[ARC] Introduce ADJUST_REG_ALLOC_ORDER.

The ARC port is changing the allocation order in the
arc_conditional_register_usage function, but this is not the proper
way. Thus, we employ ADJUST_REG_ALLOC_ORDER hook for this task.

gcc/
xxxx-xx-xx  Claudiu Zissulescu  <claziss@synopsys.com>

	* config/arc/arc-protos.h (arc_adjust_reg_alloc_order): Declare.
	* config/arc/arc.c (arc_conditional_register_usage): Remove all
	reg_alloc_order references.
	(size_alloc_order): Define.
	(arc_adjust_reg_alloc_order): New function.
	* config/arc/arc.h (REG_ALLOC_ORDER): Proper define the register
	order.
	(ADJUST_REG_ALLOC_ORDER): Define.
	(HONOR_REG_ALLOC_ORDER): Likewise.

From-SVN: r269755

4 files changed, 59 insertions, 54 deletions

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 1da0fe3..6c82a61 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,15 @@
+2019-03-18  Claudiu Zissulescu  <claziss@synopsys.com>
+
+	* config/arc/arc-protos.h (arc_adjust_reg_alloc_order): Declare.
+	* config/arc/arc.c (arc_conditional_register_usage): Remove all
+	reg_alloc_order references.
+	(size_alloc_order): Define.
+	(arc_adjust_reg_alloc_order): New function.
+	* config/arc/arc.h (REG_ALLOC_ORDER): Proper define the register
+	order.
+	(ADJUST_REG_ALLOC_ORDER): Define.
+	(HONOR_REG_ALLOC_ORDER): Likewise.
+
 2019-03-18  Richard Biener  <rguenther@suse.de>
 
 	PR target/87561
diff --git a/gcc/config/arc/arc-protos.h b/gcc/config/arc/arc-protos.h
index 1362b41..8f0f197 100644
--- a/gcc/config/arc/arc-protos.h
+++ b/gcc/config/arc/arc-protos.h
@@ -47,6 +47,7 @@ extern unsigned int arc_compute_function_type (struct function *);
 extern bool arc_is_uncached_mem_p (rtx);
 extern bool gen_operands_ldd_std (rtx *operands, bool load, bool commute);
 extern bool arc_check_multi (rtx, bool);
+extern void arc_adjust_reg_alloc_order (void);
 #endif /* RTX_CODE */
 
 extern unsigned int arc_compute_frame_size (int);
diff --git a/gcc/config/arc/arc.c b/gcc/config/arc/arc.c
index 581833b..e2eaaa4 100644
--- a/gcc/config/arc/arc.c
+++ b/gcc/config/arc/arc.c
@@ -1806,54 +1806,6 @@ arc_conditional_register_usage (void)
 	warning (0, "multiply option implies r%d is fixed", regno);
       fixed_regs [regno] = call_used_regs[regno] = 1;
     }
-  if (TARGET_Q_CLASS)
-    {
-      if (optimize_size)
-	{
-	  reg_alloc_order[0] = 0;
-	  reg_alloc_order[1] = 1;
-	  reg_alloc_order[2] = 2;
-	  reg_alloc_order[3] = 3;
-	  reg_alloc_order[4] = 12;
-	  reg_alloc_order[5] = 13;
-	  reg_alloc_order[6] = 14;
-	  reg_alloc_order[7] = 15;
-	  reg_alloc_order[8] = 4;
-	  reg_alloc_order[9] = 5;
-	  reg_alloc_order[10] = 6;
-	  reg_alloc_order[11] = 7;
-	  reg_alloc_order[12] = 8;
-	  reg_alloc_order[13] = 9;
-	  reg_alloc_order[14] = 10;
-	  reg_alloc_order[15] = 11;
-	}
-      else
-	{
-	  reg_alloc_order[2] = 12;
-	  reg_alloc_order[3] = 13;
-	  reg_alloc_order[4] = 14;
-	  reg_alloc_order[5] = 15;
-	  reg_alloc_order[6] = 1;
-	  reg_alloc_order[7] = 0;
-	  reg_alloc_order[8] = 4;
-	  reg_alloc_order[9] = 5;
-	  reg_alloc_order[10] = 6;
-	  reg_alloc_order[11] = 7;
-	  reg_alloc_order[12] = 8;
-	  reg_alloc_order[13] = 9;
-	  reg_alloc_order[14] = 10;
-	  reg_alloc_order[15] = 11;
-	}
-    }
-  if (TARGET_SIMD_SET)
-    {
-      int i;
-      for (i = ARC_FIRST_SIMD_VR_REG; i <= ARC_LAST_SIMD_VR_REG; i++)
-	reg_alloc_order [i] = i;
-      for (i = ARC_FIRST_SIMD_DMA_CONFIG_REG;
-	   i <= ARC_LAST_SIMD_DMA_CONFIG_REG; i++)
-	reg_alloc_order [i] = i;
-    }
 
   /* Reduced configuration: don't use r4-r9, r16-r25.  */
   if (TARGET_RF16)
@@ -11404,6 +11356,25 @@ gen_operands_ldd_std (rtx *operands, bool load, bool commute)
   return false;
 }
 
+/* This order of allocation is used when we compile for size.  It
+   allocates first the registers which are most probably to end up in
+   a short instruction.  */
+static const int size_alloc_order[] =
+{
+ 0, 1, 2, 3, 12, 13, 14, 15,
+ 4, 5, 6, 7, 8, 9, 10, 11
+};
+
+/* Adjust register allocation order when compiling for size.  */
+void
+arc_adjust_reg_alloc_order (void)
+{
+  const int arc_default_alloc_order[] = REG_ALLOC_ORDER;
+  memcpy (reg_alloc_order, arc_default_alloc_order, sizeof (reg_alloc_order));
+  if (optimize_size)
+    memcpy (reg_alloc_order, size_alloc_order, sizeof (size_alloc_order));
+}
+
 #undef TARGET_USE_ANCHORS_FOR_SYMBOL_P
 #define TARGET_USE_ANCHORS_FOR_SYMBOL_P arc_use_anchors_for_symbol_p
 
diff --git a/gcc/config/arc/arc.h b/gcc/config/arc/arc.h
index 894eb39..8ed469a 100644
--- a/gcc/config/arc/arc.h
+++ b/gcc/config/arc/arc.h
@@ -361,7 +361,6 @@ if (GET_MODE_CLASS (MODE) == MODE_INT		\
 
    By default, the extension registers are not available.  */
 /* Present implementations only have VR0-VR23 only.  */
-/* ??? FIXME: r27 and r31 should not be fixed registers.  */
 #define FIXED_REGISTERS \
 { 0, 0, 0, 0, 0, 0, 0, 0,	\
   0, 0, 0, 0, 0, 0, 0, 0,	\
@@ -422,12 +421,34 @@ if (GET_MODE_CLASS (MODE) == MODE_INT		\
 /* If defined, an initializer for a vector of integers, containing the
    numbers of hard registers in the order in which GCC should
    prefer to use them (from most preferred to least).  */
-#define REG_ALLOC_ORDER \
-{ 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 0, 1,			\
-  16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 				\
+#define REG_ALLOC_ORDER							\
+{									\
+  /* General registers.  */						\
+  2, 3, 12, 13, 14, 15, 1, 0, 4, 5, 6, 7, 8, 9, 10, 11,			\
+  16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 30,			\
+  /* Extension core registers.  */					\
   32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47,	\
-  48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62,		\
-  27, 28, 29, 30, 31, 63}
+  48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59,			\
+  /* VR regs.  */							\
+  64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79,	\
+  80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95,	\
+  96, 97, 98, 99, 100, 101, 102, 103, 104, 105, 106, 107, 108, 109,	\
+  110, 111, 112, 113, 114, 115, 116, 117, 118, 119, 120, 121, 122, 123, \
+  124, 125, 126, 127,							\
+  /* DMA registers.  */							\
+  128, 129, 130, 131, 132, 133, 134, 135, 136, 137, 138, 139, 140, 141, \
+  142, 143,								\
+  /* Register not used for general use.  */				\
+  62, FRAME_POINTER_REGNUM, ARG_POINTER_REGNUM,				\
+  SP_REG, ILINK1_REG, RETURN_ADDR_REGNUM, LP_COUNT, CC_REG, PCL_REG	\
+}
+
+/* Use different register alloc ordering for Thumb.  */
+#define ADJUST_REG_ALLOC_ORDER arc_adjust_reg_alloc_order ()
+
+/* Tell IRA to use the order we define rather than messing it up with its
+   own cost calculations.  */
+#define HONOR_REG_ALLOC_ORDER 1
 
 /* Internal macros to classify a register number as to whether it's a
    general purpose register for compact insns (r0-r3,r12-r15), or