Dominik Vogt wrote:
> v4:
>
> * Remoce CCZZ1 iterator.
> * Remove duplicates of CS patterns.
> * Move the skip_cs_label so that output is moved to vtarget even
> if the CS instruction was not used.
> * Removed leftover from "sne" (from an earlier version of the
> * patch).
Thanks, this looks quite good to me now. I do still have two questions:
> +; Peephole to combine a load-and-test from volatile memory which combine does
> +; not do.
> +(define_peephole2
> + [(set (match_operand:GPR 0 "register_operand")
> + (match_operand:GPR 2 "memory_operand"))
> + (set (reg CC_REGNUM)
> + (compare (match_dup 0) (match_operand:GPR 1 "const0_operand")))]
> + "s390_match_ccmode(insn, CCSmode) && TARGET_EXTIMM
> + && GENERAL_REG_P (operands[0])
> + && satisfies_constraint_T (operands[2])"
> + [(parallel
> + [(set (reg:CCS CC_REGNUM)
> + (compare:CCS (match_dup 2) (match_dup 1)))
> + (set (match_dup 0) (match_dup 2))])])
Still wondering why this is necessary. On the other hand, I guess it
cannot hurt to have the peephole either ...
> @@ -6518,13 +6533,30 @@
> [(parallel
> [(set (match_operand:SI 0 "register_operand" "")
> (match_operator:SI 1 "s390_eqne_operator"
> - [(match_operand:CCZ1 2 "register_operand")
> + [(match_operand 2 "cc_reg_operand")
> (match_operand 3 "const0_operand")]))
> (clobber (reg:CC CC_REGNUM))])]
> ""
> - "emit_insn (gen_sne (operands[0], operands[2]));
> - if (GET_CODE (operands[1]) == EQ)
> - emit_insn (gen_xorsi3 (operands[0], operands[0], const1_rtx));
> + "machine_mode mode = GET_MODE (operands[2]);
> + if (TARGET_Z196)
> + {
> + rtx cond, ite;
> +
> + if (GET_CODE (operands[1]) == NE)
> + cond = gen_rtx_NE (VOIDmode, operands[2], const0_rtx);
> + else
> + cond = gen_rtx_EQ (VOIDmode, operands[2], const0_rtx);
> + ite = gen_rtx_IF_THEN_ELSE (SImode, cond, const1_rtx, const0_rtx);
> + emit_insn (gen_rtx_SET (operands[0], ite));
> + }
> + else
> + {
> + if (mode != CCZ1mode)
> + FAIL;
> + emit_insn (gen_sne (operands[0], operands[2]));
> + if (GET_CODE (operands[1]) == EQ)
> + emit_insn (gen_xorsi3 (operands[0], operands[0], const1_rtx));
> + }
> DONE;")
>From what I can see in the rest of the patch, none of the CS changes now
actually *rely* on this change to cstorecc4 ... s390_expand_cs_tdsi only
calls cstorecc4 on !TARGET_Z196, where the above change is a no-op, and
in the TARGET_Z196 case it deliberates does *not* use cstorecc4.
Now, in general this improvement to cstorecc4 is of course valuable
in itself. But I think at this point it might be better to separate
this out into an independent patch (and measure its effect separately).
Bye,
Ulrich
--
Dr. Ulrich Weigand
GNU/Linux compilers and toolchain
[email protected]
