re PR rtl-optimization/88033 (ICE on valid code at -O2 and -O3 on…

re PR rtl-optimization/88033 (ICE on valid code at -O2 and -O3 on x86-64-linux-gnu: in remove_some_program_points_and_update_live_ranges, at lra-lives.c:1179)

gcc/
	PR rtl-optimization/88033
	* ira-lives.c (non_conflicting_reg_copy_p): Skip copies from a register
	to itself.  Use HARD_REGISTER_NUM_P.

gcc/testsuite/
	PR rtl-optimization/88033
	* gcc.target/i386/pr88033.c: New test.

From-SVN: r266282

gcc/ChangeLog

+2018-11-19  Peter Bergner  <bergner@linux.ibm.com>
+
+	PR rtl-optimization/88033
+	* ira-lives.c (non_conflicting_reg_copy_p): Skip copies from a register
+	to itself.  Use HARD_REGISTER_NUM_P.
+
 2018-11-19  Kyrylo Tkachov  <kyrylo.tkachov@arm.com>
 
 	* tree-vect-loop.c (vect_transform_loop): Disable further unrolling

gcc/ira-lives.c

@@ -1083,11 +1083,17 @@ non_conflicting_reg_copy_p (rtx_insn *insn)
   int src_regno = REGNO (SET_SRC (set));
   machine_mode mode = GET_MODE (SET_DEST (set));
 
+  /* By definition, a register does not conflict with itself, therefore we
+     do not have to handle it specially.  Returning NULL_RTX now, helps
+     simplify the callers of this function.  */
+  if (dst_regno == src_regno)
+    return NULL_RTX;
+
   /* Computing conflicts for register pairs is difficult to get right, so
      for now, disallow it.  */
-  if ((dst_regno < FIRST_PSEUDO_REGISTER
+  if ((HARD_REGISTER_NUM_P (dst_regno)
        && hard_regno_nregs (dst_regno, mode) != 1)
-      || (src_regno < FIRST_PSEUDO_REGISTER
+      || (HARD_REGISTER_NUM_P (src_regno)
 	  && hard_regno_nregs (src_regno, mode) != 1))
     return NULL_RTX;
 

gcc/testsuite/ChangeLog

+2018-11-19  Peter Bergner  <bergner@linux.ibm.com>
+
+	PR rtl-optimization/88033
+	* gcc.target/i386/pr88033.c: New test.
+
 2018-11-19  Kyrylo Tkachov  <kyrylo.tkachov@arm.com>
 
 	* gcc.target/aarch64/sve/unroll-1.c: New test.

gcc/testsuite/gcc.target/i386/pr88033.c

+/* { dg-do compile } */
+/* { dg-options "-O2" } */
+
+int
+main (long a, long *b, long c)
+{
+  if (!c)
+    return 0;
+  int g;
+  *b = (g & ~3000000000) < 0 ? a : a - g;
+  while (1)
+    ;
+  return 0;
+}