Hot/cold attributes for labels.

gcc/
        * doc/extend.texi (attribute): Document hot/cold for labels.
        * predict.c (tree_estimate_probability_bb): Handle hot/cold
        attributes on user labels.
        * predict.def (PRED_HOT_LABEL, PRED_COLD_LABEL): New.
gcc/c-family/
        * c-common.c (handle_hot_attribute): Allow labels.
        (handle_cold_attribute): Likewise.
gcc/testsuite/
        * gcc.dg/attr-hotcold-1.c: New.
        * gcc.dg/tree-ssa/attr-hotcold-2.c: New.

From-SVN: r189898

2 files changed, 36 insertions, 0 deletions

diff --git a/gcc/testsuite/gcc.dg/attr-hotcold-1.c b/gcc/testsuite/gcc.dg/attr-hotcold-1.c
new file mode 100644
index 0000000..f63a95c
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/attr-hotcold-1.c
@@ -0,0 +1,8 @@
+void f(void)
+{
+  goto A;
+ A: __attribute__((cold))
+  goto B;
+ B: __attribute__((hot))
+  return;
+}
diff --git a/gcc/testsuite/gcc.dg/tree-ssa/attr-hotcold-2.c b/gcc/testsuite/gcc.dg/tree-ssa/attr-hotcold-2.c
new file mode 100644
index 0000000..84327fe
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/tree-ssa/attr-hotcold-2.c
@@ -0,0 +1,28 @@
+/* { dg-do compile } */
+/* { dg-options "-O2 -fdump-ipa-profile_estimate-details" } */
+
+void g(void);
+void h(void);
+void f(int x, int y)
+{
+  if (x) goto A;
+  if (y) goto B;
+  return;
+
+ A: __attribute__((cold))
+  g();
+  return;
+
+ B: __attribute__((hot))
+  h();
+  return;
+}
+
+/* { dg-final { scan-ipa-dump-times "block 4, loop depth 0, count 0, freq 1\[^0-9\]" 1 "profile_estimate" } } */
+
+/* Note: we're attempting to match some number > 6000, i.e. > 60%.
+   The exact number ought to be tweekable without having to juggle
+   the testcase around too much.  */
+/* { dg-final { scan-ipa-dump-times "block 5, loop depth 0, count 0, freq \[6-9\]\[0-9\]\[0-9\]\[0-9\]" 1 "profile_estimate" } } */
+
+/* { dg-final { cleanup-tree-dump "profile_estimate" } } */