[AArch64] Catch attempts to use SVE types when SVE is disabled

This patch reports an error if code tries to use variable-length
SVE types when SVE is disabled.  We already report a similar error
for definitions or uses of SVE functions when SVE is disabled.

2019-12-02  Richard Sandiford  <richard.sandiford@arm.com>

gcc/
	* config/aarch64/aarch64.c (aarch64_report_sve_required): New function.
	(aarch64_expand_mov_immediate): Use it when attempting to measure
	the length of an SVE vector.
	(aarch64_mov_operand_p): Only allow SVE CNT immediates when
	SVE is enabled.

gcc/testsuite/
	* gcc.target/aarch64/sve/acle/general/nosve_4.c: New test.
	* gcc.target/aarch64/sve/acle/general/nosve_5.c: Likewise.
	* gcc.target/aarch64/sve/pcs/nosve_4.c: Expected a second error
	for the copy.
	* gcc.target/aarch64/sve/pcs/nosve_5.c: Likewise.
	* gcc.target/aarch64/sve/pcs/nosve_6.c: Likewise.

From-SVN: r278909

gcc/ChangeLog

 2019-12-02  Richard Sandiford  <richard.sandiford@arm.com>
 
+	* config/aarch64/aarch64.c (aarch64_report_sve_required): New function.
+	(aarch64_expand_mov_immediate): Use it when attempting to measure
+	the length of an SVE vector.
+	(aarch64_mov_operand_p): Only allow SVE CNT immediates when
+	SVE is enabled.
+
+2019-12-02  Richard Sandiford  <richard.sandiford@arm.com>
+
 	* config/aarch64/aarch64-sve-builtins.h
 	(gimple_folder::force_vector): Declare.
 	* config/aarch64/aarch64-sve-builtins.cc

gcc/config/aarch64/aarch64.c

@@ -1473,6 +1473,25 @@ aarch64_err_no_fpadvsimd (machine_mode mode)
 	     " vector types", "+nofp");
 }
 
+/* Report when we try to do something that requires SVE when SVE is disabled.
+   This is an error of last resort and isn't very high-quality.  It usually
+   involves attempts to measure the vector length in some way.  */
+static void
+aarch64_report_sve_required (void)
+{
+  static bool reported_p = false;
+
+  /* Avoid reporting a slew of messages for a single oversight.  */
+  if (reported_p)
+    return;
+
+  error ("this operation requires the SVE ISA extension");
+  inform (input_location, "you can enable SVE using the command-line"
+	  " option %<-march%>, or by using the %<target%>"
+	  " attribute or pragma");
+  reported_p = true;
+}
+
 /* Return true if REGNO is P0-P15 or one of the special FFR-related
    registers.  */
 inline bool
@@ -4525,6 +4544,11 @@ aarch64_expand_mov_immediate (rtx dest, rtx imm)
 	 folding it into the relocation.  */
       if (!offset.is_constant (&const_offset))
 	{
+	  if (!TARGET_SVE)
+	    {
+	      aarch64_report_sve_required ();
+	      return;
+	    }
 	  if (base == const0_rtx && aarch64_sve_cnt_immediate_p (offset))
 	    emit_insn (gen_rtx_SET (dest, imm));
 	  else
@@ -16864,7 +16888,7 @@ aarch64_mov_operand_p (rtx x, machine_mode mode)
   if (GET_CODE (x) == SYMBOL_REF && mode == DImode && CONSTANT_ADDRESS_P (x))
     return true;
 
-  if (aarch64_sve_cnt_immediate_p (x))
+  if (TARGET_SVE && aarch64_sve_cnt_immediate_p (x))
     return true;
 
   return aarch64_classify_symbolic_expression (x)

gcc/testsuite/ChangeLog

 2019-12-02  Richard Sandiford  <richard.sandiford@arm.com>
 
+	* gcc.target/aarch64/sve/acle/general/nosve_4.c: New test.
+	* gcc.target/aarch64/sve/acle/general/nosve_5.c: Likewise.
+	* gcc.target/aarch64/sve/pcs/nosve_4.c: Expected a second error
+	for the copy.
+	* gcc.target/aarch64/sve/pcs/nosve_5.c: Likewise.
+	* gcc.target/aarch64/sve/pcs/nosve_6.c: Likewise.
+
+2019-12-02  Richard Sandiford  <richard.sandiford@arm.com>
+
 	* gcc.target/aarch64/sve/acle/aarch64-sve-acle.exp: Run the
 	general/* tests too.
 

gcc/testsuite/gcc.target/aarch64/sve/acle/general/nosve_4.c

+/* { dg-options "-march=armv8-a" } */
+
+void
+f (__SVBool_t *x, __SVBool_t *y)
+{
+  *x = *y; /* { dg-error {this operation requires the SVE ISA extension} } */
+  *x = *y;
+}

gcc/testsuite/gcc.target/aarch64/sve/acle/general/nosve_5.c

+/* { dg-options "-march=armv8-a" } */
+
+void
+f (__SVInt8_t *x, __SVInt8_t *y)
+{
+  *x = *y; /* { dg-error {this operation requires the SVE ISA extension} } */
+  *x = *y;
+}

gcc/testsuite/gcc.target/aarch64/sve/pcs/nosve_4.c

@@ -10,5 +10,6 @@ void take_svuint8 (svuint8_t);
 void
 f (svuint8_t *ptr)
 {
-  take_svuint8 (*ptr); /* { dg-error {'take_svuint8' requires the SVE ISA extension} } */
+  take_svuint8 (*ptr); /* { dg-error {this operation requires the SVE ISA extension} } */
+  /* { dg-error {'take_svuint8' requires the SVE ISA extension} "" { target *-*-* } .-1 } */
 }

gcc/testsuite/gcc.target/aarch64/sve/pcs/nosve_5.c

@@ -11,5 +11,6 @@ void take_svuint8_eventually (float, float, float, float,
 void
 f (svuint8_t *ptr)
 {
-  take_svuint8_eventually (0, 0, 0, 0, 0, 0, 0, 0, *ptr); /* { dg-error {arguments of type '(svuint8_t|__SVUint8_t)' require the SVE ISA extension} } */
+  take_svuint8_eventually (0, 0, 0, 0, 0, 0, 0, 0, *ptr); /* { dg-error {this operation requires the SVE ISA extension} } */
+  /* { dg-error {arguments of type '(svuint8_t|__SVUint8_t)' require the SVE ISA extension} "" { target *-*-* } .-1 } */
 }

gcc/testsuite/gcc.target/aarch64/sve/pcs/nosve_6.c

@@ -10,5 +10,6 @@ void unprototyped ();
 void
 f (svuint8_t *ptr)
 {
-  unprototyped (*ptr); /* { dg-error {arguments of type '(svuint8_t|__SVUint8_t)' require the SVE ISA extension} } */
+  unprototyped (*ptr);  /* { dg-error {this operation requires the SVE ISA extension} } */
+  /* { dg-error {arguments of type '(svuint8_t|__SVUint8_t)' require the SVE ISA extension} "" { target *-*-* } .-1 } */
 }