* simplify-rtx.c (simplify_relational_operation_1): Optimize

	comparisons of POPCOUNT against zero.
	(simplify_const_relational_operation): Likewise.

	* gcc.target/ia64/builtin-popcount-1.c: New test case.
	* gcc.target/ia64/builtin-popcount-2.c: Likewise.



git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@121838 138bc75d-0d04-0410-961f-82ee72b054a4

5 files changed, 58 insertions, 0 deletions

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 73feadee38b..a5f9960a1ae 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,9 @@
+2007-02-11  Roger Sayle  <roger@eyesopen.com>
+
+	* simplify-rtx.c (simplify_relational_operation_1): Optimize
+	comparisons of POPCOUNT against zero.
+	(simplify_const_relational_operation): Likewise.
+
 2007-02-11  Manuel Lopez-Ibanez  <manu@gcc.gnu.org>
 
 	* doc/invoke.texi (Wextra): Delete outdated paragraph.
diff --git a/gcc/simplify-rtx.c b/gcc/simplify-rtx.c
index 8d8bbe52d0c..6f7c37d4c56 100644
--- a/gcc/simplify-rtx.c
+++ b/gcc/simplify-rtx.c
@@ -3802,6 +3802,27 @@ simplify_relational_operation_1 (enum rtx_code code, enum machine_mode mode,
 				    simplify_gen_binary (XOR, cmp_mode,
 							 XEXP (op0, 1), op1));
 
+  if (op0code == POPCOUNT && op1 == const0_rtx)
+    switch (code)
+      {
+      case EQ:
+      case LE:
+      case LEU:
+	/* (eq (popcount x) (const_int 0)) -> (eq x (const_int 0)).  */
+	return simplify_gen_relational (EQ, mode, GET_MODE (XEXP (op0, 0)),
+					XEXP (op0, 0), const0_rtx);
+
+      case NE:
+      case GT:
+      case GTU:
+	/* (ne (popcount x) (const_int 0)) -> (ne x (const_int 0)).  */
+	return simplify_gen_relational (EQ, mode, GET_MODE (XEXP (op0, 0)),
+					XEXP (op0, 0), const0_rtx);
+
+      default:
+	break;
+      }
+
   return NULL_RTX;
 }
 
@@ -4067,6 +4088,10 @@ simplify_const_relational_operation (enum rtx_code code,
 	      if (GET_CODE (tem) == ABS)
 		return const0_rtx;
 	    }
+
+	  /* Optimize popcount (x) < 0.  */
+	  if (GET_CODE (trueop0) == POPCOUNT && trueop1 == const0_rtx)
+	    return const_true_rtx;
 	  break;
 
 	case GE:
@@ -4081,6 +4106,10 @@ simplify_const_relational_operation (enum rtx_code code,
 	      if (GET_CODE (tem) == ABS)
 		return const_true_rtx;
 	    }
+
+	  /* Optimize popcount (x) >= 0.  */
+	  if (GET_CODE (trueop0) == POPCOUNT && trueop1 == const0_rtx)
+	    return const_true_rtx;
 	  break;
 
 	case UNGE:
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index b6a6c0a8832..92670f42758 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,8 @@
+2007-02-11  Roger Sayle  <roger@eyesopen.com>
+
+	* gcc.target/ia64/builtin-popcount-1.c: New test case.
+	* gcc.target/ia64/builtin-popcount-2.c: Likewise.
+
 2007-02-11  Tobias Schlüter  <tobi@gcc.gnu.org>
 
 	PR fortran/30478
diff --git a/gcc/testsuite/gcc.target/ia64/builtin-popcount-1.c b/gcc/testsuite/gcc.target/ia64/builtin-popcount-1.c
new file mode 100644
index 00000000000..c9641d0e6df
--- /dev/null
+++ b/gcc/testsuite/gcc.target/ia64/builtin-popcount-1.c
@@ -0,0 +1,9 @@
+/* { dg-do compile } */
+/* { dg-options "-O2" } */
+/* { dg-final { scan-assembler "popcnt" } } */
+
+int foo (int x)
+{
+  return __builtin_popcount (x);
+}
+
diff --git a/gcc/testsuite/gcc.target/ia64/builtin-popcount-2.c b/gcc/testsuite/gcc.target/ia64/builtin-popcount-2.c
new file mode 100644
index 00000000000..50ced72e728
--- /dev/null
+++ b/gcc/testsuite/gcc.target/ia64/builtin-popcount-2.c
@@ -0,0 +1,9 @@
+/* { dg-do compile } */
+/* { dg-options "-O2" } */
+/* { dg-final { scan-assembler-not "popcnt" } } */
+
+int foo (int x)
+{
+  return __builtin_popcount (x) == 0;
+}
+