Hi!
The http://gcc.gnu.org/ml/gcc-patches/1999-07/msg00031.html change
appears to be IMHO highly undesirable loophole around the lack of
TImode support on 32-bit targets. Those targets return
false from targetm.scalar_mode_supported_p (TImode) for a reason,
while for some arithmetics operation perhaps the middle-end manages
to emit something that doesn't ICE, as the following testcases shows
there are various other cases which just ICE.
While the 32-bit targets don't support __int128/__int128_t/__uint128_t,
because of the above change one can use instead
__typeof (1234567891234567891234567891234567812) or similar constructs
to get variables of that type and similarly expressions can still have
the 128-bit type, but as can be seen we don't really support those.
Thus, this patch reverts the effect of the above patch for 32-bit targets,
basically the type of the oversized literals is now __int128_t/__uint128_t
on 64-bit targets as before, but only long long/unsigned long long on
32-bit targets. While this is an ABI change, it affects only code on which
we emit pedwarn, so I'd think it is unlikely to be used in the wild.
Bootstrapped/regtested on x86_64-linux and i686-linux, ok for trunk?
2017-04-10 Jakub Jelinek <ja...@redhat.com>
PR middle-end/79788
PR middle-end/80375
* c-common.c (c_common_type_for_mode): Don't handle
widest_*_literal_type_node here.
c_common_signed_or_unsigned_type): Likewise.
(c_common_nodes_and_builtins): Set widest_*_literal_type_node
to *intTI_type_node or *intDI_type_node depending on whether
TImode is supported by the target or not.
* gcc.dg/pr79788-1.c: New test.
* gcc.dg/pr79788-2.c: New test.
--- gcc/c-family/c-common.c.jj 2017-03-31 08:39:08.000000000 +0200
+++ gcc/c-family/c-common.c 2017-04-10 13:29:10.691179060 +0200
@@ -2179,10 +2179,6 @@ c_common_type_for_mode (machine_mode mod
return (unsignedp ? int_n_trees[i].unsigned_type
: int_n_trees[i].signed_type);
- if (mode == TYPE_MODE (widest_integer_literal_type_node))
- return unsignedp ? widest_unsigned_literal_type_node
- : widest_integer_literal_type_node;
-
if (mode == QImode)
return unsignedp ? unsigned_intQI_type_node : intQI_type_node;
@@ -2412,8 +2408,6 @@ c_common_signed_or_unsigned_type (int un
return (unsignedp ? int_n_trees[i].unsigned_type
: int_n_trees[i].signed_type);
- if (type1 == widest_integer_literal_type_node || type1 ==
widest_unsigned_literal_type_node)
- return unsignedp ? widest_unsigned_literal_type_node :
widest_integer_literal_type_node;
#if HOST_BITS_PER_WIDE_INT >= 64
if (type1 == intTI_type_node || type1 == unsigned_intTI_type_node)
return unsignedp ? unsigned_intTI_type_node : intTI_type_node;
@@ -2534,10 +2528,6 @@ c_common_signed_or_unsigned_type (int un
return (unsignedp ? int_n_trees[i].unsigned_type
: int_n_trees[i].signed_type);
- if (TYPE_OK (widest_integer_literal_type_node))
- return (unsignedp ? widest_unsigned_literal_type_node
- : widest_integer_literal_type_node);
-
#if HOST_BITS_PER_WIDE_INT >= 64
if (TYPE_OK (intTI_type_node))
return unsignedp ? unsigned_intTI_type_node : intTI_type_node;
@@ -4164,17 +4154,16 @@ c_common_nodes_and_builtins (void)
#endif
/* Create the widest literal types. */
- widest_integer_literal_type_node
- = make_signed_type (HOST_BITS_PER_WIDE_INT * 2);
- lang_hooks.decls.pushdecl (build_decl (UNKNOWN_LOCATION,
- TYPE_DECL, NULL_TREE,
- widest_integer_literal_type_node));
-
- widest_unsigned_literal_type_node
- = make_unsigned_type (HOST_BITS_PER_WIDE_INT * 2);
- lang_hooks.decls.pushdecl (build_decl (UNKNOWN_LOCATION,
- TYPE_DECL, NULL_TREE,
- widest_unsigned_literal_type_node));
+ if (targetm.scalar_mode_supported_p (TImode))
+ {
+ widest_integer_literal_type_node = intTI_type_node;
+ widest_unsigned_literal_type_node = unsigned_intTI_type_node;
+ }
+ else
+ {
+ widest_integer_literal_type_node = intDI_type_node;
+ widest_unsigned_literal_type_node = unsigned_intDI_type_node;
+ }
signed_size_type_node = c_common_signed_type (size_type_node);
--- gcc/testsuite/gcc.dg/pr79788-1.c.jj 2017-04-10 13:58:33.399248477 +0200
+++ gcc/testsuite/gcc.dg/pr79788-1.c 2017-04-10 13:59:17.980699210 +0200
@@ -0,0 +1,11 @@
+/* PR middle-end/79788 */
+/* { dg-do compile } */
+/* { dg-options "-O2" } */
+
+long long
+foo (long long x, long long y)
+{
+ if (y > 1234567891234567891234567891234567812 / x) /* { dg-warning
"integer constant is too large for its type" } */
+ return x;
+ return 0;
+}
--- gcc/testsuite/gcc.dg/pr79788-2.c.jj 2017-04-10 13:58:37.171202004 +0200
+++ gcc/testsuite/gcc.dg/pr79788-2.c 2017-04-10 13:57:33.000000000 +0200
@@ -0,0 +1,11 @@
+/* PR middle-end/79788 */
+/* { dg-do compile } */
+/* { dg-options "-ftrapv" } */
+
+void bar (void);
+void
+foo (long long int p, long long int q)
+{
+ if (p >= 1234567891234567891234567891234567812 + q) /* { dg-warning
"integer constant is too large for its type" } */
+ bar ();
+}
Jakub
