[gcc r13-3350] Merge partial relation precisions properly

[gcc r13-3350] Merge partial relation precisions properly

[Andrew Macleod]

https://gcc.gnu.org/g:0205fbb91be022055c632973caa95e398b33db39

commit r13-3350-g0205fbb91be022055c632973caa95e398b33db39
Author: Andrew MacLeod <amacleod@redhat.com>
Date:   Mon Oct 17 19:00:49 2022 -0400

    Merge partial relation precisions properly
    
    When merging 2 groups of PE's, one group was simply being set to the
    other instead of properly merging them.
    
            PR tree-optimization/107273
            gcc/
            * value-relation.cc (equiv_oracle::add_partial_equiv): Merge
            instead of copying precison of each member.
    
            gcc/testsuite/
            * gcc.dg/tree-ssa/pr107273-1.c: New.
            * gcc.dg/tree-ssa/pr107273-2.c: New.

Diff:
---
 gcc/testsuite/gcc.dg/tree-ssa/pr107273-1.c | 31 ++++++++++++++++++++++++++++++
 gcc/testsuite/gcc.dg/tree-ssa/pr107273-2.c | 27 ++++++++++++++++++++++++++
 gcc/value-relation.cc                      |  2 +-
 3 files changed, 59 insertions(+), 1 deletion(-)

diff --git a/gcc/testsuite/gcc.dg/tree-ssa/pr107273-1.c b/gcc/testsuite/gcc.dg/tree-ssa/pr107273-1.c
new file mode 100644
index 00000000000..db2e2c0da55
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/tree-ssa/pr107273-1.c
@@ -0,0 +1,31 @@
+/* { dg-do run } */
+/* { dg-options "-O3" } */
+
+int printf(const char *, ...);
+int a[1] = {1};
+short b, c = 5500;
+int d;
+long e;
+char f = 1;
+int main() {
+  while (1) {
+    long g = b < 1;
+    e = g;
+    break;
+  }
+  for (; f; f--) {
+    if (e) {
+      d = -(6L | -(c & 1000));
+    }
+    char h = d;
+    if (b)
+      b = 0;
+    if (d < 200)
+      while (1)
+        printf("%d", a[c]);
+    short i = h * 210;
+    c = i;
+  }
+  return 0;
+}
+
diff --git a/gcc/testsuite/gcc.dg/tree-ssa/pr107273-2.c b/gcc/testsuite/gcc.dg/tree-ssa/pr107273-2.c
new file mode 100644
index 00000000000..337450782d9
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/tree-ssa/pr107273-2.c
@@ -0,0 +1,27 @@
+/* { dg-do run } */
+/* { dg-options "-Os" } */
+
+int a, d, f;
+char b, g;
+unsigned i;
+int main() {
+  int c = 300, h = 40;
+  char e = 1;
+  for (; a < 1; a++) {
+    c = ~((i - ~c) | e);
+  L1:
+    e = f = c;
+    if (c)
+      if (c > -200)
+        e = g % (1 << h);
+    char k = 0;
+  L2:;
+  }
+  if (b) {
+    if (d)
+      goto L2;
+    if (!b)
+      goto L1;
+  }
+  return 0;
+}
diff --git a/gcc/value-relation.cc b/gcc/value-relation.cc
index fed8a78723c..178a245f41a 100644
--- a/gcc/value-relation.cc
+++ b/gcc/value-relation.cc
@@ -380,7 +380,7 @@ equiv_oracle::add_partial_equiv (relation_kind r, tree op1, tree op2)
       EXECUTE_IF_SET_IN_BITMAP (pe1.members, 0, x, bi)
 	{
 	  m_partial[x].ssa_base = op2;
-	  m_partial[x].code = pe2.code;
+	  m_partial[x].code = pe_min (m_partial[x].code, pe2.code);
 	}
       bitmap_set_bit (pe1.members, v2);
       return;