Hi,
CSE turns (reg:DI 64)
(insn 6 3 7 2 (set (reg:DI 64)
(sign_extend:DI (subreg/u:SI (reg/v/f:DI 63 [ addr ]) 0))) x.i:6 122
{*extendsidi2_rex64} (nil))
into (reg/f:DI 64 [ addr ]). But nonzero_bits1 in rtlanal.c has
#if defined(POINTERS_EXTEND_UNSIGNED) && !defined(HAVE_ptr_extend)
/* If pointers extend unsigned and this is a pointer in Pmode, say that
all the bits above ptr_mode are known to be zero. */
/* As we do not know which address space the pointer is refering to,
we can do this only if the target does not support different pointer
or address modes depending on the address space. */
if (target_default_pointer_address_modes_p ()
&& POINTERS_EXTEND_UNSIGNED && GET_MODE (x) == Pmode
&& REG_POINTER (x))
nonzero &= GET_MODE_MASK (ptr_mode);
#endif
Setting REG_POINTER with incompatible pointer sign extension is wrong.
This patch adds a bool parameter to set_reg_attrs_from_value to
indicate if a register can be marked as a pointer. Does it look OK?
Thanks.
H.J.
---
gcc/
2012-04-05 H.J. Lu <hongjiu...@intel.com>
PR rtl-optimization/52876
* emit-rtl.c (set_reg_attrs_from_value): Add a bool parameter
to indicate if a register can be a pointer.
(gen_reg_rtx_and_attrs): Pass true to set_reg_attrs_from_value.
(set_reg_attrs_for_parm): Likewise.
* emit-rtl.h (set_reg_attrs_from_value): Add a bool parameter.
* reginfo.c (reg_scan_mark_refs): Pass false to
set_reg_attrs_from_value with incompatible pointer sign
extension.
gcc/testsuite
2012-04-05 H.J. Lu <hongjiu...@intel.com>
PR rtl-optimization/52876
* gcc.target/i386/pr52876.c: New.
diff --git a/gcc/emit-rtl.c b/gcc/emit-rtl.c
index 8d7d441..791ff5c 100644
--- a/gcc/emit-rtl.c
+++ b/gcc/emit-rtl.c
@@ -967,7 +967,7 @@ adjust_reg_mode (rtx reg, enum machine_mode mode)
have different modes, REG is a (possibly paradoxical) lowpart of X. */
void
-set_reg_attrs_from_value (rtx reg, rtx x)
+set_reg_attrs_from_value (rtx reg, rtx x, bool can_be_reg_pointer)
{
int offset;
@@ -983,14 +983,14 @@ set_reg_attrs_from_value (rtx reg, rtx x)
if (MEM_OFFSET_KNOWN_P (x))
REG_ATTRS (reg) = get_reg_attrs (MEM_EXPR (x),
MEM_OFFSET (x) + offset);
- if (MEM_POINTER (x))
+ if (can_be_reg_pointer && MEM_POINTER (x))
mark_reg_pointer (reg, 0);
}
else if (REG_P (x))
{
if (REG_ATTRS (x))
update_reg_offset (reg, x, offset);
- if (REG_POINTER (x))
+ if (can_be_reg_pointer && REG_POINTER (x))
mark_reg_pointer (reg, REGNO_POINTER_ALIGN (REGNO (x)));
}
}
@@ -1002,7 +1002,7 @@ rtx
gen_reg_rtx_and_attrs (rtx x)
{
rtx reg = gen_reg_rtx (GET_MODE (x));
- set_reg_attrs_from_value (reg, x);
+ set_reg_attrs_from_value (reg, x, true);
return reg;
}
@@ -1013,7 +1013,7 @@ void
set_reg_attrs_for_parm (rtx parm_rtx, rtx mem)
{
if (REG_P (parm_rtx))
- set_reg_attrs_from_value (parm_rtx, mem);
+ set_reg_attrs_from_value (parm_rtx, mem, true);
else if (GET_CODE (parm_rtx) == PARALLEL)
{
/* Check for a NULL entry in the first slot, used to indicate that the
diff --git a/gcc/emit-rtl.h b/gcc/emit-rtl.h
index bc91193..2f259ef 100644
--- a/gcc/emit-rtl.h
+++ b/gcc/emit-rtl.h
@@ -63,7 +63,7 @@ extern rtx copy_insn_1 (rtx);
extern rtx copy_insn (rtx);
extern rtx gen_int_mode (HOST_WIDE_INT, enum machine_mode);
extern rtx emit_copy_of_insn_after (rtx, rtx);
-extern void set_reg_attrs_from_value (rtx, rtx);
+extern void set_reg_attrs_from_value (rtx, rtx, bool);
extern void set_reg_attrs_for_parm (rtx, rtx);
extern void set_reg_attrs_for_decl_rtl (tree t, rtx x);
extern void adjust_reg_mode (rtx, enum machine_mode);
diff --git a/gcc/reginfo.c b/gcc/reginfo.c
index 6353126..585d7a8 100644
--- a/gcc/reginfo.c
+++ b/gcc/reginfo.c
@@ -1224,14 +1224,24 @@ reg_scan_mark_refs (rtx x, rtx insn)
if (REG_P (dest) && !REG_ATTRS (dest))
{
rtx src = SET_SRC (x);
+ bool can_be_reg_pointer = true;
while (GET_CODE (src) == SIGN_EXTEND
|| GET_CODE (src) == ZERO_EXTEND
|| GET_CODE (src) == TRUNCATE
|| (GET_CODE (src) == SUBREG && subreg_lowpart_p (src)))
- src = XEXP (src, 0);
+ {
+#if defined(POINTERS_EXTEND_UNSIGNED) && !defined(HAVE_ptr_extend)
+ if ((GET_CODE (src) == SIGN_EXTEND
+ && POINTERS_EXTEND_UNSIGNED)
+ || (GET_CODE (src) != SIGN_EXTEND
+ && ! POINTERS_EXTEND_UNSIGNED))
+ can_be_reg_pointer = false;
+#endif
+ src = XEXP (src, 0);
+ }
- set_reg_attrs_from_value (dest, src);
+ set_reg_attrs_from_value (dest, src, can_be_reg_pointer);
}
/* ... fall through ... */
diff --git a/gcc/testsuite/gcc.target/i386/pr52876.c
b/gcc/testsuite/gcc.target/i386/pr52876.c
new file mode 100644
index 0000000..6d5e47a
--- /dev/null
+++ b/gcc/testsuite/gcc.target/i386/pr52876.c
@@ -0,0 +1,25 @@
+/* { dg-do run { target { x32 } } } */
+/* { dg-options "-O2 -mx32 -maddress-mode=long" } */
+
+extern void abort (void);
+
+long long li;
+
+long long
+__attribute__ ((noinline))
+testfunc (void* addr)
+{
+ li = (long long)(int)addr;
+ li &= 0xffffffff;
+ return li;
+}
+
+int main (void)
+{
+ volatile long long rv_test;
+ rv_test = testfunc((void*)0x87651234);
+ if (rv_test != 0x87651234ULL)
+ abort ();
+
+ return 0;
+}
