https://gcc.gnu.org/g:1c18d6bc04872b884d9fd35989dbd579432dfff3

commit r16-9273-g1c18d6bc04872b884d9fd35989dbd579432dfff3
Author: Richard Biener <[email protected]>
Date:   Wed Jun 24 08:45:37 2026 +0200

    tree-optimization/125953 - ICE with vector pattern stmts range query
    
    Vectorizer pattern recog eventually feeds range_of_expr with both
    pattern def expressions and pattern context stmts.  While that's
    IMO not OK the ranger code has some existing defenses against
    defs that do not reside in the IL.  Just those are incomplete.
    
    The following makes them more robust.  I will cleanup the vectorizer
    side of things on trunk.
    
    I have documented gimple_ranger::range_of_expr as to how I understand
    it works (the different range_of_* APIs seem to behave slightly
    different - I find this confusing).  Esp. range_of_expr requires
    a valid 'r' input range and the return value isn't always reflecting
    that something was done.
    
            PR tree-optimization/125953
            * gimple-range.cc (gimple_ranger::range_of_expr): Document.
            Fall back to global ranges if 'stmt' is not in the IL.
    
            * gcc.dg/torture/pr125953.c: New testcase.
    
    (cherry picked from commit 79496eefdaa77840d59571cd03bccf82d2704046)

Diff:
---
 gcc/gimple-range.cc                     |  8 ++++++--
 gcc/testsuite/gcc.dg/torture/pr125953.c | 14 ++++++++++++++
 2 files changed, 20 insertions(+), 2 deletions(-)

diff --git a/gcc/gimple-range.cc b/gcc/gimple-range.cc
index 4c768ed3a07d..10269a2e39d7 100644
--- a/gcc/gimple-range.cc
+++ b/gcc/gimple-range.cc
@@ -78,6 +78,9 @@ gimple_ranger::const_query ()
   return m_cache.const_query ();
 }
 
+// Implement range of EXPR on stmt S, and return it in R.
+// Return false if no range can be calculated.
+
 bool
 gimple_ranger::range_of_expr (vrange &r, tree expr, gimple *stmt)
 {
@@ -98,8 +101,9 @@ gimple_ranger::range_of_expr (vrange &r, tree expr, gimple 
*stmt)
        fputs ("\n", dump_file);
     }
 
-  // If there is no statement, just get the global value.
-  if (!stmt)
+  // If there is no statement or stmt happens to be not in the IL,
+  // just get the global value.
+  if (!stmt || !gimple_bb (stmt))
     {
       value_range tmp (TREE_TYPE (expr));
       // If there is no global range for EXPR yet, try to evaluate it.
diff --git a/gcc/testsuite/gcc.dg/torture/pr125953.c 
b/gcc/testsuite/gcc.dg/torture/pr125953.c
new file mode 100644
index 000000000000..3a34bc3d6762
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/torture/pr125953.c
@@ -0,0 +1,14 @@
+/* { dg-do compile } */
+/* { dg-additional-options "-march=armv8.3-a+sve2" { target aarch64-*-* } } */
+
+unsigned char *begin(unsigned char *out)
+{
+  int size_0_0_0;
+  unsigned char *kRow = begin(out);
+  unsigned char *currentRow = kRow;
+  for (int x = 0; x < size_0_0_0; ++x) {
+    char k = kRow ? kRow[x] : 5;
+    out[2] = currentRow[2] * k / 255;
+  }
+  return out;
+}

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