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what can be in a group set?
- From: Paolo Bonzini <bonzini at gnu dot org>
- To: GCC Patches <gcc-patches at gcc dot gnu dot org>, Richard Sandiford <rdsandiford at googlemail dot com>
- Cc: Dimitrios Apostolou <jimis at gmx dot net>
- Date: Fri, 08 Jul 2011 09:11:39 +0200
- Subject: what can be in a group set?
df-scan.c has this code to deal with group sets:
/* It is legal to have a set destination be a parallel. */
if (GET_CODE (dst) == PARALLEL)
{
int i;
for (i = XVECLEN (dst, 0) - 1; i >= 0; i--)
{
rtx temp = XVECEXP (dst, 0, i);
if (GET_CODE (temp) == EXPR_LIST || GET_CODE (temp) == CLOBBER
|| GET_CODE (temp) == SET)
df_def_record_1 (collection_rec,
temp, bb, insn_info,
GET_CODE (temp) == CLOBBER
? flags | DF_REF_MUST_CLOBBER : flags);
}
return;
}
It seems to me that the case of (set (parallel [(set ...)])) and (set
(parallel [(clobber ...)])) is bogus. I would like to simplify it to
the following:
/* It is legal to have a set destination be a parallel. */
if (GET_CODE (dst) == PARALLEL)
{
int i;
for (i = XVECLEN (dst, 0) - 1; i >= 0; i--)
{
rtx temp = XVECEXP (dst, 0, i);
assert (GET_CODE (temp) == EXPR_LIST);
df_def_record_1 (collection_rec, temp, bb, insn_info, flags);
}
return;
}
Does this make sense? See the attached patch for the overall thing I
was thinking of.
Paolo
* df-scan.c (df_def_record_1): Assert a parallel must contain
an EXPR_LIST at this point. Receive the LOC and move its
extraction...
(df_defs_record): ... here. Remove superfluous braces.
Index: df-scan.c
===================================================================
--- df-scan.c (revision 169877)
+++ df-scan.c (working copy)
@@ -111,7 +111,7 @@ static void df_ref_record (enum df_ref_c
rtx, rtx *,
basic_block, struct df_insn_info *,
enum df_ref_type, int ref_flags);
-static void df_def_record_1 (struct df_collection_rec *, rtx,
+static void df_def_record_1 (struct df_collection_rec *, rtx *,
basic_block, struct df_insn_info *,
int ref_flags);
static void df_defs_record (struct df_collection_rec *, rtx,
@@ -2922,19 +2922,10 @@ df_read_modify_subreg_p (rtx x)
static void
df_def_record_1 (struct df_collection_rec *collection_rec,
- rtx x, basic_block bb, struct df_insn_info *insn_info,
+ rtx *loc, basic_block bb, struct df_insn_info *insn_info,
int flags)
{
- rtx *loc;
- rtx dst;
-
- /* We may recursively call ourselves on EXPR_LIST when dealing with PARALLEL
- construct. */
- if (GET_CODE (x) == EXPR_LIST || GET_CODE (x) == CLOBBER)
- loc = &XEXP (x, 0);
- else
- loc = &SET_DEST (x);
- dst = *loc;
+ rtx dst = *loc;
/* It is legal to have a set destination be a parallel. */
if (GET_CODE (dst) == PARALLEL)
@@ -2944,12 +2935,9 @@ df_def_record_1 (struct df_collection_re
for (i = XVECLEN (dst, 0) - 1; i >= 0; i--)
{
rtx temp = XVECEXP (dst, 0, i);
- if (GET_CODE (temp) == EXPR_LIST || GET_CODE (temp) == CLOBBER
- || GET_CODE (temp) == SET)
- df_def_record_1 (collection_rec,
- temp, bb, insn_info,
- GET_CODE (temp) == CLOBBER
- ? flags | DF_REF_MUST_CLOBBER : flags);
+ gcc_assert (GET_CODE (temp) == EXPR_LIST);
+ df_def_record_1 (collection_rec, &XEXP (temp, 0),
+ bb, insn_info, flags);
}
return;
}
@@ -3003,18 +2991,16 @@ df_defs_record (struct df_collection_rec
{
RTX_CODE code = GET_CODE (x);
- if (code == SET || code == CLOBBER)
- {
- /* Mark the single def within the pattern. */
- int clobber_flags = flags;
- clobber_flags |= (code == CLOBBER) ? DF_REF_MUST_CLOBBER : 0;
- df_def_record_1 (collection_rec, x, bb, insn_info, clobber_flags);
- }
+ if (code == SET)
+ df_def_record_1 (collection_rec, &SET_DEST (x), bb, insn_info, flags);
+ else if (code == CLOBBER)
+ {
+ flags |= DF_REF_MUST_CLOBBER;
+ df_def_record_1 (collection_rec, &XEXP (x, 0), bb, insn_info, flags);
+ }
else if (code == COND_EXEC)
- {
- df_defs_record (collection_rec, COND_EXEC_CODE (x),
- bb, insn_info, DF_REF_CONDITIONAL);
- }
+ df_defs_record (collection_rec, COND_EXEC_CODE (x),
+ bb, insn_info, DF_REF_CONDITIONAL);
else if (code == PARALLEL)
{
int i;