @@ decode_z_tagged(Tag,B,Bs,Literals) when (B band 16#08) =:= 0 ->
 	    decode_alloc_list(Bs, Literals);
 	4 -> % literal
 	    {{u,LitIndex},RestBs} = decode_arg(Bs),
-	    {{literal,gb_trees:get(LitIndex, Literals)},RestBs};
+	    case gb_trees:get(LitIndex, Literals) of
+		Float when is_float(Float) ->
+		    {{float,Float},RestBs};
+		Literal ->
+		    {{literal,Literal},RestBs}
+	    end;
 	_ ->
 	    ?exit({decode_z_tagged,{invalid_extended_tag,N}})
     end;
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