------- Comment #12 from hjl at lucon dot org 2007-05-13 06:36 -------
find_reg computes the cost of moving to target register too high. This kludge
adjusts the cost of moving to target register and seems to work for the
testcase:
--- gcc/reload1.c.sse 2007-04-27 05:46:12.000000000 -0700
+++ gcc/reload1.c 2007-05-12 22:30:58.000000000 -0700
@@ -1723,6 +1723,20 @@ find_reg (struct insn_chain *chain, int
HARD_REG_SET not_usable;
HARD_REG_SET used_by_other_reload;
reg_set_iterator rsi;
+ rtx body = PATTERN (chain->insn);
+ unsigned int dest_reg;
+
+ if (GET_CODE (body) == SET)
+ {
+ rtx dest = SET_DEST (body);
+
+ if ((REG_P (dest)
+ || (GET_CODE (dest) == SUBREG
+ && REG_P (SUBREG_REG (dest)))))
+ dest_reg = reg_or_subregno (dest);
+ }
+ else
+ dest_reg = FIRST_PSEUDO_REGISTER;
COPY_HARD_REG_SET (not_usable, bad_spill_regs);
IOR_HARD_REG_SET (not_usable, bad_spill_regs_global);
@@ -1746,7 +1760,7 @@ find_reg (struct insn_chain *chain, int
&& ! TEST_HARD_REG_BIT (used_by_other_reload, regno)
&& HARD_REGNO_MODE_OK (regno, rl->mode))
{
- int this_cost = spill_cost[regno];
+ int this_cost = dest_reg == regno ? 0 : spill_cost[regno];
int ok = 1;
unsigned int this_nregs = hard_regno_nregs[regno][rl->mode];
--
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=30961
