re PR target/67400 (-fno-plt doesn't work with function pointers)

	PR target/67400
	* config/i386/i386-protos.h (ix86_force_load_from_GOT_p): New.
	* config/i386/i386.c (ix86_force_load_from_GOT_p): New function.
	(ix86_legitimate_constant_p): Do not allow UNSPEC_GOTPCREL if
	ix86_force_load_from_GOT_p returns true.
	(ix86_legitimate_address_p): Allow UNSPEC_GOTPCREL if
	ix86_force_load_from_GOT_p returns true.
	(ix86_print_operand_address_as): Support UNSPEC_GOTPCREL if
	ix86_force_load_from_GOT_p returns true.
	(ix86_expand_move): Load the external function address via the
	GOT slot if ix86_force_load_from_GOT_p returns true.
	* config/i386/predicates.md (x86_64_immediate_operand): Return
	false for SYMBOL_REFs where ix86_force_load_from_GOT_p returns true.
	(x86_64_zext_immediate_operand): Ditto.

testsuite/ChangeLog:

	PR target/67400
        * gcc.target/i386/pr67400-1.c: New test.
        * gcc.target/i386/pr67400-2.c: Likewise.
        * gcc.target/i386/pr67400-3.c: Likewise.
        * gcc.target/i386/pr67400-4.c: Likewise.
        * gcc.target/i386/pr67400-5.c: Likewise.
        * gcc.target/i386/pr67400-6.c: Likewise.
        * gcc.target/i386/pr67400-7.c: Likewise.

From-SVN: r237720

gcc/ChangeLog

+2016-06-23  Uros Bizjak  <ubizjak@gmail.com>
+	    H.J. Lu  <hongjiu.lu@intel.com>
+
+	PR target/67400
+	* config/i386/i386-protos.h (ix86_force_load_from_GOT_p): New.
+	* config/i386/i386.c (ix86_force_load_from_GOT_p): New function.
+	(ix86_legitimate_constant_p): Do not allow UNSPEC_GOTPCREL if
+	ix86_force_load_from_GOT_p returns true.
+	(ix86_legitimate_address_p): Allow UNSPEC_GOTPCREL if
+	ix86_force_load_from_GOT_p returns true.
+	(ix86_print_operand_address_as): Support UNSPEC_GOTPCREL if
+	ix86_force_load_from_GOT_p returns true.
+	(ix86_expand_move): Load the external function address via the
+	GOT slot if ix86_force_load_from_GOT_p returns true.
+	* config/i386/predicates.md (x86_64_immediate_operand): Return
+	false for SYMBOL_REFs where ix86_force_load_from_GOT_p returns true.
+	(x86_64_zext_immediate_operand): Ditto.
+
 2016-06-22  Uros Bizjak  <ubizjak@gmail.com>
 
 	* config/i386/i386.c (ix86_expand_move): Simplify SYMBOL_REF handling.

gcc/config/i386/i386-protos.h

@@ -70,6 +70,7 @@ extern bool ix86_expand_set_or_movmem (rtx, rtx, rtx, rtx, rtx, rtx,
 extern bool constant_address_p (rtx);
 extern bool legitimate_pic_operand_p (rtx);
 extern bool legitimate_pic_address_disp_p (rtx);
+extern bool ix86_force_load_from_GOT_p (rtx);
 extern void print_reg (rtx, int, FILE*);
 extern void ix86_print_operand (FILE *, rtx, int);
 

gcc/config/i386/i386.c

@@ -15120,6 +15120,19 @@ darwin_local_data_pic (rtx disp)
 	  && XINT (disp, 1) == UNSPEC_MACHOPIC_OFFSET);
 }
 
+/* True if operand X should be loaded from GOT.  */
+
+bool
+ix86_force_load_from_GOT_p (rtx x)
+{
+  return (TARGET_64BIT && !TARGET_PECOFF && !TARGET_MACHO
+	  && !flag_plt && !flag_pic
+	  && ix86_cmodel != CM_LARGE
+	  && GET_CODE (x) == SYMBOL_REF
+	  && SYMBOL_REF_FUNCTION_P (x)
+	  && !SYMBOL_REF_LOCAL_P (x));
+}
+
 /* Determine if a given RTX is a valid constant.  We already know this
    satisfies CONSTANT_P.  */
 
@@ -15188,6 +15201,12 @@ ix86_legitimate_constant_p (machine_mode mode, rtx x)
       if (MACHO_DYNAMIC_NO_PIC_P)
 	return machopic_symbol_defined_p (x);
 #endif
+
+      /* External function address should be loaded
+	 via the GOT slot to avoid PLT.  */
+      if (ix86_force_load_from_GOT_p (x))
+	return false;
+
       break;
 
     CASE_CONST_SCALAR_INT:
@@ -15596,6 +15615,9 @@ ix86_legitimate_address_p (machine_mode, rtx addr, bool strict)
 	    return false;
 
 	  case UNSPEC_GOTPCREL:
+	    if (ix86_force_load_from_GOT_p (XVECEXP (XEXP (disp, 0), 0, 0)))
+	      goto is_legitimate_pic;
+	    /* FALLTHRU */
 	  case UNSPEC_PCREL:
 	    gcc_assert (flag_pic);
 	    goto is_legitimate_pic;
@@ -18169,6 +18191,12 @@ ix86_print_operand_address_as (FILE *file, rtx addr,
 	    fputs ("ds:", file);
 	  fprintf (file, HOST_WIDE_INT_PRINT_DEC, INTVAL (disp));
 	}
+      /* Load the external function address via the GOT slot to avoid PLT.  */
+      else if (GET_CODE (disp) == CONST
+	       && GET_CODE (XEXP (disp, 0)) == UNSPEC
+	       && XINT (XEXP (disp, 0), 1) == UNSPEC_GOTPCREL
+	       && ix86_force_load_from_GOT_p (XVECEXP (XEXP (disp, 0), 0, 0)))
+	output_pic_addr_const (file, disp, 0);
       else if (flag_pic)
 	output_pic_addr_const (file, disp, 0);
       else
@@ -19417,6 +19445,15 @@ ix86_expand_move (machine_mode mode, rtx operands[])
 
       if (model)
 	op1 = legitimize_tls_address (op1, model, true);
+      else if (ix86_force_load_from_GOT_p (op1))
+	{
+	  /* Load the external function address via GOT slot to avoid PLT.  */
+	  op1 = gen_rtx_UNSPEC (Pmode, gen_rtvec (1, op1),
+				UNSPEC_GOTPCREL);
+	  op1 = gen_rtx_CONST (Pmode, op1);
+	  op1 = gen_const_mem (Pmode, op1);
+	  set_mem_alias_set (op1, ix86_GOT_alias_set ());
+	}
       else
 	{
 	  tmp = legitimize_pe_coff_symbol (op1, addend != NULL_RTX);

gcc/config/i386/predicates.md

@@ -160,13 +160,18 @@
         return trunc_int_for_mode (val, SImode) == val;
       }
     case SYMBOL_REF:
+      /* TLS symbols are not constant.  */
+      if (SYMBOL_REF_TLS_MODEL (op))
+	return false;
+
+      /* Load the external function address via the GOT slot.  */
+      if (ix86_force_load_from_GOT_p (op))
+	return false;
+
       /* For certain code models, the symbolic references are known to fit.
 	 in CM_SMALL_PIC model we know it fits if it is local to the shared
 	 library.  Don't count TLS SYMBOL_REFs here, since they should fit
 	 only if inside of UNSPEC handled below.  */
-      /* TLS symbols are not constant.  */
-      if (SYMBOL_REF_TLS_MODEL (op))
-	return false;
       return (ix86_cmodel == CM_SMALL || ix86_cmodel == CM_KERNEL
 	      || (ix86_cmodel == CM_MEDIUM && !SYMBOL_REF_FAR_ADDR_P (op)));
 
@@ -207,6 +212,11 @@
 	      /* TLS symbols are not constant.  */
 	      if (SYMBOL_REF_TLS_MODEL (op1))
 		return false;
+
+	      /* Load the external function address via the GOT slot.  */
+	      if (ix86_force_load_from_GOT_p (op1))
+	        return false;
+
 	      /* For CM_SMALL assume that latest object is 16MB before
 		 end of 31bits boundary.  We may also accept pretty
 		 large negative constants knowing that all objects are
@@ -273,10 +283,15 @@
       return !(INTVAL (op) & ~(HOST_WIDE_INT) 0xffffffff);
 
     case SYMBOL_REF:
-      /* For certain code models, the symbolic references are known to fit.  */
       /* TLS symbols are not constant.  */
       if (SYMBOL_REF_TLS_MODEL (op))
 	return false;
+
+      /* Load the external function address via the GOT slot.  */
+      if (ix86_force_load_from_GOT_p (op))
+	return false;
+
+     /* For certain code models, the symbolic references are known to fit.  */
       return (ix86_cmodel == CM_SMALL
 	      || (ix86_cmodel == CM_MEDIUM
 		  && !SYMBOL_REF_FAR_ADDR_P (op)));
@@ -301,6 +316,11 @@
 	      /* TLS symbols are not constant.  */
 	      if (SYMBOL_REF_TLS_MODEL (op1))
 		return false;
+
+	      /* Load the external function address via the GOT slot.  */
+	      if (ix86_force_load_from_GOT_p (op1))
+	        return false;
+
 	      /* For small code model we may accept pretty large positive
 		 offsets, since one bit is available for free.  Negative
 		 offsets are limited by the size of NULL pointer area

gcc/testsuite/ChangeLog

+2016-06-23  H.J. Lu  <hongjiu.lu@intel.com>
+
+	PR target/67400
+        * gcc.target/i386/pr67400-1.c: New test.
+        * gcc.target/i386/pr67400-2.c: Likewise.
+        * gcc.target/i386/pr67400-3.c: Likewise.
+        * gcc.target/i386/pr67400-4.c: Likewise.
+        * gcc.target/i386/pr67400-5.c: Likewise.
+        * gcc.target/i386/pr67400-6.c: Likewise.
+        * gcc.target/i386/pr67400-7.c: Likewise.
+
 2016-06-22  David Malcolm  <dmalcolm@redhat.com>
 
 	* c-c++-common/missing-header-1.c: New test case.
@@ -355,7 +366,7 @@
 
 2016-06-15  Uros Bizjak  <ubizjak@gmail.com>
 
-        * gcc.dg/torture/float128-nan.c: Include stdint.h to define uint64_t.
+	* gcc.dg/torture/float128-nan.c: Include stdint.h to define uint64_t.
 
 2016-06-15  Alan Hayward  <alan.hayward@arm.com>
 
@@ -394,10 +405,10 @@
 
 2016-06-14  Uros Bizjak  <ubizjak@gmail.com>
 
-        * gcc.target/i386/float128-3.c: New test.
-        * gcc.target/i386/quad-sse4.c: Ditto.
-        * gcc.target/i386/quad-sse.c: Use -msse instead of -msse2.
-        Update scan strings.
+	* gcc.target/i386/float128-3.c: New test.
+	* gcc.target/i386/quad-sse4.c: Ditto.
+	* gcc.target/i386/quad-sse.c: Use -msse instead of -msse2.
+	Update scan strings.
 
 2016-06-14  Richard Biener  <rguenther@suse.de>
 

gcc/testsuite/gcc.target/i386/pr67400-1.c

+/* { dg-do compile { target { *-*-linux* && { ! ia32 } } } } */
+/* { dg-options "-O2 -fno-pic -fno-plt" } */
+
+extern void bar (void);
+
+void *
+foo (void)
+{
+  return &bar;
+}
+
+/* { dg-final { scan-assembler "mov\(l|q\)\[ \t\]*bar@GOTPCREL" } } */
+/* { dg-final { scan-assembler-not "\(mov|lea\)\(l|q\)\[ \t\]*\(\\\$|\)bar," } } */

gcc/testsuite/gcc.target/i386/pr67400-2.c

+/* { dg-do compile { target { *-*-linux* && { ! ia32 } } } } */
+/* { dg-options "-O2 -fno-pic -fno-plt" } */
+
+extern void bar (void);
+extern void *p;
+
+void
+foo (void)
+{
+  p = &bar;
+}
+
+/* { dg-final { scan-assembler "mov\(l|q\)\[ \t\]*bar@GOTPCREL" } } */
+/* { dg-final { scan-assembler-not "mov\(l|q\)\[ \t\]*\\\$bar," } } */

gcc/testsuite/gcc.target/i386/pr67400-3.c

+/* { dg-do compile { target { *-*-linux* && { ! ia32 } } } } */
+/* { dg-options "-O2 -fno-pic -fno-plt" } */
+
+static void
+bar (void)
+{
+}
+
+void *
+foo (void)
+{
+  return &bar;
+}
+
+/* { dg-final { scan-assembler "mov\(l|q\)\[ \t\]*\\\$bar," } } */
+/* { dg-final { scan-assembler-not "mov\(l|q\)\[ \t\]*bar@GOTPCREL" } } */

gcc/testsuite/gcc.target/i386/pr67400-4.c

+/* { dg-do compile { target { *-*-linux* && { ! ia32 } } } } */
+/* { dg-options "-O2 -fno-pic -fno-plt" } */
+
+extern void bar (void) __attribute__ ((visibility ("hidden")));
+
+void *
+foo (void)
+{
+  return &bar;
+}
+
+/* { dg-final { scan-assembler "mov\(l|q\)\[ \t\]*\\\$bar," } } */
+/* { dg-final { scan-assembler-not "mov\(l|q\)\[ \t\]*bar@GOTPCREL" } } */

gcc/testsuite/gcc.target/i386/pr67400-5.c

+/* { dg-do compile { target { *-*-linux* && { ! ia32 } } } } */
+/* { dg-options "-O2 -fno-pic -fno-plt" } */
+
+extern void foo (void);
+extern void bar (int, int, int, int, int, int, void *);
+
+void
+x (void)
+{
+  bar (1, 2, 3, 4, 5, 6, foo);
+}

gcc/testsuite/gcc.target/i386/pr67400-6.c

+/* { dg-do compile { target { *-*-linux* && { ! ia32 } } } } */
+/* { dg-options "-O2 -fno-pic -fno-plt" } */
+
+extern int bar (void);
+
+int
+check (void *p)
+{
+  return p != &bar;
+}
+
+/* { dg-final { scan-assembler "cmp\(l|q\)\[ \t\]*.*bar@GOTPCREL" } } */
+/* { dg-final { scan-assembler-not "mov\(l|q\)\[ \t\]*\\\$bar," } } */

gcc/testsuite/gcc.target/i386/pr67400-7.c

+/* { dg-do compile { target { *-*-linux* && { ! ia32 } } } } */
+/* { dg-options "-O2 -fno-pic -fno-plt" } */
+
+extern void bar (void);
+
+void *
+foo (void)
+{
+  return &bar+1;
+}
+
+/* { dg-final { scan-assembler "mov\(l|q\)\[ \t\]*bar@GOTPCREL" } } */
+/* { dg-final { scan-assembler-not "\(mov|lea\)\(l|q\)\[ \t\]*\(\\\$|\)bar," } } */