[NDS32] Add strict_aligned_p to machine_function and implement TARGET_EXPAND_TO_RTL_HOOK.

gcc/
	* config/nds32/nds32.c (nds32_init_machine_status,
	nds32_legitimate_index_p, nds32_legitimate_address_p): Consider
	strict_aligned_p field.
	(nds32_expand_to_rtl_hook): New function.
	(TARGET_EXPAND_TO_RTL_HOOK): Define.
	* config/nds32/nds32.h (machine_function): Add strict_aligned_p field.

From-SVN: r259222

gcc/ChangeLog

+2018-04-08  Chung-Ju Wu  <jasonwucj@gmail.com>
+
+	* config/nds32/nds32.c (nds32_init_machine_status,
+	nds32_legitimate_index_p, nds32_legitimate_address_p): Consider
+	strict_aligned_p field.
+	(nds32_expand_to_rtl_hook): New function.
+	(TARGET_EXPAND_TO_RTL_HOOK): Define.
+	* config/nds32/nds32.h (machine_function): Add strict_aligned_p field.
+
 2018-04-08  Kito Cheng  <kito.cheng@gmail.com>
 	    Chung-Ju Wu  <jasonwucj@gmail.com>
 

gcc/config/nds32/nds32.c

@@ -342,6 +342,9 @@ nds32_init_machine_status (void)
   /* Initially assume this function does NOT use fp_as_gp optimization.  */
   machine->fp_as_gp_p = 0;
 
+  /* Initially this function is not under strictly aligned situation.  */
+  machine->strict_aligned_p = 0;
+
   return machine;
 }
 
@@ -1414,8 +1417,12 @@ nds32_legitimate_index_p (machine_mode outer_mode,
 	  /* Further check if the value is legal for the 'outer_mode'.  */
 	  if (satisfies_constraint_Is16 (index))
 	    {
+	      /* If it is not under strictly aligned situation,
+		 we can return true without checking alignment.  */
+	      if (!cfun->machine->strict_aligned_p)
+		return true;
 	      /* Make sure address is half word alignment.  */
-	      if (NDS32_HALF_WORD_ALIGN_P (INTVAL (index)))
+	      else if (NDS32_HALF_WORD_ALIGN_P (INTVAL (index)))
 		return true;
 	    }
 	  break;
@@ -1430,8 +1437,12 @@ nds32_legitimate_index_p (machine_mode outer_mode,
 		    return false;
 		}
 
+	      /* If it is not under strictly aligned situation,
+		 we can return true without checking alignment.  */
+	      if (!cfun->machine->strict_aligned_p)
+		return true;
 	      /* Make sure address is word alignment.  */
-	      if (NDS32_SINGLE_WORD_ALIGN_P (INTVAL (index)))
+	      else if (NDS32_SINGLE_WORD_ALIGN_P (INTVAL (index)))
 		return true;
 	    }
 	  break;
@@ -1446,11 +1457,15 @@ nds32_legitimate_index_p (machine_mode outer_mode,
 		    return false;
 		}
 
+	      /* If it is not under strictly aligned situation,
+		 we can return true without checking alignment.  */
+	      if (!cfun->machine->strict_aligned_p)
+		return true;
 	      /* Make sure address is word alignment.
 		Currently we do not have 64-bit load/store yet,
 		so we will use two 32-bit load/store instructions to do
 		memory access and they are single word alignment.  */
-	      if (NDS32_SINGLE_WORD_ALIGN_P (INTVAL (index)))
+	      else if (NDS32_SINGLE_WORD_ALIGN_P (INTVAL (index)))
 		return true;
 	    }
 	  break;
@@ -1589,6 +1604,20 @@ nds32_adjust_insn_length (rtx_insn *insn, int length)
     }
 }
 
+/* Storage Layout.  */
+
+/* This function will be called just before expansion into rtl.  */
+static void
+nds32_expand_to_rtl_hook (void)
+{
+  /* We need to set strictly aligned situation.
+     After that, the memory address checking in nds32_legitimate_address_p()
+     will take alignment offset into consideration so that it will not create
+     unaligned [base + offset] access during the rtl optimization.  */
+  cfun->machine->strict_aligned_p = 1;
+}
+
+
 /* Register Usage.  */
 
 static void
@@ -2469,11 +2498,15 @@ nds32_legitimate_address_p (machine_mode mode, rtx x, bool strict)
 		{
 		  if (satisfies_constraint_Is14 (op1))
 		    {
+		      /* If it is not under strictly aligned situation,
+			 we can return true without checking alignment.  */
+		      if (!cfun->machine->strict_aligned_p)
+			return true;
 		      /* Make sure address is word alignment.
 			Currently we do not have 64-bit load/store yet,
 			so we will use two 32-bit load/store instructions to do
 			memory access and they are single word alignment.  */
-		      if (NDS32_SINGLE_WORD_ALIGN_P (INTVAL (op1)))
+		      else if (NDS32_SINGLE_WORD_ALIGN_P (INTVAL (op1)))
 			return true;
 		    }
 		}
@@ -4827,6 +4860,9 @@ nds32_use_blocks_for_constant_p (machine_mode mode,
 #define TARGET_PROMOTE_FUNCTION_MODE \
   default_promote_function_mode_always_promote
 
+#undef TARGET_EXPAND_TO_RTL_HOOK
+#define TARGET_EXPAND_TO_RTL_HOOK nds32_expand_to_rtl_hook
+
 
 /* Layout of Source Language Data Types.  */
 

gcc/config/nds32/nds32.h

@@ -296,6 +296,15 @@ struct GTY(()) machine_function
   /* Indicate that whether this function
      uses fp_as_gp optimization.  */
   int fp_as_gp_p;
+  /* Indicate that whether this function is under strictly aligned
+     situation for legitimate address checking.  This flag informs
+     nds32_legitimate_address_p() how to treat offset alignment:
+       1. The IVOPT phase needs to detect available range for memory access,
+	  such as checking [base + 32767] ~ [base + (-32768)].
+	  For this case we do not want address to be strictly aligned.
+       2. The rtl lowering and optimization are close to target code.
+	  For this case we need address to be strictly aligned.  */
+  int strict_aligned_p;
 };
 
 /* A C structure that contains the arguments information.  */