re PR tree-optimization/19831 (Missing DSE/malloc/free optimization)

2013-10-29  Marc Glisse  <marc.glisse@inria.fr>

	PR tree-optimization/19831
gcc/
	* tree-ssa-alias.c (stmt_kills_ref_p_1): Handle BUILT_IN_FREE.

gcc/testsuite/
	* gcc.dg/tree-ssa/alias-25.c: New file.

From-SVN: r204160

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index a683e9a2546f133a203da1c10665f83a1e6d267a..3bb38ebf4fb4533ef02d8ecc48c7a8c810970575 100644 (file)
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,8 @@
+2013-10-29  Marc Glisse  <marc.glisse@inria.fr>
+
+       PR tree-optimization/19831
+       * tree-ssa-alias.c (stmt_kills_ref_p_1): Handle BUILT_IN_FREE.
+
 2013-10-29  Andrew MacLeod  <amacleod@redhat.com>
 
        * tree-outof-ssa.h: Remove include files.

diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index 8f1e5ebac835b9506c89f415fed06d1c67e6b63c..69937edf632818f6f9e24c7bff51c45ff3a51c48 100644 (file)
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,8 @@
+2013-10-29  Marc Glisse  <marc.glisse@inria.fr>
+
+       PR tree-optimization/19831
+       * gcc.dg/tree-ssa/alias-25.c: New file.
+
 2013-10-29  Richard Biener  <rguenther@suse.de>
 
        * g++.dg/vect/slp-pr56812.cc: Adjust with respect to -fvect-cost-model

diff --git a/gcc/testsuite/gcc.dg/tree-ssa/alias-25.c b/gcc/testsuite/gcc.dg/tree-ssa/alias-25.c
new file mode 100644 (file)
index 0000000..f5705d0
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/tree-ssa/alias-25.c
@@ -0,0 +1,12 @@
+/* { dg-do compile } */
+/* { dg-options "-O1 -fdump-tree-optimized" } */
+
+void f (long *p) {
+  *p = 42;
+  p[4] = 42;
+  __builtin_free (p);
+}
+
+/* { dg-final { scan-tree-dump-not "= 42" "optimized" } } */
+/* { dg-final { cleanup-tree-dump "optimized" } } */
+

diff --git a/gcc/tree-ssa-alias.c b/gcc/tree-ssa-alias.c
index a3046ad4f8127e43147a6275a562e0432943b6f8..4db83bd1f983ad75bddd34968cc75f22a6273c8c 100644 (file)
--- a/gcc/tree-ssa-alias.c
+++ b/gcc/tree-ssa-alias.c
@@ -2057,6 +2057,16 @@ stmt_kills_ref_p_1 (gimple stmt, ao_ref *ref)
          && DECL_BUILT_IN_CLASS (callee) == BUILT_IN_NORMAL)
        switch (DECL_FUNCTION_CODE (callee))
          {
+         case BUILT_IN_FREE:
+           {
+             tree ptr = gimple_call_arg (stmt, 0);
+             tree base = ao_ref_base (ref);
+             if (base && TREE_CODE (base) == MEM_REF
+                 && TREE_OPERAND (base, 0) == ptr)
+               return true;
+             break;
+           }
+
          case BUILT_IN_MEMCPY:
          case BUILT_IN_MEMPCPY:
          case BUILT_IN_MEMMOVE: