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[PATCH, 4.7] Fix PR 48226, Allow Iterator::vector vector on powerpc with VSX
- From: Michael Meissner <meissner at linux dot vnet dot ibm dot com>
- To: gcc-patches at gcc dot gnu dot org, dje dot gcc at gmail dot com
- Date: Mon, 21 Mar 2011 19:23:59 -0400
- Subject: [PATCH, 4.7] Fix PR 48226, Allow Iterator::vector vector on powerpc with VSX
This patch fixes a problem discovered by compiling the boost libraries with VSX
enabled. In the middle of a template is the code:
namespace boost
{
// ...
template <typename Iterator>
struct apply
{
// ...
typedef typename Iterator::vector vector;
// ...
};
}
The conditional keyword 'vector' is being handled by rs6000_macro_to_expand,
and it wants to peek at the next keyword. If the next keyword is also vector,
rs6000_macro_to_expand will be called recursively, and the expansion of vector
into vector will be lost.
I have boostrapped the following patch and it fixes the problem, and causes no
regressions in the make check out. Is this ok to install in the trunk? I
would also like to backport this to the 4.6 branch (after the 4.6 release) and
the 4.5 branch which also have the same problem.
[gcc]
2011-03-21 Michael Meissner <meissner@linux.vnet.ibm.com>
PR target/48226
* config/rs6000/rs6000-c.c (rs6000_macro_to_expand): If we see a
vector when peeking at the next token for vector, don't expand the
keywords.
[gcc/testsuite]
2011-03-21 Michael Meissner <meissner@linux.vnet.ibm.com>
PR target/48226
* gcc.target/powerpc/pr48226.c: New file.
Index: gcc/testsuite/gcc.target/powerpc/pr48226.c
===================================================================
--- gcc/testsuite/gcc.target/powerpc/pr48226.c (revision 0)
+++ gcc/testsuite/gcc.target/powerpc/pr48226.c (revision 0)
@@ -0,0 +1,14 @@
+/* { dg-do compile } */
+/* { dg-skip-if "" { powerpc*-*-darwin* } { "*" } { "" } } */
+/* { dg-require-effective-target powerpc_vsx_ok } */
+/* { dg-options "-O3 -mcpu=power7" } */
+
+/* The bug shows up if you compile with -maltivec or -mcpu=power7, due to one
+ of the vector's being eliminated due to rs6000_macro_to_expand being called
+ recursively. */
+
+struct vector {
+ float v[4];
+};
+
+struct vector vector = { 1.0, 2.0, 3.0, 4.0 };
Index: gcc/config/rs6000/rs6000-c.c
===================================================================
--- gcc/config/rs6000/rs6000-c.c (revision 171246)
+++ gcc/config/rs6000/rs6000-c.c (working copy)
@@ -182,7 +182,10 @@ rs6000_macro_to_expand (cpp_reader *pfil
expand_this = C_CPP_HASHNODE (__vector_keyword);
expand_bool_pixel = __bool_keyword;
}
- else if (ident)
+ /* The boost libraries have code with Iterator::vector vector in it. If
+ we allow the normal handling, this module will be called recursively,
+ and the vector will be skipped.; */
+ else if (ident && (ident != C_CPP_HASHNODE (__vector_keyword)))
{
enum rid rid_code = (enum rid)(ident->rid_code);
if (ident->type == NT_MACRO)
--
Michael Meissner, IBM
5 Technology Place Drive, M/S 2757, Westford, MA 01886-3141, USA
meissner@linux.vnet.ibm.com fax +1 (978) 399-6899