Account for high/lo_sum simplification with displacements

gcc/
	* simplify-rtx.c (simplify_replace_fn_rtx): Simplify (lo_sum
	(high x) y) to y if x and y have the same base.

gcc/testsuite/
	* gcc.c-torture/compile/20150108.c: New test.

git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@219729 138bc75d-0d04-0410-961f-82ee72b054a4

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 621223d..b9f45a0 100644 (file)
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,8 @@
+2015-01-16  Robert Suchanek  <robert.suchanek@imgtec.com>
+
+       * simplify-rtx.c (simplify_replace_fn_rtx): Simplify (lo_sum
+       (high x) y) to y if x and y have the same base.
+
 2015-01-16  James Greenhalgh  <james.greenhalgh@arm.com>
 
        * config/arm/cortex-a57.md: New.

diff --git a/gcc/simplify-rtx.c b/gcc/simplify-rtx.c
index 4ee63d2..d26267d 100644 (file)
--- a/gcc/simplify-rtx.c
+++ b/gcc/simplify-rtx.c
@@ -539,9 +539,15 @@ simplify_replace_fn_rtx (rtx x, const_rtx old_rtx,
          op0 = simplify_replace_fn_rtx (XEXP (x, 0), old_rtx, fn, data);
          op1 = simplify_replace_fn_rtx (XEXP (x, 1), old_rtx, fn, data);
 
-         /* (lo_sum (high x) x) -> x  */
-         if (GET_CODE (op0) == HIGH && rtx_equal_p (XEXP (op0, 0), op1))
-           return op1;
+         /* (lo_sum (high x) y) -> y where x and y have the same base.  */
+         if (GET_CODE (op0) == HIGH)
+           {
+             rtx base0, base1, offset0, offset1;
+             split_const (XEXP (op0, 0), &base0, &offset0);
+             split_const (op1, &base1, &offset1);
+             if (rtx_equal_p (base0, base1))
+               return op1;
+           }
 
          if (op0 == XEXP (x, 0) && op1 == XEXP (x, 1))
            return x;

diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index ac7c7f2..ffc6794 100644 (file)
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,7 @@
+2015-01-16  Robert Suchanek  <robert.suchanek@imgtec.com>
+
+       * gcc.c-torture/compile/20150108.c: New test.
+
 2015-01-16  Eric Botcazou  <ebotcazou@adacore.com>
 
        * gcc.target/visium: New directory.

diff --git a/gcc/testsuite/gcc.c-torture/compile/20150108.c b/gcc/testsuite/gcc.c-torture/compile/20150108.c
new file mode 100644 (file)
index 0000000..62ba372
--- /dev/null
+++ b/gcc/testsuite/gcc.c-torture/compile/20150108.c
@@ -0,0 +1,22 @@
+long long a[10];
+long long b, c, d, k, m, n, o, p, q, r, s, t, u, v, w;
+int e, f, g, h, i, j, l, x;
+
+int fn1 () {
+  for (; x; x++)
+    if (x & 1)
+      s = h | g;
+    else
+      s = f | e;
+  l = ~0;
+  m = 1 | k;
+  n = i;
+  o = j;
+  p = f | e;
+  q = h | g;
+  w = d | c | a[1];
+  t = c;
+  v = b | c;
+  u = v;
+  r = b | a[4];
+  return e;