{
rtx_insn *before_arg = get_last_insn ();
+ /* On targets with weird calling conventions (e.g. PA) it's
+ hard to ensure that all cases of argument overlap between
+ stack and registers work. Play it safe and bail out. */
+ if (ARGS_GROW_DOWNWARD && !STACK_GROWS_DOWNWARD)
+ {
+ sibcall_failure = 1;
+ break;
+ }
+
if (store_one_arg (&args[i], argblock, flags,
adjusted_args_size.var != 0,
reg_parm_stack_space)
partial, reg, 0, argblock,
GEN_INT (argvec[argnum].locate.offset.constant),
reg_parm_stack_space,
- ARGS_SIZE_RTX (argvec[argnum].locate.alignment_pad));
+ ARGS_SIZE_RTX (argvec[argnum].locate.alignment_pad), false);
/* Now mark the segment we just used. */
if (ACCUMULATE_OUTGOING_ARGS)
/* This isn't already where we want it on the stack, so put it there.
This can either be done with push or copy insns. */
- emit_push_insn (arg->value, arg->mode, TREE_TYPE (pval), NULL_RTX,
+ if (!emit_push_insn (arg->value, arg->mode, TREE_TYPE (pval), NULL_RTX,
parm_align, partial, reg, used - size, argblock,
ARGS_SIZE_RTX (arg->locate.offset), reg_parm_stack_space,
- ARGS_SIZE_RTX (arg->locate.alignment_pad));
+ ARGS_SIZE_RTX (arg->locate.alignment_pad), true))
+ sibcall_failure = 1;
/* Unless this is a partially-in-register argument, the argument is now
in the stack. */
emit_push_insn (arg->value, arg->mode, TREE_TYPE (pval), size_rtx,
parm_align, partial, reg, excess, argblock,
ARGS_SIZE_RTX (arg->locate.offset), reg_parm_stack_space,
- ARGS_SIZE_RTX (arg->locate.alignment_pad));
+ ARGS_SIZE_RTX (arg->locate.alignment_pad), false);
/* Unless this is a partially-in-register argument, the argument is now
in the stack.
}
#endif
+/* If reading SIZE bytes from X will end up reading from
+ Y return the number of bytes that overlap. Return -1
+ if there is no overlap or -2 if we can't determine
+ (for example when X and Y have different base registers). */
+
+static int
+memory_load_overlap (rtx x, rtx y, HOST_WIDE_INT size)
+{
+ rtx tmp = plus_constant (Pmode, x, size);
+ rtx sub = simplify_gen_binary (MINUS, Pmode, tmp, y);
+
+ if (!CONST_INT_P (sub))
+ return -2;
+
+ HOST_WIDE_INT val = INTVAL (sub);
+
+ return IN_RANGE (val, 1, size) ? val : -1;
+}
+
/* Generate code to push X onto the stack, assuming it has mode MODE and
type TYPE.
MODE is redundant except when X is a CONST_INT (since they don't
carry mode info).
SIZE is an rtx for the size of data to be copied (in bytes),
needed only if X is BLKmode.
+ Return true if successful. May return false if asked to push a
+ partial argument during a sibcall optimization (as specified by
+ SIBCALL_P) and the incoming and outgoing pointers cannot be shown
+ to not overlap.
ALIGN (in bits) is maximum alignment we can assume.
for arguments passed in registers. If nonzero, it will be the number
of bytes required. */
-void
+bool
emit_push_insn (rtx x, machine_mode mode, tree type, rtx size,
unsigned int align, int partial, rtx reg, int extra,
rtx args_addr, rtx args_so_far, int reg_parm_stack_space,
- rtx alignment_pad)
+ rtx alignment_pad, bool sibcall_p)
{
rtx xinner;
enum direction stack_direction = STACK_GROWS_DOWNWARD ? downward : upward;
xinner = x;
+ int nregs = partial / UNITS_PER_WORD;
+ rtx *tmp_regs = NULL;
+ int overlapping = 0;
+
if (mode == BLKmode
|| (STRICT_ALIGNMENT && align < GET_MODE_ALIGNMENT (mode)))
{
PARM_BOUNDARY. Assume the caller isn't lying. */
set_mem_align (target, align);
+ /* If part should go in registers and pushing to that part would
+ overwrite some of the values that need to go into regs, load the
+ overlapping values into temporary pseudos to be moved into the hard
+ regs at the end after the stack pushing has completed.
+ We cannot load them directly into the hard regs here because
+ they can be clobbered by the block move expansions.
+ See PR 65358. */
+
+ if (partial > 0 && reg != 0 && mode == BLKmode
+ && GET_CODE (reg) != PARALLEL)
+ {
+ overlapping = memory_load_overlap (XEXP (x, 0), temp, partial);
+ if (overlapping > 0)
+ {
+ gcc_assert (overlapping % UNITS_PER_WORD == 0);
+ overlapping /= UNITS_PER_WORD;
+
+ tmp_regs = XALLOCAVEC (rtx, overlapping);
+
+ for (int i = 0; i < overlapping; i++)
+ tmp_regs[i] = gen_reg_rtx (word_mode);
+
+ for (int i = 0; i < overlapping; i++)
+ emit_move_insn (tmp_regs[i],
+ operand_subword_force (target, i, mode));
+ }
+ else if (overlapping == -1)
+ overlapping = 0;
+ /* Could not determine whether there is overlap.
+ Fail the sibcall. */
+ else
+ {
+ overlapping = 0;
+ if (sibcall_p)
+ return false;
+ }
+ }
emit_block_move (target, xinner, size, BLOCK_OP_CALL_PARM);
}
}
has a size a multiple of a word. */
for (i = size - 1; i >= not_stack; i--)
if (i >= not_stack + offset)
- emit_push_insn (operand_subword_force (x, i, mode),
+ if (!emit_push_insn (operand_subword_force (x, i, mode),
word_mode, NULL_TREE, NULL_RTX, align, 0, NULL_RTX,
0, args_addr,
GEN_INT (args_offset + ((i - not_stack + skip)
* UNITS_PER_WORD)),
- reg_parm_stack_space, alignment_pad);
+ reg_parm_stack_space, alignment_pad, sibcall_p))
+ return false;
}
else
{
}
}
- /* If part should go in registers, copy that part
- into the appropriate registers. Do this now, at the end,
- since mem-to-mem copies above may do function calls. */
+ /* Move the partial arguments into the registers and any overlapping
+ values that we moved into the pseudos in tmp_regs. */
if (partial > 0 && reg != 0)
{
/* Handle calls that pass values in multiple non-contiguous locations.
if (GET_CODE (reg) == PARALLEL)
emit_group_load (reg, x, type, -1);
else
- {
+ {
gcc_assert (partial % UNITS_PER_WORD == 0);
- move_block_to_reg (REGNO (reg), x, partial / UNITS_PER_WORD, mode);
+ move_block_to_reg (REGNO (reg), x, nregs - overlapping, mode);
+
+ for (int i = 0; i < overlapping; i++)
+ emit_move_insn (gen_rtx_REG (word_mode, REGNO (reg)
+ + nregs - overlapping + i),
+ tmp_regs[i]);
+
}
}
if (alignment_pad && args_addr == 0)
anti_adjust_stack (alignment_pad);
+
+ return true;
}
\f
/* Return X if X can be used as a subtarget in a sequence of arithmetic
extern rtx push_block (rtx, int, int);
/* Generate code to push something onto the stack, given its mode and type. */
-extern void emit_push_insn (rtx, machine_mode, tree, rtx, unsigned int,
- int, rtx, int, rtx, rtx, int, rtx);
+extern bool emit_push_insn (rtx, machine_mode, tree, rtx, unsigned int,
+ int, rtx, int, rtx, rtx, int, rtx, bool);
/* Expand an assignment that stores the value of FROM into TO. */
extern void expand_assignment (tree, tree, bool);
projects / gcc.git / commitdiff