i386: Fix regression after refactoring legitimize_pe_coff_symbol, ix86_GOT_alias_set and PE_COFF_LEGITIMIZE_EXTERN_DECL [PR115635]

This patch fixes 3 bugs reported after merging the "Add DLL
import/export implementation to AArch64" series.
https://gcc.gnu.org/pipermail/gcc-patches/2024-June/653955.html The
series refactors the i386 codebase to reuse it in AArch64, which
triggers some bugs.

Bug 115661 - [15 Regression] wrong code at -O{2,3} on x86_64-linux-gnu
since r15-1599-g63512c72df09b4
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=115661

Bug 115635 - [15 regression] Bootstrap fails with failed self-test
with the rust fe (diagnostic-path.cc:1153: test_empty_path: FAIL:
ASSERT_FALSE ((path.interprocedural_p ()))) since
r15-1599-g63512c72df09b4
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=115635

Issue 1. In some code, i386 has been relying on the
legitimize_pe_coff_symbol call on all platforms and should return
NULL_RTX if it is not supported.

Fix: NULL_RTX handling has been added when the target does not support
PECOFF.

Issue 2. ix86_GOT_alias_set is used on all platforms and cannot be
extracted to mingw.

Fix: ix86_GOT_alias_set has been returned as it was and is used on all
platforms for i386.

Bug 115643 - [15 regression] aarch64-w64-mingw32 support today breaks
x86_64-w64-mingw32 build cannot represent relocation type BFD_RELOC_64
since r15-1602-ged20feebd9ea31
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=115643

Issue 3. PE_COFF_EXTERN_DECL_SHOULD_BE_LEGITIMIZED has been added and
used with a negative operator for a complex expression without braces.

Fix: Braces has been added, and
PE_COFF_EXTERN_DECL_SHOULD_BE_LEGITIMIZED has been renamed to
PE_COFF_LEGITIMIZE_EXTERN_DECL.

2024-06-28  Evgeny Karpov <Evgeny.Karpov@microsoft.com>

	gcc/ChangeLog:
	PR bootstrap/115635
	PR target/115643
	PR target/115661
	* config/aarch64/cygming.h
	(PE_COFF_EXTERN_DECL_SHOULD_BE_LEGITIMIZED): Rename to
	PE_COFF_LEGITIMIZE_EXTERN_DECL.
	(PE_COFF_LEGITIMIZE_EXTERN_DECL): Likewise.
	* config/i386/cygming.h (GOT_ALIAS_SET): Remove the diffinition to
	reuse it from i386.h.
	(PE_COFF_EXTERN_DECL_SHOULD_BE_LEGITIMIZED): Rename to
	PE_COFF_LEGITIMIZE_EXTERN_DECL.
	(PE_COFF_LEGITIMIZE_EXTERN_DECL): Likewise.
	* config/i386/i386-expand.cc (ix86_expand_move): Return
	ix86_GOT_alias_set.
	* config/i386/i386-expand.h (ix86_GOT_alias_set): Likewise.
	* config/i386/i386.cc (ix86_GOT_alias_set): Likewise.
	* config/i386/i386.h (GOT_ALIAS_SET): Likewise.
	* config/mingw/winnt-dll.cc (get_dllimport_decl): Use
	GOT_ALIAS_SET.
	(legitimize_pe_coff_symbol): Rename to
	PE_COFF_LEGITIMIZE_EXTERN_DECL.
	* config/mingw/winnt-dll.h (ix86_GOT_alias_set): Declare
	ix86_GOT_alias_set.

8 files changed, 23 insertions, 10 deletions

diff --git a/gcc/config/aarch64/cygming.h b/gcc/config/aarch64/cygming.h
index e264887..9ce140a 100644
--- a/gcc/config/aarch64/cygming.h
+++ b/gcc/config/aarch64/cygming.h
@@ -186,7 +186,7 @@ still needed for compilation.  */
 #undef GOT_ALIAS_SET
 #define GOT_ALIAS_SET mingw_GOT_alias_set ()
 
-#define PE_COFF_EXTERN_DECL_SHOULD_BE_LEGITIMIZED 1
+#define PE_COFF_LEGITIMIZE_EXTERN_DECL 1
 
 #define HAVE_64BIT_POINTERS 1
 
diff --git a/gcc/config/i386/cygming.h b/gcc/config/i386/cygming.h
index 0493b3b..9c8c7e3 100644
--- a/gcc/config/i386/cygming.h
+++ b/gcc/config/i386/cygming.h
@@ -470,10 +470,7 @@ do {						\
 # define HAVE_GAS_ALIGNED_COMM 0
 #endif
 
-#undef GOT_ALIAS_SET
-#define GOT_ALIAS_SET mingw_GOT_alias_set ()
-
-#define PE_COFF_EXTERN_DECL_SHOULD_BE_LEGITIMIZED \
-  ix86_cmodel == CM_LARGE_PIC || ix86_cmodel == CM_MEDIUM_PIC
+#define PE_COFF_LEGITIMIZE_EXTERN_DECL \
+  (ix86_cmodel == CM_LARGE_PIC || ix86_cmodel == CM_MEDIUM_PIC)
 
 #define HAVE_64BIT_POINTERS TARGET_64BIT_DEFAULT
diff --git a/gcc/config/i386/i386-expand.cc b/gcc/config/i386/i386-expand.cc
index dd2c3a8..a4434c1 100644
--- a/gcc/config/i386/i386-expand.cc
+++ b/gcc/config/i386/i386-expand.cc
@@ -414,6 +414,10 @@ ix86_expand_move (machine_mode mode, rtx operands[])
 	{
 #if TARGET_PECOFF
 	  tmp = legitimize_pe_coff_symbol (op1, addend != NULL_RTX);
+#else
+	  tmp = NULL_RTX;
+#endif
+
 	  if (tmp)
 	    {
 	      op1 = tmp;
@@ -425,7 +429,6 @@ ix86_expand_move (machine_mode mode, rtx operands[])
 	      op1 = operands[1];
 	      break;
 	    }
-#endif
 	}
 
       if (addend)
diff --git a/gcc/config/i386/i386-expand.h b/gcc/config/i386/i386-expand.h
index 5e02df1..56bee29 100644
--- a/gcc/config/i386/i386-expand.h
+++ b/gcc/config/i386/i386-expand.h
@@ -34,6 +34,7 @@ struct expand_vec_perm_d
 };
 
 rtx legitimize_tls_address (rtx x, enum tls_model model, bool for_mov);
+alias_set_type ix86_GOT_alias_set (void);
 rtx legitimize_pic_address (rtx orig, rtx reg);
 
 bool insn_defines_reg (unsigned int regno1, unsigned int regno2,
diff --git a/gcc/config/i386/i386.cc b/gcc/config/i386/i386.cc
index 92e3c67..6f742ef 100644
--- a/gcc/config/i386/i386.cc
+++ b/gcc/config/i386/i386.cc
@@ -11242,6 +11242,17 @@ ix86_cannot_force_const_mem (machine_mode mode, rtx x)
   return !ix86_legitimate_constant_p (mode, x);
 }
 
+/* Return a unique alias set for the GOT.  */
+
+alias_set_type
+ix86_GOT_alias_set (void)
+{
+  static alias_set_type set = -1;
+  if (set == -1)
+    set = new_alias_set ();
+  return set;
+}
+
 /* Nonzero if the constant value X is a legitimate general operand
    when generating PIC code.  It is given that flag_pic is on and
    that X satisfies CONSTANT_P.  */
diff --git a/gcc/config/i386/i386.h b/gcc/config/i386/i386.h
index 9ed225e..147b12c 100644
--- a/gcc/config/i386/i386.h
+++ b/gcc/config/i386/i386.h
@@ -2259,7 +2259,7 @@ extern int const svr4_debugger_register_map[FIRST_PSEUDO_REGISTER];
 /* Which processor to tune code generation for.  These must be in sync
    with processor_cost_table in i386-options.cc.  */
 
-#define GOT_ALIAS_SET -1
+#define GOT_ALIAS_SET ix86_GOT_alias_set ()
 
 enum processor_type
 {
diff --git a/gcc/config/mingw/winnt-dll.cc b/gcc/config/mingw/winnt-dll.cc
index 66c445c..f74495b 100644
--- a/gcc/config/mingw/winnt-dll.cc
+++ b/gcc/config/mingw/winnt-dll.cc
@@ -139,7 +139,7 @@ get_dllimport_decl (tree decl, bool beimport)
     }
 
   rtl = gen_const_mem (Pmode, rtl);
-  set_mem_alias_set (rtl, mingw_GOT_alias_set ());
+  set_mem_alias_set (rtl, GOT_ALIAS_SET);
 
   SET_DECL_RTL (to, rtl);
   SET_DECL_ASSEMBLER_NAME (to, get_identifier (name));
@@ -206,7 +206,7 @@ legitimize_pe_coff_symbol (rtx addr, bool inreg)
 	}
     }
 
-  if (!PE_COFF_EXTERN_DECL_SHOULD_BE_LEGITIMIZED)
+  if (!PE_COFF_LEGITIMIZE_EXTERN_DECL)
     return NULL_RTX;
 
   if (GET_CODE (addr) == SYMBOL_REF
diff --git a/gcc/config/mingw/winnt-dll.h b/gcc/config/mingw/winnt-dll.h
index 14ca743..659d9c1 100644
--- a/gcc/config/mingw/winnt-dll.h
+++ b/gcc/config/mingw/winnt-dll.h
@@ -22,6 +22,7 @@ http://www.gnu.org/licenses/.  */
 #ifndef USED_FOR_TARGET
 
 extern bool is_imported_p (rtx x);
+extern alias_set_type ix86_GOT_alias_set (void);
 extern alias_set_type mingw_GOT_alias_set (void);
 extern rtx legitimize_pe_coff_symbol (rtx addr, bool inreg);