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bug fix for merge_assigned_reloads
- From: Joern Rennecke <amylaar at cs dot tu-berlin dot de>
- To: gcc-patches at gcc dot gnu dot org
- Date: Thu, 30 May 2002 20:52:18 +0200 (MEST)
- Subject: bug fix for merge_assigned_reloads
- Reply-to: joern dot rennecke at superh dot com
In SH gcc mainline, for execute/930628-1.c -O2 -m4, this instruction:
(insn 862 665 55 (set (reg:SI 216)
(plus:SI (reg:SI 212)
(reg:SI 313))) 23 {*addsi3_compact} (nil)
(nil))
gets these reloads:
Reload 0: reload_in (SI) = (plus:SI (reg/f:SI 14 r14)
(const_int 444 [0x1bc]))
GENERAL_REGS, RELOAD_FOR_OUTPUT_ADDRESS (opnum = 0)
reload_in_reg: (plus:SI (reg/f:SI 14 r14)
(const_int 444 [0x1bc]))
Reload 1: reload_in (SI) = (plus:SI (reg/f:SI 14 r14)
(const_int 444 [0x1bc]))
GENERAL_REGS, RELOAD_FOR_OTHER_ADDRESS (opnum = 0)
reload_in_reg: (plus:SI (reg/f:SI 14 r14)
(const_int 444 [0x1bc]))
Reload 2: reload_in (SI) = (plus:SI (reg/f:SI 14 r14)
(const_int 444 [0x1bc]))
GENERAL_REGS, RELOAD_FOR_INPUT_ADDRESS (opnum = 2)
reload_in_reg: (plus:SI (reg/f:SI 14 r14)
(const_int 444 [0x1bc]))
Reload 3: reload_in (SI) = (mem:SI (plus:SI (plus:SI (reg/f:SI 14 r14)
(const_int 444 [0x
(const_int 36 [0x24]))
reload_out (SI) = (mem:SI (plus:SI (plus:SI (reg/f:SI 14 r14)
(const_int 444 [0x
(const_int 40 [0x28]))
GENERAL_REGS, RELOAD_OTHER (opnum = 0), can't combine
reload_in_reg: (reg:SI 212)
reload_out_reg: (reg:SI 216)
Reload 4: reload_in (SI) = (mem:SI (plus:SI (plus:SI (reg/f:SI 14 r14)
(const_int 444 [0x
(const_int 48 [0x30]))
GENERAL_REGS, RELOAD_FOR_INPUT (opnum = 2), can't combine
reload_in_reg: (reg:SI 313)
reload 3 gets r1 as reload register, all other reloads get r0.
Then merge_assigned_reloads is called. It merges reload 1 and 2 into a
RELOAD_OTHER, but then proceeds to change reload 0 to RELOAD_OTHER,
resulting in r to be clobbered:
0x1210 <main+112>: mov.w 0x12c0 <main+288>,r1 ! 0x1bc
0x1212 <main+114>: add r14,r1
0x1214 <main+116>: mov.l @(36,r1),r2
0x1216 <main+118>: mov.l @(48,r1),r1
0x1218 <main+120>: add r1,r2
0x121a <main+122>: mov.l r2,@(40,r1)
Thu May 30 19:23:18 2002 J"orn Rennecke <joern.rennecke@superh.com>
* reload1.c (merge_assigned_reloads): Don't change reloads
other than RELOAD_FOR_INPUT_ADDRESS / RELOAD_FOR_INPADDR_ADDRESS
to RELOAD_OTHER when there are conflicting input reloads.
*** reload1.c-orig Thu May 23 21:16:55 2002
--- reload1.c Thu May 30 19:24:18 2002
*************** merge_assigned_reloads (insn)
*** 6098,6108 ****
--- 6098,6116 ----
if they were for inputs, RELOAD_OTHER for outputs. Note that
this test is equivalent to looking for reloads for this operand
number. */
+ /* We must take special care when there are two or more reloads to
+ be merged and a RELOAD_FOR_OUTPUT_ADDRESS reload that loads the
+ same value or a part of it; we must not change its type if there
+ is a conflicting input. */
if (rld[i].when_needed == RELOAD_OTHER)
for (j = 0; j < n_reloads; j++)
if (rld[j].in != 0
&& rld[j].when_needed != RELOAD_OTHER
+ && rld[j].when_needed != RELOAD_FOR_OTHER_ADDRESS
+ && (! conflicting_input
+ || rld[j].when_needed == RELOAD_FOR_INPUT_ADDRESS
+ || rld[j].when_needed == RELOAD_FOR_INPADDR_ADDRESS)
&& reg_overlap_mentioned_for_reload_p (rld[j].in,
rld[i].in))
rld[j].when_needed