aarch64, Darwin: Constrain page offset values to fit in the relocation.

This fixes issue gcc-mirror#52. We need to constrain the offsets in the @PAGE/@PAGEOFFS relocations to fit in a 24bit field - +/- 8Mb. Signed-off-by: Iain Sandoe <iain@sandoe.co.uk> gcc/ * config/aarch64/aarch64.c (aarch64_load_symref_appropriately): If the offset will not fit into the relocation, then rewrite it as an addition.
fxcoudert · Nov 26, 2021 · 4b9a61d · 4b9a61d
1 parent ff04b0a
commit 4b9a61d
Showing 1 changed file with 2 additions and 2 deletions.
diff --git a/gcc/config/aarch64/aarch64.c b/gcc/config/aarch64/aarch64.c
@@ -3543,15 +3543,15 @@ aarch64_load_symref_appropriately (rtx dest, rtx imm,
 	    rtx sym, off;
 	    split_const (imm, &sym, &off);
 	    /* Negative offsets don't work, whether by intention is TBD.  */
-	    if (INTVAL (off) < 0)
+	    if (INTVAL (off) < 0 || INTVAL (off) > 8 * 1024 * 1024)
 	      {
 		emit_move_insn (tmp_reg, gen_rtx_HIGH (mode, sym));
 		emit_insn (gen_add_losym (dest, tmp_reg, sym));
 		/* FIXME: add the SI option if/when we support ilp32.  */
 		emit_insn (gen_adddi3 (dest, dest, off));
 		return;
 	      }
-	   /* else positive offset is OK.  */
+	   /* else small enough positive offset is OK.  */
 	  }
 	emit_move_insn (tmp_reg, gen_rtx_HIGH (mode, imm));
 	emit_insn (gen_add_losym (dest, tmp_reg, imm));