This patch makes LRA apply register filters. This plus the recog
change is enough for correct code generation, but a follow-on IRA
patch improves the allocation.
All the new code should be optimised away on targets that don't
use register filters. That's because get_register_filter just
wraps "return nullptr" on those targets.
gcc/
* lra-constraints.cc (process_alt_operands): Check register filters.
---
gcc/lra-constraints.cc | 13 ++++++++++++-
1 file changed, 12 insertions(+), 1 deletion(-)
diff --git a/gcc/lra-constraints.cc b/gcc/lra-constraints.cc
index 0607c8be7cb..9b6a2af5b75 100644
--- a/gcc/lra-constraints.cc
+++ b/gcc/lra-constraints.cc
@@ -2149,6 +2149,7 @@ process_alt_operands (int only_alternative)
int reload_nregs, reload_sum;
bool costly_p;
enum reg_class cl;
+ const HARD_REG_SET *cl_filter;
/* Calculate some data common for all alternatives to speed up the
function. */
@@ -2514,6 +2515,7 @@ process_alt_operands (int only_alternative)
|| spilled_pseudo_p (op))
win = true;
cl = GENERAL_REGS;
+ cl_filter = nullptr;
goto reg;
default:
@@ -2523,7 +2525,10 @@ process_alt_operands (int only_alternative)
case CT_REGISTER:
cl = reg_class_for_constraint (cn);
if (cl != NO_REGS)
- goto reg;
+ {
+ cl_filter = get_register_filter (cn);
+ goto reg;
+ }
break;
case CT_CONST_INT:
@@ -2567,6 +2572,7 @@ process_alt_operands (int only_alternative)
win = true;
cl = base_reg_class (VOIDmode, ADDR_SPACE_GENERIC,
ADDRESS, SCRATCH);
+ cl_filter = nullptr;
badop = false;
goto reg;
@@ -2600,6 +2606,8 @@ process_alt_operands (int only_alternative)
this_alternative_exclude_start_hard_regs
|= ira_exclude_class_mode_regs[cl][mode];
this_alternative_set |= reg_class_contents[cl];
+ if (cl_filter)
+ this_alternative_exclude_start_hard_regs |= ~*cl_filter;
if (costly_p)
{
this_costly_alternative
@@ -2613,6 +2621,9 @@ process_alt_operands (int only_alternative)
if (hard_regno[nop] >= 0
&& in_hard_reg_set_p (this_alternative_set,
mode, hard_regno[nop])
+ && (!cl_filter
+ || TEST_HARD_REG_BIT (*cl_filter,
+ hard_regno[nop]))
&& ((REG_ATTRS (op) && (decl = REG_EXPR (op)) != NULL
&& VAR_P (decl) && DECL_HARD_REGISTER (decl))
|| !(TEST_HARD_REG_BIT
--
2.25.1
