My PR54131 fix caused PR54009 to raise its ugly head again. Allowing
all LO_SUM addresses in the 'Y' constraint (mem_operand_gpr) wasn't
quite correct. We still need to check for wrap when offsetting for
multiple words/regs. Fixing that means the LO_SUM addresses not
accepted by 'Y' need an address reload.
OK assuming powerpc64 and powerpc-linux regression testing passes?
PR target/54009
* config/rs6000/rs6000.c (mem_operand_gpr): Check that LO_SUM
addresses won't wrap when offsetting.
(rs6000_secondary_reload): Provide secondary reloads needed for
wrapping LO_SUM addresses.
Index: gcc/config/rs6000/rs6000.c
===================================================================
--- gcc/config/rs6000/rs6000.c (revision 195707)
+++ gcc/config/rs6000/rs6000.c (working copy)
@@ -5135,17 +5135,14 @@ mem_operand_gpr
if (TARGET_POWERPC64 && (offset & 3) != 0)
return false;
+ extra = GET_MODE_SIZE (mode) - UNITS_PER_WORD;
+ gcc_assert (extra >= 0);
+
if (GET_CODE (addr) == LO_SUM)
- /* We know by alignment that ABI_AIX medium/large model toc refs
- will not cross a 32k boundary, since all entries in the
- constant pool are naturally aligned and we check alignment for
- other medium model toc-relative addresses. For ABI_V4 and
- ABI_DARWIN lo_sum addresses, we just check that 64-bit
- offsets are 4-byte aligned. */
- return true;
+ /* For lo_sum addresses, we must allow any offset except one that
+ causes a wrap, so test only the low 16 bits. */
+ offset = ((offset & 0xffff) ^ 0x8000) - 0x8000;
- extra = GET_MODE_SIZE (mode) - UNITS_PER_WORD;
- gcc_assert (extra >= 0);
return offset + 0x8000 < 0x10000u - extra;
}
@@ -13823,19 +13819,31 @@ rs6000_secondary_reload
&& MEM_P (x)
&& GET_MODE_SIZE (GET_MODE (x)) >= UNITS_PER_WORD)
{
- rtx off = address_offset (XEXP (x, 0));
- unsigned int extra = GET_MODE_SIZE (GET_MODE (x)) - UNITS_PER_WORD;
+ rtx addr = XEXP (x, 0);
+ rtx off = address_offset (addr);
- if (off != NULL_RTX
- && (INTVAL (off) & 3) != 0
- && (unsigned HOST_WIDE_INT) INTVAL (off) + 0x8000 < 0x10000 - extra)
+ if (off != NULL_RTX)
{
- if (in_p)
- sri->icode = CODE_FOR_reload_di_load;
+ unsigned int extra = GET_MODE_SIZE (GET_MODE (x)) - UNITS_PER_WORD;
+ unsigned HOST_WIDE_INT offset = INTVAL (off);
+
+ /* We need a secondary reload when our legitimate_address_p
+ says the address is good (as otherwise the entire address
+ will be reloaded), and the offset is not a multiple of
+ four. */
+ if ((GET_CODE (addr) == LO_SUM
+ || offset + 0x8000 < 0x10000 - extra)
+ && (offset & 3) != 0)
+ {
+ if (in_p)
+ sri->icode = CODE_FOR_reload_di_load;
+ else
+ sri->icode = CODE_FOR_reload_di_store;
+ sri->extra_cost = 2;
+ ret = NO_REGS;
+ }
else
- sri->icode = CODE_FOR_reload_di_store;
- sri->extra_cost = 2;
- ret = NO_REGS;
+ default_p = true;
}
else
default_p = true;
@@ -13845,25 +13853,43 @@ rs6000_secondary_reload
&& MEM_P (x)
&& GET_MODE_SIZE (GET_MODE (x)) > UNITS_PER_WORD)
{
- rtx off = address_offset (XEXP (x, 0));
- unsigned int extra = GET_MODE_SIZE (GET_MODE (x)) - UNITS_PER_WORD;
+ rtx addr = XEXP (x, 0);
+ rtx off = address_offset (addr);
- /* We need a secondary reload only when our legitimate_address_p
- says the address is good (as otherwise the entire address
- will be reloaded). So for mode sizes of 8 and 16 this will
- be when the offset is in the ranges [0x7ffc,0x7fff] and
- [0x7ff4,0x7ff7] respectively. Note that the address we see
- here may have been manipulated by legitimize_reload_address. */
- if (off != NULL_RTX
- && ((unsigned HOST_WIDE_INT) INTVAL (off) - (0x8000 - extra)
- < UNITS_PER_WORD))
+ if (off != NULL_RTX)
{
- if (in_p)
- sri->icode = CODE_FOR_reload_si_load;
+ unsigned int extra = GET_MODE_SIZE (GET_MODE (x)) - UNITS_PER_WORD;
+ unsigned HOST_WIDE_INT offset = INTVAL (off);
+
+ /* We need a secondary reload when our legitimate_address_p
+ says the address is good (as otherwise the entire address
+ will be reloaded), and we have a wrap.
+
+ legitimate_lo_sum_address_p allows LO_SUM addresses to
+ have any offset so test for wrap in the low 16 bits.
+
+ legitimate_offset_address_p checks for the range
+ [-0x8000,0x7fff] for mode size of 8 and [-0x8000,0x7ff7]
+ for mode size of 16. We wrap at [0x7ffc,0x7fff] and
+ [0x7ff4,0x7fff] respectively, so test for the
+ intersection of these ranges, [0x7ffc,0x7fff] and
+ [0x7ff4,0x7ff7] respectively.
+
+ Note that the address we see here may have been
+ manipulated by legitimize_reload_address. */
+ if (GET_CODE (addr) == LO_SUM
+ ? ((offset & 0xffff) ^ 0x8000) >= 0x10000 - extra
+ : offset - (0x8000 - extra) < UNITS_PER_WORD)
+ {
+ if (in_p)
+ sri->icode = CODE_FOR_reload_si_load;
+ else
+ sri->icode = CODE_FOR_reload_si_store;
+ sri->extra_cost = 2;
+ ret = NO_REGS;
+ }
else
- sri->icode = CODE_FOR_reload_si_store;
- sri->extra_cost = 2;
- ret = NO_REGS;
+ default_p = true;
}
else
default_p = true;
--
Alan Modra
Australia Development Lab, IBM
