[AARCH64]Fix ldr_got_small and ldr_got_small_28k patterns to only allow DImode address.

[Renlin Li]

Hi all,

The only allowed addressing mode for aarch64 is DImode, AKA Pmode.
ptr_mode could be SImode or DImode depending on the ABI used.

This patch here fixes the addressing mode of two patterns as DImode.
If any other mode is ever used, somewhere in the compiler might go wrong.


aarch64-none-elf regression test Okay without regressions.

Okay to commit?

Regards,
Renlin

gcc/ChangeLog:

2018-01-03  Renlin Li  <renlin...@arm.com>

        * config/aarch64/aarch64.c (aarch64_load_symref_appropriately): Make
        sure address is Pmode.
        * config/aarch64/aarch64.md (ldr_got_small): Fix address mode as
        DImode.
        (ldr_got_small_28k): Likewise.

diff --git a/gcc/config/aarch64/aarch64.c b/gcc/config/aarch64/aarch64.c
index 1da313f..9e9d2ea 100644
--- a/gcc/config/aarch64/aarch64.c
+++ b/gcc/config/aarch64/aarch64.c
@@ -1406,10 +1406,6 @@ aarch64_load_symref_appropriately (rtx dest, rtx imm,
 	    rtx s = gen_rtx_SYMBOL_REF (Pmode, "_GLOBAL_OFFSET_TABLE_");
 	    crtl->uses_pic_offset_table = 1;
 	    emit_move_insn (gp_rtx, gen_rtx_HIGH (Pmode, s));
-
-	    if (mode != GET_MODE (gp_rtx))
-             gp_rtx = gen_lowpart (mode, gp_rtx);
-
 	  }
 
 	if (mode == ptr_mode)
@@ -1451,13 +1447,19 @@ aarch64_load_symref_appropriately (rtx dest, rtx imm,
 
 	rtx insn;
 	rtx mem;
-	rtx tmp_reg = dest;
+	rtx tmp_reg;
 	machine_mode mode = GET_MODE (dest);
 
 	if (can_create_pseudo_p ())
-	  tmp_reg = gen_reg_rtx (mode);
+	  tmp_reg = gen_reg_rtx (Pmode);
+	else
+	{
+	  gcc_assert (HARD_REGISTER_P (dest));
+	  if (mode != Pmode)
+	    tmp_reg = gen_rtx_REG (Pmode, REGNO (dest));
+	}
 
-	emit_move_insn (tmp_reg, gen_rtx_HIGH (mode, imm));
+	emit_move_insn (tmp_reg, gen_rtx_HIGH (Pmode, imm));
 	if (mode == ptr_mode)
 	  {
 	    if (mode == DImode)
diff --git a/gcc/config/aarch64/aarch64.md b/gcc/config/aarch64/aarch64.md
index f1e2a07..a1f2d2d 100644
--- a/gcc/config/aarch64/aarch64.md
+++ b/gcc/config/aarch64/aarch64.md
@@ -5407,9 +5407,9 @@
 
 (define_insn "ldr_got_small_<mode>"
   [(set (match_operand:PTR 0 "register_operand" "=r")
-	(unspec:PTR [(mem:PTR (lo_sum:PTR
-			      (match_operand:PTR 1 "register_operand" "r")
-			      (match_operand:PTR 2 "aarch64_valid_symref" "S")))]
+	(unspec:PTR [(mem:PTR (lo_sum:DI
+			      (match_operand:DI 1 "register_operand" "r")
+			      (match_operand:DI 2 "aarch64_valid_symref" "S")))]
 		    UNSPEC_GOTSMALLPIC))]
   ""
   "ldr\\t%<w>0, [%1, #:got_lo12:%c2]"
@@ -5430,9 +5430,9 @@
 
 (define_insn "ldr_got_small_28k_<mode>"
   [(set (match_operand:PTR 0 "register_operand" "=r")
-	(unspec:PTR [(mem:PTR (lo_sum:PTR
-			      (match_operand:PTR 1 "register_operand" "r")
-			      (match_operand:PTR 2 "aarch64_valid_symref" "S")))]
+	(unspec:PTR [(mem:PTR (lo_sum:DI
+			      (match_operand:DI 1 "register_operand" "r")
+			      (match_operand:DI 2 "aarch64_valid_symref" "S")))]
 		    UNSPEC_GOTSMALLPIC28K))]
   ""
   "ldr\\t%<w>0, [%1, #:<got_modifier>:%c2]"