From: Eric Botcazou <ebotcazou@adacore.com>
Date: Thu, 22 May 2025 14:25:07 +0000 (+0200)
Subject: Fix oversight about big-endian targets in latest change
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=d7f24e37d4bcb80c21c391d32f0f29594b71c2ee;p=thirdparty%2Fgcc.git

Fix oversight about big-endian targets in latest change

Bit-fields are stored left-justified for big-endian targets.

gcc/
	* dwarf2out.cc (loc_list_from_tree_1) <COMPONENT_REF>: Add specific
	handling of bit-fields for big-endian targets.
---

diff --git a/gcc/dwarf2out.cc b/gcc/dwarf2out.cc
index 713a55108aa..d1a55dbcbcb 100644
--- a/gcc/dwarf2out.cc
+++ b/gcc/dwarf2out.cc
@@ -19764,18 +19764,35 @@ loc_list_from_tree_1 (tree loc, int want_address,
 	    {
 	      if (TYPE_UNSIGNED (TREE_TYPE (loc)))
 		{
-		  const unsigned HOST_WIDE_INT mask
-		    = (HOST_WIDE_INT_1U << bitsize) - 1;
-		  add_loc_descr (&deref, uint_loc_descriptor (mask));
-		  add_loc_descr (&deref, new_loc_descr (DW_OP_and, 0, 0));
+		  if (BYTES_BIG_ENDIAN)
+		    {
+		      const unsigned HOST_WIDE_INT shift
+			= size * BITS_PER_UNIT - bitsize;
+		      add_loc_descr (&deref, uint_loc_descriptor (shift));
+		      add_loc_descr (&deref, new_loc_descr (DW_OP_shr, 0, 0));
+		    }
+		  else
+		    {
+		      const unsigned HOST_WIDE_INT mask
+			= (HOST_WIDE_INT_1U << bitsize) - 1;
+		      add_loc_descr (&deref, uint_loc_descriptor (mask));
+		      add_loc_descr (&deref, new_loc_descr (DW_OP_and, 0, 0));
+		    }
 		}
 	      else
 		{
-		  const unsigned HOST_WIDE_INT shift
+		  const unsigned HOST_WIDE_INT shiftr
 		    = DWARF2_ADDR_SIZE * BITS_PER_UNIT - bitsize;
-		  add_loc_descr (&deref, uint_loc_descriptor (shift));
-		  add_loc_descr (&deref, new_loc_descr (DW_OP_shl, 0, 0));
-		  add_loc_descr (&deref, uint_loc_descriptor (shift));
+		  const unsigned HOST_WIDE_INT shiftl
+		    = BYTES_BIG_ENDIAN
+		      ? (DWARF2_ADDR_SIZE - size) * BITS_PER_UNIT
+		      : shiftr;
+		  if (shiftl > 0)
+		    {
+		      add_loc_descr (&deref, uint_loc_descriptor (shiftl));
+		      add_loc_descr (&deref, new_loc_descr (DW_OP_shl, 0, 0));
+		    }
+		  add_loc_descr (&deref, uint_loc_descriptor (shiftr));
 		  add_loc_descr (&deref, new_loc_descr (DW_OP_shra, 0, 0));
 		}
 	    }