[PATCH V2] aarch64: Do not alter force_reg returned rtx expanding pauth builtins

[Andrea Corallo]

Hi all,

here the reworked patch addressing Richard's suggestions.

Regtested and bootsraped on aarch64-linux-gnu.

Okay for trunk?

Thanks!

  Andrea


>From 946d22aa247f2d1bb0c6b10a6e6db415b34feff2 Mon Sep 17 00:00:00 2001
From: Andrea Corallo <andrea.cora...@arm.com>
Date: Mon, 21 Sep 2020 13:52:45 +0100
Subject: [PATCH] aarch64: Do not alter force_reg returned rtx expanding pauth
 builtins

2020-09-21  Andrea Corallo  <andrea.cora...@arm.com>

        * config/aarch64/aarch64-builtins.c
        (aarch64_general_expand_builtin): Do not alter value on a
        force_reg returned rtx.
---
 gcc/config/aarch64/aarch64-builtins.c | 13 ++-----------
 1 file changed, 2 insertions(+), 11 deletions(-)

diff --git a/gcc/config/aarch64/aarch64-builtins.c 
b/gcc/config/aarch64/aarch64-builtins.c
index b787719cf5e..d7eb8772b14 100644
--- a/gcc/config/aarch64/aarch64-builtins.c
+++ b/gcc/config/aarch64/aarch64-builtins.c
@@ -2079,20 +2079,13 @@ aarch64_general_expand_builtin (unsigned int fcode, 
tree exp, rtx target,
       arg0 = CALL_EXPR_ARG (exp, 0);
       op0 = force_reg (Pmode, expand_normal (arg0));
 
-      if (!target)
-       target = gen_reg_rtx (Pmode);
-      else
-       target = force_reg (Pmode, target);
-
-      emit_move_insn (target, op0);
-
       if (fcode == AARCH64_PAUTH_BUILTIN_XPACLRI)
        {
          rtx lr = gen_rtx_REG (Pmode, R30_REGNUM);
          icode = CODE_FOR_xpaclri;
          emit_move_insn (lr, op0);
          emit_insn (GEN_FCN (icode) ());
-         emit_move_insn (target, lr);
+         return lr;
        }
       else
        {
@@ -2122,11 +2115,9 @@ aarch64_general_expand_builtin (unsigned int fcode, tree 
exp, rtx target,
          emit_move_insn (x17_reg, op0);
          emit_move_insn (x16_reg, op1);
          emit_insn (GEN_FCN (icode) ());
-         emit_move_insn (target, x17_reg);
+         return x17_reg;
        }
 
-      return target;
-
     case AARCH64_JSCVT:
       {
        expand_operand ops[2];
-- 
2.17.1