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[COMMITTED,PR,tree-optimization/107052] range-ops: Take into account nonzero mask in popcount.

Message ID 20221005122236.1579762-2-aldyh@redhat.com
State New
Headers show
Series [COMMITTED,PR,tree-optimization/107052] range-ops: Take into account nonzero mask in popcount. | expand

Commit Message

Aldy Hernandez Oct. 5, 2022, 12:22 p.m. UTC 
PR tree-optimization/107052

gcc/ChangeLog:

	* gimple-range-op.cc (cfn_popcount::fold_range): Take into account
	nonzero bit mask.
---
 gcc/gimple-range-op.cc                   | 15 ++++++++++++---
 gcc/testsuite/gcc.dg/tree-ssa/pr107052.c | 13 +++++++++++++
 2 files changed, 25 insertions(+), 3 deletions(-)
 create mode 100644 gcc/testsuite/gcc.dg/tree-ssa/pr107052.c
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Patch

diff --git a/gcc/gimple-range-op.cc b/gcc/gimple-range-op.cc
index 5b71d1cce6d..42ebc7d6ce5 100644
--- a/gcc/gimple-range-op.cc
+++ b/gcc/gimple-range-op.cc
@@ -422,15 +422,24 @@  public:
   virtual bool fold_range (irange &r, tree type, const irange &lh,
 			   const irange &rh, relation_kind rel) const
   {
+    if (lh.undefined_p ())
+      return false;
+    unsigned prec = TYPE_PRECISION (type);
+    wide_int nz = lh.get_nonzero_bits ();
+    wide_int pop = wi::shwi (wi::popcount (nz), prec);
     // Calculating the popcount of a singleton is trivial.
     if (lh.singleton_p ())
       {
-	wide_int nz = lh.get_nonzero_bits ();
-	wide_int pop = wi::shwi (wi::popcount (nz), TYPE_PRECISION (type));
 	r.set (type, pop, pop);
 	return true;
       }
-    return cfn_ffs::fold_range (r, type, lh, rh, rel);
+    if (cfn_ffs::fold_range (r, type, lh, rh, rel))
+      {
+	int_range<2> tmp (type, wi::zero (prec), pop);
+	r.intersect (tmp);
+	return true;
+      }
+    return false;
   }
 } op_cfn_popcount;
 
diff --git a/gcc/testsuite/gcc.dg/tree-ssa/pr107052.c b/gcc/testsuite/gcc.dg/tree-ssa/pr107052.c
new file mode 100644
index 00000000000..88b5213160d
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/tree-ssa/pr107052.c
@@ -0,0 +1,13 @@ 
+// { dg-do compile }
+// { dg-options "-O2 -fdump-tree-evrp" }
+
+void link_failure();
+void f(int a)
+{
+  a &= 0x300;
+  int b =  __builtin_popcount(a);
+  if (b > 3)
+    link_failure();
+}
+
+// { dg-final { scan-tree-dump-not "link_failure" "evrp" } }