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[PATCH] Fix latent bug in replace_uses_by
- From: Richard Biener <rguenther at suse dot de>
- To: gcc-patches at gcc dot gnu dot org
- Date: Thu, 20 Feb 2014 15:51:54 +0100 (CET)
- Subject: [PATCH] Fix latent bug in replace_uses_by
- Authentication-results: sourceware.org; auth=none
The following fixes an ICE I got when building libjava with a local
patch. This causes us to substitute &MEM[&a, 5] into MEM[_3, 0]
to MEM[&MEM[&a, 5], 0] and then asking stmt_ends_bb_p which doesn't
expect such bogus MEM_REFs. The MEM_REF is canonicalized by
calling fold_stmt on it later, but the fix is of course to move
the marking of altered BBs before doing the actual substitution
(only then we are sure to catch all previous bb-ending stmts).
I also noticed we don't verify MEM_REFs on LHSs.
Bootstrapped and tested on x86_64-unknown-linux-gnu, applied
to trunk and branch (it's a regression uncovered by the fix for PR60115).
Richard.
2014-02-20 Richard Biener <rguenther@suse.de>
* tree-cfg.c (replace_uses_by): Mark altered BBs before
doing the substitution.
(verify_gimple_assign_single): Also verify bare MEM_REFs
on the lhs.
Index: gcc/tree-cfg.c
===================================================================
--- gcc/tree-cfg.c (revision 207936)
+++ gcc/tree-cfg.c (working copy)
@@ -1677,6 +1677,11 @@ replace_uses_by (tree name, tree val)
FOR_EACH_IMM_USE_STMT (stmt, imm_iter, name)
{
+ /* Mark the block if we change the last stmt in it. */
+ if (cfgcleanup_altered_bbs
+ && stmt_ends_bb_p (stmt))
+ bitmap_set_bit (cfgcleanup_altered_bbs, gimple_bb (stmt)->index);
+
FOR_EACH_IMM_USE_ON_STMT (use, imm_iter)
{
replace_exp (use, val);
@@ -1701,11 +1706,6 @@ replace_uses_by (tree name, tree val)
gimple orig_stmt = stmt;
size_t i;
- /* Mark the block if we changed the last stmt in it. */
- if (cfgcleanup_altered_bbs
- && stmt_ends_bb_p (stmt))
- bitmap_set_bit (cfgcleanup_altered_bbs, gimple_bb (stmt)->index);
-
/* FIXME. It shouldn't be required to keep TREE_CONSTANT
on ADDR_EXPRs up-to-date on GIMPLE. Propagation will
only change sth from non-invariant to invariant, and only
@@ -3986,7 +3986,9 @@ verify_gimple_assign_single (gimple stmt
return true;
}
- if (handled_component_p (lhs))
+ if (handled_component_p (lhs)
+ || TREE_CODE (lhs) == MEM_REF
+ || TREE_CODE (lhs) == TARGET_MEM_REF)
res |= verify_types_in_gimple_reference (lhs, true);
/* Special codes we cannot handle via their class. */