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[Committed] Type-safety for unprototyped abs builtin
- From: Roger Sayle <roger at eyesopen dot com>
- To: gcc-patches at gcc dot gnu dot org
- Cc: Ulrich Weigand <Ulrich dot Weigand at de dot ibm dot com>
- Date: Tue, 11 Jan 2005 22:10:22 -0700 (MST)
- Subject: [Committed] Type-safety for unprototyped abs builtin
The following patch should fix the failure of gcc.dg/ftrapv-2.c on
s390x-ibm-linux as reported by Ulrich Weigand. The problem is that
calls to unprototyped builtin functions don't have their arguments
promoted to their assumed types. In the case of ftrapv-2.c, we were
calling "abs" with a long argument, and without a function prototype
the front-end doesn't attempt to cast the long to an "int". The
mistake is then in the middle-end, where fold_builtin_abs checks
that the single argument has integer type, but neither checks nor
coerces it to the required width. Fortunately, this mistake is
tolerated by the poor typing in the RTL expanders, but using -ftrapv
is enough to expose the problem.
The following patch has been tested on i686-pc-linux-gnu with a full
"make bootstrap", all default languages, and regression tested with a
top-level "make -k check" with no new failures. I've also confirmed
that this resolves the ftrapv-2.c ICE in a cross-compiler cc1 to
s390x-ibm-linux.
Committed to mainline CVS.
2005-01-11 Roger Sayle <roger@eyesopen.com>
* builtins.c (fold_builtin_fabs): Convert argument to the appropriate
type as args of unprototyped builtins aren't automatically promoted.
(fold_builtin_abs): Likewise.
Index: builtins.c
===================================================================
RCS file: /cvs/gcc/gcc/gcc/builtins.c,v
retrieving revision 1.411
diff -c -3 -p -r1.411 builtins.c
*** builtins.c 7 Jan 2005 09:00:50 -0000 1.411
--- builtins.c 12 Jan 2005 02:56:34 -0000
*************** fold_builtin_fabs (tree arglist, tree ty
*** 7449,7454 ****
--- 7449,7455 ----
return 0;
arg = TREE_VALUE (arglist);
+ arg = fold_convert (type, arg);
if (TREE_CODE (arg) == REAL_CST)
return fold_abs_const (arg, type);
return fold (build1 (ABS_EXPR, type, arg));
*************** fold_builtin_abs (tree arglist, tree typ
*** 7465,7470 ****
--- 7466,7472 ----
return 0;
arg = TREE_VALUE (arglist);
+ arg = fold_convert (type, arg);
if (TREE_CODE (arg) == INTEGER_CST)
return fold_abs_const (arg, type);
return fold (build1 (ABS_EXPR, type, arg));
Roger
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