+/* Try to align loads and stores within a span of memory. This is
+ called by both the ELF and the COFF sh targets. ABFD and SEC are
+ the BFD and section we are examining. CONTENTS is the contents of
+ the section. SWAP is the routine to call to swap two instructions.
+ RELOCS is a pointer to the internal relocation information, to be
+ passed to SWAP. PLABEL is a pointer to the current label in a
+ sorted list of labels; LABEL_END is the end of the list. START and
+ STOP are the range of memory to examine. If a swap is made,
+ *PSWAPPED is set to true. */
+
+boolean
+_bfd_sh_align_load_span (abfd, sec, contents, swap, relocs,
+ plabel, label_end, start, stop, pswapped)
+ bfd *abfd;
+ asection *sec;
+ bfd_byte *contents;
+ boolean (*swap) PARAMS ((bfd *, asection *, PTR, bfd_byte *, bfd_vma));
+ PTR relocs;
+ bfd_vma **plabel;
+ bfd_vma *label_end;
+ bfd_vma start;
+ bfd_vma stop;
+ boolean *pswapped;
+{
+ bfd_vma i;
+
+ /* Instructions should be aligned on 2 byte boundaries. */
+ if ((start & 1) == 1)
+ ++start;
+
+ /* Now look through the unaligned addresses. */
+ i = start;
+ if ((i & 2) == 0)
+ i += 2;
+ for (; i < stop; i += 4)
+ {
+ unsigned int insn;
+ const struct sh_opcode *op;
+ unsigned int prev_insn = 0;
+ const struct sh_opcode *prev_op = NULL;
+
+ insn = bfd_get_16 (abfd, contents + i);
+ op = sh_insn_info (insn);
+ if (op == NULL
+ || (op->flags & (LOAD | STORE)) == 0)
+ continue;
+
+ /* This is a load or store which is not on a four byte boundary. */
+
+ while (*plabel < label_end && **plabel < i)
+ ++*plabel;
+
+ if (i > start)
+ {
+ prev_insn = bfd_get_16 (abfd, contents + i - 2);
+ prev_op = sh_insn_info (prev_insn);
+
+ /* If the load/store instruction is in a delay slot, we
+ can't swap. */
+ if (prev_op == NULL
+ || (prev_op->flags & DELAY) != 0)
+ continue;
+ }
+ if (i > start
+ && (*plabel >= label_end || **plabel != i)
+ && prev_op != NULL
+ && (prev_op->flags & (LOAD | STORE)) == 0
+ && ! sh_insns_conflict (prev_insn, prev_op, insn, op))
+ {
+ boolean ok;
+
+ /* The load/store instruction does not have a label, and
+ there is a previous instruction; PREV_INSN is not
+ itself a load/store instruction, and PREV_INSN and
+ INSN do not conflict. */
+
+ ok = true;
+
+ if (i >= start + 4)
+ {
+ unsigned int prev2_insn;
+ const struct sh_opcode *prev2_op;
+
+ prev2_insn = bfd_get_16 (abfd, contents + i - 4);
+ prev2_op = sh_insn_info (prev2_insn);
+
+ /* If the instruction before PREV_INSN has a delay
+ slot--that is, PREV_INSN is in a delay slot--we
+ can not swap. */
+ if (prev2_op == NULL
+ || (prev2_op->flags & DELAY) != 0)
+ ok = false;
+
+ /* If the instruction before PREV_INSN is a load,
+ and it sets a register which INSN uses, then
+ putting INSN immediately after PREV_INSN will
+ cause a pipeline bubble, so there is no point to
+ making the swap. */
+ if (ok
+ && (prev2_op->flags & LOAD) != 0
+ && sh_load_use (prev2_insn, prev2_op, insn, op))
+ ok = false;
+ }
+
+ if (ok)
+ {
+ if (! (*swap) (abfd, sec, relocs, contents, i - 2))
+ return false;
+ *pswapped = true;
+ continue;
+ }
+ }
+
+ while (*plabel < label_end && **plabel < i + 2)
+ ++*plabel;
+
+ if (i + 2 < stop
+ && (*plabel >= label_end || **plabel != i + 2))
+ {
+ unsigned int next_insn;
+ const struct sh_opcode *next_op;
+
+ /* There is an instruction after the load/store
+ instruction, and it does not have a label. */
+ next_insn = bfd_get_16 (abfd, contents + i + 2);
+ next_op = sh_insn_info (next_insn);
+ if (next_op != NULL
+ && (next_op->flags & (LOAD | STORE)) == 0
+ && ! sh_insns_conflict (insn, op, next_insn, next_op))
+ {
+ boolean ok;
+
+ /* NEXT_INSN is not itself a load/store instruction,
+ and it does not conflict with INSN. */
+
+ ok = true;
+
+ /* If PREV_INSN is a load, and it sets a register
+ which NEXT_INSN uses, then putting NEXT_INSN
+ immediately after PREV_INSN will cause a pipeline
+ bubble, so there is no reason to make this swap. */
+ if (prev_op != NULL
+ && (prev_op->flags & LOAD) != 0
+ && sh_load_use (prev_insn, prev_op, next_insn, next_op))
+ ok = false;
+
+ /* If INSN is a load, and it sets a register which
+ the insn after NEXT_INSN uses, then doing the
+ swap will cause a pipeline bubble, so there is no
+ reason to make the swap. However, if the insn
+ after NEXT_INSN is itself a load or store
+ instruction, then it is misaligned, so
+ optimistically hope that it will be swapped
+ itself, and just live with the pipeline bubble if
+ it isn't. */
+ if (ok
+ && i + 4 < stop
+ && (op->flags & LOAD) != 0)
+ {
+ unsigned int next2_insn;
+ const struct sh_opcode *next2_op;
+
+ next2_insn = bfd_get_16 (abfd, contents + i + 4);
+ next2_op = sh_insn_info (next2_insn);
+ if ((next2_op->flags & (LOAD | STORE)) == 0
+ && sh_load_use (insn, op, next2_insn, next2_op))
+ ok = false;
+ }
+
+ if (ok)
+ {
+ if (! (*swap) (abfd, sec, relocs, contents, i))
+ return false;
+ *pswapped = true;
+ continue;
+ }
+ }
+ }
+ }
+
+ return true;
+}
+