simplify-rtx.c (simplify_relational_operation_1): Handle simplification…

simplify-rtx.c (simplify_relational_operation_1): Handle simplification identities for BICS patterns.

2014-12-08  Sandra Loosemore  <sandra@codesourcery.com>

	gcc/
	* simplify-rtx.c (simplify_relational_operation_1): Handle
	simplification identities for BICS patterns.

	gcc/testsuite/
	* gcc.target/aarch64/bics_4.c: New.

From-SVN: r218503

gcc/ChangeLog

+2014-12-08  Sandra Loosemore  <sandra@codesourcery.com>
+
+	* simplify-rtx.c (simplify_relational_operation_1): Handle
+	simplification identities for BICS patterns.
+
 2014-12-08  Trevor Saunders  <tsaunders@mozilla.com>
 
 	* config/nvptx/nvptx.c: Convert htabs to hash_table.

gcc/simplify-rtx.c

@@ -4550,6 +4550,32 @@ simplify_relational_operation_1 (enum rtx_code code, machine_mode mode,
 				    simplify_gen_binary (XOR, cmp_mode,
 							 XEXP (op0, 1), op1));
 
+  /* (eq/ne (and x y) x) simplifies to (eq/ne (and (not y) x) 0), which
+     can be implemented with a BICS instruction on some targets, or
+     constant-folded if y is a constant.  */
+  if ((code == EQ || code == NE)
+      && op0code == AND
+      && rtx_equal_p (XEXP (op0, 0), op1)
+      && !side_effects_p (op1))
+    {
+      rtx not_y = simplify_gen_unary (NOT, cmp_mode, XEXP (op0, 1), cmp_mode);
+      rtx lhs = simplify_gen_binary (AND, cmp_mode, not_y, XEXP (op0, 0));
+
+      return simplify_gen_relational (code, mode, cmp_mode, lhs, const0_rtx);
+    }
+
+  /* Likewise for (eq/ne (and x y) y).  */
+  if ((code == EQ || code == NE)
+      && op0code == AND
+      && rtx_equal_p (XEXP (op0, 1), op1)
+      && !side_effects_p (op1))
+    {
+      rtx not_x = simplify_gen_unary (NOT, cmp_mode, XEXP (op0, 0), cmp_mode);
+      rtx lhs = simplify_gen_binary (AND, cmp_mode, not_x, XEXP (op0, 1));
+
+      return simplify_gen_relational (code, mode, cmp_mode, lhs, const0_rtx);
+    }
+
   /* (eq/ne (bswap x) C1) simplifies to (eq/ne x C2) with C2 swapped.  */
   if ((code == EQ || code == NE)
       && GET_CODE (op0) == BSWAP

gcc/testsuite/ChangeLog

+2014-12-08  Sandra Loosemore  <sandra@codesourcery.com>
+
+	* gcc.target/aarch64/bics_4.c: New.
+
 2014-12-08  Mark Wielaard  <mjw@redhat.com>
 
 	PR debug/60782

gcc/testsuite/gcc.target/aarch64/bics_4.c

+/* { dg-do run } */
+/* { dg-options "-O2 --save-temps -fno-inline" } */
+
+extern void abort (void);
+
+int
+bics_si_test1 (int a, int b, int c)
+{
+  if ((a & b) == a)
+    return a;
+  else
+    return c;
+}
+
+int
+bics_si_test2 (int a, int b, int c)
+{
+  if ((a & b) == b)
+    return b;
+  else
+    return c;
+}
+
+typedef long long s64;
+
+s64
+bics_di_test1 (s64 a, s64 b, s64 c)
+{
+  if ((a & b) == a)
+    return a;
+  else
+    return c;
+}
+
+s64
+bics_di_test2 (s64 a, s64 b, s64 c)
+{
+  if ((a & b) == b)
+    return b;
+  else
+    return c;
+}
+
+int
+main ()
+{
+  int x;
+  s64 y;
+
+  x = bics_si_test1 (0xf00d, 0xf11f, 0);
+  if (x != 0xf00d)
+    abort ();
+
+  x = bics_si_test1 (0xf11f, 0xf00d, 0);
+  if (x != 0)
+    abort ();
+
+  x = bics_si_test2 (0xf00d, 0xf11f, 0);
+  if (x != 0)
+    abort ();
+
+  x = bics_si_test2 (0xf11f, 0xf00d, 0);
+  if (x != 0xf00d)
+    abort ();
+
+  y = bics_di_test1 (0x10001000f00dll, 0x12341000f00dll, 0ll);
+  if (y != 0x10001000f00dll)
+    abort ();
+
+  y = bics_di_test1 (0x12341000f00dll, 0x10001000f00dll, 0ll);
+  if (y != 0)
+    abort ();
+
+  y = bics_di_test2 (0x10001000f00dll, 0x12341000f00dll, 0ll);
+  if (y != 0)
+    abort ();
+
+  y = bics_di_test2 (0x12341000f00dll, 0x10001000f00dll, 0ll);
+  if (y != 0x10001000f00dll)
+    abort ();
+
+  return 0;
+}
+
+/* { dg-final { scan-assembler-times "bics\twzr, w\[0-9\]+, w\[0-9\]+" 2 } } */
+/* { dg-final { scan-assembler-times "bics\txzr, x\[0-9\]+, x\[0-9\]+" 2 } } */
+/* { dg-final { cleanup-saved-temps } } */