Flag to turn on/off the recognition of fused multiply-add and multiply-sub

git-svn-id: https://yquem.inria.fr/compcert/svn/compcert/trunk@706 fca1b0fc-160b-0410-b1d3-a4f43f01ea2e

7 files changed, 69 insertions, 61 deletions

diff --git a/backend/Selection.v b/backend/Selection.v
index 6554e429..1de6ae3c 100644
--- a/backend/Selection.v
+++ b/backend/Selection.v
@@ -712,6 +712,8 @@ Definition shru (e1: expr) (e2: expr) :=
 
 (** ** Floating-point arithmetic *)
 
+Parameter use_fused_mul : unit -> bool.
+
 (*
 Definition addf (e1: expr) (e2: expr) :=
   match e1, e2 with
@@ -749,14 +751,16 @@ Definition addf_match (e1: expr) (e2: expr) :=
   end.
 
 Definition addf (e1: expr) (e2: expr) :=
-  match addf_match e1 e2 with
-  | addf_case1 t1 t2 t3 =>
-      Eop Omuladdf (t1:::t2:::t3:::Enil)
-  | addf_case2 t1 t2 t3 =>
-      Elet t1 (Eop Omuladdf (lift t2:::lift t3:::Eletvar 0:::Enil))
-  | addf_default e1 e2 =>
-      Eop Oaddf (e1:::e2:::Enil)
-  end.
+  if use_fused_mul tt then
+    match addf_match e1 e2 with
+    | addf_case1 t1 t2 t3 =>
+        Eop Omuladdf (t1:::t2:::t3:::Enil)
+    | addf_case2 t1 t2 t3 =>
+        Eop Omuladdf (t2:::t3:::t1:::Enil)
+    | addf_default e1 e2 =>
+        Eop Oaddf (e1:::e2:::Enil)
+    end
+  else Eop Oaddf (e1:::e2:::Enil).
 
 (*
 Definition subf (e1: expr) (e2: expr) :=
@@ -783,12 +787,14 @@ Definition subf_match (e1: expr) (e2: expr) :=
   end.
 
 Definition subf (e1: expr) (e2: expr) :=
-  match subf_match e1 e2 with
-  | subf_case1 t1 t2 t3 =>
-      Eop Omulsubf (t1:::t2:::t3:::Enil)
-  | subf_default e1 e2 =>
-      Eop Osubf (e1:::e2:::Enil)
-  end.
+  if use_fused_mul tt then
+    match subf_match e1 e2 with
+    | subf_case1 t1 t2 t3 =>
+        Eop Omulsubf (t1:::t2:::t3:::Enil)
+    | subf_default e1 e2 =>
+        Eop Osubf (e1:::e2:::Enil)
+    end
+  else Eop Osubf (e1:::e2:::Enil).
 
 (** ** Truncations and sign extensions *)
 
diff --git a/backend/Selectionproof.v b/backend/Selectionproof.v
index bd4dd233..784823b0 100644
--- a/backend/Selectionproof.v
+++ b/backend/Selectionproof.v
@@ -722,13 +722,13 @@ Theorem eval_addf:
   eval_expr ge sp e m le b (Vfloat y) ->
   eval_expr ge sp e m le (addf a b) (Vfloat (Float.add x y)).
 Proof.
-  intros until y; unfold addf; case (addf_match a b); intros; InvEval.
+  intros until y; unfold addf.
+  destruct (use_fused_mul tt).
+  case (addf_match a b); intros; InvEval.
   EvalOp. simpl. congruence.
-  econstructor. eauto. EvalOp. econstructor. eauto with evalexpr. 
-  econstructor. eauto with evalexpr. econstructor. 
-  econstructor. simpl. reflexivity. constructor.
-  simpl. subst y. rewrite Float.addf_commut. auto.
+  EvalOp. simpl. rewrite Float.addf_commut. congruence.
   EvalOp.
+  intros. EvalOp.
 Qed.
  
 Theorem eval_subf:
@@ -737,9 +737,12 @@ Theorem eval_subf:
   eval_expr ge sp e m le b (Vfloat y) ->
   eval_expr ge sp e m le (subf a b) (Vfloat (Float.sub x y)).
 Proof.
-  intros until y; unfold subf; case (subf_match a b); intros.
+  intros until y; unfold subf.
+  destruct (use_fused_mul tt).
+  case (subf_match a b); intros.
   InvEval. EvalOp. simpl. congruence. 
   EvalOp.
+  intros. EvalOp.
 Qed.
 
 Theorem eval_cast8signed:
diff --git a/caml/Driver.ml b/caml/Driver.ml
index 659422e9..dacc9dcb 100644
--- a/caml/Driver.ml
+++ b/caml/Driver.ml
@@ -11,6 +11,7 @@
 (* *********************************************************************)
 
 open Printf
+open Clflags
 
 (* Location of the standard library *)
 
@@ -20,19 +21,6 @@ let stdlib_path = ref(
   with Not_found ->
     Configuration.stdlib_path)
 
-(* Command-line flags *)
-
-let prepro_options = ref ([]: string list)
-let linker_options = ref ([]: string list)
-let exe_name = ref "a.out"
-let option_flonglong = ref false
-let option_dclight = ref false
-let option_dasm = ref false
-let option_E = ref false
-let option_S = ref false
-let option_c = ref false
-let option_v = ref false
-
 let command cmd =
   if !option_v then begin
     prerr_string "+ "; prerr_string cmd; prerr_endline ""
@@ -273,6 +261,7 @@ Preprocessing options:
   -U<symb>       Undefine preprocessor symbol
 Compilation options:
   -flonglong     Treat 'long long' as 'long' and 'long double' as 'double'
+  -fmadd         Use fused multiply-add and multiply-sub instructions
   -dclight       Save generated Clight in <file>.light.c
   -dasm          Save generated assembly in <file>.s
 Linking options:
@@ -308,6 +297,10 @@ let rec parse_cmdline i =
       option_flonglong := true;
       parse_cmdline (i + 1)
     end else
+    if s = "-fmadd" then begin
+      option_fmadd := true;
+      parse_cmdline (i + 1)
+    end else
     if s = "-dclight" then begin
       option_dclight := true;
       parse_cmdline (i + 1)
diff --git a/extraction/.depend b/extraction/.depend
index 4f6abc22..ac888a52 100644
--- a/extraction/.depend
+++ b/extraction/.depend
@@ -33,13 +33,13 @@
     Locations.cmx InterfGraph.cmx Datatypes.cmx Conventions.cmx \
     ../caml/Camlcoq.cmx BinPos.cmx BinInt.cmx AST.cmx ../caml/Coloringaux.cmi 
 ../caml/Driver.cmo: ../caml/PrintPPC.cmi ../caml/PrintCsyntax.cmo Main.cmi \
-    Errors.cmi Csyntax.cmi ../caml/Configuration.cmo ../caml/Cil2Csyntax.cmo \
-    ../caml/Camlcoq.cmo ../caml/CMtypecheck.cmi ../caml/CMparser.cmi \
-    ../caml/CMlexer.cmi 
+    Errors.cmi Csyntax.cmi ../caml/Configuration.cmo ../caml/Clflags.cmo \
+    ../caml/Cil2Csyntax.cmo ../caml/Camlcoq.cmo ../caml/CMtypecheck.cmi \
+    ../caml/CMparser.cmi ../caml/CMlexer.cmi 
 ../caml/Driver.cmx: ../caml/PrintPPC.cmx ../caml/PrintCsyntax.cmx Main.cmx \
-    Errors.cmx Csyntax.cmx ../caml/Configuration.cmx ../caml/Cil2Csyntax.cmx \
-    ../caml/Camlcoq.cmx ../caml/CMtypecheck.cmx ../caml/CMparser.cmx \
-    ../caml/CMlexer.cmx 
+    Errors.cmx Csyntax.cmx ../caml/Configuration.cmx ../caml/Clflags.cmx \
+    ../caml/Cil2Csyntax.cmx ../caml/Camlcoq.cmx ../caml/CMtypecheck.cmx \
+    ../caml/CMparser.cmx ../caml/CMlexer.cmx 
 ../caml/Floataux.cmo: Integers.cmi ../caml/Camlcoq.cmo 
 ../caml/Floataux.cmx: Integers.cmx ../caml/Camlcoq.cmx 
 ../caml/Linearizeaux.cmo: Maps.cmi Lattice.cmi LTL.cmi Datatypes.cmi \
@@ -87,8 +87,8 @@ Cminorgen.cmi: Zmax.cmi Specif.cmi OrderedType.cmi Ordered.cmi Mem.cmi \
 Cminor.cmi: Values.cmi Specif.cmi Mem.cmi Maps.cmi Integers.cmi \
     Globalenvs.cmi Floats.cmi Datatypes.cmi CList.cmi BinPos.cmi BinInt.cmi \
     AST.cmi 
-CminorSel.cmi: Values.cmi Op.cmi Integers.cmi Globalenvs.cmi Datatypes.cmi \
-    CList.cmi BinInt.cmi AST.cmi 
+CminorSel.cmi: Values.cmi Specif.cmi Op.cmi Mem.cmi Integers.cmi \
+    Globalenvs.cmi Datatypes.cmi Cminor.cmi CList.cmi BinInt.cmi AST.cmi 
 Coloring.cmi: Specif.cmi Registers.cmi RTLtyping.cmi RTL.cmi Op.cmi Maps.cmi \
     Locations.cmi InterfGraph.cmi Datatypes.cmi Coqlib.cmi Conventions.cmi \
     CList.cmi BinInt.cmi AST.cmi 
@@ -137,8 +137,8 @@ Linearize.cmi: Specif.cmi OrderedType.cmi Ordered.cmi Op.cmi Maps.cmi \
     Lattice.cmi LTLin.cmi LTL.cmi Errors.cmi Datatypes.cmi Coqlib.cmi \
     CString.cmi CList.cmi CInt.cmi BinPos.cmi BinInt.cmi Ascii.cmi AST.cmi 
 Linear.cmi: Values.cmi Specif.cmi Op.cmi Mem.cmi Locations.cmi Integers.cmi \
-    Globalenvs.cmi Datatypes.cmi Coqlib.cmi CList.cmi BinPos.cmi BinInt.cmi \
-    AST.cmi 
+    Globalenvs.cmi Datatypes.cmi Coqlib.cmi Conventions.cmi CList.cmi \
+    BinPos.cmi BinInt.cmi AST.cmi 
 Locations.cmi: Values.cmi Specif.cmi Datatypes.cmi Coqlib.cmi BinPos.cmi \
     BinInt.cmi AST.cmi 
 LTLin.cmi: Values.cmi Specif.cmi Op.cmi Mem.cmi Locations.cmi Integers.cmi \
@@ -176,7 +176,7 @@ Registers.cmi: Specif.cmi OrderedType.cmi Ordered.cmi Maps.cmi Datatypes.cmi \
 Reload.cmi: Specif.cmi Parallelmove.cmi Op.cmi Locations.cmi Linear.cmi \
     LTLin.cmi Datatypes.cmi Conventions.cmi CList.cmi AST.cmi 
 RTLgen.cmi: Switch.cmi Specif.cmi Registers.cmi RTL.cmi Op.cmi Maps.cmi \
-    Integers.cmi Errors.cmi Datatypes.cmi Coqlib.cmi CminorSel.cmi \
+    Integers.cmi Errors.cmi Datatypes.cmi Coqlib.cmi CminorSel.cmi Cminor.cmi \
     CString.cmi CList.cmi BinPos.cmi Ascii.cmi AST.cmi 
 RTL.cmi: Values.cmi Registers.cmi Op.cmi Mem.cmi Maps.cmi Integers.cmi \
     Globalenvs.cmi Datatypes.cmi CList.cmi BinPos.cmi BinInt.cmi AST.cmi 
@@ -249,10 +249,12 @@ Cminor.cmo: Values.cmi Specif.cmi Mem.cmi Maps.cmi Integers.cmi \
 Cminor.cmx: Values.cmx Specif.cmx Mem.cmx Maps.cmx Integers.cmx \
     Globalenvs.cmx Floats.cmx Datatypes.cmx CList.cmx BinPos.cmx BinInt.cmx \
     AST.cmx Cminor.cmi 
-CminorSel.cmo: Values.cmi Op.cmi Integers.cmi Globalenvs.cmi Datatypes.cmi \
-    CList.cmi BinInt.cmi AST.cmi CminorSel.cmi 
-CminorSel.cmx: Values.cmx Op.cmx Integers.cmx Globalenvs.cmx Datatypes.cmx \
-    CList.cmx BinInt.cmx AST.cmx CminorSel.cmi 
+CminorSel.cmo: Values.cmi Specif.cmi Op.cmi Mem.cmi Integers.cmi \
+    Globalenvs.cmi Datatypes.cmi Cminor.cmi CList.cmi BinInt.cmi AST.cmi \
+    CminorSel.cmi 
+CminorSel.cmx: Values.cmx Specif.cmx Op.cmx Mem.cmx Integers.cmx \
+    Globalenvs.cmx Datatypes.cmx Cminor.cmx CList.cmx BinInt.cmx AST.cmx \
+    CminorSel.cmi 
 Coloring.cmo: Specif.cmi Registers.cmi RTLtyping.cmi RTL.cmi Op.cmi Maps.cmi \
     Locations.cmi InterfGraph.cmi Datatypes.cmi Coqlib.cmi Conventions.cmi \
     ../caml/Coloringaux.cmi CList.cmi BinInt.cmi AST.cmi Coloring.cmi 
@@ -366,11 +368,11 @@ Linearize.cmx: Specif.cmx OrderedType.cmx Ordered.cmx Op.cmx Maps.cmx \
     FSetAVL.cmx Errors.cmx Datatypes.cmx Coqlib.cmx CString.cmx CList.cmx \
     BinPos.cmx BinInt.cmx Ascii.cmx AST.cmx Linearize.cmi 
 Linear.cmo: Values.cmi Specif.cmi Op.cmi Mem.cmi Locations.cmi Integers.cmi \
-    Globalenvs.cmi Datatypes.cmi Coqlib.cmi CList.cmi BinPos.cmi BinInt.cmi \
-    AST.cmi Linear.cmi 
+    Globalenvs.cmi Datatypes.cmi Coqlib.cmi Conventions.cmi CList.cmi \
+    BinPos.cmi BinInt.cmi AST.cmi Linear.cmi 
 Linear.cmx: Values.cmx Specif.cmx Op.cmx Mem.cmx Locations.cmx Integers.cmx \
-    Globalenvs.cmx Datatypes.cmx Coqlib.cmx CList.cmx BinPos.cmx BinInt.cmx \
-    AST.cmx Linear.cmi 
+    Globalenvs.cmx Datatypes.cmx Coqlib.cmx Conventions.cmx CList.cmx \
+    BinPos.cmx BinInt.cmx AST.cmx Linear.cmi 
 Locations.cmo: Values.cmi Specif.cmi Datatypes.cmi Coqlib.cmi BinPos.cmi \
     BinInt.cmi AST.cmi Locations.cmi 
 Locations.cmx: Values.cmx Specif.cmx Datatypes.cmx Coqlib.cmx BinPos.cmx \
@@ -453,12 +455,12 @@ Reload.cmx: Specif.cmx Parallelmove.cmx Op.cmx Locations.cmx Linear.cmx \
     LTLin.cmx Datatypes.cmx Conventions.cmx CList.cmx AST.cmx Reload.cmi 
 RTLgen.cmo: Switch.cmi Specif.cmi Registers.cmi ../caml/RTLgenaux.cmo RTL.cmi \
     Op.cmi Maps.cmi Integers.cmi Errors.cmi Datatypes.cmi Coqlib.cmi \
-    CminorSel.cmi CString.cmi CList.cmi BinPos.cmi Ascii.cmi AST.cmi \
-    RTLgen.cmi 
+    CminorSel.cmi Cminor.cmi CString.cmi CList.cmi BinPos.cmi Ascii.cmi \
+    AST.cmi RTLgen.cmi 
 RTLgen.cmx: Switch.cmx Specif.cmx Registers.cmx ../caml/RTLgenaux.cmx RTL.cmx \
     Op.cmx Maps.cmx Integers.cmx Errors.cmx Datatypes.cmx Coqlib.cmx \
-    CminorSel.cmx CString.cmx CList.cmx BinPos.cmx Ascii.cmx AST.cmx \
-    RTLgen.cmi 
+    CminorSel.cmx Cminor.cmx CString.cmx CList.cmx BinPos.cmx Ascii.cmx \
+    AST.cmx RTLgen.cmi 
 RTL.cmo: Values.cmi Registers.cmi Op.cmi Mem.cmi Maps.cmi Integers.cmi \
     Globalenvs.cmi Datatypes.cmi CList.cmi BinPos.cmi BinInt.cmi AST.cmi \
     RTL.cmi 
@@ -472,11 +474,11 @@ RTLtyping.cmx: Specif.cmx Registers.cmx ../caml/RTLtypingaux.cmx RTL.cmx \
     Op.cmx Maps.cmx Errors.cmx Datatypes.cmx Coqlib.cmx Conventions.cmx \
     CString.cmx CList.cmx Ascii.cmx AST.cmx RTLtyping.cmi 
 Selection.cmo: Specif.cmi Op.cmi Integers.cmi Datatypes.cmi Compare_dec.cmi \
-    CminorSel.cmi Cminor.cmi CList.cmi BinPos.cmi BinInt.cmi AST.cmi \
-    Selection.cmi 
+    CminorSel.cmi Cminor.cmi ../caml/Clflags.cmo CList.cmi BinPos.cmi \
+    BinInt.cmi AST.cmi Selection.cmi 
 Selection.cmx: Specif.cmx Op.cmx Integers.cmx Datatypes.cmx Compare_dec.cmx \
-    CminorSel.cmx Cminor.cmx CList.cmx BinPos.cmx BinInt.cmx AST.cmx \
-    Selection.cmi 
+    CminorSel.cmx Cminor.cmx ../caml/Clflags.cmx CList.cmx BinPos.cmx \
+    BinInt.cmx AST.cmx Selection.cmi 
 Setoid.cmo: Datatypes.cmi Setoid.cmi 
 Setoid.cmx: Datatypes.cmx Setoid.cmi 
 Specif.cmo: Datatypes.cmi Specif.cmi 
diff --git a/extraction/Makefile b/extraction/Makefile
index 54933cc0..044f89f0 100644
--- a/extraction/Makefile
+++ b/extraction/Makefile
@@ -22,6 +22,7 @@ FILES=\
   Coqlib.ml Maps.ml Ordered.ml Errors.ml AST.ml Iteration.ml Integers.ml \
   ../caml/Camlcoq.ml ../caml/Floataux.ml Floats.ml Parmov.ml Values.ml \
   Mem.ml Globalenvs.ml \
+  ../caml/Clflags.ml \
   Csyntax.ml Ctyping.ml Cminor.ml Csharpminor.ml Cshmgen.ml \
   Cminorgen.ml \
   Op.ml CminorSel.ml \
diff --git a/extraction/extraction.v b/extraction/extraction.v
index abb792c0..69034bc1 100644
--- a/extraction/extraction.v
+++ b/extraction/extraction.v
@@ -50,6 +50,9 @@ Extract Constant Iteration.GenIter.iterate =>
    in iter".
 
 
+(* Selection *)
+Extract Constant Selection.use_fused_mul => "(fun () -> !Clflags.option_fmadd)".
+
 (* RTLgen *)
 Extract Constant RTLgen.compile_switch => "RTLgenaux.compile_switch".
 Extract Constant RTLgen.more_likely => "RTLgenaux.more_likely".
diff --git a/test/c/Makefile b/test/c/Makefile
index c6cd9289..bff62114 100644
--- a/test/c/Makefile
+++ b/test/c/Makefile
@@ -1,7 +1,7 @@
 include ../../Makefile.config
 
 CCOMP=../../ccomp
-CCOMPFLAGS=-stdlib ../../runtime -dclight -dasm
+CCOMPFLAGS=-stdlib ../../runtime -fmadd -dclight -dasm
 
 CFLAGS=-O1 -Wall