Bernd Schmidt - Invalid CALL_INSN_FUNCTION_USAGE for certain libcalls (original) (raw)

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• From: Bernd Schmidt <bernds_cb1 at t-online dot de>
• To: GCC Patches
• Date: Wed, 28 Feb 2007 01:41:40 +0100
• Subject: Invalid CALL_INSN_FUNCTION_USAGE for certain libcalls

The Blackfin stores arguments in registers R0, R1, R2, and subsequent ones on the stack. A function with two DImode args (e.g. __divdi3) takes its first arg in R0/R1, and the second is split between R2 and the stack. Unfortunately, for a library call, we emit a (use (reg:DI R2)) in the CALL_INSN_FUNCTION_USAGE, which means that R3 is considered live in places where it really is dead. That caused spill failures when the new multiplication patterns I added recently are used.Fixed with the patch below, which transfers a bit of code from load_register_parameters to emit_library_call_value_1 to make it take partial regs into account.Bootstrapped & regression tested on i686-linux, tested for a while in our local Blackfin tree. Committed as 122396.

Bernd

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Index: ChangeLog

--- ChangeLog (revision 122395) +++ ChangeLog (working copy) @@ -1,3 +1,8 @@ +2007-02-28 Bernd Schmidt bernd.schmidt@analog.com + + * calls.c (emit_library_call_value_1): Handle partial registers + correctly when building up CALL_INSN_FUNCTION_USAGE. + 2007-02-27 John David Anglin dave.anglin@nrc-cnrc.gc.ca * pa/predicates.md (move_src_operand): Allow zero for mode. Index: calls.c

--- calls.c (revision 122395) +++ calls.c (working copy) @@ -3774,7 +3774,18 @@ emit_library_call_value_1 (int retval, r if (reg != 0 && GET_CODE (reg) == PARALLEL) use_group_regs (&call_fusage, reg); else if (reg != 0) - use_reg (&call_fusage, reg);

•    {

•  int partial = argvec[count].partial;

•  if (partial)

•    {

•      int nregs;

•          gcc_assert (partial % UNITS_PER_WORD == 0);

•      nregs = partial / UNITS_PER_WORD;

•      use_regs (&call_fusage, REGNO (reg), nregs);

•    }

•  else

•    use_reg (&call_fusage, reg);

• } } /* Pass the function the address in which to return a structure value. */