Hi,
this is a follow-up to http://gcc.gnu.org/ml/gcc-patches/2013-06/msg00895.html
which fixed the 3. issue partially. This resulted in gcc.dg/guality/param-2.c
being compiled with -fno-var-tracking-assignments.
The attached testcase param-3.c is identical to param-2.c but without the
special option; it fails (at least) for SPARC & PowerPC on the one hand and
for SPARC64 & x86-64 on the other hand. The first issue is that var-tracking.c
cannot track values for multiple-part variables; rather than implementing
this, which looks quite daunting to me, the patch simply reverts to location
tracking for multiple-part parameters, on the grounds that they are rarely
modified in practice. The second issue is that var-tracking.c doesn't handle
multiple-part parameters coming in a PARALLEL, like on SPARC64 & x86-64.
Tested on x86-64 & PowerPC Linux and SPARC & SPARC64 Solaris, OK for mainline?
2013-10-24 Eric Botcazou <ebotca...@adacore.com>
* var-tracking.c (track_expr_p): Do not track declarations for parts
of tracked parameters.
(add_stores): Do not track values for tracked parameters passed in
multiple locations.
(vt_get_decl_and_offset): Handle PARALLEL.
(vt_add_function_parameter): Handle parameters with incoming PARALLEL.
2013-10-24 Eric Botcazou <ebotca...@adacore.com>
* gcc.dg/guality/param-3.c: New test.
--
Eric Botcazou
Index: var-tracking.c
===================================================================
--- var-tracking.c (revision 203876)
+++ var-tracking.c (working copy)
@@ -5065,6 +5065,11 @@ track_expr_p (tree expr, bool need_rtl)
&maxsize);
if (!DECL_P (innerdecl)
|| DECL_IGNORED_P (innerdecl)
+ /* Do not track declarations for parts of tracked parameters
+ since we want to track them as a whole instead. */
+ || (TREE_CODE (innerdecl) == PARM_DECL
+ && DECL_MODE (innerdecl) != BLKmode
+ && TREE_CODE (TREE_TYPE (innerdecl)) != UNION_TYPE)
|| TREE_STATIC (innerdecl)
|| bitsize <= 0
|| bitpos + bitsize > 256
@@ -5919,6 +5924,20 @@ add_stores (rtx loc, const_rtx expr, voi
if (type != MO_VAL_SET)
goto log_and_return;
+ /* We cannot track values for multiple-part variables, so we track only
+ locations for tracked parameters passed either by invisible reference
+ or directly in multiple locations. */
+ if (track_p
+ && REG_P (loc)
+ && REG_EXPR (loc)
+ && TREE_CODE (REG_EXPR (loc)) == PARM_DECL
+ && DECL_MODE (REG_EXPR (loc)) != BLKmode
+ && ((MEM_P (DECL_INCOMING_RTL (REG_EXPR (loc)))
+ && XEXP (DECL_INCOMING_RTL (REG_EXPR (loc)), 0) != arg_pointer_rtx)
+ || (GET_CODE (DECL_INCOMING_RTL (REG_EXPR (loc))) == PARALLEL
+ && XVECLEN (DECL_INCOMING_RTL (REG_EXPR (loc)), 0) > 1)))
+ goto log_and_return;
+
v = find_use_val (oloc, mode, cui);
if (!v)
@@ -9447,6 +9466,32 @@ vt_get_decl_and_offset (rtx rtl, tree *d
return true;
}
}
+ else if (GET_CODE (rtl) == PARALLEL)
+ {
+ tree decl = NULL_TREE;
+ HOST_WIDE_INT offset = MAX_VAR_PARTS;
+ int len = XVECLEN (rtl, 0), i;
+
+ for (i = 0; i < len; i++)
+ {
+ rtx reg = XEXP (XVECEXP (rtl, 0, i), 0);
+ if (!REG_P (reg) || !REG_ATTRS (reg))
+ break;
+ if (!decl)
+ decl = REG_EXPR (reg);
+ if (REG_EXPR (reg) != decl)
+ break;
+ if (REG_OFFSET (reg) < offset)
+ offset = REG_OFFSET (reg);
+ }
+
+ if (i == len)
+ {
+ *declp = decl;
+ *offsetp = offset;
+ return true;
+ }
+ }
else if (MEM_P (rtl))
{
if (MEM_ATTRS (rtl))
@@ -9532,6 +9577,28 @@ vt_add_function_parameter (tree parm)
p.outgoing = incoming;
vec_safe_push (windowed_parm_regs, p);
}
+ else if (GET_CODE (incoming) == PARALLEL)
+ {
+ rtx outgoing
+ = gen_rtx_PARALLEL (VOIDmode, rtvec_alloc (XVECLEN (incoming, 0)));
+ int i;
+
+ for (i = 0; i < XVECLEN (incoming, 0); i++)
+ {
+ rtx reg = XEXP (XVECEXP (incoming, 0, i), 0);
+ parm_reg_t p;
+ p.incoming = reg;
+ reg = gen_rtx_REG_offset (reg, GET_MODE (reg),
+ OUTGOING_REGNO (REGNO (reg)), 0);
+ p.outgoing = reg;
+ XVECEXP (outgoing, 0, i)
+ = gen_rtx_EXPR_LIST (VOIDmode, reg,
+ XEXP (XVECEXP (incoming, 0, i), 1));
+ vec_safe_push (windowed_parm_regs, p);
+ }
+
+ incoming = outgoing;
+ }
else if (MEM_P (incoming)
&& REG_P (XEXP (incoming, 0))
&& HARD_REGISTER_P (XEXP (incoming, 0)))
@@ -9665,6 +9732,20 @@ vt_add_function_parameter (tree parm)
}
}
}
+ else if (GET_CODE (incoming) == PARALLEL && !dv_onepart_p (dv))
+ {
+ int i;
+
+ for (i = 0; i < XVECLEN (incoming, 0); i++)
+ {
+ rtx reg = XEXP (XVECEXP (incoming, 0, i), 0);
+ offset = REG_OFFSET (reg);
+ gcc_assert (REGNO (reg) < FIRST_PSEUDO_REGISTER);
+ attrs_list_insert (&out->regs[REGNO (reg)], dv, offset, reg);
+ set_variable_part (out, reg, dv, offset,
+ VAR_INIT_STATUS_INITIALIZED, NULL, INSERT);
+ }
+ }
else if (MEM_P (incoming))
{
incoming = var_lowpart (mode, incoming);
/* { dg-do run } */
/* { dg-options "-g" } */
/* { dg-skip-if "" { *-*-* } { "*" } { "-O0" "-O1" } } */
typedef __UINTPTR_TYPE__ uintptr_t;
__attribute__((noinline, noclone)) int
sub (int a, int b)
{
return a - b;
}
typedef struct { uintptr_t pa; uintptr_t pb; } fatp_t
__attribute__ ((aligned (2 * __alignof__ (uintptr_t))));
__attribute__((noinline, noclone)) void
foo (fatp_t str, int a, int b)
{
int i = sub (a, b);
if (i == 0) /* BREAK */
foo (str, a - 1, b);
}
int
main (void)
{
fatp_t ptr = { 31415927, 27182818 };
foo (ptr, 1, 2);
return 0;
}
/* { dg-final { gdb-test 20 "str.pa" "31415927" } } */
/* { dg-final { gdb-test 20 "str.pb" "27182818" } } */