diff mbox series

Compare loop bounds in ipa-icf

Message ID ZldFWQlnVW8pHvTm@kam.mff.cuni.cz
State New
Headers show
Series Compare loop bounds in ipa-icf | expand

Commit Message

Jan Hubicka May 29, 2024, 3:10 p.m. UTC 
Hi,
this testcase shows another poblem with missing comparators for metadata
in ICF. With value ranges available to loop optimizations during early
opts we can estimate number of iterations based on guarding condition that
can be split away by the fnsplit pass. This patch disables ICF when
number of iteraitons does not match.

Bootstrapped/regtesed x86_64-linux, will commit it shortly

gcc/ChangeLog:

	PR ipa/115277
	* ipa-icf-gimple.cc (func_checker::compare_loops):

gcc/testsuite/ChangeLog:

	* gcc.c-torture/compile/pr115277.c: New test.
diff mbox series

Patch

diff --git a/gcc/ipa-icf-gimple.cc b/gcc/ipa-icf-gimple.cc
index c25eb24710f..4c3174b68b6 100644
--- a/gcc/ipa-icf-gimple.cc
+++ b/gcc/ipa-icf-gimple.cc
@@ -543,6 +543,10 @@  func_checker::compare_loops (basic_block bb1, basic_block bb2)
     return return_false_with_msg ("unroll");
   if (!compare_variable_decl (l1->simduid, l2->simduid))
     return return_false_with_msg ("simduid");
+  if ((l1->any_upper_bound != l2->any_upper_bound)
+      || (l1->any_upper_bound
+	  && (l1->nb_iterations_upper_bound != l2->nb_iterations_upper_bound)))
+    return return_false_with_msg ("nb_iterations_upper_bound");
 
   return true;
 }
diff --git a/gcc/testsuite/gcc.c-torture/compile/pr115277.c b/gcc/testsuite/gcc.c-torture/compile/pr115277.c
new file mode 100644
index 00000000000..27449eb254f
--- /dev/null
+++ b/gcc/testsuite/gcc.c-torture/compile/pr115277.c
@@ -0,0 +1,28 @@ 
+int array[1000];
+void
+test (int a)
+{
+        if (__builtin_expect (a > 3, 1))
+                return;
+        for (int i = 0; i < a; i++)
+                array[i]=i;
+}
+void
+test2 (int a)
+{
+        if (__builtin_expect (a > 10, 1))
+                return;
+        for (int i = 0; i < a; i++)
+                array[i]=i;
+}
+int
+main()
+{
+        test(1);
+        test(2);
+        test(3);
+        test2(10);
+        if (array[9] != 9)
+                __builtin_abort ();
+        return 0;
+}