Don't increase callee-saved register cost by 1000x, which leads to that
callee-saved registers aren't used to preserve local variable values
across calls, by capping the scale to 300.
PR rtl-optimization/111673
PR rtl-optimization/115932
PR rtl-optimization/116028
PR rtl-optimization/117081
PR rtl-optimization/118497
* ira-color.cc (assign_hard_reg): Cap callee-saved register cost
scale to 300.
Signed-off-by: H.J. Lu <[email protected]>
---
gcc/ira-color.cc | 16 ++++++++++++++--
1 file changed, 14 insertions(+), 2 deletions(-)
diff --git a/gcc/ira-color.cc b/gcc/ira-color.cc
index 0699b349a1a..707ff188250 100644
--- a/gcc/ira-color.cc
+++ b/gcc/ira-color.cc
@@ -2175,13 +2175,25 @@ assign_hard_reg (ira_allocno_t a, bool retry_p)
/* We need to save/restore the hard register in
epilogue/prologue. Therefore we increase the cost. */
{
+ int scale;
+ if (optimize_size)
+ scale = 1;
+ else
+ {
+ scale = REG_FREQ_FROM_BB (ENTRY_BLOCK_PTR_FOR_FN (cfun));
+ /* Don't increase callee-saved register cost by 1000x,
+ which leads to that callee-saved registers aren't
+ used to preserve local variable values across calls,
+ by capping the scale to 300. */
+ if (REG_FREQ_MAX == 1000 && scale == REG_FREQ_MAX)
+ scale = 300;
+ }
rclass = REGNO_REG_CLASS (hard_regno);
add_cost = ((ira_memory_move_cost[mode][rclass][0]
+ ira_memory_move_cost[mode][rclass][1])
* saved_nregs / hard_regno_nregs (hard_regno,
mode) - 1)
- * (optimize_size ? 1 :
- REG_FREQ_FROM_BB (ENTRY_BLOCK_PTR_FOR_FN (cfun)));
+ * scale;
cost += add_cost;
full_cost += add_cost;
}
--
2.48.1
