From a9c283a506663a1bb97330a609a3c443043424b1 Mon Sep 17 00:00:00 2001 From: Steven Bosscher Date: Sat, 18 Aug 2012 13:44:00 +0000 Subject: [PATCH] sparseset.c (sparseset_alloc): Use non-clearing allocation. * sparseset.c (sparseset_alloc): Use non-clearing allocation. Tell valgrind not to worry about reading from unitialized memory. From-SVN: r190503 --- gcc/ChangeLog | 5 +++++ gcc/sparseset.c | 10 ++++++---- 2 files changed, 11 insertions(+), 4 deletions(-) diff --git a/gcc/ChangeLog b/gcc/ChangeLog index 9dd5e9c54f3..2282536c1ab 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -1,3 +1,8 @@ +2012-08-18 Steven Bosscher + + * sparseset.c (sparseset_alloc): Use non-clearing allocation. Tell + valgrind not to worry about reading from unitialized memory. + 2012-08-18 Steven Bosscher PR middle-end/54313 diff --git a/gcc/sparseset.c b/gcc/sparseset.c index 823919a886e..35a2c3e1a34 100644 --- a/gcc/sparseset.c +++ b/gcc/sparseset.c @@ -30,12 +30,14 @@ sparseset_alloc (SPARSESET_ELT_TYPE n_elms) unsigned int n_bytes = sizeof (struct sparseset_def) + ((n_elms - 1) * 2 * sizeof (SPARSESET_ELT_TYPE)); - /* We use xcalloc rather than xmalloc to silence some valgrind uninitialized + sparseset set = XNEWVAR(struct sparseset_def, n_bytes); + + /* Mark the sparseset as defined to silence some valgrind uninitialized read errors when accessing set->sparse[n] when "n" is not, and never has been, in the set. These uninitialized reads are expected, by design and - harmless. If this turns into a performance problem due to some future - additional users of sparseset, we can revisit this decision. */ - sparseset set = (sparseset) xcalloc (1, n_bytes); + harmless. */ + VALGRIND_DISCARD (VALGRIND_MAKE_MEM_DEFINED (set, n_bytes)); + set->dense = &(set->elms[0]); set->sparse = &(set->elms[n_elms]); set->size = n_elms;