[Bug rtl-optimization/87065] [7/8/9 Regression] combine causes ICE in trunc_int_for_mode

[jakub at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=87065

--- Comment #8 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
--- gcc/combine.c.jj    2018-08-24 08:55:25.000000000 +0200
+++ gcc/combine.c       2018-08-24 11:00:01.974006314 +0200
@@ -6495,7 +6495,7 @@ simplify_if_then_else (rtx x)
                          pc_rtx, pc_rtx, 0, 0, 0);
       if (reg_mentioned_p (from, false_rtx))
        false_rtx = subst (known_cond (copy_rtx (false_rtx), false_code,
-                                  from, false_val),
+                                      from, false_val),
                           pc_rtx, pc_rtx, 0, 0, 0);

       SUBST (XEXP (x, 1), swapped ? false_rtx : true_rtx);
@@ -9515,12 +9515,13 @@ known_cond (rtx x, enum rtx_code cond, r
          if (COMPARISON_P (x))
            {
              if (comparison_dominates_p (cond, code))
-               return const_true_rtx;
+               return (VECTOR_MODE_P (GET_MODE (x))
+                       ? CONSTM1_RTX (GET_MODE (x)) : const_true_rtx);

              code = reversed_comparison_code (x, NULL);
              if (code != UNKNOWN
                  && comparison_dominates_p (cond, code))
-               return const0_rtx;
+               return CONST0_RTX (GET_MODE (x));
              else
                return x;
            }
@@ -9563,7 +9564,7 @@ known_cond (rtx x, enum rtx_code cond, r
          /* We must simplify subreg here, before we lose track of the
             original inner_mode.  */
          new_rtx = simplify_subreg (GET_MODE (x), r,
-                                inner_mode, SUBREG_BYTE (x));
+                                    inner_mode, SUBREG_BYTE (x));
          if (new_rtx)
            return new_rtx;
          else
@@ -9588,7 +9589,7 @@ known_cond (rtx x, enum rtx_code cond, r
          /* We must simplify the zero_extend here, before we lose
             track of the original inner_mode.  */
          new_rtx = simplify_unary_operation (ZERO_EXTEND, GET_MODE (x),
-                                         r, inner_mode);
+                                             r, inner_mode);
          if (new_rtx)
            return new_rtx;
          else

fixes the ICE, but there are other latent issues.