[gcc/devel/fortran_unsigned] Compare loop bounds in ipa-icf

[Thomas Kﾃｶnig via Gcc-cvs]

https://gcc.gnu.org/g:0b5b178caea0417ff23d0609b1416e3f3e4f6689

commit 0b5b178caea0417ff23d0609b1416e3f3e4f6689
Author: Jan Hubicka <hubi...@ucw.cz>
Date:   Mon Jul 22 18:01:57 2024 +0200

    Compare loop bounds in ipa-icf
    
    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): compare loop
            bounds.
    
    gcc/testsuite/ChangeLog:
    
            * gcc.c-torture/compile/pr115277.c: New test.

Diff:
---
 gcc/ipa-icf-gimple.cc                          |  4 ++++
 gcc/testsuite/gcc.c-torture/compile/pr115277.c | 28 ++++++++++++++++++++++++++
 2 files changed, 32 insertions(+)

diff --git a/gcc/ipa-icf-gimple.cc b/gcc/ipa-icf-gimple.cc
index c25eb24710f6..4c3174b68b67 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 000000000000..27449eb254f8
--- /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;
+}