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rs6000: Don't use HARD_FRAME_POINTER_REGNUM if it's not live in pro_and_epilogue (PR91518)

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This bug is exposed by FRE refactor of r263875.  Comparing the fre
dump file shows no obvious change of the segment fault function proves
it to be a target issue.
frame_pointer_needed is set to true in reload pass setup_can_eliminate,
but regs_ever_live[31] is false, pro_and_epilogue uses it without live
check causing CPU2006 465.tonto segment fault of loading from invalid
addresses due to r31 not saved/restored.  Thus, add HARD_FRAME_POINTER_REGNUM
live check with frame_pointer_needed_indeed when generating pro_and_epilogue
instructions.

gcc/ChangeLog

2020-04-27  Xiong Hu Luo  <luoxhu@linux.ibm.com>

	PR target/91518
	* config/rs6000/rs6000-logue.c (frame_pointer_needed_indeed):
	New variable.
	(rs6000_emit_prologue_components):
	Check with frame_pointer_needed_indeed.
	(rs6000_emit_epilogue_components): Likewise.
	(rs6000_emit_prologue): Likewise.
	(rs6000_emit_epilogue): Set frame_pointer_needed_indeed.
This commit is contained in:
Xionghu Luo 2020-04-26 20:37:27 -05:00
parent bfdea9ae81
commit f6955089db
2 changed files with 25 additions and 9 deletions
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11
gcc/ChangeLog
View file

@ -1,3 +1,14 @@
2020-04-27 Xiong Hu Luo <luoxhu@linux.ibm.com>
PR target/91518
* config/rs6000/rs6000-logue.c (frame_pointer_needed_indeed):
New variable.
(rs6000_emit_prologue_components):
Check with frame_pointer_needed_indeed.
(rs6000_emit_epilogue_components): Likewise.
(rs6000_emit_prologue): Likewise.
(rs6000_emit_epilogue): Set frame_pointer_needed_indeed.
2020-04-25 David Edelsohn <dje.gcc@gmail.com>
* config/rs6000/rs6000-logue.c (rs6000_stack_info): Don't push a

23
gcc/config/rs6000/rs6000-logue.c
View file

@ -58,6 +58,8 @@ static bool rs6000_save_toc_in_prologue_p (void);
static rs6000_stack_t stack_info;
/* Set if HARD_FRAM_POINTER_REGNUM is really needed. */
static bool frame_pointer_needed_indeed = false;
/* Label number of label created for -mrelocatable, to call to so we can
get the address of the GOT section */
@ -2735,9 +2737,9 @@ void
rs6000_emit_prologue_components (sbitmap components)
{
rs6000_stack_t *info = rs6000_stack_info ();
rtx ptr_reg = gen_rtx_REG (Pmode, frame_pointer_needed
? HARD_FRAME_POINTER_REGNUM
: STACK_POINTER_REGNUM);
rtx ptr_reg = gen_rtx_REG (Pmode, frame_pointer_needed_indeed
? HARD_FRAME_POINTER_REGNUM
: STACK_POINTER_REGNUM);
machine_mode reg_mode = Pmode;
int reg_size = TARGET_32BIT ? 4 : 8;
@ -2815,9 +2817,9 @@ void
rs6000_emit_epilogue_components (sbitmap components)
{
rs6000_stack_t *info = rs6000_stack_info ();
rtx ptr_reg = gen_rtx_REG (Pmode, frame_pointer_needed
? HARD_FRAME_POINTER_REGNUM
: STACK_POINTER_REGNUM);
rtx ptr_reg = gen_rtx_REG (Pmode, frame_pointer_needed_indeed
? HARD_FRAME_POINTER_REGNUM
: STACK_POINTER_REGNUM);
machine_mode reg_mode = Pmode;
int reg_size = TARGET_32BIT ? 4 : 8;
@ -2996,7 +2998,10 @@ rs6000_emit_prologue (void)
&& (lookup_attribute ("no_split_stack",
DECL_ATTRIBUTES (cfun->decl))
== NULL));
frame_pointer_needed_indeed
= frame_pointer_needed && df_regs_ever_live_p (HARD_FRAME_POINTER_REGNUM);
/* Offset to top of frame for frame_reg and sp respectively. */
HOST_WIDE_INT frame_off = 0;
HOST_WIDE_INT sp_off = 0;
@ -3658,7 +3663,7 @@ rs6000_emit_prologue (void)
}
/* Set frame pointer, if needed. */
if (frame_pointer_needed)
if (frame_pointer_needed_indeed)
{
insn = emit_move_insn (gen_rtx_REG (Pmode, HARD_FRAME_POINTER_REGNUM),
sp_reg_rtx);
@ -4534,7 +4539,7 @@ rs6000_emit_epilogue (enum epilogue_type epilogue_type)
}
/* If we have a frame pointer, we can restore the old stack pointer
from it. */
else if (frame_pointer_needed)
else if (frame_pointer_needed_indeed)
{
frame_reg_rtx = sp_reg_rtx;
if (DEFAULT_ABI == ABI_V4)