[SH] Add TARGET_DYNSHIFT macro

[SH] Add TARGET_DYNSHIFT macro

[Oleg Endo]

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Hello,

Currently the check for availability of dynamic shift instructions on a
particular SH target is repeated in several places.  The attached patch
adds a new macro for that.

Tested with 'make all'.  CSiBE result-size (-m4-single -ml
-mpretend-cmove) also doesn't show any change.

OK?

Cheers,
Oleg

ChangeLog:

	* config/sh/sh.h (TARGET_DYNSHIFT): New macro.
	(SH_DYNAMIC_SHIFT_COST): Use it.
	* config/sh/sh.c (expand_ashiftrt, shl_sext_kind): Likewise.
	(sh_dynamicalize_shift_p): Add TARGET_DYNSHIFT condition.  Add 
	sanity check for input value.  Add function description.
	* config/sh/sh.md (ashlsi3, ashlsi3_std, ashrsi3_d, lshrsi3, 
	lshrsi3_d): Use TARGET_DYNSHIFT.

[-- Attachment #2: sh_target_dynshift.patch --]
[-- Type: text/x-patch, Size: 4394 bytes --]

Index: gcc/config/sh/sh.c
===================================================================
--- gcc/config/sh/sh.c	(revision 189746)
+++ gcc/config/sh/sh.c	(working copy)
@@ -3437,7 +3437,7 @@
   char func[18];
   int value;
 
-  if (TARGET_SH3 || TARGET_SH2A)
+  if (TARGET_DYNSHIFT)
     {
       if (!CONST_INT_P (operands[2]))
 	{
@@ -3507,10 +3507,16 @@
   return true;
 }
 
+/* Return true if it is potentially beneficial to use a dynamic shift
+   instruction (shad / shar) instead of a combination of 1/2/8/16 
+   shift instructions for the specified shift count.
+   If dynamic shifts are not available, always return false.  */
 bool
 sh_dynamicalize_shift_p (rtx count)
 {
-  return shift_insns[INTVAL (count) & 31] > 1 + SH_DYNAMIC_SHIFT_COST;
+  gcc_assert (CONST_INT_P (count));
+  return TARGET_DYNSHIFT
+	 && (shift_insns[INTVAL (count) & 31] > 1 + SH_DYNAMIC_SHIFT_COST);
 }
 
 /* Try to find a good way to implement the combiner pattern
@@ -3886,7 +3892,7 @@
 	    }
 	}
     }
-  if (TARGET_SH3 || TARGET_SH2A)
+  if (TARGET_DYNSHIFT)
     {
       /* Try to use a dynamic shift.  */
       cost = shift_insns[32 - insize] + 1 + SH_DYNAMIC_SHIFT_COST;
Index: gcc/config/sh/sh.h
===================================================================
--- gcc/config/sh/sh.h	(revision 189746)
+++ gcc/config/sh/sh.h	(working copy)
@@ -1928,6 +1928,13 @@
 /* Nonzero if access to memory by bytes is no faster than for words.  */
 #define SLOW_BYTE_ACCESS 1
 
+/* Nonzero if the target supports dynamic shift instructions
+   like shad and shld.  */
+#define TARGET_DYNSHIFT (TARGET_SH3 || TARGET_SH2A)
+
+#define SH_DYNAMIC_SHIFT_COST \
+  (TARGET_HARD_SH4 ? 1 : TARGET_DYNSHIFT ? (optimize_size ? 1 : 2) : 20)
+
 /* Immediate shift counts are truncated by the output routines (or was it
    the assembler?).  Shift counts in a register are truncated by SH.  Note
    that the native compiler puts too large (> 32) immediate shift counts
@@ -2317,11 +2324,6 @@
    prologue rather than duplicate around each call.  */
 #define ACCUMULATE_OUTGOING_ARGS TARGET_ACCUMULATE_OUTGOING_ARGS
 
-#define SH_DYNAMIC_SHIFT_COST \
-  (TARGET_HARD_SH4 ? 1	\
-   : (TARGET_SH3 || TARGET_SH2A) ? (optimize_size ? 1 : 2) : 20)
-
-
 #define NUM_MODES_FOR_MODE_SWITCHING { FP_MODE_NONE }
 
 #define OPTIMIZE_MODE_SWITCHING(ENTITY) (TARGET_SH4 || TARGET_SH2A_DOUBLE)
Index: gcc/config/sh/sh.md
===================================================================
--- gcc/config/sh/sh.md	(revision 189747)
+++ gcc/config/sh/sh.md	(working copy)
@@ -3514,7 +3514,7 @@
   if (CONST_INT_P (operands[2])
       && sh_dynamicalize_shift_p (operands[2]))
     operands[2] = force_reg (SImode, operands[2]);
-  if (TARGET_SH3 || TARGET_SH2A)
+  if (TARGET_DYNSHIFT)
     {
       emit_insn (gen_ashlsi3_std (operands[0], operands[1], operands[2]));
       DONE;
@@ -3530,14 +3530,13 @@
 	(ashift:SI (match_operand:SI 1 "arith_reg_operand" "0,0,0,0")
 		   (match_operand:SI 2 "nonmemory_operand" "r,M,P27,?ri")))
    (clobber (match_scratch:SI 3 "=X,X,X,&r"))]
-  "(TARGET_SH3 || TARGET_SH2A)
-   || (TARGET_SH1 && satisfies_constraint_P27 (operands[2]))"
+  "TARGET_DYNSHIFT || (TARGET_SH1 && satisfies_constraint_P27 (operands[2]))"
   "@
    shld	%2,%0
    add	%0,%0
    shll%O2	%0
    #"
-  "(TARGET_SH3 || TARGET_SH2A)
+  "TARGET_DYNSHIFT
    && reload_completed
    && CONST_INT_P (operands[2])
    && ! satisfies_constraint_P27 (operands[2])"
@@ -3797,7 +3796,7 @@
   [(set (match_operand:SI 0 "arith_reg_dest" "=r")
 	(ashiftrt:SI (match_operand:SI 1 "arith_reg_operand" "0")
 		     (neg:SI (match_operand:SI 2 "arith_reg_operand" "r"))))]
-  "TARGET_SH3 || TARGET_SH2A"
+  "TARGET_DYNSHIFT"
   "shad	%2,%0"
   [(set_attr "type" "dyn_shift")])
 
@@ -3912,7 +3911,7 @@
   if (CONST_INT_P (operands[2])
       && sh_dynamicalize_shift_p (operands[2]))
     operands[2] = force_reg (SImode, operands[2]);
-  if ((TARGET_SH3 || TARGET_SH2A)
+  if (TARGET_DYNSHIFT
       && arith_reg_operand (operands[2], GET_MODE (operands[2])))
     {
       rtx count = copy_to_mode_reg (SImode, operands[2]);
@@ -3928,7 +3927,7 @@
   [(set (match_operand:SI 0 "arith_reg_dest" "=r")
 	(lshiftrt:SI (match_operand:SI 1 "arith_reg_operand" "0")
 		     (neg:SI (match_operand:SI 2 "arith_reg_operand" "r"))))]
-  "TARGET_SH3 || TARGET_SH2A"
+  "TARGET_DYNSHIFT"
   "shld	%2,%0"
   [(set_attr "type" "dyn_shift")])
 

Re: [SH] Add TARGET_DYNSHIFT macro

[Kaz Kojima]

Oleg Endo <oleg.endo@t-online.de> wrote:
> Currently the check for availability of dynamic shift instructions on a
> particular SH target is repeated in several places.  The attached patch
> adds a new macro for that.
> 
> Tested with 'make all'.  CSiBE result-size (-m4-single -ml
> -mpretend-cmove) also doesn't show any change.
> 
> OK?

OK.

Regards,
	kaz