re PR target/52076 (bloated code for setting single bits in bitfields on m68k)

	PR target/52076
	* config/m68k/m68k.md (xorsi3_internal): Twiddle constraints to
	improve code density for small immediate to memory case.
	(insv): Better handle bitfield assignments when the field is
	being set to all ones.
	* config/m68k/predicates.md (reg_or_pow2_m1_operand): New
	operand predicate.

	PR target/52076
	* gcc.target/m68k/pr52076-1.c: New test.
	* gcc.target/m68k/pr52076-2.c: New test.

From-SVN: r220015

3 files changed, 29 insertions, 5 deletions

diff --git a/gcc/config/m68k/.m68k.md.swp b/gcc/config/m68k/.m68k.md.swp
new file mode 100755
index 0000000..36d7681
--- /dev/null
+++ b/gcc/config/m68k/.m68k.md.swp
diff --git a/gcc/config/m68k/m68k.md b/gcc/config/m68k/m68k.md
index d34ad1d..6bb296e 100644
--- a/gcc/config/m68k/m68k.md
+++ b/gcc/config/m68k/m68k.md
@@ -3838,9 +3838,9 @@
   "")
 
 (define_insn "xorsi3_internal"
-  [(set (match_operand:SI 0 "nonimmediate_operand" "=do,m")
-	(xor:SI (match_operand:SI 1 "general_operand" "%0,0")
-                (match_operand:SI 2 "general_operand" "di,dKT")))]
+  [(set (match_operand:SI 0 "nonimmediate_operand" "=d,o,m")
+	(xor:SI (match_operand:SI 1 "general_operand" "%0, 0,0")
+                (match_operand:SI 2 "general_operand" "di,dK,dKT")))]
 
   "!TARGET_COLDFIRE"
 {
@@ -5583,9 +5583,20 @@
   [(set (zero_extract:SI (match_operand:SI 0 "nonimmediate_operand" "")
 			 (match_operand:SI 1 "const_int_operand" "")
 			 (match_operand:SI 2 "const_int_operand" ""))
-	(match_operand:SI 3 "register_operand" ""))]
+	(match_operand:SI 3 "reg_or_pow2_m1_operand" ""))]
   "TARGET_68020 && TARGET_BITFIELD"
-  "")
+  "
+{
+  /* Special case initializing a field to all ones. */
+  if (GET_CODE (operands[3]) == CONST_INT)
+    {
+      if (exact_log2 (INTVAL (operands[3]) + 1) != INTVAL (operands[1]))
+	operands[3] = force_reg (SImode, operands[3]);
+      else
+	operands[3] = constm1_rtx;
+
+    }
+}")
 
 (define_insn "*insv_bfins_mem"
   [(set (zero_extract:SI (match_operand:QI 0 "memory_operand" "+o")
diff --git a/gcc/config/m68k/predicates.md b/gcc/config/m68k/predicates.md
index a7b5c42..c652f10 100644
--- a/gcc/config/m68k/predicates.md
+++ b/gcc/config/m68k/predicates.md
@@ -244,3 +244,16 @@
 		 || reload_in_progress
 		 || reload_completed));
 })
+
+;; Used to detect when an operand is either a register
+;; or a constant that is all ones in its lower bits.
+;; Used by insv pattern to help detect when we're initializing
+;; a bitfield to all ones.
+
+(define_predicate "reg_or_pow2_m1_operand"
+  (match_code "reg,const_int")
+{
+  return (REG_P (op)
+	  || (GET_CODE (op) == CONST_INT
+	      && exact_log2 (INTVAL (op) + 1) >= 0));
+})