Re: [PATCH, AARCH64] Fix ICE in CCMP (PR64015)

[Jiong Wang]

On 15/12/14 08:41, Zhenqiang Chen wrote:

-----Original Message-----
From: Richard Henderson [mailto:r...@redhat.com]
Sent: Saturday, December 13, 2014 3:26 AM
To: Zhenqiang Chen
Cc: Marcus Shawcroft; gcc-patches@gcc.gnu.org
Subject: Re: [PATCH, AARCH64] Fix ICE in CCMP (PR64015)

-         tree lhs = gimple_assign_lhs (g);
          enum machine_mode mode = TYPE_MODE (TREE_TYPE (lhs));
          rtx target = gen_reg_rtx (mode);
+
+         start_sequence ();
          tmp = emit_cstore (target, icode, NE, cc_mode, cc_mode,
                             0, tmp, const0_rtx, 1, mode);
          if (tmp)
-           return tmp;
+           {
+             rtx seq = get_insns ();
+             end_sequence ();
+             emit_insn (prep_seq);
+             emit_insn (gen_seq);
+             emit_insn (seq);
+             return tmp;
+           }
+         end_sequence ();

Given that you're already doing delete_insns_since (last) at the end of this
function, I don't think you need a new sequence around the emit_cstore.
Just

        emit_insn (prep_seq);
        emit_insn (gen_seq);
        tmp = emit_cstore (...);
        if (tmp)
          return tmp;

Updated.

+  int unsignedp = code == LTU || code == LEU || code == GTU || code
+ == GEU;

You don't need to examine the code, you can look at the argument:

   TYPE_UNSIGNED (TREE_TYPE (treeop0))

Updated.

+  op0 = prepare_operand (icode, op0, 2, op_mode, cmp_mode,
+ unsignedp);
+  op1 = prepare_operand (icode, op1, 3, op_mode, cmp_mode,
+ unsignedp);  if (!op0 || !op1)
+    {
+      end_sequence ();
+      return NULL_RTX;
+    }
+  *prep_seq = get_insns ();
+  end_sequence ();
+
+  cmp = gen_rtx_fmt_ee ((enum rtx_code) code, cmp_mode, op0, op1);
+ target = gen_rtx_REG (CCmode, CC_REGNUM);
+
+  create_output_operand (&ops[0], target, CCmode);
+ create_fixed_operand (&ops[1], cmp);  create_fixed_operand (&ops[2],
+ op0);  create_fixed_operand (&ops[3], op1);

Hmm.  With so many fixed operands, I think you may be better off not
creating the cmp<mode> expander in the first place.  Just inline the
SELECT_CC_MODE and everything right here.

In the patch, I use prepare_operand (icode, op0, 2, ...) to do the operand MODE 
conversion (from HI/QI to SI), which needs a cmp<mode> expander. Without it, I 
have to add additional codes to do the conversion (as it in previous patch, which 
leads to PR64015).

Ping~,

verified this patch will pass speck2k6 build without ICE anymore.

Thanks!
-Zhenqiang