OpenE2K
/
gcc
2
0
Fork 0
Code Issues Pull Requests Projects Releases Wiki Activity

loop.c (first_loop_store_insn): New file-scope variable. 

* loop.c (first_loop_store_insn): New file-scope variable.
	(prescan_loop): Set it.
	(check_dbra_loop): Check if a store depends on a register
	that is set after the store.

From-SVN: r25034
This commit is contained in:
J"orn Rennecke 1999-02-04 23:10:46 +00:00 committed by Joern Rennecke
parent a5af23fe12
commit 2d4fde68c3
2 changed files with 33 additions and 3 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

7
gcc/ChangeLog
View File

@ -1,3 +1,10 @@
Fri Feb 5 07:09:29 1999 J"orn Rennecke <amylaar@cygnus.co.uk>
* loop.c (first_loop_store_insn): New file-scope variable.
(prescan_loop): Set it.
(check_dbra_loop): Check if a store depends on a register
that is set after the store.
Fri Feb 5 06:55:15 1999 J"orn Rennecke <amylaar@cygnus.co.uk> Fri Feb 5 06:55:15 1999 J"orn Rennecke <amylaar@cygnus.co.uk>
* unroll.c (entire file): Remove tabs / spaces at end of lines. * unroll.c (entire file): Remove tabs / spaces at end of lines.

29
gcc/loop.c
View File

@ -173,6 +173,9 @@ static char *moved_once;
static rtx loop_store_mems; static rtx loop_store_mems;
/* The insn where the first of these was found. */
static rtx first_loop_store_insn;
typedef struct loop_mem_info { typedef struct loop_mem_info {
rtx mem; /* The MEM itself. */ rtx mem; /* The MEM itself. */
rtx reg; /* Corresponding pseudo, if any. */ rtx reg; /* Corresponding pseudo, if any. */
@ -2404,6 +2407,7 @@ prescan_loop (start, end)
loop_has_volatile = 0; loop_has_volatile = 0;
loop_has_tablejump = 0; loop_has_tablejump = 0;
loop_store_mems = NULL_RTX; loop_store_mems = NULL_RTX;
first_loop_store_insn = NULL_RTX;
loop_mems_idx = 0; loop_mems_idx = 0;
num_mem_sets = 0; num_mem_sets = 0;
@ -2456,6 +2460,8 @@ prescan_loop (start, end)
loop_has_tablejump = 1; loop_has_tablejump = 1;
note_stores (PATTERN (insn), note_addr_stored); note_stores (PATTERN (insn), note_addr_stored);
if (! first_loop_store_insn && loop_store_mems)
first_loop_store_insn = insn;
if (! loop_has_multiple_exit_targets if (! loop_has_multiple_exit_targets
&& GET_CODE (insn) == JUMP_INSN && GET_CODE (insn) == JUMP_INSN
@ -7682,9 +7688,26 @@ check_dbra_loop (loop_end, insn_count, loop_start, loop_info)
case, the insn should have been moved out of the loop. */ case, the insn should have been moved out of the loop. */
if (num_mem_sets == 1) if (num_mem_sets == 1)
reversible_mem_store {
= (! unknown_address_altered struct induction *v;
&& ! invariant_p (XEXP (loop_store_mems, 0)));
reversible_mem_store
= (! unknown_address_altered
&& ! invariant_p (XEXP (loop_store_mems, 0)));
/* If the store depends on a register that is set after the
store, it depends on the initial value, and is thus not
reversible. */
for (v = bl->giv; reversible_mem_store && v; v = v->next_iv)
{
if (v->giv_type == DEST_REG
&& reg_mentioned_p (v->dest_reg,
XEXP (loop_store_mems, 0))
&& (INSN_LUID (v->insn)
> INSN_LUID (first_loop_store_insn)))
reversible_mem_store = 0;
}
}
} }
else else
return 0; return 0;