backport: re PR rtl-optimization/48141 (DSE compile time hog)

	Backported from mainline
	2011-03-17  Jakub Jelinek  <jakub@redhat.com>

	PR rtl-optimization/48141
	* dse.c (record_store): If no positions are needed in an insn
	that cannot be deleted, at least unchain it from active_local_stores.

	* gcc.dg/pr48141.c: New test.

From-SVN: r172132

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index f28377a9623ebfa6e7b4b2114e8c3de19ebcfd69..23e70e3201bf62979d5496a43c7f5cec158172cf 100644 (file)
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,12 @@
+2011-04-07  Jakub Jelinek  <jakub@redhat.com>
+
+       Backported from mainline
+       2011-03-17  Jakub Jelinek  <jakub@redhat.com>
+
+       PR rtl-optimization/48141
+       * dse.c (record_store): If no positions are needed in an insn
+       that cannot be deleted, at least unchain it from active_local_stores.
+
 2011-04-07  Jakub Jelinek  <jakub@redhat.com>
 
        PR tree-optimization/46491

diff --git a/gcc/dse.c b/gcc/dse.c
index 844fd51c96c296f66ad02e25830ebf43ebc41445..cf3ddceea82d62af9ceab76cb722cb9b382546e7 100644 (file)
--- a/gcc/dse.c
+++ b/gcc/dse.c
@@ -1588,8 +1588,7 @@ record_store (rtx body, bb_info_t bb_info)
 
       /* An insn can be deleted if every position of every one of
         its s_infos is zero.  */
-      if (any_positions_needed_p (s_info)
-         || ptr->cannot_delete)
+      if (any_positions_needed_p (s_info))
        del = false;
 
       if (del)
@@ -1600,8 +1599,9 @@ record_store (rtx body, bb_info_t bb_info)
            last->next_local_store = ptr->next_local_store;
          else
            active_local_stores = ptr->next_local_store;
-         
-         delete_dead_store_insn (insn_to_delete);
+
+         if (!insn_to_delete->cannot_delete)
+           delete_dead_store_insn (insn_to_delete);
        }
       else
        last = ptr;

diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index d4904a60e2c62f8be9c50eddb533445cf034742c..fc75684014d2ea53c59e729ed93a04f93da7455e 100644 (file)
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,6 +1,11 @@
 2011-04-07  Jakub Jelinek  <jakub@redhat.com>
 
        Backported from mainline
+       2011-03-17  Jakub Jelinek  <jakub@redhat.com>
+
+       PR rtl-optimization/48141
+       * gcc.dg/pr48141.c: New test.
+
        2010-11-15  Jakub Jelinek  <jakub@redhat.com>
 
        PR tree-optimization/46491

diff --git a/gcc/testsuite/gcc.dg/pr48141.c b/gcc/testsuite/gcc.dg/pr48141.c
new file mode 100644 (file)
index 0000000..c2ef79f
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/pr48141.c
@@ -0,0 +1,17 @@
+/* PR rtl-optimization/48141 */
+/* { dg-do compile } */
+/* { dg-options "-O -fno-tree-fre" } */
+
+#define A i = 0;
+#define B A A A A A A A A A A
+#define C B B B B B B B B B B
+#define D C C C C C C C C C C
+#define E D D D D D D D D D D
+
+int
+foo (void)
+{
+  volatile int i = 0;
+  E E E E E E E E E E E
+  return 0;
+}