[project @ 1999-01-23 17:38:52 by sof]

do_if_stmt: insert extra (I_) to avoid minInt blues.

diff --git a/ghc/compiler/absCSyn/PprAbsC.lhs b/ghc/compiler/absCSyn/PprAbsC.lhs
index f5456b8..9531325 100644 (file)
--- a/ghc/compiler/absCSyn/PprAbsC.lhs
+++ b/ghc/compiler/absCSyn/PprAbsC.lhs
@@ -170,6 +170,7 @@ pprAbsC (CSwitch discrim [(tag,alt_code)] deflt) c -- only one alt
       Just dc ->               -- make it an "if"
                 do_if_stmt discrim tag alt_code dc c
 
+-- What problem is the re-ordering trying to solve ?
 pprAbsC (CSwitch discrim [(tag1@(MachInt i1 _), alt_code1),
                              (tag2@(MachInt i2 _), alt_code2)] deflt) c
   | empty_deflt && ((i1 == 0 && i2 == 1) || (i1 == 1 && i2 == 0))
@@ -625,9 +626,23 @@ do_if_stmt discrim tag alt_code deflt c
                                      deflt alt_code
                                      (addrModeCosts discrim Rhs) c
       other              -> let
-                              cond = hcat [ pprAmode discrim,
-                                         ptext SLIT(" == "),
-                                         pprAmode (CLit tag) ]
+                              cond = hcat [ pprAmode discrim
+                                          , ptext SLIT(" == ")
+                                          , tcast
+                                          , pprAmode (CLit tag)
+                                          ]
+                               -- to be absolutely sure that none of the 
+                               -- conversion rules hit, e.g.,
+                               --
+                               --     minInt is different to (int)minInt
+                               --
+                               -- in C (when minInt is a number not a constant
+                               --  expression which evaluates to it.)
+                               -- 
+                              tcast =
+                                case other of
+                                  MachInt _ signed | signed    -> ptext SLIT("(I_)")
+                                  _ -> empty
                            in
                            ppr_if_stmt cond
                                         alt_code deflt