From 92c40297991f51e7fa942f29517bc4398fce33f9 Mon Sep 17 00:00:00 2001
From: Richard Biener <rguenther@suse.de>
Date: Thu, 22 Feb 2024 14:22:29 +0100
Subject: [PATCH] tree-optimization/114048 - ICE in copy_reference_ops_from_ref
The following adds another omission to the assert verifying we're
not running into spurious off == -1.
PR tree-optimization/114048
* tree-ssa-sccvn.cc (copy_reference_ops_from_ref): MEM_REF
can also produce -1 off.
* gcc.dg/torture/pr114048.c: New testcase.
---
gcc/testsuite/gcc.dg/torture/pr114048.c | 25 +++++++++++++++++++++++++
gcc/tree-ssa-sccvn.cc | 2 ++
2 files changed, 27 insertions(+)
create mode 100644 gcc/testsuite/gcc.dg/torture/pr114048.c
diff --git a/gcc/testsuite/gcc.dg/torture/pr114048.c b/gcc/testsuite/gcc.dg/torture/pr114048.c
new file mode 100644
index 000000000000..338000b30062
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/torture/pr114048.c
@@ -0,0 +1,25 @@
+/* { dg-do compile } */
+
+typedef struct {
+ void *child[2];
+ char otherbits;
+} critbit0_node;
+
+int allprefixed_traverse(char *top)
+{
+ if (top)
+ {
+ critbit0_node *q = (void *)top - 1;
+ int direction = 0;
+ for (;; ++direction)
+ switch (allprefixed_traverse(q->child[direction]))
+ {
+ case 1:
+ break;
+ case 0:
+ return 0;
+ default:
+ return 1;
+ }
+ }
+}
diff --git a/gcc/tree-ssa-sccvn.cc b/gcc/tree-ssa-sccvn.cc
index 3e93685e80a6..2587eb1c5052 100644
--- a/gcc/tree-ssa-sccvn.cc
+++ b/gcc/tree-ssa-sccvn.cc
@@ -1185,6 +1185,8 @@ copy_reference_ops_from_ref (tree ref, vec<vn_reference_op_s> *result)
else
{
gcc_assert (known_ne (op.off, -1)
+ /* The constant offset can be -1. */
+ || op.opcode == MEM_REF
/* Out-of-bound indices can compute to
a known -1 offset. */
|| ((op.opcode == ARRAY_REF
--
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