Karl Meakin <karl.mea...@arm.com> writes:
> @@ -763,6 +784,68 @@ (define_expand "cbranchcc4"
> ""
> )
>
> +;; Emit a `CB<cond> (register)` or `CB<cond> (immediate)` instruction.
> +;; The immediate range depends on the comparison code.
> +;; Comparisons against immediates outside this range fall back to
> +;; CMP + B<cond>.
> +(define_insn "aarch64_cb<INT_CMP:code><GPI:mode>"
> + [(set (pc) (if_then_else (INT_CMP
> + (match_operand:GPI 0 "register_operand" "r")
> + (match_operand:GPI 1 "nonmemory_operand"
> + "r<INT_CMP:cmpbr_imm_constraint>"))
> + (label_ref (match_operand 2))
> + (pc)))]
> + "TARGET_CMPBR && aarch64_cb_rhs (<INT_CMP:CODE>, operands[1])"
> + {
> + if (get_attr_far_branch (insn) == FAR_BRANCH_YES)
> + return aarch64_gen_far_branch (operands, 2, "L",
> + "cb<INT_CMP:inv_cmp_op>\\t%<w>0, %<w>1,
> ");
> + else
> + return "cb<INT_CMP:cmp_op>\\t%<w>0, %<w>1, %l2";
> + }
> + [(set_attr "type" "branch")
> + (set (attr "length")
> + (if_then_else (and (ge (minus (match_dup 2) (pc))
> + (const_int BRANCH_LEN_N_1Kib))
> + (lt (minus (match_dup 2) (pc))
> + (const_int BRANCH_LEN_P_1Kib)))
> + (const_int 4)
> + (const_int 8)))
> + (set (attr "far_branch")
> + (if_then_else (and (ge (minus (match_dup 2) (pc))
> + (const_int BRANCH_LEN_N_1Kib))
> + (lt (minus (match_dup 2) (pc))
> + (const_int BRANCH_LEN_P_1Kib)))
> + (const_string "no")
> + (const_string "yes")))]
> +)
> +
> +;; Emit a `CBB<cond> (register)` or `CBH<cond> (register)` instruction.
> +(define_insn "aarch64_cb<INT_CMP:code><SHORT:mode>"
> + [(set (pc) (if_then_else (INT_CMP
> + (match_operand:SHORT 0 "register_operand" "r")
> + (match_operand:SHORT 1 "aarch64_reg_or_zero" "rZ"))
> + (label_ref (match_operand 2))
> + (pc)))]
> + "TARGET_CMPBR"
> + "cb<SHORT:cmpbr_suffix><INT_CMP:cmp_op>\\t%<w>0, %<w>1, %l2"
This instruction also needs to handle far branches, in a similar way
to the GPI one. (It would be good to have a test for that too).
Why does the code for u32_x0_uge_64 etc. not change? I would have
expected 64 to be in range for that, whether it's treated as >= 64
or as > 63.
Otherwise it looks good, thanks.
Richard
