gcc/

	Backport from trunk r247603.
	2016-05-04  Kyrylo Tkachov  <kyrylo.tkachov@arm.com>

	* config/aarch64/aarch64.md (prefetch); Adjust predicate and
	constraint on operand 0 to allow more general addressing modes.
	Adjust output template.
	* config/aarch64/aarch64.c (aarch64_address_valid_for_prefetch_p):
	New function.
	* config/aarch64/aarch64-protos.h
	(aarch64_address_valid_for_prefetch_p): Declare prototype.
	* config/aarch64/constraints.md (Dp): New address constraint.
	* config/aarch64/predicates.md (aarch64_prefetch_operand): New
	predicate.

	gcc/testsuite/
	Backport from trunk r247603.
	2016-05-04  Kyrylo Tkachov  <kyrylo.tkachov@arm.com>

	* gcc.target/aarch64/prfm_imm_offset_1.c: New test.

Change-Id: I048b116d85fedbf2e79bc1d075dfcd2160de40b3

6 files changed, 59 insertions, 10 deletions

diff --git a/gcc/config/aarch64/aarch64-protos.h b/gcc/config/aarch64/aarch64-protos.h
index 9543f8c9f29..2895a2a97b5 100644
--- a/gcc/config/aarch64/aarch64-protos.h
+++ b/gcc/config/aarch64/aarch64-protos.h
@@ -301,6 +301,7 @@ extern struct tune_params aarch64_tune_params;
 
 HOST_WIDE_INT aarch64_initial_elimination_offset (unsigned, unsigned);
 int aarch64_get_condition_code (rtx);
+bool aarch64_address_valid_for_prefetch_p (rtx, bool);
 bool aarch64_bitmask_imm (HOST_WIDE_INT val, machine_mode);
 unsigned HOST_WIDE_INT aarch64_and_split_imm1 (HOST_WIDE_INT val_in);
 unsigned HOST_WIDE_INT aarch64_and_split_imm2 (HOST_WIDE_INT val_in);
diff --git a/gcc/config/aarch64/aarch64.c b/gcc/config/aarch64/aarch64.c
index 8dffe6f10e4..71f9819745f 100644
--- a/gcc/config/aarch64/aarch64.c
+++ b/gcc/config/aarch64/aarch64.c
@@ -4549,6 +4549,24 @@ aarch64_classify_address (struct aarch64_address_info *info,
     }
 }
 
+/* Return true if the address X is valid for a PRFM instruction.
+   STRICT_P is true if we should do strict checking with
+   aarch64_classify_address.  */
+
+bool
+aarch64_address_valid_for_prefetch_p (rtx x, bool strict_p)
+{
+  struct aarch64_address_info addr;
+
+  /* PRFM accepts the same addresses as DImode...  */
+  bool res = aarch64_classify_address (&addr, x, DImode, MEM, strict_p);
+  if (!res)
+    return false;
+
+  /* ... except writeback forms.  */
+  return addr.type != ADDRESS_REG_WB;
+}
+
 bool
 aarch64_symbolic_address_p (rtx x)
 {
diff --git a/gcc/config/aarch64/aarch64.md b/gcc/config/aarch64/aarch64.md
index adc280f67d9..7cc32dd037c 100644
--- a/gcc/config/aarch64/aarch64.md
+++ b/gcc/config/aarch64/aarch64.md
@@ -519,27 +519,31 @@
 )
 
 (define_insn "prefetch"
-  [(prefetch (match_operand:DI 0 "register_operand" "r")
+  [(prefetch (match_operand:DI 0 "aarch64_prefetch_operand" "Dp")
             (match_operand:QI 1 "const_int_operand" "")
             (match_operand:QI 2 "const_int_operand" ""))]
   ""
   {
-    const char * pftype[2][4] = 
+    const char * pftype[2][4] =
     {
-      {"prfm\\tPLDL1STRM, %a0",
-       "prfm\\tPLDL3KEEP, %a0",
-       "prfm\\tPLDL2KEEP, %a0",
-       "prfm\\tPLDL1KEEP, %a0"},
-      {"prfm\\tPSTL1STRM, %a0",
-       "prfm\\tPSTL3KEEP, %a0",
-       "prfm\\tPSTL2KEEP, %a0",
-       "prfm\\tPSTL1KEEP, %a0"},
+      {"prfm\\tPLDL1STRM, %0",
+       "prfm\\tPLDL3KEEP, %0",
+       "prfm\\tPLDL2KEEP, %0",
+       "prfm\\tPLDL1KEEP, %0"},
+      {"prfm\\tPSTL1STRM, %0",
+       "prfm\\tPSTL3KEEP, %0",
+       "prfm\\tPSTL2KEEP, %0",
+       "prfm\\tPSTL1KEEP, %0"},
     };
 
     int locality = INTVAL (operands[2]);
 
     gcc_assert (IN_RANGE (locality, 0, 3));
 
+    /* PRFM accepts the same addresses as a 64-bit LDR so wrap
+       the address into a DImode MEM so that aarch64_print_operand knows
+       how to print it.  */
+    operands[0] = gen_rtx_MEM (DImode, operands[0]);
     return pftype[INTVAL(operands[1])][locality];
   }
   [(set_attr "type" "load1")]
diff --git a/gcc/config/aarch64/constraints.md b/gcc/config/aarch64/constraints.md
index 224beef7ced..b43f08b7bbd 100644
--- a/gcc/config/aarch64/constraints.md
+++ b/gcc/config/aarch64/constraints.md
@@ -222,3 +222,8 @@
  A constraint that matches an immediate operand valid for AdvSIMD scalar."
  (and (match_code "const_int")
       (match_test "aarch64_simd_imm_scalar_p (op, GET_MODE (op))")))
+
+(define_address_constraint "Dp"
+  "@internal
+ An address valid for a prefetch instruction."
+ (match_test "aarch64_address_valid_for_prefetch_p (op, true)"))
diff --git a/gcc/config/aarch64/predicates.md b/gcc/config/aarch64/predicates.md
index e83d45b3945..8e3ea9b4696 100644
--- a/gcc/config/aarch64/predicates.md
+++ b/gcc/config/aarch64/predicates.md
@@ -165,6 +165,9 @@
        (match_test "aarch64_legitimate_address_p (mode, XEXP (op, 0), PARALLEL,
 					       0)")))
 
+(define_predicate "aarch64_prefetch_operand"
+  (match_test "aarch64_address_valid_for_prefetch_p (op, false)"))
+
 (define_predicate "aarch64_valid_symref"
   (match_code "const, symbol_ref, label_ref")
 {
diff --git a/gcc/testsuite/gcc.target/aarch64/prfm_imm_offset_1.c b/gcc/testsuite/gcc.target/aarch64/prfm_imm_offset_1.c
new file mode 100644
index 00000000000..26ab9139cbc
--- /dev/null
+++ b/gcc/testsuite/gcc.target/aarch64/prfm_imm_offset_1.c
@@ -0,0 +1,18 @@
+/* { dg-do compile } */
+/* { dg-options "-O2" } */
+
+/* Check that we can generate the immediate-offset addressing
+   mode for PRFM.  */
+
+#define ARRSIZE 65
+int *bad_addr[ARRSIZE];
+
+void
+prefetch_for_read (void)
+{
+  int i;
+  for (i = 0; i < ARRSIZE; i++)
+    __builtin_prefetch (bad_addr[i] + 2, 0, 0);
+}
+
+/* { dg-final { scan-assembler-times "prfm.*\\\[x\[0-9\]+, 8\\\]" 1 } } */