The xsize and ysize arguments to memrefs_conflict_p are encode such
that:
- 0 means the size is unknown
- >0 means the size is known
- <0 means that the negative of the size is a worst-case size after
alignment
In other words, the sign effectively encodes a boolean; it isn't
meant to be taken literally. With poly_ints these correspond to:
- known_zero (...)
- may_gt (..., 0)
- may_lt (..., 0)
respectively.
2017-10-23 Richard Sandiford <richard.sandif...@linaro.org>
Alan Hayward <alan.hayw...@arm.com>
David Sherwood <david.sherw...@arm.com>
gcc/
* alias.c (addr_side_effect_eval): Take the size as a poly_int64
rather than an int. Use plus_constant.
(memrefs_conflict_p): Take the sizes as poly_int64s rather than ints.
Take the offset "c" as a poly_int64 rather than a HOST_WIDE_INT.
Index: gcc/alias.c
===================================================================
--- gcc/alias.c 2017-10-23 17:16:50.356530167 +0100
+++ gcc/alias.c 2017-10-23 17:25:47.476533124 +0100
@@ -148,7 +148,6 @@ struct GTY(()) alias_set_entry {
};
static int rtx_equal_for_memref_p (const_rtx, const_rtx);
-static int memrefs_conflict_p (int, rtx, int, rtx, HOST_WIDE_INT);
static void record_set (rtx, const_rtx, void *);
static int base_alias_check (rtx, rtx, rtx, rtx, machine_mode,
machine_mode);
@@ -2295,9 +2294,9 @@ get_addr (rtx x)
is not modified by the memory reference then ADDR is returned. */
static rtx
-addr_side_effect_eval (rtx addr, int size, int n_refs)
+addr_side_effect_eval (rtx addr, poly_int64 size, int n_refs)
{
- int offset = 0;
+ poly_int64 offset = 0;
switch (GET_CODE (addr))
{
@@ -2318,11 +2317,7 @@ addr_side_effect_eval (rtx addr, int siz
return addr;
}
- if (offset)
- addr = gen_rtx_PLUS (GET_MODE (addr), XEXP (addr, 0),
- gen_int_mode (offset, GET_MODE (addr)));
- else
- addr = XEXP (addr, 0);
+ addr = plus_constant (GET_MODE (addr), XEXP (addr, 0), offset);
addr = canon_rtx (addr);
return addr;
@@ -2372,7 +2367,8 @@ offset_overlap_p (poly_int64 c, poly_int
If that is fixed the TBAA hack for union type-punning can be removed. */
static int
-memrefs_conflict_p (int xsize, rtx x, int ysize, rtx y, HOST_WIDE_INT c)
+memrefs_conflict_p (poly_int64 xsize, rtx x, poly_int64 ysize, rtx y,
+ poly_int64 c)
{
if (GET_CODE (x) == VALUE)
{
@@ -2417,13 +2413,13 @@ memrefs_conflict_p (int xsize, rtx x, in
else if (GET_CODE (x) == LO_SUM)
x = XEXP (x, 1);
else
- x = addr_side_effect_eval (x, abs (xsize), 0);
+ x = addr_side_effect_eval (x, may_lt (xsize, 0) ? -xsize : xsize, 0);
if (GET_CODE (y) == HIGH)
y = XEXP (y, 0);
else if (GET_CODE (y) == LO_SUM)
y = XEXP (y, 1);
else
- y = addr_side_effect_eval (y, abs (ysize), 0);
+ y = addr_side_effect_eval (y, may_lt (ysize, 0) ? -ysize : ysize, 0);
if (GET_CODE (x) == SYMBOL_REF && GET_CODE (y) == SYMBOL_REF)
{
@@ -2436,7 +2432,7 @@ memrefs_conflict_p (int xsize, rtx x, in
through alignment adjustments (i.e., that have negative
sizes), because we can't know how far they are from each
other. */
- if (xsize < 0 || ysize < 0)
+ if (may_lt (xsize, 0) || may_lt (ysize, 0))
return -1;
/* If decls are different or we know by offsets that there is no overlap,
we win. */
@@ -2467,6 +2463,7 @@ memrefs_conflict_p (int xsize, rtx x, in
else if (x1 == y)
return memrefs_conflict_p (xsize, x0, ysize, const0_rtx, c);
+ poly_int64 cx1, cy1;
if (GET_CODE (y) == PLUS)
{
/* The fact that Y is canonicalized means that this
@@ -2483,22 +2480,21 @@ memrefs_conflict_p (int xsize, rtx x, in
return memrefs_conflict_p (xsize, x0, ysize, y0, c);
if (rtx_equal_for_memref_p (x0, y0))
return memrefs_conflict_p (xsize, x1, ysize, y1, c);
- if (CONST_INT_P (x1))
+ if (poly_int_rtx_p (x1, &cx1))
{
- if (CONST_INT_P (y1))
+ if (poly_int_rtx_p (y1, &cy1))
return memrefs_conflict_p (xsize, x0, ysize, y0,
- c - INTVAL (x1) + INTVAL (y1));
+ c - cx1 + cy1);
else
- return memrefs_conflict_p (xsize, x0, ysize, y,
- c - INTVAL (x1));
+ return memrefs_conflict_p (xsize, x0, ysize, y, c - cx1);
}
- else if (CONST_INT_P (y1))
- return memrefs_conflict_p (xsize, x, ysize, y0, c + INTVAL (y1));
+ else if (poly_int_rtx_p (y1, &cy1))
+ return memrefs_conflict_p (xsize, x, ysize, y0, c + cy1);
return -1;
}
- else if (CONST_INT_P (x1))
- return memrefs_conflict_p (xsize, x0, ysize, y, c - INTVAL (x1));
+ else if (poly_int_rtx_p (x1, &cx1))
+ return memrefs_conflict_p (xsize, x0, ysize, y, c - cx1);
}
else if (GET_CODE (y) == PLUS)
{
@@ -2512,8 +2508,9 @@ memrefs_conflict_p (int xsize, rtx x, in
if (x == y1)
return memrefs_conflict_p (xsize, const0_rtx, ysize, y0, c);
- if (CONST_INT_P (y1))
- return memrefs_conflict_p (xsize, x, ysize, y0, c + INTVAL (y1));
+ poly_int64 cy1;
+ if (poly_int_rtx_p (y1, &cy1))
+ return memrefs_conflict_p (xsize, x, ysize, y0, c + cy1);
else
return -1;
}
@@ -2537,11 +2534,11 @@ memrefs_conflict_p (int xsize, rtx x, in
return offset_overlap_p (c, xsize, ysize);
/* Can't properly adjust our sizes. */
- if (!CONST_INT_P (x1))
+ if (!CONST_INT_P (x1)
+ || !can_div_trunc_p (xsize, INTVAL (x1), &xsize)
+ || !can_div_trunc_p (ysize, INTVAL (x1), &ysize)
+ || !can_div_trunc_p (c, INTVAL (x1), &c))
return -1;
- xsize /= INTVAL (x1);
- ysize /= INTVAL (x1);
- c /= INTVAL (x1);
return memrefs_conflict_p (xsize, x0, ysize, y0, c);
}
@@ -2562,9 +2559,9 @@ memrefs_conflict_p (int xsize, rtx x, in
unsigned HOST_WIDE_INT uc = sc;
if (sc < 0 && pow2_or_zerop (-uc))
{
- if (xsize > 0)
+ if (may_gt (xsize, 0))
xsize = -xsize;
- if (xsize)
+ if (maybe_nonzero (xsize))
xsize += sc + 1;
c -= sc + 1;
return memrefs_conflict_p (xsize, canon_rtx (XEXP (x, 0)),
@@ -2577,9 +2574,9 @@ memrefs_conflict_p (int xsize, rtx x, in
unsigned HOST_WIDE_INT uc = sc;
if (sc < 0 && pow2_or_zerop (-uc))
{
- if (ysize > 0)
+ if (may_gt (ysize, 0))
ysize = -ysize;
- if (ysize)
+ if (maybe_nonzero (ysize))
ysize += sc + 1;
c += sc + 1;
return memrefs_conflict_p (xsize, x,
@@ -2589,9 +2586,10 @@ memrefs_conflict_p (int xsize, rtx x, in
if (CONSTANT_P (x))
{
- if (CONST_INT_P (x) && CONST_INT_P (y))
+ poly_int64 cx, cy;
+ if (poly_int_rtx_p (x, &cx) && poly_int_rtx_p (y, &cy))
{
- c += (INTVAL (y) - INTVAL (x));
+ c += cy - cx;
return offset_overlap_p (c, xsize, ysize);
}
@@ -2613,7 +2611,9 @@ memrefs_conflict_p (int xsize, rtx x, in
sizes), because we can't know how far they are from each
other. */
if (CONSTANT_P (y))
- return (xsize < 0 || ysize < 0 || offset_overlap_p (c, xsize, ysize));
+ return (may_lt (xsize, 0)
+ || may_lt (ysize, 0)
+ || offset_overlap_p (c, xsize, ysize));
return -1;
}
