Merge pull request #40 from AbsInt/inline-asm

GCC-style extended inline asm.

The subset implemented is:

- zero or one output
- output constraints "=r" (to register) or "=m" (to memory)
- zero, one or several inputs
- input constraints "r" (in register), "m" (in memory), "i" and "n" (compile-time integer constant)
- clobbered registers (the 3rd argument)
- both anonymous (%3) and named (%[name]) operands
- modifiers %R and %Q to refer to the most significant / least significant part of a register pair holding a 64-bit integer. (Undocumented GCC ARM feature.)

All asm statements are treated as "volatile", possibly modifying memory and condition codes.

1 files changed, 23 insertions, 1 deletions

diff --git a/backend/PrintAnnot.ml b/backend/PrintAnnot.ml
index 995f22dd..88f5d8d6 100644
--- a/backend/PrintAnnot.ml
+++ b/backend/PrintAnnot.ml
@@ -148,7 +148,29 @@ let print_annot_val print_preg oc txt args =
   print_annot_text print_preg "<internal error>" oc txt
     (List.map (fun r -> AA_base r) args)
 
-(* Print CompCert version and command-line as asm comment *)
+(** Inline assembly *)
+
+let re_asm_param = Str.regexp "%%\\|%[0-9]+"
+
+let print_inline_asm print_preg oc txt sg args res =
+  let operands =
+    if sg.sig_res = None then args else res @ args in
+  let print_fragment = function
+  | Str.Text s ->
+      output_string oc s
+  | Str.Delim "%%" ->
+      output_char oc '%'
+  | Str.Delim s ->
+      let n = int_of_string (String.sub s 1 (String.length s - 1)) in
+      try
+        print_preg oc (List.nth operands n)
+      with Failure _ ->
+        fprintf oc "<bad parameter %s>" s in
+  List.iter print_fragment (Str.full_split re_asm_param txt);
+  fprintf oc "\n"
+
+
+(** Print CompCert version and command-line as asm comment *)
 
 let print_version_and_options oc comment =
   fprintf oc "%s File generated by CompCert %s\n" comment Configuration.version;