thumb1.md (define_split): Split 64bit constant in earlier stage.

gcc/ChangeLog:

2014-06-19  Terry Guo  <terry.guo@arm.com>

	* config/arm/thumb1.md (define_split): Split 64bit constant in earlier
	stage.

gcc/testsuite/ChangeLog:

2014-06-19  Terry Guo  <terry.guo@arm.com>

	* gcc.target/arm/thumb1-load-64bit-constant-1.c: New test.
	* gcc.target/arm/thumb1-load-64bit-constant-2.c: Ditto.
	* gcc.target/arm/thumb1-load-64bit-constant-3.c: Ditto.

From-SVN: r211817

gcc/ChangeLog

+2014-06-19  Terry Guo  <terry.guo@arm.com>
+
+	* config/arm/thumb1.md (define_split): Split 64bit constant in earlier
+	stage.
+
 2014-06-18  Segher Boessenkool  <segher@kernel.crashing.org>
 
 	* config/rs6000/rs6000.h (FIXED_REGISTERS): Update comment.

gcc/config/arm/thumb1.md

@@ -633,6 +633,25 @@
    (set_attr "pool_range" "*,*,*,*,*,*,1018,*,*")
    (set_attr "conds" "set,clob,*,*,nocond,nocond,nocond,nocond,nocond")])
 
+; Split the load of 64-bit constant into two loads for high and low 32-bit parts respectively
+; to see if we can load them in fewer instructions or fewer cycles.
+; For the small 64-bit integer constants that satisfy constraint J, the instruction pattern
+; thumb1_movdi_insn has a better way to handle them.
+(define_split
+  [(set (match_operand:ANY64 0 "arm_general_register_operand" "")
+       (match_operand:ANY64 1 "const_double_operand" ""))]
+  "TARGET_THUMB1 && reload_completed && !satisfies_constraint_J (operands[1])"
+  [(set (match_dup 0) (match_dup 1))
+   (set (match_dup 2) (match_dup 3))]
+  "
+  operands[2] = gen_highpart (SImode, operands[0]);
+  operands[3] = gen_highpart_mode (SImode, GET_MODE (operands[0]),
+                                  operands[1]);
+  operands[0] = gen_lowpart (SImode, operands[0]);
+  operands[1] = gen_lowpart (SImode, operands[1]);
+  "
+)
+
 (define_split
   [(set (match_operand:SI 0 "register_operand" "")
 	(match_operand:SI 1 "const_int_operand" ""))]

gcc/testsuite/ChangeLog

+2014-06-19  Terry Guo  <terry.guo@arm.com>
+
+	* gcc.target/arm/thumb1-load-64bit-constant-1.c: New test.
+	* gcc.target/arm/thumb1-load-64bit-constant-2.c: Ditto.
+	* gcc.target/arm/thumb1-load-64bit-constant-3.c: Ditto.
+
 2014-06-19  Tobias Burnus  <burnus@net-b.de>
 
 	* gfortran.dg/coarray/collectives_2.f90: Extend

gcc/testsuite/gcc.target/arm/thumb1-load-64bit-constant-1.c

+/* { dg-require-effective-target arm_thumb1_ok } */
+/* { dg-do compile } */
+/* { dg-options "-Os" } */
+/* { dg-skip-if "" { ! { arm_thumb1 } } } */
+
+extern long long madd (long long a, long long b);
+
+long long
+foo ()
+{
+  return madd (0x0000000100000001LL, 0x0000011100000001LL);
+}
+
+/* { dg-final { scan-assembler-not "ldr" } } */

gcc/testsuite/gcc.target/arm/thumb1-load-64bit-constant-2.c

+/* { dg-require-effective-target arm_thumb1_ok } */
+/* { dg-do compile } */
+/* { dg-options "-O2" } */
+/* { dg-skip-if "" { ! { arm_thumb1 } } } */
+
+extern long long madd (long long a);
+
+long long
+foo ()
+{
+  return madd (0x0000000100000001LL);
+}
+
+/* { dg-final { scan-assembler-not "ldr" } } */

gcc/testsuite/gcc.target/arm/thumb1-load-64bit-constant-3.c

+/* { dg-require-effective-target arm_thumb1_ok } */
+/* { dg-do compile } */
+/* { dg-options "-Os" } */
+/* { dg-skip-if "" { ! { arm_thumb1 } } } */
+
+long long
+foo (int len)
+{
+  return (long long) (((long long) 1 << len) - 1);
+}
+
+/* { dg-final { scan-assembler-not "ldr" } } */
+/* { dg-final { scan-assembler-times "neg" 1 } } */
+