From: Christoph Müllner <christoph.muell...@vrull.eu>
This patch restructures the loop over the GP registers
which saves/restores then as part of the prologue/epilogue.
No functional change is intended by this patch, but it
offers the possibility to use load-pair/store-pair instructions.
gcc/ChangeLog:
* config/riscv/riscv.cc (riscv_next_saved_reg): New function.
(riscv_is_eh_return_data_register): New function.
(riscv_for_each_saved_reg): Restructure loop.
Signed-off-by: Christoph Müllner <christoph.muell...@vrull.eu>
---
gcc/config/riscv/riscv.cc | 94 +++++++++++++++++++++++++++------------
1 file changed, 66 insertions(+), 28 deletions(-)
diff --git a/gcc/config/riscv/riscv.cc b/gcc/config/riscv/riscv.cc
index 6dd2ab2d11e..a8d5e1dac7f 100644
--- a/gcc/config/riscv/riscv.cc
+++ b/gcc/config/riscv/riscv.cc
@@ -4835,6 +4835,49 @@ riscv_save_restore_reg (machine_mode mode, int regno,
fn (gen_rtx_REG (mode, regno), mem);
}
+/* Return the next register up from REGNO up to LIMIT for the callee
+ to save or restore. OFFSET will be adjusted accordingly.
+ If INC is set, then REGNO will be incremented first. */
+
+static unsigned int
+riscv_next_saved_reg (unsigned int regno, unsigned int limit,
+ HOST_WIDE_INT *offset, bool inc = true)
+{
+ if (inc)
+ regno++;
+
+ while (regno <= limit)
+ {
+ if (BITSET_P (cfun->machine->frame.mask, regno - GP_REG_FIRST))
+ {
+ *offset = *offset - UNITS_PER_WORD;
+ break;
+ }
+
+ regno++;
+ }
+ return regno;
+}
+
+/* Return TRUE if provided REGNO is eh return data register. */
+
+static bool
+riscv_is_eh_return_data_register (unsigned int regno)
+{
+ unsigned int i, regnum;
+
+ if (!crtl->calls_eh_return)
+ return false;
+
+ for (i = 0; (regnum = EH_RETURN_DATA_REGNO (i)) != INVALID_REGNUM; i++)
+ if (regno == regnum)
+ {
+ return true;
+ }
+
+ return false;
+}
+
/* Call FN for each register that is saved by the current function.
SP_OFFSET is the offset of the current stack pointer from the start
of the frame. */
@@ -4844,36 +4887,31 @@ riscv_for_each_saved_reg (poly_int64 sp_offset,
riscv_save_restore_fn fn,
bool epilogue, bool maybe_eh_return)
{
HOST_WIDE_INT offset;
+ unsigned int regno;
+ unsigned int start = GP_REG_FIRST;
+ unsigned int limit = GP_REG_LAST;
/* Save the link register and s-registers. */
- offset = (cfun->machine->frame.gp_sp_offset - sp_offset).to_constant ();
- for (unsigned int regno = GP_REG_FIRST; regno <= GP_REG_LAST; regno++)
- if (BITSET_P (cfun->machine->frame.mask, regno - GP_REG_FIRST))
- {
- bool handle_reg = !cfun->machine->reg_is_wrapped_separately[regno];
-
- /* If this is a normal return in a function that calls the eh_return
- builtin, then do not restore the eh return data registers as that
- would clobber the return value. But we do still need to save them
- in the prologue, and restore them for an exception return, so we
- need special handling here. */
- if (epilogue && !maybe_eh_return && crtl->calls_eh_return)
- {
- unsigned int i, regnum;
-
- for (i = 0; (regnum = EH_RETURN_DATA_REGNO (i)) != INVALID_REGNUM;
- i++)
- if (regno == regnum)
- {
- handle_reg = FALSE;
- break;
- }
- }
-
- if (handle_reg)
- riscv_save_restore_reg (word_mode, regno, offset, fn);
- offset -= UNITS_PER_WORD;
- }
+ offset = (cfun->machine->frame.gp_sp_offset - sp_offset).to_constant ()
+ + UNITS_PER_WORD;
+ for (regno = riscv_next_saved_reg (start, limit, &offset, false);
+ regno <= limit;
+ regno = riscv_next_saved_reg (regno, limit, &offset))
+ {
+ if (cfun->machine->reg_is_wrapped_separately[regno])
+ continue;
+
+ /* If this is a normal return in a function that calls the eh_return
+ builtin, then do not restore the eh return data registers as that
+ would clobber the return value. But we do still need to save them
+ in the prologue, and restore them for an exception return, so we
+ need special handling here. */
+ if (epilogue && !maybe_eh_return
+ && riscv_is_eh_return_data_register (regno))
+ continue;
+
+ riscv_save_restore_reg (word_mode, regno, offset, fn);
+ }
/* This loop must iterate over the same space as its companion in
riscv_compute_frame_info. */
--
2.38.1
