[PR124572, LRA]: Deal with generation of reload insns during elimination

It was assumed that elimination in LRA does not generate new reload
insns.  In the testcase the elimination of SFP subreg generates reload
insn of the subreg and this insn is added at end of RTL code.  The insn
is also skipped for necessary processing.  This results in ICE.  The patch
checks creation of reloads insn during elimination, insert them in the right
place, and add them for later processing.

gcc/ChangeLog:

	PR rtl-optimization/124572
	* lra-eliminations.cc (lra_eliminate): Push new reload insns for
	eliminations in insns.

gcc/testsuite/ChangeLog:

	PR rtl-optimization/124572
	* gcc.target/aarch64/pr124572.c: New.

diff --git a/gcc/lra-eliminations.cc b/gcc/lra-eliminations.cc
index 8e68cb70dcffc5fe2d2efb56c1bbce33c29e84d3..e2a6ebfff1607a027d9f870b942c26253ab5da0e 100644 (file)
--- a/gcc/lra-eliminations.cc
+++ b/gcc/lra-eliminations.cc
@@ -1544,8 +1544,19 @@ lra_eliminate (bool final_p, bool first_p)
   EXECUTE_IF_SET_IN_BITMAP (&insns_with_changed_offsets, 0, uid, bi)
     /* A dead insn can be deleted in process_insn_for_elimination.  */
     if (lra_insn_recog_data[uid] != NULL)
-      process_insn_for_elimination (lra_insn_recog_data[uid]->insn,
-                                   final_p, first_p);
+      {
+       rtx_insn *insn = lra_insn_recog_data[uid]->insn;
+       start_sequence ();
+       process_insn_for_elimination (insn, final_p, first_p);
+       rtx_insn *first = get_insns ();
+       end_sequence ();
+       if (first != NULL)
+         {
+           lra_assert (!final_p);
+           lra_process_new_insns (insn, first, NULL,
+                                  "Inserting elimination insn", true);
+         }
+      }
   bitmap_clear (&insns_with_changed_offsets);
 
 lra_eliminate_done:

diff --git a/gcc/testsuite/gcc.target/aarch64/pr124572.c b/gcc/testsuite/gcc.target/aarch64/pr124572.c
new file mode 100644 (file)
index 0000000..edadfc3
--- /dev/null
+++ b/gcc/testsuite/gcc.target/aarch64/pr124572.c
@@ -0,0 +1,10 @@
+/* { dg-do compile } */
+/* { dg-options "-O2" } */
+
+int e() {
+  char f;
+  long tt = (long)&f;
+  tt+=1;
+  int g = tt;
+  return g + 3;
+}