On 01/08/14 16:13, Jakub Jelinek wrote:
Please add a function comment for it (perhaps saying that it is like
single_set but never allows more than one SET).
Ok with that change.
My bad. Thanks for catching it.
Attaching the installed patch for reference.
Jeff
commit 12e467a657653de484178f0d0d66786a92d62ebe
Author: law <law@138bc75d-0d04-0410-961f-82ee72b054a4>
Date: Thu Jan 9 04:42:38 2014 +0000
* ree.c (get_sub_rtx): New function, extracted from...
(merge_def_and_ext): Here.
(combine_reaching_defs): Use get_sub_rtx.
git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@206454
138bc75d-0d04-0410-961f-82ee72b054a4
diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index f63918e..e4872f2 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,9 @@
+2014-01-08 Jeff Law <l...@redhat.com>
+
+ * ree.c (get_sub_rtx): New function, extracted from...
+ (merge_def_and_ext): Here.
+ (combine_reaching_defs): Use get_sub_rtx.
+
2014-01-08 Eric Botcazou <ebotca...@adacore.com>
* cgraph.h (varpool_variable_node): Do not choke on null node.
diff --git a/gcc/ree.c b/gcc/ree.c
index ec09c7a..1c4f3ad 100644
--- a/gcc/ree.c
+++ b/gcc/ree.c
@@ -580,27 +580,21 @@ make_defs_and_copies_lists (rtx extend_insn, const_rtx
set_pat,
return ret;
}
-/* Merge the DEF_INSN with an extension. Calls combine_set_extension
- on the SET pattern. */
-
-static bool
-merge_def_and_ext (ext_cand *cand, rtx def_insn, ext_state *state)
+/* If DEF_INSN has single SET expression, possibly buried inside
+ a PARALLEL, return the address of the SET expression, else
+ return NULL. This is similar to single_set, except that
+ single_set allows multiple SETs when all but one is dead. */
+static rtx *
+get_sub_rtx (rtx def_insn)
{
- enum machine_mode ext_src_mode;
- enum rtx_code code;
- rtx *sub_rtx;
- rtx s_expr;
- int i;
-
- ext_src_mode = GET_MODE (XEXP (SET_SRC (cand->expr), 0));
- code = GET_CODE (PATTERN (def_insn));
- sub_rtx = NULL;
+ enum rtx_code code = GET_CODE (PATTERN (def_insn));
+ rtx *sub_rtx = NULL;
if (code == PARALLEL)
{
- for (i = 0; i < XVECLEN (PATTERN (def_insn), 0); i++)
+ for (int i = 0; i < XVECLEN (PATTERN (def_insn), 0); i++)
{
- s_expr = XVECEXP (PATTERN (def_insn), 0, i);
+ rtx s_expr = XVECEXP (PATTERN (def_insn), 0, i);
if (GET_CODE (s_expr) != SET)
continue;
@@ -609,7 +603,7 @@ merge_def_and_ext (ext_cand *cand, rtx def_insn, ext_state
*state)
else
{
/* PARALLEL with multiple SETs. */
- return false;
+ return NULL;
}
}
}
@@ -618,10 +612,27 @@ merge_def_and_ext (ext_cand *cand, rtx def_insn,
ext_state *state)
else
{
/* It is not a PARALLEL or a SET, what could it be ? */
- return false;
+ return NULL;
}
gcc_assert (sub_rtx != NULL);
+ return sub_rtx;
+}
+
+/* Merge the DEF_INSN with an extension. Calls combine_set_extension
+ on the SET pattern. */
+
+static bool
+merge_def_and_ext (ext_cand *cand, rtx def_insn, ext_state *state)
+{
+ enum machine_mode ext_src_mode;
+ rtx *sub_rtx;
+
+ ext_src_mode = GET_MODE (XEXP (SET_SRC (cand->expr), 0));
+ sub_rtx = get_sub_rtx (def_insn);
+
+ if (sub_rtx == NULL)
+ return false;
if (REG_P (SET_DEST (*sub_rtx))
&& (GET_MODE (SET_DEST (*sub_rtx)) == ext_src_mode
@@ -707,8 +718,13 @@ combine_reaching_defs (ext_cand *cand, const_rtx set_pat,
ext_state *state)
/* If there is an overlap between the destination of DEF_INSN and
CAND->insn, then this transformation is not safe. Note we have
to test in the widened mode. */
+ rtx *dest_sub_rtx = get_sub_rtx (def_insn);
+ if (dest_sub_rtx == NULL
+ || !REG_P (SET_DEST (*dest_sub_rtx)))
+ return false;
+
rtx tmp_reg = gen_rtx_REG (GET_MODE (SET_DEST (PATTERN (cand->insn))),
- REGNO (SET_DEST (PATTERN (def_insn))));
+ REGNO (SET_DEST (*dest_sub_rtx)));
if (reg_overlap_mentioned_p (tmp_reg, SET_DEST (PATTERN (cand->insn))))
return false;
