gcc/

	Backport from trunk r225996.
	2015-07-20  Kyrylo Tkachov  <kyrylo.tkachov@arm.com>

	* combine.c (combine_simplify_rtx): Move simplification step
	before various transformations/substitutions.

	gcc/
	Backport from trunk r225997.
	2015-07-20  Kyrylo Tkachov  <kyrylo.tkachov@arm.com>

	* simplify-rtx.c (simplify_unary_operation_1, NEG case):
	(neg (x ? (neg y) : y)) -> !x ? (neg y) : y.

	gcc/testsuite/
	Backport from trunk r225997.
	2015-07-20  Kyrylo Tkachov  <kyrylo.tkachov@arm.com>

	* gcc.target/aarch64/neg_abs_1.c: New test.

Change-Id: Ib48417a225b1654ea0c37d256e99639d22005a10

3 files changed, 88 insertions, 45 deletions

diff --git a/gcc/combine.c b/gcc/combine.c
index e35e45968ac..21e5ee594f1 100644
--- a/gcc/combine.c
+++ b/gcc/combine.c
@@ -5511,6 +5511,51 @@ combine_simplify_rtx (rtx x, machine_mode op0_mode, int in_dest,
       SUBST (XEXP (x, 1), temp);
     }
 
+  /* Try to fold this expression in case we have constants that weren't
+     present before.  */
+  temp = 0;
+  switch (GET_RTX_CLASS (code))
+    {
+    case RTX_UNARY:
+      if (op0_mode == VOIDmode)
+	op0_mode = GET_MODE (XEXP (x, 0));
+      temp = simplify_unary_operation (code, mode, XEXP (x, 0), op0_mode);
+      break;
+    case RTX_COMPARE:
+    case RTX_COMM_COMPARE:
+      {
+	machine_mode cmp_mode = GET_MODE (XEXP (x, 0));
+	if (cmp_mode == VOIDmode)
+	  {
+	    cmp_mode = GET_MODE (XEXP (x, 1));
+	    if (cmp_mode == VOIDmode)
+	      cmp_mode = op0_mode;
+	  }
+	temp = simplify_relational_operation (code, mode, cmp_mode,
+					      XEXP (x, 0), XEXP (x, 1));
+      }
+      break;
+    case RTX_COMM_ARITH:
+    case RTX_BIN_ARITH:
+      temp = simplify_binary_operation (code, mode, XEXP (x, 0), XEXP (x, 1));
+      break;
+    case RTX_BITFIELD_OPS:
+    case RTX_TERNARY:
+      temp = simplify_ternary_operation (code, mode, op0_mode, XEXP (x, 0),
+					 XEXP (x, 1), XEXP (x, 2));
+      break;
+    default:
+      break;
+    }
+
+  if (temp)
+    {
+      x = temp;
+      code = GET_CODE (temp);
+      op0_mode = VOIDmode;
+      mode = GET_MODE (temp);
+    }
+
   /* If this is a simple operation applied to an IF_THEN_ELSE, try
      applying it to the arms of the IF_THEN_ELSE.  This often simplifies
      things.  Check for cases where both arms are testing the same
@@ -5610,51 +5655,6 @@ combine_simplify_rtx (rtx x, machine_mode op0_mode, int in_dest,
 	}
     }
 
-  /* Try to fold this expression in case we have constants that weren't
-     present before.  */
-  temp = 0;
-  switch (GET_RTX_CLASS (code))
-    {
-    case RTX_UNARY:
-      if (op0_mode == VOIDmode)
-	op0_mode = GET_MODE (XEXP (x, 0));
-      temp = simplify_unary_operation (code, mode, XEXP (x, 0), op0_mode);
-      break;
-    case RTX_COMPARE:
-    case RTX_COMM_COMPARE:
-      {
-	machine_mode cmp_mode = GET_MODE (XEXP (x, 0));
-	if (cmp_mode == VOIDmode)
-	  {
-	    cmp_mode = GET_MODE (XEXP (x, 1));
-	    if (cmp_mode == VOIDmode)
-	      cmp_mode = op0_mode;
-	  }
-	temp = simplify_relational_operation (code, mode, cmp_mode,
-					      XEXP (x, 0), XEXP (x, 1));
-      }
-      break;
-    case RTX_COMM_ARITH:
-    case RTX_BIN_ARITH:
-      temp = simplify_binary_operation (code, mode, XEXP (x, 0), XEXP (x, 1));
-      break;
-    case RTX_BITFIELD_OPS:
-    case RTX_TERNARY:
-      temp = simplify_ternary_operation (code, mode, op0_mode, XEXP (x, 0),
-					 XEXP (x, 1), XEXP (x, 2));
-      break;
-    default:
-      break;
-    }
-
-  if (temp)
-    {
-      x = temp;
-      code = GET_CODE (temp);
-      op0_mode = VOIDmode;
-      mode = GET_MODE (temp);
-    }
-
   /* First see if we can apply the inverse distributive law.  */
   if (code == PLUS || code == MINUS
       || code == AND || code == IOR || code == XOR)
diff --git a/gcc/simplify-rtx.c b/gcc/simplify-rtx.c
index 7dd45ec61db..f29cc1b1de2 100644
--- a/gcc/simplify-rtx.c
+++ b/gcc/simplify-rtx.c
@@ -978,6 +978,32 @@ simplify_unary_operation_1 (enum rtx_code code, machine_mode mode, rtx op)
       if (GET_CODE (op) == NEG)
 	return XEXP (op, 0);
 
+      /* (neg (x ? (neg y) : y)) == !x ? (neg y) : y.
+	 If comparison is not reversible use
+	 x ? y : (neg y).  */
+      if (GET_CODE (op) == IF_THEN_ELSE)
+	{
+	  rtx cond = XEXP (op, 0);
+	  rtx true_rtx = XEXP (op, 1);
+	  rtx false_rtx = XEXP (op, 2);
+
+	  if ((GET_CODE (true_rtx) == NEG
+	       && rtx_equal_p (XEXP (true_rtx, 0), false_rtx))
+	       || (GET_CODE (false_rtx) == NEG
+		   && rtx_equal_p (XEXP (false_rtx, 0), true_rtx)))
+	    {
+	      if (reversed_comparison_code (cond, NULL_RTX) != UNKNOWN)
+		temp = reversed_comparison (cond, mode);
+	      else
+		{
+		  temp = cond;
+		  std::swap (true_rtx, false_rtx);
+		}
+	      return simplify_gen_ternary (IF_THEN_ELSE, mode,
+					    mode, temp, true_rtx, false_rtx);
+	    }
+	}
+
       /* (neg (plus X 1)) can become (not X).  */
       if (GET_CODE (op) == PLUS
 	  && XEXP (op, 1) == const1_rtx)
diff --git a/gcc/testsuite/gcc.target/aarch64/neg_abs_1.c b/gcc/testsuite/gcc.target/aarch64/neg_abs_1.c
new file mode 100644
index 00000000000..cb2a387088c
--- /dev/null
+++ b/gcc/testsuite/gcc.target/aarch64/neg_abs_1.c
@@ -0,0 +1,17 @@
+/* { dg-do compile } */
+/* { dg-options "-save-temps -O2" } */
+
+int
+f1 (int x)
+{
+  return x < 0 ? x : -x;
+}
+
+long long
+f2 (long long x)
+{
+  return x < 0 ? x : -x;
+}
+
+/* { dg-final { scan-assembler-not "\tneg\tw\[0-9\]*.*" } } */
+/* { dg-final { scan-assembler-not "\tneg\tx\[0-9\]*.*" } } */