Hi!
The following testcase ICEs, because optimize_crc_loop inserts a call
statement before labels instead of after labels.
Fixed thusly (plus fixed other issues noticed around it),
bootstrapped/regtested on x86_64-linux and i686-linux, ok for trunk/15.2?
2025-06-17 Jakub Jelinek <ja...@redhat.com>
PR tree-optimization/120677
* gimple-crc-optimization.cc (crc_optimization::optimize_crc_loop):
Insert before gsi_after_labels instead of gsi_start_bb. Use
gimple_bb (output_crc) instead of output_crc->bb. Formatting fix.
* gcc.c-torture/execute/pr120677.c: New test.
--- gcc/gimple-crc-optimization.cc.jj 2025-04-08 14:08:51.619276743 +0200
+++ gcc/gimple-crc-optimization.cc 2025-06-16 21:52:55.864229216 +0200
@@ -1261,15 +1261,12 @@ crc_optimization::optimize_crc_loop (gph
loc = EXPR_LOCATION (phi_result);
/* Add IFN call and write the return value in the phi_result. */
- gcall *call
- = gimple_build_call_internal (ifn, 3,
- m_crc_arg,
- m_data_arg,
- polynomial_arg);
+ gcall *call = gimple_build_call_internal (ifn, 3, m_crc_arg, m_data_arg,
+ polynomial_arg);
gimple_call_set_lhs (call, phi_result);
gimple_set_location (call, loc);
- gimple_stmt_iterator si = gsi_start_bb (output_crc->bb);
+ gimple_stmt_iterator si = gsi_after_labels (gimple_bb (output_crc));
gsi_insert_before (&si, call, GSI_SAME_STMT);
/* Remove phi statement, which was holding CRC result. */
--- gcc/testsuite/gcc.c-torture/execute/pr120677.c.jj 2025-06-16
21:58:57.149514696 +0200
+++ gcc/testsuite/gcc.c-torture/execute/pr120677.c 2025-06-16
21:58:29.438876302 +0200
@@ -0,0 +1,31 @@
+/* PR tree-optimization/120677 */
+/* { dg-do run { target int32plus } } */
+
+unsigned a;
+int b, e;
+
+int
+foo (int d)
+{
+ switch (d)
+ {
+ case 0:
+ case 2:
+ return 0;
+ default:
+ return 1;
+ }
+}
+
+int
+main ()
+{
+ for (b = 8; b; b--)
+ if (a & 1)
+ a = a >> 1 ^ 20000000;
+ else
+ a >>= 1;
+ e = foo (0);
+ if (e || a)
+ __builtin_abort ();
+}
Jakub
