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re PR rtl-optimization/60452 (wrong code at -O1 with large offsets in the frame)

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PR rtl-optimization/60452
	* rtlanal.c (rtx_addr_can_trap_p_1): Fix head comment.
	<case REG>: Return 1 for invalid offsets from the frame pointer.

From-SVN: r208837
This commit is contained in:
Eric Botcazou 2014-03-26 07:38:30 +00:00 committed by Eric Botcazou
parent d615d76322
commit c7e30a96b1
4 changed files with 50 additions and 12 deletions
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6
gcc/ChangeLog
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@ -1,3 +1,9 @@
2014-03-26 Eric Botcazou <ebotcazou@adacore.com>
PR rtl-optimization/60452
* rtlanal.c (rtx_addr_can_trap_p_1): Fix head comment.
<case REG>: Return 1 for invalid offsets from the frame pointer.
2014-03-26 Marek Polacek <polacek@redhat.com>
PR c/37428

42
gcc/rtlanal.c
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@ -224,10 +224,10 @@ rtx_varies_p (const_rtx x, bool for_alias)
return 0;
}
/* Return nonzero if the use of X as an address in a MEM can cause a trap.
MODE is the mode of the MEM (not that of X) and UNALIGNED_MEMS controls
whether nonzero is returned for unaligned memory accesses on strict
alignment machines. */
/* Return nonzero if the use of X+OFFSET as an address in a MEM with SIZE
bytes can cause a trap. MODE is the mode of the MEM (not that of X) and
UNALIGNED_MEMS controls whether nonzero is returned for unaligned memory
references on strict alignment machines. */
static int
rtx_addr_can_trap_p_1 (const_rtx x, HOST_WIDE_INT offset, HOST_WIDE_INT size,
@ -235,11 +235,12 @@ rtx_addr_can_trap_p_1 (const_rtx x, HOST_WIDE_INT offset, HOST_WIDE_INT size,
{
enum rtx_code code = GET_CODE (x);
if (STRICT_ALIGNMENT
&& unaligned_mems
&& GET_MODE_SIZE (mode) != 0)
/* The offset must be a multiple of the mode size if we are considering
unaligned memory references on strict alignment machines. */
if (STRICT_ALIGNMENT && unaligned_mems && GET_MODE_SIZE (mode) != 0)
{
HOST_WIDE_INT actual_offset = offset;
#ifdef SPARC_STACK_BOUNDARY_HACK
/* ??? The SPARC port may claim a STACK_BOUNDARY higher than
the real alignment of %sp. However, when it does this, the
@ -298,8 +299,27 @@ rtx_addr_can_trap_p_1 (const_rtx x, HOST_WIDE_INT offset, HOST_WIDE_INT size,
return 0;
case REG:
/* As in rtx_varies_p, we have to use the actual rtx, not reg number. */
if (x == frame_pointer_rtx || x == hard_frame_pointer_rtx
/* Stack references are assumed not to trap, but we need to deal with
nonsensical offsets. */
if (x == frame_pointer_rtx)
{
HOST_WIDE_INT adj_offset = offset - STARTING_FRAME_OFFSET;
if (size == 0)
size = GET_MODE_SIZE (mode);
if (FRAME_GROWS_DOWNWARD)
{
if (adj_offset < frame_offset || adj_offset + size - 1 >= 0)
return 1;
}
else
{
if (adj_offset < 0 || adj_offset + size - 1 >= frame_offset)
return 1;
}
return 0;
}
/* ??? Need to add a similar guard for nonsensical offsets. */
if (x == hard_frame_pointer_rtx
|| x == stack_pointer_rtx
/* The arg pointer varies if it is not a fixed register. */
|| (x == arg_pointer_rtx && fixed_regs[ARG_POINTER_REGNUM]))
@ -320,9 +340,7 @@ rtx_addr_can_trap_p_1 (const_rtx x, HOST_WIDE_INT offset, HOST_WIDE_INT size,
if (XEXP (x, 0) == pic_offset_table_rtx && CONSTANT_P (XEXP (x, 1)))
return 0;
/* - or it is an address that can't trap plus a constant integer,
with the proper remainder modulo the mode size if we are
considering unaligned memory references. */
/* - or it is an address that can't trap plus a constant integer. */
if (CONST_INT_P (XEXP (x, 1))
&& !rtx_addr_can_trap_p_1 (XEXP (x, 0), offset + INTVAL (XEXP (x, 1)),
size, mode, unaligned_mems))

4
gcc/testsuite/ChangeLog
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@ -1,3 +1,7 @@
2014-03-26 Eric Botcazou <ebotcazou@adacore.com>
* gcc.c-torture/execute/20140326-1.c: New test.
2014-03-25 Jan Hubicka <hubicka@ucw.cz>
PR ipa/60315

10
gcc/testsuite/gcc.c-torture/execute/20140326-1.c Normal file
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@ -0,0 +1,10 @@
int a;
int
main (void)
{
char e[2] = { 0, 0 }, f = 0;
if (a == 131072)
f = e[a];
return f;
}