+2003-06-26 Richard Henderson <rth@redhat.com>
+
+ * flow.c (propagate_one_insn): Preserve live-at-end registers
+ across tail calls.
+
2003-06-26 J"orn Rennecke <joern.rennecke@superh.com>
* reload.c (can_reload_into): New function.
if (GET_CODE (insn) == CALL_INSN)
{
- int i;
+ regset live_at_end;
+ bool sibcall_p;
rtx note, cond;
+ int i;
cond = NULL_RTX;
if (GET_CODE (PATTERN (insn)) == COND_EXEC)
mark_set_1 (pbi, CLOBBER, XEXP (XEXP (note, 0), 0),
cond, insn, pbi->flags);
- /* Calls change all call-used and global registers. */
+ /* Calls change all call-used and global registers; sibcalls do not
+ clobber anything that must be preserved at end-of-function. */
+
+ sibcall_p = SIBLING_CALL_P (insn);
+ live_at_end = EXIT_BLOCK_PTR->global_live_at_start;
for (i = 0; i < FIRST_PSEUDO_REGISTER; i++)
- if (TEST_HARD_REG_BIT (regs_invalidated_by_call, i))
+ if (TEST_HARD_REG_BIT (regs_invalidated_by_call, i)
+ && ! (sibcall_p && REGNO_REG_SET_P (live_at_end, i)))
{
/* We do not want REG_UNUSED notes for these registers. */
mark_set_1 (pbi, CLOBBER, regno_reg_rtx[i], cond, insn,