[Bug rtl-optimization/38272] [4.4 Regression] Revision 142207 caused libgomp.fortran/threadprivate2.f90

["hjl dot tools at gmail dot com" <gcc-bugzilla at gcc dot gnu dot org>]

------- Comment #5 from hjl dot tools at gmail dot com  2008-11-28 21:11 -------
do_input_reload has

  if (optimize && reload_inherited[j] && rl->in
      && MEM_P (rl->in)
      && MEM_P (rl->in_reg)
      && reload_spill_index[j] >= 0
      && TEST_HARD_REG_BIT (reg_reloaded_valid, reload_spill_index[j]))
    rl->in = regno_reg_rtx[reg_reloaded_contents[reload_spill_index[j]]];

(gdb) call debug_rtx (insn)
(insn 151 47 48 3 /tmp/foo.f90:6 (set (reg:SI 1 dx [87])
        (mem/u/c:SI (const:SI (unspec:SI [
                        (symbol_ref:SI ("__threadprivate2_MOD_foo") [flags
0x60] <var_decl 0x7ffff7fd3780 foo>)
                    ] 8)) [0 S4 A8])) 47 {*movsi_1} (expr_list:REG_EQUIV
(mem/u/c:SI (const:SI (unspec:SI [
                        (symbol_ref:SI ("__threadprivate2_MOD_foo") [flags
0x60] <var_decl 0x7ffff7fd3780 foo>)
                    ] 8)) [0 S4 A8])
        (nil)))
(gdb) p *rl
$6 = {in = 0x7ffff7e959c0, out = 0x0, rclass = GENERAL_REGS, inmode = SImode, 
  outmode = VOIDmode, mode = SImode, nregs = 1, inc = 0, 
  in_reg = 0x7ffff7e959c0, out_reg = 0x0, regno = -1, 
  reg_rtx = 0x7ffff7e819c0, opnum = 1, secondary_in_reload = -1, 
  secondary_out_reload = -1, secondary_in_icode = CODE_FOR_nothing, 
  secondary_out_icode = CODE_FOR_nothing, when_needed = RELOAD_FOR_INPUT, 
  optional = 1, nocombine = 0, secondary_p = 0, nongroup = 0}
(gdb) call debug_rtx (rl->in)
(mem/u/c:SI (const:SI (unspec:SI [
                (symbol_ref:SI ("__threadprivate2_MOD_foo") [flags 0x60]
<var_decl 0x7ffff7fd3780 foo>)
            ] 8)) [0 S4 A8])
(gdb) call debug_rtx (rl->in_reg)
(mem/u/c:SI (const:SI (unspec:SI [
                (symbol_ref:SI ("__threadprivate2_MOD_foo") [flags 0x60]
<var_decl 0x7ffff7fd3780 foo>)
            ] 8)) [0 S4 A8])
(gdb) call debug_rtx (rl->reg_rtx)
(reg:SI 2 cx [80])
(gdb) p reload_spill_index[j]
$7 = 1
(gdb) 

It replaces rl->in with an reg_rtx different from rl->reg_rtx and confused
IRA. I don't know if it is a reload or IRA bug. This patch fixes the testcase.

--- reload1.c.foo       2008-11-21 06:06:55.000000000 -0800
+++ reload1.c   2008-11-28 12:56:54.000000000 -0800
@@ -7508,6 +7508,8 @@ do_input_reload (struct insn_chain *chai
       && MEM_P (rl->in)
       && MEM_P (rl->in_reg)
       && reload_spill_index[j] >= 0
+      && (rl->reg_rtx == 0
+         || REGNO (rl->reg_rtx) == (unsigned int) reload_spill_index[j])
       && TEST_HARD_REG_BIT (reg_reloaded_valid, reload_spill_index[j]))
     rl->in = regno_reg_rtx[reg_reloaded_contents[reload_spill_index[j]]];



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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=38272