This patch fixes the original problem that HJL was having with x32 in
PR 47727, it is more constraint than HJL's patch only care about what
is happening inside a CONST; if we allow it for other cases,
the RTL and generated code is incorrect as it does not have the needed
zero extend. This allows ILP32 to work correctlya and allows &a + 2 to
be still generated correctly when doing a convert_memory_address_addr_space.
OK? Bootstrapped and tested on x86_64-linux-gnu (though not with x32 but
visually looked at the failing testcase with a much older compiler).
Also tested on aarch64-linux-gnu with no regressions and also fixing ld.so
for ILP32.
Thanks,
Andrew Pinski
ChangeLog:
* explow.c (convert_memory_address_addr_space): Rename to ...
(convert_memory_address_addr_space_1): This. Add in_const argument.
Inside a CONST RTL, permute the conversion and addition of constant
for zero and sign extended pointers.
(convert_memory_address_addr_space): New function.
---
gcc/explow.c | 40 ++++++++++++++++++++++++++++------------
1 files changed, 28 insertions(+), 12 deletions(-)
diff --git a/gcc/explow.c b/gcc/explow.c
index eb7dc85..64017a0 100644
--- a/gcc/explow.c
+++ b/gcc/explow.c
@@ -310,11 +310,13 @@ break_out_memory_refs (rtx x)
an address in the address space's address mode, or vice versa (TO_MODE says
which way). We take advantage of the fact that pointers are not allowed to
overflow by commuting arithmetic operations over conversions so that address
- arithmetic insns can be used. */
+ arithmetic insns can be used. IN_CONST is true if this conversion is inside
+ a CONST. */
-rtx
-convert_memory_address_addr_space (enum machine_mode to_mode ATTRIBUTE_UNUSED,
- rtx x, addr_space_t as ATTRIBUTE_UNUSED)
+static rtx
+convert_memory_address_addr_space_1 (enum machine_mode to_mode
ATTRIBUTE_UNUSED,
+ rtx x, addr_space_t as ATTRIBUTE_UNUSED,
+ bool in_const)
{
#ifndef POINTERS_EXTEND_UNSIGNED
gcc_assert (GET_MODE (x) == to_mode || GET_MODE (x) == VOIDmode);
@@ -370,8 +372,8 @@ convert_memory_address_addr_space (enum machine_mode
to_mode ATTRIBUTE_UNUSED,
case CONST:
return gen_rtx_CONST (to_mode,
- convert_memory_address_addr_space
- (to_mode, XEXP (x, 0), as));
+ convert_memory_address_addr_space_1
+ (to_mode, XEXP (x, 0), as, true));
break;
case PLUS:
@@ -381,16 +383,18 @@ convert_memory_address_addr_space (enum machine_mode
to_mode ATTRIBUTE_UNUSED,
does not change it or if one operand is a constant and we are
using a ptr_extend instruction (POINTERS_EXTEND_UNSIGNED < 0).
We can always safely permute them if we are making the address
- narrower. */
+ narrower. Inside a CONST RTL, this is safe for both pointers
+ zero or sign extended as pointers cannot wrap. */
if (GET_MODE_SIZE (to_mode) < GET_MODE_SIZE (from_mode)
|| (GET_CODE (x) == PLUS
&& CONST_INT_P (XEXP (x, 1))
- && (XEXP (x, 1) == convert_memory_address_addr_space
- (to_mode, XEXP (x, 1), as)
- || POINTERS_EXTEND_UNSIGNED < 0)))
+ && ((in_const && POINTERS_EXTEND_UNSIGNED !=0)
+ || XEXP (x, 1) == convert_memory_address_addr_space_1
+ (to_mode, XEXP (x, 1), as, in_const)
+ || POINTERS_EXTEND_UNSIGNED < 0)))
return gen_rtx_fmt_ee (GET_CODE (x), to_mode,
- convert_memory_address_addr_space
- (to_mode, XEXP (x, 0), as),
+ convert_memory_address_addr_space_1
+ (to_mode, XEXP (x, 0), as, in_const),
XEXP (x, 1));
break;
@@ -402,6 +406,18 @@ convert_memory_address_addr_space (enum machine_mode
to_mode ATTRIBUTE_UNUSED,
x, POINTERS_EXTEND_UNSIGNED);
#endif /* defined(POINTERS_EXTEND_UNSIGNED) */
}
+
+/* Given X, a memory address in address space AS' pointer mode, convert it to
+ an address in the address space's address mode, or vice versa (TO_MODE says
+ which way). We take advantage of the fact that pointers are not allowed to
+ overflow by commuting arithmetic operations over conversions so that address
+ arithmetic insns can be used. */
+
+rtx
+convert_memory_address_addr_space (enum machine_mode to_mode, rtx x,
addr_space_t as)
+{
+ return convert_memory_address_addr_space_1 (to_mode, x, as, false);
+}
/* Return something equivalent to X but valid as a memory address for something
of mode MODE in the named address space AS. When X is not itself valid,
--
1.7.2.5
