gcc/gcc5-pr65401.patch

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2015-03-13 18:15:06 +00:00
2015-03-13 Jakub Jelinek <jakub@redhat.com>
PR rtl-optimization/65401
* combine.c (rtx_equal_for_field_assignment_p): Add widen_x
argument. If true, adjust_address_nv of x with big-endian
correction for the mode widening to GET_MODE (y).
(make_field_assignment): Don't do MEM mode widening here.
Use MEM_P instead of GET_CODE == MEM.
* gcc.c-torture/execute/pr65401.c: New test.
--- gcc/combine.c.jj 2015-02-03 10:38:46.000000000 +0100
+++ gcc/combine.c 2015-03-13 18:46:45.710940306 +0100
@@ -475,7 +475,7 @@ static rtx force_to_mode (rtx, machine_m
unsigned HOST_WIDE_INT, int);
static rtx if_then_else_cond (rtx, rtx *, rtx *);
static rtx known_cond (rtx, enum rtx_code, rtx, rtx);
-static int rtx_equal_for_field_assignment_p (rtx, rtx);
+static int rtx_equal_for_field_assignment_p (rtx, rtx, bool = false);
static rtx make_field_assignment (rtx);
static rtx apply_distributive_law (rtx);
static rtx distribute_and_simplify_rtx (rtx, int);
@@ -9184,8 +9184,23 @@ known_cond (rtx x, enum rtx_code cond, r
assignment as a field assignment. */
static int
-rtx_equal_for_field_assignment_p (rtx x, rtx y)
+rtx_equal_for_field_assignment_p (rtx x, rtx y, bool widen_x)
{
+ if (widen_x && GET_MODE (x) != GET_MODE (y))
+ {
+ if (GET_MODE_SIZE (GET_MODE (x)) > GET_MODE_SIZE (GET_MODE (y)))
+ return 0;
+ if (BYTES_BIG_ENDIAN != WORDS_BIG_ENDIAN)
+ return 0;
+ /* For big endian, adjust the memory offset. */
+ if (BYTES_BIG_ENDIAN)
+ x = adjust_address_nv (x, GET_MODE (y),
+ -subreg_lowpart_offset (GET_MODE (x),
+ GET_MODE (y)));
+ else
+ x = adjust_address_nv (x, GET_MODE (y), 0);
+ }
+
if (x == y || rtx_equal_p (x, y))
return 1;
@@ -9339,16 +9354,15 @@ make_field_assignment (rtx x)
/* The second SUBREG that might get in the way is a paradoxical
SUBREG around the first operand of the AND. We want to
pretend the operand is as wide as the destination here. We
- do this by creating a new MEM in the wider mode for the sole
+ do this by adjusting the MEM to wider mode for the sole
purpose of the call to rtx_equal_for_field_assignment_p. Also
note this trick only works for MEMs. */
else if (GET_CODE (rhs) == AND
&& paradoxical_subreg_p (XEXP (rhs, 0))
- && GET_CODE (SUBREG_REG (XEXP (rhs, 0))) == MEM
+ && MEM_P (SUBREG_REG (XEXP (rhs, 0)))
&& CONST_INT_P (XEXP (rhs, 1))
- && rtx_equal_for_field_assignment_p (gen_rtx_MEM (GET_MODE (dest),
- XEXP (SUBREG_REG (XEXP (rhs, 0)), 0)),
- dest))
+ && rtx_equal_for_field_assignment_p (SUBREG_REG (XEXP (rhs, 0)),
+ dest, true))
c1 = INTVAL (XEXP (rhs, 1)), other = lhs;
else if (GET_CODE (lhs) == AND
&& CONST_INT_P (XEXP (lhs, 1))
@@ -9357,16 +9371,15 @@ make_field_assignment (rtx x)
/* The second SUBREG that might get in the way is a paradoxical
SUBREG around the first operand of the AND. We want to
pretend the operand is as wide as the destination here. We
- do this by creating a new MEM in the wider mode for the sole
+ do this by adjusting the MEM to wider mode for the sole
purpose of the call to rtx_equal_for_field_assignment_p. Also
note this trick only works for MEMs. */
else if (GET_CODE (lhs) == AND
&& paradoxical_subreg_p (XEXP (lhs, 0))
- && GET_CODE (SUBREG_REG (XEXP (lhs, 0))) == MEM
+ && MEM_P (SUBREG_REG (XEXP (lhs, 0)))
&& CONST_INT_P (XEXP (lhs, 1))
- && rtx_equal_for_field_assignment_p (gen_rtx_MEM (GET_MODE (dest),
- XEXP (SUBREG_REG (XEXP (lhs, 0)), 0)),
- dest))
+ && rtx_equal_for_field_assignment_p (SUBREG_REG (XEXP (lhs, 0)),
+ dest, true))
c1 = INTVAL (XEXP (lhs, 1)), other = rhs;
else
return x;
--- gcc/testsuite/gcc.c-torture/execute/pr65401.c.jj 2015-03-13 18:36:30.639817393 +0100
+++ gcc/testsuite/gcc.c-torture/execute/pr65401.c 2015-03-13 18:42:02.693485127 +0100
@@ -0,0 +1,59 @@
+/* PR rtl-optimization/65401 */
+
+struct S { unsigned short s[64]; };
+
+__attribute__((noinline, noclone)) void
+foo (struct S *x)
+{
+ unsigned int i;
+ unsigned char *s;
+
+ s = (unsigned char *) x->s;
+ for (i = 0; i < 64; i++)
+ x->s[i] = s[i * 2] | (s[i * 2 + 1] << 8);
+}
+
+__attribute__((noinline, noclone)) void
+bar (struct S *x)
+{
+ unsigned int i;
+ unsigned char *s;
+
+ s = (unsigned char *) x->s;
+ for (i = 0; i < 64; i++)
+ x->s[i] = (s[i * 2] << 8) | s[i * 2 + 1];
+}
+
+int
+main ()
+{
+ unsigned int i;
+ struct S s;
+ if (sizeof (unsigned short) != 2)
+ return 0;
+ for (i = 0; i < 64; i++)
+ s.s[i] = i + ((64 - i) << 8);
+ foo (&s);
+#if __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__
+ for (i = 0; i < 64; i++)
+ if (s.s[i] != (64 - i) + (i << 8))
+ __builtin_abort ();
+#elif __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__
+ for (i = 0; i < 64; i++)
+ if (s.s[i] != i + ((64 - i) << 8))
+ __builtin_abort ();
+#endif
+ for (i = 0; i < 64; i++)
+ s.s[i] = i + ((64 - i) << 8);
+ bar (&s);
+#if __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__
+ for (i = 0; i < 64; i++)
+ if (s.s[i] != (64 - i) + (i << 8))
+ __builtin_abort ();
+#elif __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__
+ for (i = 0; i < 64; i++)
+ if (s.s[i] != i + ((64 - i) << 8))
+ __builtin_abort ();
+#endif
+ return 0;
+}