Re: [097/nnn] poly_int: alter_reg

[Jeff Law]

On 10/23/2017 11:39 AM, Richard Sandiford wrote:
> This patch makes alter_reg cope with polynomial mode sizes.
> 
> 
> 2017-10-23  Richard Sandiford  
>   Alan Hayward  
>   David Sherwood  
> 
> gcc/
>   * reload1.c (spill_stack_slot_width): Change element type
>   from unsigned int to poly_uint64_pod.
>   (alter_reg): Treat mode sizes as polynomial.
OK.
Jeff

[097/nnn] poly_int: alter_reg

[Richard Sandiford]

This patch makes alter_reg cope with polynomial mode sizes.


2017-10-23  Richard Sandiford  
Alan Hayward  
David Sherwood  

gcc/
* reload1.c (spill_stack_slot_width): Change element type
from unsigned int to poly_uint64_pod.
(alter_reg): Treat mode sizes as polynomial.

Index: gcc/reload1.c
===
--- gcc/reload1.c   2017-10-23 17:25:38.242865029 +0100
+++ gcc/reload1.c   2017-10-23 17:25:44.492640380 +0100
@@ -200,7 +200,7 @@ #define spill_indirect_levels   \
 static rtx spill_stack_slot[FIRST_PSEUDO_REGISTER];
 
 /* Width allocated so far for that stack slot.  */
-static unsigned int spill_stack_slot_width[FIRST_PSEUDO_REGISTER];
+static poly_uint64_pod spill_stack_slot_width[FIRST_PSEUDO_REGISTER];
 
 /* Record which pseudos needed to be spilled.  */
 static regset_head spilled_pseudos;
@@ -2142,10 +2142,10 @@ alter_reg (int i, int from_reg, bool don
 {
   rtx x = NULL_RTX;
   machine_mode mode = GET_MODE (regno_reg_rtx[i]);
-  unsigned int inherent_size = PSEUDO_REGNO_BYTES (i);
+  poly_uint64 inherent_size = GET_MODE_SIZE (mode);
   unsigned int inherent_align = GET_MODE_ALIGNMENT (mode);
   machine_mode wider_mode = wider_subreg_mode (mode, reg_max_ref_mode[i]);
-  unsigned int total_size = GET_MODE_SIZE (wider_mode);
+  poly_uint64 total_size = GET_MODE_SIZE (wider_mode);
   unsigned int min_align = GET_MODE_BITSIZE (reg_max_ref_mode[i]);
   poly_int64 adjust = 0;
 
@@ -2174,10 +2174,15 @@ alter_reg (int i, int from_reg, bool don
{
  rtx stack_slot;
 
+ /* The sizes are taken from a subreg operation, which guarantees
+that they're ordered.  */
+ gcc_checking_assert (ordered_p (total_size, inherent_size));
+
  /* No known place to spill from => no slot to reuse.  */
  x = assign_stack_local (mode, total_size,
  min_align > inherent_align
- || total_size > inherent_size ? -1 : 0);
+ || may_gt (total_size, inherent_size)
+ ? -1 : 0);
 
  stack_slot = x;
 
@@ -2189,7 +2194,7 @@ alter_reg (int i, int from_reg, bool don
  adjust = inherent_size - total_size;
  if (maybe_nonzero (adjust))
{
- unsigned int total_bits = total_size * BITS_PER_UNIT;
+ poly_uint64 total_bits = total_size * BITS_PER_UNIT;
  machine_mode mem_mode
= int_mode_for_size (total_bits, 1).else_blk ();
  stack_slot = adjust_address_nv (x, mem_mode, adjust);
@@ -2203,9 +2208,10 @@ alter_reg (int i, int from_reg, bool don
 
   /* Reuse a stack slot if possible.  */
   else if (spill_stack_slot[from_reg] != 0
-  && spill_stack_slot_width[from_reg] >= total_size
-  && (GET_MODE_SIZE (GET_MODE (spill_stack_slot[from_reg]))
-  >= inherent_size)
+  && must_ge (spill_stack_slot_width[from_reg], total_size)
+  && must_ge (GET_MODE_SIZE
+  (GET_MODE (spill_stack_slot[from_reg])),
+  inherent_size)
   && MEM_ALIGN (spill_stack_slot[from_reg]) >= min_align)
x = spill_stack_slot[from_reg];
 
@@ -2221,16 +2227,21 @@ alter_reg (int i, int from_reg, bool don
  if (partial_subreg_p (mode,
GET_MODE (spill_stack_slot[from_reg])))
mode = GET_MODE (spill_stack_slot[from_reg]);
- if (spill_stack_slot_width[from_reg] > total_size)
-   total_size = spill_stack_slot_width[from_reg];
+ total_size = ordered_max (total_size,
+   spill_stack_slot_width[from_reg]);
  if (MEM_ALIGN (spill_stack_slot[from_reg]) > min_align)
min_align = MEM_ALIGN (spill_stack_slot[from_reg]);
}
 
+ /* The sizes are taken from a subreg operation, which guarantees
+that they're ordered.  */
+ gcc_checking_assert (ordered_p (total_size, inherent_size));
+
  /* Make a slot with that size.  */
  x = assign_stack_local (mode, total_size,
  min_align > inherent_align
- || total_size > inherent_size ? -1 : 0);
+ || may_gt (total_size, inherent_size)
+ ? -1 : 0);
  stack_slot = x;
 
  /* Cancel the  big-endian correction done in assign_stack_local.
@@ -2241,7 +2252,7 @@ alter_reg (int i, int from_reg, bool don
  adjust = GET_MODE_SIZE (mode) - total_size;
  if (maybe_nonzero (adjust))
{
-