was Re: [PATCH] Change replace_rtx if from is a REG (PR target/70245, take 2)
On Thu, Mar 17, 2016 at 11:07:03PM +1030, Alan Modra wrote:
> By the look of what you posted in the bugzilla, the pattern is the
> parallel emitted by rs6000_emit_savres_rtx. In that parallel, the
> stack memory locations for register saves are described relative to
> whatever frame_reg_rtx is in use, which may be r12.
> rs6000_frame_related wants to translate the frame_reg_rtx into stack
> pointer plus offset for debug info.
>
> The parallel matches save_gpregs_<mode>_r12 and similar in rs6000.md,
> which emit a call to an out-of-line register save function. This
> function actually takes r12 as a parameter, hence the (use (reg:P 12))
> in the pattern.
>
> rs6000_frame_related probably should just be replacing individual
> SETs in the parallel using simplify_replace_rtx. Especially since
> after calling replace_rtx, it already iterates over them to simplify.
Like this. Bootstrapped and regression tested powerpc64le-linux
and powerpc64-linux.
Modify SETs rather than using replace_rtx on the whole insn.
Removes fragile hacks preventing USE and CLOBBER being modified.
* config/rs6000/rs6000.c (rs6000_frame_related): Rewrite.
diff --git a/gcc/config/rs6000/rs6000.c b/gcc/config/rs6000/rs6000.c
index fb522fb..67bcbc8 100644
--- a/gcc/config/rs6000/rs6000.c
+++ b/gcc/config/rs6000/rs6000.c
@@ -24712,7 +24712,7 @@ output_probe_stack_range (rtx reg1, rtx reg2)
}
/* Add to 'insn' a note which is PATTERN (INSN) but with REG replaced
- with (plus:P (reg 1) VAL), and with REG2 replaced with RREG if REG2
+ with (plus:P (reg 1) VAL), and with REG2 replaced with REPL2 if REG2
is not NULL. It would be nice if dwarf2out_frame_debug_expr could
deduce these equivalences by itself so it wasn't necessary to hold
its hand so much. Don't be tempted to always supply d2_f_d_e with
@@ -24722,22 +24722,28 @@ output_probe_stack_range (rtx reg1, rtx reg2)
static rtx
rs6000_frame_related (rtx insn, rtx reg, HOST_WIDE_INT val,
- rtx reg2, rtx rreg)
+ rtx reg2, rtx repl2)
{
- rtx real, temp;
+ rtx patt, repl;
- if (REGNO (reg) == STACK_POINTER_REGNUM && reg2 == NULL_RTX)
+ repl = NULL_RTX;
+ if (REGNO (reg) == STACK_POINTER_REGNUM)
+ gcc_checking_assert (val == 0);
+ else
+ repl = gen_rtx_PLUS (Pmode, gen_rtx_REG (Pmode, STACK_POINTER_REGNUM),
+ GEN_INT (val));
+
+ patt = PATTERN (insn);
+ if (!repl && !reg2)
{
/* No need for any replacement. Just set RTX_FRAME_RELATED_P. */
int i;
- gcc_checking_assert (val == 0);
- real = PATTERN (insn);
- if (GET_CODE (real) == PARALLEL)
- for (i = 0; i < XVECLEN (real, 0); i++)
- if (GET_CODE (XVECEXP (real, 0, i)) == SET)
+ if (GET_CODE (patt) == PARALLEL)
+ for (i = 0; i < XVECLEN (patt, 0); i++)
+ if (GET_CODE (XVECEXP (patt, 0, i)) == SET)
{
- rtx set = XVECEXP (real, 0, i);
+ rtx set = XVECEXP (patt, 0, i);
/* If this PARALLEL has been emitted for out-of-line
register save functions, or store multiple, then omit
@@ -24752,79 +24758,49 @@ rs6000_frame_related (rtx insn, rtx reg,
HOST_WIDE_INT val,
return insn;
}
- /* copy_rtx will not make unique copies of registers, so we need to
- ensure we don't have unwanted sharing here. */
- if (reg == reg2)
- reg = gen_raw_REG (GET_MODE (reg), REGNO (reg));
-
- if (reg == rreg)
- reg = gen_raw_REG (GET_MODE (reg), REGNO (reg));
-
- real = copy_rtx (PATTERN (insn));
-
- if (reg2 != NULL_RTX)
- real = replace_rtx (real, reg2, rreg);
-
- if (REGNO (reg) == STACK_POINTER_REGNUM)
- gcc_checking_assert (val == 0);
- else
- real = replace_rtx (real, reg,
- gen_rtx_PLUS (Pmode, gen_rtx_REG (Pmode,
- STACK_POINTER_REGNUM),
- GEN_INT (val)));
-
- /* We expect that 'real' is either a SET or a PARALLEL containing
+ /* We expect that 'patt' is either a SET or a PARALLEL containing
SETs (and possibly other stuff). In a PARALLEL, all the SETs
- are important so they all have to be marked RTX_FRAME_RELATED_P. */
+ are important so they all have to be marked RTX_FRAME_RELATED_P.
+ Call simplify_replace_rtx on the SETs rather than the whole insn
+ so as to leave the other stuff alone (for example USE of r12). */
- if (GET_CODE (real) == SET)
+ if (GET_CODE (patt) == SET)
{
- rtx set = real;
-
- temp = simplify_rtx (SET_SRC (set));
- if (temp)
- SET_SRC (set) = temp;
- temp = simplify_rtx (SET_DEST (set));
- if (temp)
- SET_DEST (set) = temp;
- if (GET_CODE (SET_DEST (set)) == MEM)
- {
- temp = simplify_rtx (XEXP (SET_DEST (set), 0));
- if (temp)
- XEXP (SET_DEST (set), 0) = temp;
- }
+ if (repl)
+ patt = simplify_replace_rtx (patt, reg, repl);
+ if (reg2)
+ patt = simplify_replace_rtx (patt, reg2, repl2);
}
- else
+ else if (GET_CODE (patt) == PARALLEL)
{
int i;
- gcc_assert (GET_CODE (real) == PARALLEL);
- for (i = 0; i < XVECLEN (real, 0); i++)
- if (GET_CODE (XVECEXP (real, 0, i)) == SET)
+ patt = shallow_copy_rtx (patt);
+ XVEC (patt, 0) = shallow_copy_rtvec (XVEC (patt, 0));
+
+ for (i = 0; i < XVECLEN (patt, 0); i++)
+ if (GET_CODE (XVECEXP (patt, 0, i)) == SET)
{
- rtx set = XVECEXP (real, 0, i);
-
- temp = simplify_rtx (SET_SRC (set));
- if (temp)
- SET_SRC (set) = temp;
- temp = simplify_rtx (SET_DEST (set));
- if (temp)
- SET_DEST (set) = temp;
- if (GET_CODE (SET_DEST (set)) == MEM)
- {
- temp = simplify_rtx (XEXP (SET_DEST (set), 0));
- if (temp)
- XEXP (SET_DEST (set), 0) = temp;
- }
+ rtx set = XVECEXP (patt, 0, i);
+
+ if (repl)
+ set = simplify_replace_rtx (set, reg, repl);
+ if (reg2)
+ set = simplify_replace_rtx (set, reg2, repl2);
+ XVECEXP (patt, 0, i) = set;
+
/* Omit eh_frame info for any user-defined global regs. */
if (!REG_P (SET_SRC (set))
|| !fixed_reg_p (REGNO (SET_SRC (set))))
RTX_FRAME_RELATED_P (set) = 1;
}
}
+ else
+ gcc_unreachable ();
RTX_FRAME_RELATED_P (insn) = 1;
- add_reg_note (insn, REG_FRAME_RELATED_EXPR, real);
+ if (repl || reg2)
+ add_reg_note (insn, REG_FRAME_RELATED_EXPR, patt);
return insn;
}
--
Alan Modra
Australia Development Lab, IBM
