aarch64-simd.md (aarch64_sub<mode>_compare0): New pattern.

2017-07-11  Michael Collison  <michael.collison@arm.com>

	* config/aarch64/aarch64-simd.md(aarch64_sub<mode>_compare0):
	New pattern.
	* testsuite/gcc.target/aarch64/cmp-2.c: New testcase.

From-SVN: r250148

gcc/ChangeLog

+2017-07-11  Michael Collison  <michael.collison@arm.com>
+
+	* config/aarch64/aarch64-simd.md (aarch64_sub<mode>_compare0):
+	New pattern.
+
 2017-07-11  Carl Love  <cel@us.ibm.com>
 
 	* config/rs6000/rs6000-c.c: Add support for builtins

gcc/config/aarch64/aarch64.md

@@ -1905,6 +1905,17 @@
   [(set_attr "type" "alus_sreg,alus_imm,alus_imm")]
 )
 
+(define_insn "aarch64_sub<mode>_compare0"
+  [(set (reg:CC_NZ CC_REGNUM)
+	(compare:CC_NZ
+	 (minus:GPI (match_operand:GPI 0 "register_operand" "r")
+		   (match_operand:GPI 1 "aarch64_plus_operand" "r"))
+	 (const_int 0)))]
+  ""
+  "cmp\\t%<w>0, %<w>1"
+  [(set_attr "type" "alus_sreg")]
+)
+
 (define_insn "*compare_neg<mode>"
   [(set (reg:CC_Z CC_REGNUM)
 	(compare:CC_Z

gcc/testsuite/ChangeLog

+2017-07-11  Michael Collison  <michael.collison@arm.com>
+
+	* testsuite/gcc.target/aarch64/cmp-2.c: New testcase.
+
 2017-07-11  Paolo Carlini  <paolo.carlini@oracle.com>
 
 	PR c++/51270

gcc/testsuite/gcc.target/aarch64/cmp-2.c

+/* { dg-do compile } */
+/* { dg-options "-O2" } */
+
+int lt (int x, int y)
+{
+  if ((x - y) < 0)
+    return 10;
+
+  return 0;
+}
+
+int ge (int x, int y)
+{
+  if ((x - y) >= 0)
+    return 10;
+
+  return 0;
+}
+
+/* { dg-final { scan-assembler-times "csel\t" 2 } } */
+/* { dg-final { scan-assembler-not "sub\t" } } */