re PR target/86014 ([AArch64] missed LDP optimization)

gcc/
2018-08-02  Jackson Woodruff  <jackson.woodruff@arm.com>

	PR target/86014
	* config/aarch64/aarch64.c (aarch64_operands_adjust_ok_for_ldpstp):
	No longer check last store for clobber of address register.


gcc/testsuite
2018-08-02  Jackson Woodruff  <jackson.woodruff@arm.com>

	PR target/86014
	* gcc.target/aarch64/ldp_stp_13.c: New test.

From-SVN: r263249

gcc/ChangeLog

+2018-08-02  Jackson Woodruff  <jackson.woodruff@arm.com>
+
+	PR target/86014
+	* config/aarch64/aarch64.c (aarch64_operands_adjust_ok_for_ldpstp):
+	No longer check last store for clobber of address register.
+
 2018-08-02  Martin Liska  <mliska@suse.cz>
 
         PR gcov-profile/86817

gcc/config/aarch64/aarch64.c

@@ -17270,9 +17270,26 @@ aarch64_operands_adjust_ok_for_ldpstp (rtx *operands, bool load,
 	return false;
     }
 
-  /* Check if addresses are clobbered by load.  */
-  if (load)
-    for (int i = 0; i < num_insns; i++)
+  /* Check if the registers are of same class.  */
+  rclass = REG_P (reg[0]) && FP_REGNUM_P (REGNO (reg[0]))
+    ? FP_REGS : GENERAL_REGS;
+
+  for (int i = 1; i < num_insns; i++)
+    if (REG_P (reg[i]) && FP_REGNUM_P (REGNO (reg[i])))
+      {
+	if (rclass != FP_REGS)
+	  return false;
+      }
+    else
+      {
+	if (rclass != GENERAL_REGS)
+	  return false;
+      }
+
+  /* Only the last register in the order in which they occur
+     may be clobbered by the load.  */
+  if (rclass == GENERAL_REGS && load)
+    for (int i = 0; i < num_insns - 1; i++)
       if (reg_mentioned_p (reg[i], mem[i]))
 	return false;
 
@@ -17312,22 +17329,6 @@ aarch64_operands_adjust_ok_for_ldpstp (rtx *operands, bool load,
       && MEM_ALIGN (mem[0]) < 8 * BITS_PER_UNIT)
     return false;
 
-  /* Check if the registers are of same class.  */
-  rclass = REG_P (reg[0]) && FP_REGNUM_P (REGNO (reg[0]))
-    ? FP_REGS : GENERAL_REGS;
-
-  for (int i = 1; i < num_insns; i++)
-    if (REG_P (reg[i]) && FP_REGNUM_P (REGNO (reg[i])))
-      {
-	if (rclass != FP_REGS)
-	  return false;
-      }
-    else
-      {
-	if (rclass != GENERAL_REGS)
-	  return false;
-      }
-
   return true;
 }
 

gcc/testsuite/ChangeLog

+2018-08-02  Jackson Woodruff  <jackson.woodruff@arm.com>
+
+	PR target/86014
+	* gcc.target/aarch64/ldp_stp_13.c: New test.
+
 2018-08-02  Thomas Preud'homme  <thomas.preudhomme@linaro.org>
 
 	PR target/85434

gcc/testsuite/gcc.target/aarch64/ldp_stp_13.c

+/* { dg-do compile } */
+/* { dg-options "-O2 -mabi=ilp32" } */
+
+long long
+load_long (long long int *arr)
+{
+  return arr[400] << 1 + arr[401] << 1 + arr[403] << 1 + arr[404] << 1;
+}
+
+/* { dg-final { scan-assembler-times "ldp\tx\[0-9\]+, x\[0-9\]+, " 2 } } */
+
+int
+load (int *arr)
+{
+  return arr[527] << 1 + arr[400] << 1 + arr[401] << 1 + arr[528] << 1;
+}
+
+/* { dg-final { scan-assembler-times "ldp\tw\[0-9\]+, w\[0-9\]+, " 2 } } */