re PR target/60203 (Support long double/_Decimal128 direct move on power8)

2014-02-18  Michael Meissner  <meissner@linux.vnet.ibm.com>

	PR target/60203
	* config/rs6000/rs6000.md (mov<mode>_64bit, TF/TDmode moves):
	Split 64-bit moves into 2 patterns.  Do not allow the use of
	direct move for TDmode in little endian, since the decimal value
	has little endian bytes within a word, but the 64-bit pieces are
	ordered in a big endian fashion, and normal subreg's of TDmode are
	not allowed.
	(mov<mode>_64bit_dm): Likewise.
	(movtd_64bit_nodm): Likewise.

From-SVN: r207868

gcc/ChangeLog

+2014-02-18  Michael Meissner  <meissner@linux.vnet.ibm.com>
+
+	PR target/60203
+	* config/rs6000/rs6000.md (mov<mode>_64bit, TF/TDmode moves):
+	Split 64-bit moves into 2 patterns.  Do not allow the use of
+	direct move for TDmode in little endian, since the decimal value
+	has little endian bytes within a word, but the 64-bit pieces are
+	ordered in a big endian fashion, and normal subreg's of TDmode are
+	not allowed.
+	(mov<mode>_64bit_dm): Likewise.
+	(movtd_64bit_nodm): Likewise.
+
 2014-02-18  Eric Botcazou  <ebotcazou@adacore.com>
 
 	PR tree-optimization/60174

gcc/config/rs6000/rs6000.md

@@ -9526,10 +9526,16 @@
 ;; It's important to list Y->r and r->Y before r->r because otherwise
 ;; reload, given m->r, will try to pick r->r and reload it, which
 ;; doesn't make progress.
-(define_insn_and_split "*mov<mode>_64bit"
+
+;; We can't split little endian direct moves of TDmode, because the words are
+;; not swapped like they are for TImode or TFmode.  Subregs therefore are
+;; problematical.  Don't allow direct move for this case.
+
+(define_insn_and_split "*mov<mode>_64bit_dm"
   [(set (match_operand:FMOVE128 0 "nonimmediate_operand" "=m,d,d,Y,r,r,r,wm")
 	(match_operand:FMOVE128 1 "input_operand" "d,m,d,r,YGHF,r,wm,r"))]
   "TARGET_HARD_FLOAT && TARGET_FPRS && TARGET_POWERPC64
+   && (<MODE>mode != TDmode || WORDS_BIG_ENDIAN)
    && (gpc_reg_operand (operands[0], <MODE>mode)
        || gpc_reg_operand (operands[1], <MODE>mode))"
   "#"
@@ -9538,6 +9544,18 @@
 { rs6000_split_multireg_move (operands[0], operands[1]); DONE; }
   [(set_attr "length" "8,8,8,12,12,8,8,8")])
 
+(define_insn_and_split "*movtd_64bit_nodm"
+  [(set (match_operand:TD 0 "nonimmediate_operand" "=m,d,d,Y,r,r")
+	(match_operand:TD 1 "input_operand" "d,m,d,r,YGHF,r"))]
+  "TARGET_HARD_FLOAT && TARGET_FPRS && TARGET_POWERPC64 && !WORDS_BIG_ENDIAN
+   && (gpc_reg_operand (operands[0], TDmode)
+       || gpc_reg_operand (operands[1], TDmode))"
+  "#"
+  "&& reload_completed"
+  [(pc)]
+{ rs6000_split_multireg_move (operands[0], operands[1]); DONE; }
+  [(set_attr "length" "8,8,8,12,12,8")])
+
 (define_insn_and_split "*mov<mode>_32bit"
   [(set (match_operand:FMOVE128 0 "nonimmediate_operand" "=m,d,d,Y,r,r")
 	(match_operand:FMOVE128 1 "input_operand" "d,m,d,r,YGHF,r"))]