+2014-04-11 Joern Rennecke <joern.rennecke@embecosm.com>
+
+ PR rtl-optimization/60651
+ * mode-switching.c (optimize_mode_switching): Make sure to emit
+ sets of a lower numbered entity before sets of a higher numbered
+ entity to a mode of the same or lower priority.
+ When creating a seginfo for a basic block that starts with a code
+ label, move the insertion point past the code label.
+ (new_seginfo): Document and enforce requirement that
+ NOTE_INSN_BASIC_BLOCK only appears for empty blocks.
+ * doc/tm.texi.in: Document ordering constraint for emitted mode sets.
+ * doc/tm.texi: Regenerate.
+
2014-01-11 Joern Rennecke <joern.rennecke@embecosm.com>
PR target/60811
\f
/* This function will allocate a new BBINFO structure, initialized
- with the MODE, INSN, and basic block BB parameters. */
+ with the MODE, INSN, and basic block BB parameters.
+ INSN may not be a NOTE_INSN_BASIC_BLOCK, unless it is an empty
+ basic block; that allows us later to insert instructions in a FIFO-like
+ manner. */
static struct seginfo *
new_seginfo (int mode, rtx insn, int bb, HARD_REG_SET regs_live)
{
struct seginfo *ptr;
+
+ gcc_assert (!NOTE_INSN_BASIC_BLOCK_P (insn)
+ || insn == BB_END (NOTE_BASIC_BLOCK (insn)));
ptr = XNEW (struct seginfo);
ptr->mode = mode;
ptr->insn_ptr = insn;
break;
if (e)
{
- ptr = new_seginfo (no_mode, BB_HEAD (bb), bb->index, live_now);
+ rtx ins_pos = BB_HEAD (bb);
+ if (LABEL_P (ins_pos))
+ ins_pos = NEXT_INSN (ins_pos);
+ gcc_assert (NOTE_INSN_BASIC_BLOCK_P (ins_pos));
+ if (ins_pos != BB_END (bb))
+ ins_pos = NEXT_INSN (ins_pos);
+ ptr = new_seginfo (no_mode, ins_pos, bb->index, live_now);
add_seginfo (info + bb->index, ptr);
bitmap_clear_bit (transp[bb->index], j);
}
{
emitted = true;
if (NOTE_INSN_BASIC_BLOCK_P (ptr->insn_ptr))
- emit_insn_after (mode_set, ptr->insn_ptr);
+ /* We need to emit the insns in a FIFO-like manner,
+ i.e. the first to be emitted at our insertion
+ point ends up first in the instruction steam.
+ Because we made sure that NOTE_INSN_BASIC_BLOCK is
+ only used for initially empty basic blocks, we
+ can archive this by appending at the end of
+ the block. */
+ emit_insn_after
+ (mode_set, BB_END (NOTE_BASIC_BLOCK (ptr->insn_ptr)));
else
emit_insn_before (mode_set, ptr->insn_ptr);
}